Reports for December, 2000
You Inseparable You
Pause for Reflection
High Moon
A Break in the Weather
Back on Track
Unexpected Encounter in the Night Sky
Close but no Cluster
Veiled and Voluptuous
Two out of Three ain't Bad
On the Threshold of the Seen
More Galaxies than you can Shake a Scope At
General Public Cordially Invited
Imaginosity
The Real Thing
Reports for February, 2001

You Inseparable You

The weather here in the SF Bay Area is expected to hold through Thursday. After Thursday, we hope to get the "monsoon season". (Without it we could be entering into a drought to go along with the current shortage in electricity and natural gas.) The evening was available to me so I headed on up to BC Elementary for an hour or so. Transparency was satisfactory (4.6 ULTM) but the moon is now at 50%. The sky awash in light. Deepsky is out. (I could hardly make out Cetus to the south with the moon in Pisces. What a difference between a 50% moon and the 33% just a few nights earlier....)

The split of Iota was OK but unstable. 12th magnitude field star, direct but not obvious. Looked over my hour 2 to 3 objeservation list and noticed several objects in Cetus. Decided to look for a close double instead. (Preferably somewhere near the circumpolar region -- as far away from Luna as possible.) Noticed Omicron Persei. Tight split (1 arc-second) with disparate magnitudes (3.9 & 8.5). A real test. Tried at 120X -- not a chance. Bumped to 180X (elongated? and skiddish). Installed 3x barlow with 25mm (210X nominal): A bit jumpy in the field of view -- but is that a turqoise gray 9th magnitude star at 120 degrees PA?.) Went to 360X (Nice little airy disk, with "triangular" diffraction rings jumping around in the FOV. Anything there?) 600X: Real squirrelly but not much better than 360X. Still nice airy disk and diffraction rings though.

At no magnification did I get a "conclusive" split. Checked the planets. Not particularly clean tonight. Cassini present but not "etched in black". Jupiter, nah... Perhaps a good steady night will turn the trick.

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Pause for Reflection

Took the scope out briefly last night (in the backyard). With the moon out, I only wanted to check sky stability. The Saturn view was about average. (Cassini was visible but smeared.) It amazed me how much bad sky conditions can mimic poor optics (and vice versa).

A also had the loan of a Bauch and Laumb (Criterion) 4000 SCT (1980's vintage). This no-longer-available model has a four inch objective and 1000mm focal length. It shipped with 25mm(?) and 12.5mm(?) eps (40 and 80X respectively). The thing is remarkably portable -- but lacked a tripod. I set it up on a stool to view from. Due to general inaccessibility and small size, the finderscope proved useless. The main optics were out of coliimation, but had potential. Once properly aligned, the scope might make a good rich field sweeper. While in "sweeper" mode, I was able to view of Saturn. At 80X, I would expect to just make out the Cassini division -- but between the seeing and the mis-alignment, this was not possible.

Based on the above experience (and others I've had using binoculars and through the finderscope) I've come to the following preliminary conclusions:

• Aperture is of "overstated" importance.
• Magnification is really important (too little or too much can injure the viewing experience.)
• Optical quality is supremely important.
• Seeing (stability + transparency) is as important as optical quality. (Poor seeing / bad optics is practically indistinguishable.)
• A wide, flat, field, of view improves the viewing experience significantly.
• A "clean" (free of haze, low light scatter) field of view is essential where low surface brightness objects are to be detected.
• Ease of scope control and good eyepiece accessibility can help minimize frustration when viewing (and therefore improve the viewing experience).

After I wrote the above, I went out to check the seeing and run a tight double-star test. The test involved comparing Omicron Persi (a disparate magnitude, 1 arc-second separated double) with Zeta Persi (a solitary star of comparable magnitude). Before doing the test, I turned the scope on Jupiter and Saturn to evaluate seeing. Stability was much improved over Tuesday's observations of Omicron -- but still not excellent -- possibly 7/10. Transparency was pretty good too (even with the moon and the backyard location).

While checking Jupiter I noticed a small black disk proceding slightly south of the SEB. At first sight, the disk had progressed by just a few seconds of arc from the limb. This particular disk seemed smaller than that of the last transit's recently witnessed. The location was also further south -- outside the dark SEB region. I scouted ahead for the bright reflection of the satellite (Europa?), but could detect nothing. I then opted to resume my double-star testing while keeping in mind that I would return to Jupiter once the test was concluded. (The idea would be to see where the satellite emerged -- on the far limb -- and how far it lead its shadow by.)

To complicate all this, I also had a third test in mind. That test was to get a general idea of the average number of stars visible in the FOV per "round" degree of arc. The idea being that, as depth of magnitude increases, the FOV should show a geometric increase in the number of stars visible to the eye. One key to this test is to view outside the Milky Way (since star counts are disproportionately high in this region). A second key is to use a high enough magnification to simplify the counting of stars. As it turns out, the ideal time to do this test is while readying the use of the clock drive -- since in so doing you end up waiting several minutes as the target drifts into the FOV (clock drive clutched but not turned on). This evening I counted anywhere from 2 to 9 stars -- with an average of about 5. Based on some hypothetical considerations/calculations (and an arc-minute field size of the 210X 25mm / 3x barlow combination) the count suggested that tonight's deepsky limit was roughly magnitude 11.2.

Now to the "double-star test": Omicron and Zeta were indistinguishable in terms of what I could make out in the airy disks surrounding them. Both disks showed a jumpy "tri-partite" diffraction image at 600X. At the center of this region was a tiny, spurious, "star-disk", and like its diffraction "rings" jumped around in the FOV. Frequently, at one of the nodes of the "tri-partite diffraction region" I would see a gray "star". In both cases the "star" tended to appear to the east and slightly south of the primary. (Although it could also appear at either of the other two nodes as well.) Since Zeta Persi is not double, I can only conclude that the Omicron double -- if resolvable -- may only be so resolved in my scope under the most stable viewing conditions.

With star count and double-star tests concluded, I turned the scope back on Jupiter. This, just after the satellite emerged from the far limb of the planet (just above the southern frontier of the SEB). In this instance the satellite itself emerged about 3/5ths the diameter of Jupiter ahead of the shadow. (Perhaps 20 - 25 arc-seconds.) This fact, combined with the more northerly transit plane, and the smaller disk-shadow suggested that this particular satellite certainly differed from that present during my last transit observation.

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High Moon

Slipped the scope out of for a quick check of sky stability and a peek at Jupiter and Saturn (now high overhead by 7:30 or so in the evening). Had no plans to make any exhaustive observations -- I'm afraid the moon is a big discouraging factor for me since it ruins my dark adaptation and floods a large portion of the sky with deepsky suppressing light.

Lined the scope up on Polaris -- thought I'd review my star fields drawing from last year. With the great "floodlight in the sky", fewer stars were visible than in the past. I even had trouble picking out the 9th magnitude companion of Polaris. Decided to use the "opportunity" to characterize eps based on the amount of "presence" the companion showed. Surprisingly, the companion was more "present" at lower magnifcations than at higher. Best views were seen at 50 and 70X. The amount of presence deteriorated as magnification increased. In fact while using the barlow at 210/360/540/600 I had to slightly avert my vision to see it at all. Currently, I have no way of accounting for this phenomenon (exit pupil size?). It did seem that light scatter increased with magnification. The sky itself was reasonably transparent (Iota Cass was directly visible -- even with the Moon. Saturn gave rather nice views of the ring system.) Regardless of the cause of the phenomenon, it does suggest that bumping up magnification to separate disparate-brightness tight doubles may be a mistaken strategy. (I probably should stay close to 180X when attempting Omicron Persi and avoid the barlow whose additional elements seem to contribute to the problem.)

As mentioned, Saturn looked very nice --- at both 210 and 360X. There was very little "image jump" and only a slight amount of "out of focus" effect. The moons layed out as follows:

                                      (110)	
                                      *              (90)
                                         O              *
                                    * (105)
                                        * (100)

Saturn was very close to the moon this evening. While waiting to engage the clock drive I saw very few stars pass through the 210X FOV.

After fifteen or twenty minutes admiring Saturn, I switched over to Jupiter. While waiting to engage the drive, I counted anywhere from 0 to 5 stars (2 average) in the 210X FOV. This is half the count seen last evening while observing Omicron and Zeta Persi. Unlike last evening, Jupiter itself sported a split SEB. Otherwise, the same basic details were present: NEB, NTB, NNTB, a hint of the dove's footprints on the EB. Feature contrast was low. All four satellites were well clear of the planet.

In general, if I had one concern about the MK-67's planetary performance I would say it's lack of image contrast. (My main concern about deepsky is the "star haze" that makes low surface brightness nebulosity diificult to detect with certainty.)

A Break in the Weather

Been rainy and overcast since Saturday. (The sky was even a little psychzophrenic this evening.) But by 8:15 much of it had cleared up. Took out the scope, made a quick check of Jupiter (stable but "fuzzy") and decided to do a brief star count sampling. The number of the evening was "3". Ranged from zero to 6 stars. The moon's at about 80% right now. By the time I made my count it had entered into the middle 60 degrees of the sky. Definitely doing its "floodlighting thing". I made sure to park the scope in the "moonshade". Allowed my eyes to dark adapt. Couldn't make out Iota Cassiopeia directly so I figure the UTLM was less than 4.0.

According to my corrected figures, I was only seeing down to about magnitude 10.6. Subtracting the usual add-on magnitude of 7.5 for the scope, the ULTM was therefore about 3.1. This seems quite low -- but the moon was very bright, poorly positioned and I did this check from by backyard. I also have to consider the possibility that my eyes had not fully adapted. If this is the case, and we assume that backyard seeing with the current moon was actually around 3.7 then I should have seen an average of 5 stars with a range of 2 to 9. More data is needed under a wide variety of conditions before a complete picture is possible...

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Back on Track

Fascinating evening of "observation". The combination of rainy weather and lunar floodlighting finally relented. This created an opportunity to get out and resume my observing plan. Hoping to make the most out it, I headed up to the ridge. Had the scope assembled by 6:15 (PST) or so. Made the usual sky checks: Iota Cass (magnitude 4.6) directly susceptible to unaided view. A nice clean split, 12th magnitude field star just barely visible at 120X.

Directed the scope on M31. The hope was to find something, anything, that smacked of NGC206 - a massive star cluster in our spiral neighbor's southwest spiral arm. 50X reconnaisance revealed quite a bit of mottled texture in both spiral arms but nothing suggested a 1 arc-minute knot of the type expected. Switched over to 120X for a more detailed view. Immediately noted significant background darkening (perhaps by a whole unit of magnitude). This is a well established phenomenon - one I try to exploit whenever the object I'm looking for has a fairly small angular diameter (1 arc-minute or less).

Spent a half an hour or so inspecting along the galactic "lens". Noticed a "fuzzy star" with a "prominent" but slightly diffuse core located about 35 arc-minutes from the center of M31 and 20 arc-minutes (or so) from that of M32. The fuzziness was displaced maybe 3 or 4 arc-minutes away from the centerline of spiral arm towards M32 (near a pair of 11th magnitude field stars). This is my best shot so far at identifying anything that might be a 2+ MLY distant massive globular cluster. The object itself was certainly no more than 1 arc-minute in diameter, spherical in shape, with a border that rapidly dissipates into space. Probably very close to the 12th magnitude in surface brightness. In many ways it looked more like a dim planetary with a "bright" central star but lacked the usual ring-structure. In general the technique I used in finding the object was the same one used in finding dim planetaries. "Look for something like an out of focus star - and that'll be it."

After writing this I found a nice photo of the layout of M31 on the web . It showed NGC206 positioned just about where I "saw" it. However, I may have mistaken the position of the centerline of the galactic arm somewhat. At least now, if the object I found isn't 206, I have a much better idea of where to look next time...

The next object on tap was galaxy M77. M77 is located about one degree east of Delta Ceti. As a Messier object, and bearing a listed magnitude of 8.9, I didn't expect much difficulty turning it up. In fact it took only a few minutes to locate Delta Ceti in the sky, slew the scope around, center the star in the finder and shift the required distance east to reveal M77. At first I didn't believe the object to be a galaxy. Unlike "NGC206" it looked like a reflecting nebula. Like "NGC206" it included, in this case, an even more brilliant core star. As it turned out M77 is a Siefert Galaxy. Such galaxies are quite "quasar-like" and have extremely brilliant, compact cores. In the case of M77, certainly as bright as the blue 10th magnitude field star that lay roughly 1 arc-minute to M77's west-southwest. The rest of the structure was much more ambiguous to characterize. At 120X, it didn't seem to be any larger than an arc-minute or so in diameter. (It looked maybe 3 arc minutes in apparent size at 50X.) My notes say the brighter part of the galaxy elongated slightly south-southwest to the north-northeast. The core cast a greenish-blue hue. This thing is quite striking and I'd recommend anyone with a modest scope track it down...

The next galaxy was as difficult to turn up as M77 was easy. NGC1055 lies in the same 1 degree field as M77 (perhaps 40 minutes north and west forming a triangle with Delta Ceti which can be seen in the same 1 degree field as NGC1055 -- when you can see it!)

While searching for NGC1055 I immediately centered on a pair of 9th magnitude field stars (separated by roughly 10 minutes of arc). 1055 forms a rough equilateral triangle with this pair (in the direction of M77). Unfortunately, under the less than 5.0 ULTM conditions of the evening, this super-elongated galaxy could only just be just detected with averted vision. (At least it could be seen.) Most definitely I need to revisit this object under darker conditions. It should make a nice "frontier of visibility" test -- especially as my observing eye improves.

Unlike NGC1055, I did not definitively find next galaxy (NGC891) this evening --despite 45 minutes of constant search, position checks and position cross-checks.

NGC891 is located about 3 degrees west of Gamma Andromeda. Gamma Andromeda itself is an exquisite double star of colors yellow and "blue". The pair is separated by about 10 second of arc. Beautiful at 50X. I was unaware of Gamma's "duplicity" when I first acquired it in the FOV. In fact, the secondary star (of about magnitude 6 to my eye) looked distinctly "gold" -- not blue -- on first look. After a quick check of Harrington's "The Deep Sky" -- I noticed the secondary was "blue". Subsequently, I had no trouble seeing it as blue when double-checking. Interesting...

As for NGC891, I'd be lying if I said I found it -- although I have high confidence in the fact that I precisely positioned it in my 50X FOV. (This was done by triangulating on Gamma and a pair of 5th and sixth magnitude finderscope field stars.) I imagine that if I am ever to make this one out, it will be under 6.0 conditions and possibly require averted vision to boot!

So this leads me up to my latest tools for evaluating "faint fuzzies" (for susceptibility of view). As a programmer I can whip up various calculators to provide me with decent estimates of an object's surface brightness (based on it's listed magnitude and apparent size). Allowing for the usual batch of strangenesses and ideosyncracies - like super bright galactic cores (and the opposite), plus differences between the way the eye works and photographic plates etc -- I can get a passable sense of whether or not I should be able to find a particular object on any given night, based on where it is located in the sky and any particular magnification.

To accomplish this, I actually had to develop two calculators -- one The Limiting Magnitude Calculator allows me to determine the "reach" of my (or other) telescopes on any given night. The other, Deepsky Susceptibility Calculator allows me to calculate the surface brightness of a particular object based on its type and determine if a particular scope, on a particular night of seeing has a chance of showing it. Both of these programs are currently under development and will require much empirical validation. But, even in their current form they are proving helpful. (Later I hope to develop one for evaluating double-stars for separation as well.)

So what were the numbers for tonight?

Under the 4.8 ULTM conditions experienced (once fully dark and dark-adapted), the scope should have had no difficult making out objects down to magnitude 11.0 at 50X and 11.6 at 120X. The dimmest "average" spiral galaxy I should have been able to make out would have a listed magnitude of 11.5 (4X3 arc minutes in apparent size). To determine the actual surface brightness of a specific galaxy I use the other program:

M77 is magnitude 8.9. It's apparent size is 6X5 arc-minutes. It has a (spiral galaxy based) surface brightness value of 9.8. Well within the 11.5 value calculated above at 50X. NGC1055 bears a published magnitude of 10.6. With an apparent size of 8X3 arc-minutes, its surface brightness is roughly magnitude 11.2 -- just under the 11.5 limit of a 150mm scope using a 50X ep. NGC891, has a listed magnitude of 10.0 and apparent size of 13x3 arc-minutes. It's surface brightness: 11.0. I couldn't locate this galaxy at all. Not bad for a first cut -- obviously it will require a lot more grooming before becoming the well-honed tool for evaluating deepsky object susceptibilty that I hope it to become.

I left the Ridge around 10pm. On getting home I noticed that Boulder Creek was fogged in. This was one occasion where the difference between a night of productive observation and productive non-observation came down to "location, location, location".

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Unexpected Encounter in the Night Sky

The months of January and February typically offer few breaks from the relentless rain, low-flying clouds (fog), and overcast that accompanies the northern California "monsoon" season. So with the weather presenting another opprotunity to get out and about astronomically, I took advantage and headed back up to the Ridge.

On this occasion, the sky was even darker than last night (Iota Cassiopeia's 12th magnitude field star was easily acquired at 120X and Chi Cassiopeia (magnitude 4.9) was also viewable with unaided sight. In addition, with Cassiopeia now slipping into the San Jose lightdome (to the north), I'd estimate that I could see down to magnitude 5.5 directly overhead. (This means that telescopically I would just be able to directly see magnitude 11.7 surface brightness objects using my 35mm 50X eyepiece and 12.3 magnitude objects with the 15mm - 120X eyepiece.)

So under these improved conditions I elected to revisit the objects viewed the previous evening and verify that even a little darker is better.

I started out with a revisit to M31 in hopes of nailing down NGC206 in the southwest spiral arm. No real progress here, whatever little hazy patch that this distant cluster is will have to wait for an even darker night. So now I have another good reason for returning again and again to that glorious assemblage of dust, gas, suns and luminosity that comprise the "Capital Galaxy" of our Local Group.

I then swung the scope around on Cetus for a quick review of NGC1055. 1055 had proved difficult but not impossible the previous evening. In searching for it, I came across an object that looked suspicious like M77 -- only perceptibly dimmer and slightly larger. I remembered from my notes of the last evening that M77 was bordered by an 11th magnitude field star (about 1 to 2 arc minutes away). The fact that this object was dimmer and no such field star was present made me suspicious. In fact, the object itself was at the base of an obvious ?-mark shaped asterism of 8th and 9th magnitude stars that would have been impossible to overlook the previous evening. In sighting along the scope I determined that I was actually positioned about 1 degree west of a 5th star south and west of Delta Ceti. The question mark just had to be answered: What is this thing?

On returning home, I consulted some software received when I bought my MK-67 (Argonaut). The object is designated NGC936, an "elongated galaxy with bright core". It's magnitude listed as 10.1. That, along with its 4X4 arc-minute diameter size (as viewed by me), gives it an average surface brightness of at least 10.5 (compared to that of M77 which is 9.8). The thing is pretty bright and I wonder how Messier missed it. Not that I wonder how he missed NGC1055 however...

After recording this "discovery", I retraced my star-hopping steps and centered on Delta Ceti, quickly viewed M77, verified that it was, in fact, as bright as I had remembered (plus the presence of the field star) and centered once again on the two 10th magnitude stars less than a degree northwest that triangulate with NGC1055. On this occasion, I noticed something of interest. Last night I noticed an 11.5 magnitude field star butt up against the side of the galaxy. When you direct your attention on the star, the faint smear of light from the galaxy disappears. When you "intend" to see the galaxy (by averting your vision away from the star), the star disappears and the smudge becomes apparent. Meanwhile, since I knew that the next object has a surface brightness comparable to 1055 I decided to really get a handle on how these faint fuzzies reveal themselves to the eye. M77 and NGC936 would be no help - since they both have easily detected bright "Seyfert Galaxy" cores. Both 1055 and 891 are your garden variety spiral's with more distended cores blending into less luminous (and possibly visually undetectable) spiral arms. Once you find one of these faint jobs you definitely want to accustom your eye to them since they are so easy to miss without practice...

So now for the main event: Harrington has some very nice things to say about NGC891 in Andromeda and he also advises that the object is very difficult to track down through a backyard scope. Last night I believed him. Tonight my opinion has shifted (somewhat). First the charts in his book seem to be a little off. The galaxy is located significantly closer (maybe 45 arc-minutes) to Gamma Andromeda than first gathered looking at his chart. Second the star field he describes does not map against what is seen in the average scope. So last night I was effectively looking for the right thing in the wrong place. Here's how you may find this object:

Center the scope on Gamma Andromeda. Bask in the view of this wonderful low power double for a few minutes. Try to see the companion as blue then again and see it as gold. (It works both ways for me.) Then shift Gamma Andromeda slightly to the north (maybe 15 arc-minutes). Next use your slow motion controls and move due east by two degrees. Start paying attention to the FOV in detail. Slowly progress another 30 arc-minutes. Once a yellow 7th magnitude star enters the FOV (from the east) the galaxy is somewhere in the FOV about 20 arc-minutes west of the star and slightly to the north. If the night is dark (5.5ULTM), and you have at least a full five inches of aperture on your scope and a one degree field of view ep, you will catch sight of it as a ghostly lens-shaped tube of diaphanous light oriented SSW to NNE. With averted vision, you may just get a sense of a dark lane bisecting the edge-on spiral. You will certainly notice that the western edge is somehow "sharper" than the east. (But these details will require the additional magnitude of depth you get when you avert your eyes away from the object.) Should you come to find this thing you will be entranced, amazed, and rejuvenated. It could become a life-long fascination, hovering as it does just on the border between the seen and the unseen -- like a thousand other deepsky objects -- at the limit of your eye, scope and dark sky capability.

On the radio the blues program was over, and so was my night of observing. 9:00PM. Time to head home and hope that I could resolve the riddle of the question mark with a Seyfert Galaxy at its point.

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Close but no Cluster

Got home from work a little late. Attended to a few things domestic. Noticed how dark the sky looked. Due to the late hour, and a dis-inclination to drive up to the Ridge, packed up the scope and headed on up to Boulder Creek Elementary School. Before this however, I took some time to pull together an observing plan. The bulk of the objects were to be double and multiple stars but as it turned out, the sky was quite unstable and, at best, I could only coax the MCT to do a nasty split of Iota Cassiopeia. 12th mag field star was direct at 120X however (required moderate aversion at 50X however). Iota itself was plainly visible. I'd venture to say that it was a 4.7 ULTM night.

Sometimes you make good plans, God laughs, the sky changes and you gotta adapt. My adaptation was to junk the double-star stuff and concentrate on finding NGC604 in M33.

As it turned out, I spent an hour an half slowly scanning everything from due north to due east of the galactic core. All this time the thing was staring me right in the eye. The brightest part of this galaxy is not in the core, it's the highly ionized nebula itself! How, you might ask, did I come to this conclusion?

Originally I expected to see a knot of bright, but smeared out light maybe 1/60th of the FOV in size. I figured the knot would have a surface brightness similar to the core. I also figured that it would be further out from the core in the FOV. Now, harboring mis-conceptions is a sure fire way to ensure defeat in any undertaking. The only difference between defeat and failure in the current endeavour however was the fact that I had plenty of time to just stay with it. I also had a photograph of the galaxy with labeling to indicate the location of my target. Unfortunately the phot gave no indication of scale, so I had no idea of whether NGC604 was found anywhere within the FOV of my 1 degree 50X ep.

What I did have was a general sense of the layout of stars that formed an "orion-like" asterism of 9th and 10th magnitude stars northwest of the galactic core. With this asterism in mind I set out to map the asterism against what I was seeing in the FOV. After several minutes of visual pattern parsing I finally "groked" the asterism and arrived at a perception that the 9.5 magnitude star at the outermost left foot of the Orion-figure was my goal. Why the "star" wouldn't come to focus and my was it bright. Certainly brighter than any part of the Triangulum Galaxy itself! No wonder I missed it. It was nothing like I expected. But little did I know...

I switched over to my 120X ep and examined my find. Sure enough, it wouldn't come to focus -- but neither would the 8.5 magnitude blue star about 5 arc-minutes distant from it! I attributed the problem to instability (this while noting that other stars in the FOV would come to focus). I added a comment to my field notes: "NGC604 appears to be a blue out of focus field star about 25 arc-minutes north-northeast of the galactic core. Be careful though don't mistake it for an even brighter field star 5 arc-minutes west of it."

On returning home I did a little research on the web. Grabbed a nice under-exposed image of M33 and started parsing for the hunter asterism. Found one of several. Traced out the stars making it up the most likely candidate. Discovered that what I believe it to be might actually prove itself out. More telescope time and research is needed before I can make any definitive statements. But at least now I have a better sense of what I'm looking for.

While viewing M33 I made an estimate of the 15 arc-second circular star count. Figured roughly 10 stars. This equates to a limiting magnitude of about 11.7 at 50X and 5.5 ULTM. Mty count is probably a little off. It is also likely that the star density in this region is a little higher than the usual. Still, the numbers aren't bad.

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Veiled and Voluptuous

Venus is now at eastern elongation. Early in the evening I set up the scope (in the backyard) for a quick look. By 6:00PM PST (this time of year), dusk is still accumulating -- but it is reasonably dark. Currently, Venus hangs about 40 degrees above the southwest horizon. Through the scope, She chooses to reveal about 50 percent of her veiled beauty.

Local atmospheric stability is probably 6 or 7 of 10. There is less chromatic aberration than usual (although a hint of orange-yellow kisses Aphrodites sunward cheek). Certainly the leading edge of the disk is by far the brightest. The poles diminish in brightness in a more leisurely fashion than the terminator. The terminator does not appear to be an exact straight line. Any deformations are gradual and unstable. The terminator is a deep blue-gray (deeper than the polar regions). There is little doubt that the deformations along the terminator are due to local atmospheric turbulence. Darkening toward the terminator is trigonometric rather than linear. (As the eye approaches the Venusian terminator, the surface brightness of the disk falls off quickly the more you approach it.) The bulk of the planet appears "solar yellow". A small thumbprint of yellow-gray begins about midway from the leading edge toward the terminator (at the center of the visible portion of the disk.). The root of the thumbprint is oriented toward the terminator. It widens and darkens to engulf it.

Venus offers nothing to the eye in terms of detail. However, one's imagination can conjure up many possibilities for the surface itself. (Ranging from the impenetrable rainforests imagined in the early part of the last century to the scaldingly-hot, acid-blown desert emerging out of the modern era of space probes and radar-detected topology.) Venus is neither hospitable to the eye nor to the designs of human habitation. But who can possibly guess Her true value in the scheme of things?

By 6:45 Iota Cassiopeia was almost (but not quite) directly visible to the eye. Meanwhile Gamma Ceti was very close to the same general altitude to the south. With the two stars in such symetrical relation, it made sense to compare these two tightly-coupled star views.

Iota was a nice clean split at 180x (10mm Ultrascopic). In searching for it, I noticed that other naked eye stars gave nice "airy disks" with palpable diffraction rings (at this high magnification). So seeing conditions were pretty good for the comparison (stability probably 7/10). While Iota Cassiopeia is triple, Gamma Ceti is double. The two closest components of Iota are of the 4.7 and 7.0 magnitudes. Gamma's components are of magnitudes 3.6 and 6.2. The separation of the closer Iota pairing is 2.3 arc- seconds. That of Gamma Ceti is 2.8. Of the two, Iota was the significantly cleaner split.

Gamma's primary is a pure, radiant white. The secondary appears dim blue gray. (It's color is blanched out by the brighter primary.) Delta's primary trails the secondary across the sky. This is not one of the prettier double star combinations. But it makes an excellent above average seeing split in a 150mm scope. To be complete, I have to say that sky conditions to the south were perhaps a tad worse than those to the north this evening. It's possible that the Delta split suffered somewhat from this.

In checking Iota I noticed that, even without the usual direct naked eye view of the system, its 12th magnitude field star could be held directly in the 180X ep. This confirms that magnification has a significant effect on telescopic limiting magnitude. (At 120X if I can make out Iota directly I can see the 12th mag field star directly in the scope. At 50X it takes moderate aversion.) I suspect you pick up another .3 to .5 magnitudes by going from 120 to 180X.

Moved on to again try and pin down NGC604 in M33. Concentrated on the 11th magnitude blue-green "fuzzy star" noted last evening. Located M33 through the finder. (Just barely perceptible this evening while viewing from my backyard.) Decided to use the 70X 25mm Ultrascopic instead of the 35mm as the "sweeper". Noticed the field was flatter in the 25mm than the 35mm. Starpoints were also sharper. (The 35mm may be flawed -- but the stability is also better this evening. Of course, I've also lost a half magnitude LTM due to the backyard location.) With the star centered, I turned on the clock drive and installed the 10mm -180x ep. The object is obviously ill-defined at this magnification. But no nebulosity was apparent. Added the OIII filter to the ep. A lot of stars winked out (due to the 2 magnitude loss narrowband filter effect), but the 9th magnitude field star 5 arc minutes west and slightly north of the target remained perceptibly brighter (by about a magnitude) than the target. But both were visible. (Usually an 11th magnitude star would not remain visible with the filter installed in my 150mm scope.) Pulled my hat brim down to block as much stray light as possible. The goal was to catch sight of any nebulosity around the "diffuse star". And catch it, just barely, I did. It took several minutes of dark-adaptation, but I began to make out a vague "arrowhead shape" of nebulosity encompassing the star. The nebulosity had an apparent diameter a little larger than Jupiter (when viewed at the same magnification). The arrowhead points away from M33 core (pointing north-north east). (This can not be "star haze" because such a phenomenon doesn't usually show up when I am using the 180X ep.) The evidence for actually having located NGC604 is mounting.

Now to be honest, I've seen pictures of this object. The brighter central portion of "The Orion Nebula of M33" does take this shape. But I have no idea which way it points. (That will be the test.) I also inspected the area around this NGC604 candidate. Every once in a while I'd catch sight of a very much smaller piece of nebulosity (some 3-4 arc-minutes to the southeast). More follow up here is needed.

Now to move on... Under current backyard viewing conditions I propose to see if I can make out NGC891 before moving on to open cluster M34.

My first pass at finding NGC891 failed miserably. Using the 70X ep as a sweeper changes the general appearance of things. I also noticed high thin clouds moving in. Basically, by this point I only had the zenith overhead to give me dark-sky views. Fortunately Perseus is in this region (though Gamma Andromeda had begun to plunge into the high thin cloud region.) Had no trouble turning up M34 however. This mid-density open cluster is quite obvious -- even in a 7x35mm finder. In addition M34 also lies on the same declination as Gamma Andromeda. So it can simply be found by slewing due east 6 or 7 degrees to encounter the cluster.

M34 itself consists of thirty or forty easily detected 10th and 11th magnitude stars. Most concentrate into a "cruciform" pattern oriented along a north-south axis. (The base of the cricifix to the north.) Other bright stars seem to encircle (or should I say "ensquare" the cross. More detailed inspection showed numerous 12th and 13th background stars. These create a true "star haze" which makes for a lovely backdrop to the crucifix. The backdrop however, fails to spread out as far as the dozen or so bright stars comprising the perimeter. The cricifix itself is truncated at the top. This southern extension is dominated by a single wide-pair of 10th magnitude stars oriented more or less along the east-west axis.

To the west of the cruciform section, is a nice pair of stars separated by about 20 arc-seconds. Other star pairs are easily detected throughout the cluster, but these two are the most closely coupled of the brighter components.

The entire cluster can be seen in the 40 arc-minute field of my 25mm 70X ep. I found myself intrigued by the "circumscribed cross" pattern. But in lingering over the eyepiece, I was even more attracted to the hundreds of 12 plus magnitude stars that supported it in the depths of the night sky.

Before putting away the scope, I made one more pass at turning up NGC891. I attempted this using both the 35 and 25mm ep. Due to the sub-5.0 ULTM seeing of the evening, at best I was only able to make out a "hint" of inconclusive nebulosity in the expected sky location. When searching for similar "deep fuzzies", I would never have acceded to the "fact" of finding any object that displayed so little of itself in the scope. What a difference a half a magnitude makes.

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Two out of Three ain't Bad

Rain is expected to return in the next few days. So I put together a short term observation list and headed up to the Ridge. Managed to arrive early. (I take a lot of pleasure in watching the sky darken and the stars turn on slowly.) After setting up the scope (and while the sky was still fairly light) took a quick look at Jupiter. Noticed a large dark knot of material on the NEB. Looked a lot like the GRS but as I recall the GRS is embedded in the SEB. The NEB, NTB, and NTTB were are plainly apparent. The SEB was singular and the STB was clearly discernable on it's northern facing edge. (The pole facing edge blended into the SPR.) No hint of dove' footprints on the EB.

Based on the amount of detail seen on Jupiter, sky stability was at least 7/10. I spun the scope around on Iota Cassiopeia right after viewing Jupiter. The sky was still fairly bright. (To the south-southwest considerable illumination remained from the sun well below the horizon.)

Iota was a nice clean split at 180X. Its 12th mag field star just directly perceptible. Conditions were promising for more double-star observations. Tonight I would be working a trio of doubles in Aries.

Of Epsilon, Mu, and Pi Ari, I managed to turn up Pi first. The Pi system is triple. Primary of magnitude 4.9 accompanied by an 8.4 magnitude secondary (at 3.3 arc-seconds) and a 10.5 magnitude component (at 24 arc-seconds). In terms of sky position, the 10.5 magnitude tertiary leads the other two across the sky. The 8.4 magnitude secondary follows the primary slightly to the south. The primary is golden-white, secondary blue-white and the tertiary pale blue. The 3.3 arc-second gap between the primary and secondary looked wide to me. At 10.5 magnitude and 24 arc-second separation, the tertiary was well out of the light scatter from the primary and was easily made out. The tighter pair could be resolved at 50X -- under moments of steadiest seeing.

Mu Arietis is located about 2 degrees northwest of Pi. Both Mu and Pi are the brighter members of wide line of sight doubles in the finderscope. Mu consists of a 6 magnitude primary and relatively distant (19.4 arc-second) 12.5 magnitude secondary. Despite the relatively wide separation, I used the 10mm Ultrascopic ep (180X) to offset the secondary's dimness. Even this approach was not enough to conclusively make out the secondary in the FOV. (The sky by this time was quite dark - 5.4 ULTM.) Certainly the light smear from the 6th magnitude primary washed the dimmer secondary completely out. It's possible that 360X may have revealed the secondary -- although barlow lenses damp out magnitude-magnification effects somewhat due to additional elements in the light path.

Epsilon Arietis forms an easy finderscope triangle with Pi and Mu. ( Epsilon is found in the direction of the Pleiades). Primary and secondary are quite close in visual magnitude (5.7 & 6.0). Separation is said to be 1.3 arc-secondary. (Some references say 5.2/5.5 separation 1.5"). My observation notes from this evening say that the split was somewhat wider than I expected -- so the later figure is probably more accurate. I also recall that the difference in luminosity was more substantial than either of the two sets of figures above suggest. (Actual values are probably along the lines of magnitudes 5.2 and 6.0.) Regardless the split was very clean. The primary displayed a fine golden-white color while the secondary looked aqamarine. In terms of position, the secondary leads the primary across the sky (to the east-northeast). The primary, like those of Mu and Pi, all showed very nice spurious disks. The night (and the optics) were an exceptional combination for double-star work.

NOTE: Since making this series of double-star observations, I developed a third observation astronomy calculator to help determine how susceptible a particular binary pair are to resolution based on scope size and seeing conditions. That calculator The Double Star Resolution Calculatoris available to assist myself (and other astronomers) evaluate whether or not they may be able to successfully resolve a particular binary under specific seeing conditions.

With three "first lights" behind me, I moved on to review several objects that have caused me problems and doubts. The first is the 2X1 arc-minute "Great Nebula of the Triangulum Galaxy" - NGC604. As a result of previous efforts to find this object (as well as photographic research on the web) I am now pretty clear about its location (at the tip of M33's northeast spiral arm (near an asterism shaped like a human figure). Tonight's search began by centering M33 in the 50X FOV. I then advanced the right ascension until I could lock the clock drive. With the scope pre-positioned I dropped in the 180X ep. While waiting for M33 to drift into the field I made some 15 arc-minute star counts. Numbers varied between roughly 8 and 12. Assuming an average of 10, I was easily making out stars down to magnitude 11.7 without much effort.

After several minutes, M33 core drifted into the 180X FOV. It looked much smaller than at 50X. (This despite the high magnification.) Once again it is clear magnification "washes out" surface brightness in extended objects and show you less -- not more. With M33 core in the FOV I dropped in the 50X EP. The clock drive gave me an extended opportunity to "absorb" details of the galaxy. After a while I began to make out the spiral arms. (Orientation north-south with ansae taking off at right angles east-west repectively.) At the tip of the northeast spiral I could make out the southern foot of the "mini-Orion asterism" I personally use to orient myself to NGC604. (Star diagonals make orientation very difficult since they can be conveniently used to rotate the ep around the tube axis.) With averted vision, I noticed a small diffuse spot (just west and slightly north of the southern foot of the figure).

To assist in confirming this I pulled out the 25mm Ultrascopic (70X) and viewed the locale first without and later with the OIII nebula-enhancing filter. With the filter I could make out all six stars of the asterism (although the star comprising the southern belt position was not directly perceptible with the filter in place). Meanwhile the spot of nebulosity became more sapient to the eye. I then installed the 15mm (120X) ultrascopic ep (with filter). The nebulosity held up to magnification well, so I bumped up to 180X. At 180X with OIII, the nebulosity was definitely confirmed. However it's shape seemed ill-defined and any sense of the "arrowhead" I expected seemed to flit back and forth like a magnet alternately polarized. Throughout this entire series, the stellar core I had noticed previously was not particular salient (but could be detected occasionally). The blue green coloration noticed previously held up nicely however.

I am now satisfied that I have knowingly glimpsed the "Great Nebula of M33" and would like to add that it was not as "easy" to locate or to detect as some observers have suggested.

In keeping with this theme of verifcation, I also took some time to finalize the location and visible extent of the bright nebula catalogued as NGC281 located near Alpha Cassiopeia. The object has a calculated surface luminosity of 13.0 so I did not expect to have much luck in seeing it. However, the fact that it's cumulative magnitude is 7.0 gave me the idea that the combination of finderscope and OIII filter would allow me to precisely locate the nebula in the center of the 50X FOV. Once all doubts were banished as to its location, I could rightly determine whether or not it could be seen - even with such a low "average" surface brightness.

As it turned out this approach worked great. I centered the finder on alpha cass. Shifted due east about a degree and a half and Bingo, with OIII filter in place before the finderscope, I distinctly made out the "sheen" of the nebula. Switching over to the main scope, I determined that even at 50X with no OIII filter this nebula could be detected -- as long as you knew precisely where to look and what to look for.

Inserting the 25mm / OIII combination in the scope, I determined that the brightest patch of nebulosity was perhaps 10 arc-minutes wide by 20 arc-minutes in length. In sweeping the field adjacent to this patch, it became very obvious that the nebula extended well outside the FOV in an irregular shape. (I determined this by noting just where the sky got truly black again during the sweep.) Before installing the filter (while using the 35mm Ultrascopic) I noticed a 30 by 15 arc minute "ellipse" of 7 and 8th magnitude stars. One of which (the westernmost) seems to be right at the heart of the brightest portion of the patch.

Once I finished my double-check of 281, and with filter still in place, I swung the scope around briefly on the Great Orion Nebula in Orion for a check of how much more nebulosity was apparent using the filter. My guess is that the filter basically doubled the size of visible nebulosity. The thing was an excellent investment.

As I write up these notes, I am also thinking how apropros it was to view M42 after having visited something like it in an entirely different galaxy on this same evening -- NGC 604.

Another object I wanted to confirm this evening was NGC147 (a distant companion galaxy to the Great Andromeda Galaxy) located in Cassiopeia. Of the four companion galaxies (M32, M110, NGC185 and NGC147, 147 is the most difficult to acquire in a 150mm scope. In searching for 147 I spent a few moments appreciating its more obvious sibling elliptical galaxy 185 first. Then I carefully shifted 185 a half a degree south and a degree (or so) west. No cigar... I repeated this operation several more times. On the third attempt, I made out the faint "sheen" of 147's elliptical core. Once I identified it, it was quite possible to view it directly -- but only under averted vision did it give any hint as to its general elliptical shape.

With the above success to gird me, I turned the scope on M31. The hope, once again was to locate the star cloud (NGC206) in the southwest spiral arm. I spent perhaps a half an hour with clock drive engaged at 180X perusing the suspected location. As I did so I made a quick star count in the FOV. Easily 20 to 25 stars could be counted as the galaxy drifted nearer. (24 stars per non Milky Way 15 degree field suggests that you are seeing down to about magnitude 12.3.) Aside from the star counts, and a better sense of the suspected NGC206 region of M31, I made no real progress here this evening. As Andromeda begins to sink westward, opportunities to make this identification are dwindling...

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On the Threshold of the Seen

Decided to assemble the scope for backyard observations this evening. My only goal was to continue the quest for NGC206 in M31. Evaluated some photos of M31. I have yet to find one that shows the relationship between the core of M31, M32 and NGC206. In evaluating the photos I was able to identify a "patch of light" about 40 arc-minutes way from the core and 20 (or so) from M32. The patch matches the desciption in Harrignton's book. Unfortunately, Harrington indicates that NGC206 is twice as far as that away from the core. So to begin with I began my observation series at Harrington's suggested more remote location in the vacinity of a 7th magnitude yellow star along the midline of the southwest spiral arm. An exhaustive review at both 50 and 120X revealed nothing that mapped against Harrington's description.

NOTE: Research done on the WWW a few days after this report indicated that the position cited above is correct. However, NGC206's actual position may be further toward M32 than I originally though. Basically, I need to give a more thorough 120X inspection somewhat south of the region I inspected on this particular evening.

Once this detailed survey was complete I focused on the region 40 arc-seconds out from the core. Noticed the same triangle of 10th magnitude stars found near my previous NGC206 candidate. Spent about fifteen minutes dark-adapting my sight at 120X. Subsequently nothing conclusive was seen during a meticulous examination of +- 10 arc-minutes of the locale.

As a test, I wanted to get an idea of how far the faint luminosity of M31 extended beyond the galactic plane. Had to swing the scope several degrees north and south of M31 before I could make out "dark" sky again. M31 is huge! Before knocking off for the evening, I made one final test. Swung the scope on M110 (at 50X). Noticed that all but about 2 arc-minutes of the central core of this elliptical galaxy could be made out (using direct vision). Sky conditions directly overhead were not bad -- perhaps even 5.0. But lower down into the Boulder Creek lightdome (to the northwest), it was difficult to acquire Kappa Cassiopeia directly (magnitude 4.2). Since M31 shared this part of the sky, its clear that I was limited to about magnitude 11 (at 120X) during my detailed sweeps of the two regions. Therefore, I have to assume that NGC206 is not much brighter than the background luminosity of M31 and that it probably has a photgraphic magnitude in the realm of magnitude 12.0.

NOTE: While analyzing astro-photos of the region around NGC204, I happened to notice that extended M31 star cloud nebulosity associated with M31 engulfs M32 but not M110. I need to follow up on this in a future session.

As it stands now, I hope to get at least one more chance during this viewing season to repeat the kind of detailed surveys described above (under 5.5 ULTM conditions). If nothing turns up, then the likelyhood is that this object -- if within the range of 150mm as Harrignton contends -- will require dark sky conditions that are rapidly becoming impossible to find (due to the unavoidable light pollution which has settled down on this part of the country.)

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More Galaxies than you can Shake a Scope At

Continued fine weather (and my understanding wife) allowed me to again go out this evening and continue my astronomical quest. 32 of the 34 celestial objects planned for the month of January have now been identified and described. With the prospect of a change of weather ahead I felt it useful to begin rounding up some of the more difficult objects planned for the early part of February. I also hoped to continue efforts at locating the star cloud NGC206 in the Great Andromeda Galaxy.

As usual, I began my hunt for first lights with those objects skirting the southern horizon. During the winter months this part of the sky is a window onto distant galaxies. That window exists because our own galactic lens continues southeast into Orion via Perseus and Taurus. Also due to this estrangement, the sky west of Orion is somewhat lacking in bright stars. Navigation by star hopping can be quite challenging. Given the combination of poor celestial landmarks and cold temperatures most amateur astronomers find excellent reasons for not observing some of its treasures...

The particular treasures planned for this evening began with the so called Fornax Galaxy Cluster spread out rather broadly with a primary concentration of members just east of the Chi Fornacis asterism. The cluster itself consists of eigtheen galaxies susceptible to amateur equipment. I made no attempt to find, describe or even identify all eighteen of them. My goal was simply to get a sense of their brightness and distribution strictly in one concentrated region east of the Chi asterism.

In scanning this region I quickly noticed a vein of 7 to 10 magnitude stars oriented along a more or less north-south line. In the same 1 degree field (as the brightest of these stars) was one obvious, one directly acquirable, and one avertedly acquired galaxy. Shifting the scope along the north-south spine of stars revealed several others. Moving the field perpendicular to this axis (to the east?) revealed another pair. Many of the brighter galaxies had tiny starlike cores. Even those requiring averted vision displayed a hint of the same. Small scopes are only able to reveal the brightest members of the group. The brightest of these are likely to be Seyfert galaxies with their brilliant quasar like centers.

The process of locating Chi Fornacis was quite demanding. The sky to the south appeared generally hazy and grey. The brightest stars visible to the unaided eye are all equal to or less than magnitude 4. (Stars on the zenith -- at least early on in the evening -- exceeded magnitude 5.) One star (Theta Eridani) was bright enough to catch my eye immediately. By consulting star charts and linearizing off stars in Orion, I was able to determine what star it was and begin a systematic effort to locate the Chi asterism. As it happened I used Theta to align my finderscope. Even at 50X it was obviously double. The 3.1 magnitude gold primary appeared about a magnitude brighter than the yellow secondary. The secondary (at magnitude 4.1) trailed the primary across the sky (separation 8 arc-seconds). In some ways the pair reminds me of Gamma Andromeda (but with more closely matching luminosities). Possession of this information in the future should make it a lot easier to find the Fornax Cluster -- should I choose to make a project of better describing and accurately identifying its components.

My observation plan did include three particular members of the cluster. These were NGC1365 (1 degree southeast of the Chi asterism), and NGC1316 and NGC1317 (both in the same FOV 1 and one-half degree southwest of the asterism).

I found NGC1365 to be a rather large (5 arc-minute diameter) ellipsoidally-shaped, elusive patch of light with a hint of a starlike point. In appearance it was somewhat reminescent of a very dim, relatively large globular cluster. 1365 required moderate aversion to acquire, but could be held with direct vision once located. I got a sense that any elongation falls along the north-south axis.

Unlike 1365, NGC1316 was easily acquired. Like other Seyfert types, roundish with an obvious star-like central core. 1316 is bright enough to show detectable dimming to the edge of perception. It appeared perhaps 3X4 arc-minutes in size elongated along the north-south axis.

NGC1317 shares the same 1 degree FOV with 1316. That FOV is dominated by a "tailfin" asterism of 8th and 9th magnitude stars positioned to the east. 1317, bearing an average surface brightness of roughly 11.8, was only perceptible to extremely averted sight. It appeared a dwarfish sub-one arc-minute blur with the hint of a 12th magnitude central point for a core. This particular galaxy dwells on the limits of perceptibility by a 150mm telescope under average seeing conditions.

Having found the Fornax Cluster in general and identifying three of it's members, I was now ready to head north out of greyish non-descript regions of Eridanus -- but not before viewing the planetary nebula NGC1360.

Many planetary nebulae appear like small out of focus stars in the FOV. Not 1360. This particular planetary looks more like the kind of light scatter that surrounds many stars at low to medium magnifications. In this particular case the 10th magnitude star near its center was not bright enough to engender the degree of haze I was seeing. -- Nor did a star of similar magnitude (10) in the same field display the same degree of scatter. To confirm that I had actually found the planetary, I installed the 70X 25mm ep with OIII filter. The nearby 10th magnitude field star dimmed out almost to the point of extinction. In addition there was no sign of star haze in its presence. Meanwhile, the nebulosity identified as 1360 stood out distinctively. While it's core star was almost (but not quite) extinguished. 1360's is quite large (perhaps 6 or 7 arc-minutes in diameter). No sign of a gap appeared between the nebulosity and the central star. Nor was there any indication of a distinct frontier at the edges.

I had hoped to find one more galaxy (from my observing list). That object (NGC1300) did not present itself to my eye but I can't be sure that I had found the correct FOV. As I was verifying this, high thin clouds climbed up and engulfed the Eridanus region. Before it completely dominated the sky, I made a quick check of M31 in hopes of catching a hint of NGC206. In so doing, nothing presented itself but I did once again find the asterism that lies in the general locale. (Unfortunately I focused my scrutiny on the wrong side of the asterism and found only "imaginosity" as my reward.)

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General Public Cordially Invited

Amateur astronomy can be an excellent cure for "Saturday Night Fever". On this particular Saturday, the Fever took me away from the usual lonely sojourn (to the Ridge), and deposited me down in the Hollow of the Low Flying Fowl. There I, and perhaps twenty other amateur astronomers, temporarily commandeered the park's south field and set up our scopes.

Dominating the scene were a number of SCTs. Apertures ranged from a single four inch NextStar to an eleven inch Celestron (C11). Several 10 inch Dobs were also present, along with at least one eight and one ten inch LX200. I set up the MK-67 near fellow Santa Cruz Astronomy Club member Ralph. Ralph and I had observed together previously at the private SCAC observing site in Bonny Dune. His scope has excellent optics. More importantly Ralph is a genuinely likeable fellow. I truly enjoy his fine, cultured company.

Most participants had arrived well before dusk. The event was well publicized and a large contingent of "the interested public" were anticipated. As the sky slowly darkened, the bulk of the tubes were turned on M42 in Orion. This impressive object (and later the Pleides) would prove most popular with the crowds that later started showing up (headlights ablaze) just as our eyes were becoming dark-adapted...

As observations began in earnest, the crescent moon (replete with "Earthglow") hung about 20 degrees over the southwest horizon. In fact the theme for this particular evening was "the Moon". A slide show and presentation by a SCAC club member was in progress in the Quail Hollow Main House. (At one time Quail Hollow Ranch had been privately held. Cattle and horses probably once grazed in the large field where we setup.) A visitor approached me, and at her request I turned the scope on the moon. At 50X it fit nicely within the FOV. Mares Focundatitatis and Crisium dominated the view. Of the large craters, Stevinus was most obvious. The edge of the moon "shivered" with turbulence. (As the night progressed, all in attendence would "shiver" as well - with the cold.) Atmospheric stability was none too good. (It had not been very good the last - first -time I had observed here either). General instability was verified when I made my usual checks of Iota Cassiopeia (elongated - not even a dirty split) and Saturn (Cassini visible intermittently). The temperature was dropping. Earlier Ralph had turned his scope on Venus. The defocused image showed some marginal tube currents. The temperature gradient, however, was not enough to cause ongoing problems with our scopes. But it did result in the last of the scopes being packed up and moved out by 10:30PST. (The last Quail Hollow session ended at the "Witching hour" with the gentle encouragement of the park docent.)

Even with the moon up, transparency was pretty good (for this particular locale). To the unaided eye, Iota Cassiopeia was just direct (ULTM=4.6). As the night progressed (especially after moon-set), I would say (light domes of Santa Cruz - southwest - and San Jose - north - notwithstanding), transparency improved to an ULTM of 5.0. Interestingly enough, later in the evening, I had a visitor who asked me what I thought of sky conditions. With my usual enthusiasm for this topic, I approached an answer by explaining how I usually assess the sky based on stars in Cassiopeia and how this translated into what I would later be able to see through the scope. I made the especial point of saying that I needed good dark nights (ULTM>5.0) to get the kind of deepsky views my neighbor Ralph and his 10 inch scope would get even on "poor" (ULTM<4.0) nights.

My other neighbor - Jeff - had setup a four inch NextStar "next door". We took a look at M42 in his scope, followed by mine, then Ralphs. The NextStar could just barely reveal the 7.9 magnitude member of the trapezium. (Unforunately, the ep's FOV was "curved" and the trapezium could only be resolved near the center of the field.) Nebular gases were gray and less expansive than in the six inch. The tongue of darkness licking at the Trapezium lacked depth of contrast. There was no sense of the dark slash of absorption nebulosity opposite the trapezium from the tongue behind it. The six inch showed the bright nebula as "white" rather than "grey". The trapezium was visible no matter where its position in the FOV. The dark slash was just visible with averted vision. The ten inch showed the dark slash obviously. (In fact I had first noticed this feature in the ten inch, then traced my way backwards through the series of scopes to determine where it was lost. I had never seen it before in my six inch.) The ten inch also showed only the four main stars of the trapezium - stability was just too poor for detecting any others.

Ralph and I then turned the 10 inch on M78. M78 was very obvious in his scope. (I had seen it before in mine and didn't bother to view it.) I was particularly interested in viewing NGC 2071 (north-northeast of M78). This "bright" nebulosity surrounds a 9.5 magnitude star. A second star of similar magnitude lies very close by in the same field. Both stars showed "star glow" in his scope (as I have seen in mine). Although the nebula should be easy in a ten inch (even under less than perfect skies) it was confounded with the star. Again a tough call.

Earlier I had toured around the observing site. During the tour, I came across a first-time observer - Matt. The sky was still relatively light at that time but Orion's Sword could be made out. I helped Matt take aim on M42 and we checked it out through his 30X 50mm super wide field ep. The low power and bright sky robbed the image of contrast but the 10 inch Discovery Dob-Newt gave a decent view. After this we turned the scope on Jupiter. The low power view showed a very bright tight disc with 3 tack sharp satellites in attendence. The SEB and NEB were possible even at this low power. Later I had a chance to view M31 through the scope as well. Dust lanes between M31 core from M110 were obvious. (They are difficult in my 6 inch under similar conditions.) M32 and M110 gave nice views as well. Matt showed a lot of enthusiasm for these objects. I also turned him on to the Double Cluster in Perseus. It really hasn't been that long ago that I was just learning about some of these same objects.

With the sky getting "dark", I returned to my own scope. Showed a nice old lady the Pleiades (at her request). I explained that the best view was through the finderscope. We talked a little about how the Pleiades could be thought of as "The Seven Wives" joined with the "Seven Husbands" of Ursa Major.

I resumed my own agenda: Find NGC206 in M31! With Ralph's "Goto" and one magnitude deeper reach, this turned out to be a cinch. Unfortunately after determining 206's position in Ralph's scope, I was only able to just barely imagine it in my own scope. So final, certain detection of this object will have to wait for a clear, dark, night up on the Ridge.

While looking for 206, I misquoted the reference as "NGC604". This swung the scope around on M33. Once again, what is obvious in the ten inch is a challenge in the six. The "Great Nebula of the Triangulum Galaxy" was easy.

By this time Ralph was starting to show enthusiasm for the faint stuff. So we rolled up the planetary NGC2022 in Orion. Damn, the thing was sharp and tight. Again, in my scope it is difficult and diffuse. In the ten inch, obvious and well aspected. (Circular, greyish white with a sharp outer edge between frontier and space.) Finally one more object: Galaxy NGC1300 in Eridanus. Punch in the coordinates. Listen to the coffee grinder mechanism chug along until the scope stops. Then there it is. Large oval fuzzy patch, barely brighter than the murky gray sky surrowunding it. (This one will be a challenge in the 6 inch -- I'm sure of it.)

As I was tracking down NGC206 in my own scope, I overheard Ralph talking with a visitor about seeing some "spiral arms" on a galaxy. I suggested they view M33 (since it was face on rather than edge on like M31). Ralph re-oriented the scope on M33 again. His visitor wandered off and I explained what to look for to Ralph. First I centered NGC604 in the FOV. Then I described 604's position in relation to the spiral arm. Ralph used my observing chair to sit comfortably and allow his observing eye to relax using NGC604 as a target. After awhile I heard Ralph begin sub-vocalizing phrases like "I see it", and "wow". I think Ralph had his breakthrough.

Earlier in the evening we had also turned the ten inch on NGC891 in Andromeda. Again the galaxy was an obvious "scratch of light" in the ten inch. (Under similar conditions it would prove somehwat difficult in the 6 inch.) It was in seeing NGC891 that Ralph began to get "deep fuzzy" fever.

My own scope was broken down and stored in the hatchback before 9:30. Ralph had left earlier. (He had another commitment.) I spent about a half an hour talking with the park's docent about the gravitational effects galactic core black holes have on nearby globular clusters. The docents background was in ecology. The idea of "herding for protection" seemed like a perfectly good metaphor as to why such clusters took form...

After storing the scope and accessories, I noticed a small group of folks struggling to set up and use a 60mm refractor in the parking lot. It was clear they were having problems. I stopped by to help out. Though the little scope had decent optics, the altazimuth mount was unstable and difficult to line up on any particular object. (It had its own mind about where it was willing to point. Rather than fight it I tended to reposition the tripod as a unit.) The finder also required some adjustment. We were able to get a look at Jupiter, Saturn, the Pleides, and M42 through the little scope. Planet views were nice and sharp. Stars in the Pleiades also. M42 was unspectacular. Only noticed the Trapezium as a single star -- but we were using the low power ep due to the problems with the mount. With a decent equatorial mount this little scope could be fun! But the current high level of frustration with the mount was likely to simply turn off most users.

Once small scope viewing was over, we had an extended conversation about stellar evolution. Discussion centered on the fact that the Pleiades were probably once very much like M42 in Orion. We also talked a little about the fusion of heavy elements in massive stars. The lyrics "We are stardust, we are golden, and we've got to get ourselves back to the garden." came to mind. Someone said, "It makes you feel so insignificant!". More lyrics came to mind: "Wake up and find out that you are the eyes of the world..."

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Imaginosity

Somewhere between the border of what is, and what could be, is the threshold of the possible. To step over that threshold is to venture outside the realms of the sure, the certain, and the safe. To take this step means to take all risks of gain or loss solely upon oneself. It means to wander alone, un-protected and un-supported by one's peers. Like a wilderbeast alone on the veldt, or an antelope that leaves solitary footprints on silently falling snow.

Imagine a solitary figure hunched over a telescope, barrel pointed towards the heavens. Slowly the scope repositions under the guidance of the figure's hand. Even more slowly the Earth rotates. Silently, new aspects of the sky present themselves to the astronomer's questing eye. Most of what is seen is easily categorized. Stars and more stars. Faint stars in large numbers barely catch the eye's notice. Brighter stars turn up in numbers that exceed what can be reliably counted without patience and diligence. A few very bright stars easily capture the attention.

Occasionally a dull patch of light presents itself. If bright enough, or if looked for by the astronomer, such patches may be noticed. Many such patches, either on the very threshold of the perceptible, or lacking any perceptible form, or devoid of any definable frontier to the darkness of space, are missed. If detected, there is no gurantee that the object will be recognized for what it is; Distant galaxy? Star Cluster? Bright Nebula? What? And where is it anyway? What is it's designation?

On this one occasion the object turns out to be a comet. It is quite dim, lacks any perceptible tail. Questions begin: Is it really a comet? If so, which one? Has it ever been seen before? Is it on the charts? Where exactly is the scope directed to in the sky? Unless our astronomer is actively looking for comets, has an extraordinary amount of experience with the sky, and is very familiar with how comets present themselves in the telescope, the sky continues to drift, the scope, to re-position. New objects, many familiar to the eye, continue to present themselves. And this particular object will go unrecognized, unidentifed, undocumented, perhaps to be claimed by another, more diligent, more thorough, more confident, more willing to work hard and take the necessary risks of investing time and energy and of being just plain wrong.

On the other extreme, our solitary figure may very well be inspecting a familiar part of the sky. The object to be found is well-understood by type, brightness, angular displacement. But the conditions under which the astronomer works are challenging. The sky is unstable or lacks transparency. The object is difficult for the equipment. The moon brightens the vault of the sky, and spoils the astronomers visual adaptation. Like the moon, light from nearby homes and streetlamps reach out to invade the retina. Meanwhile the nearby town projects a halo of luminosity over an entire quadrant of the sky.

Knowing the position of the target, the astronomer quickly directs the scope on his target. More likely however, this is a "first light" and the astronomer searches out one star in the heavens after another. First a bright star -- easy to the unaided eye, then a dimmer one near the brighter star in the smaller finderscope attached to the main one. Thence a pair of even dimmer stars at the limits of the finder. Finally the astronomer repositions the scope one degree to the north and another to the east. Having accomplished this task, nothing is immediately apparent to the astronomers eye in the main scope. Perhaps a very dull glow, at the limits of averted sight. Not having ever seen this object before how can there be certainty? Perhaps the scope is not even pointing in the right direction. (Was that one degree north or one degree south?)Begin again, find the bright star, the dimmer star, the wide optical pair, then more carefully, one degree to the north and another to the east. Still, only that faint will-o-wisp undefinable in shape, barely brighter than the sky around it. No edge. No definition. No shape. No neon sign proudly announcing "You've found it!". Dwelling on the threshold of the possible.

Such is how it was this night as I continued my quest for NGC206. Despite it's convenient location in the southwest spiral arm of the magnificent spiral galaxy M31. Despite the near 5.0 ULTM skies. Despite having seen what I was looking for the night before under similar conditions through a larger-apertured telescope. Despite having just read on the web that another astronomer had seen this very self-same object with a scope barely half the aperture of my own.

To be fair, a close inspection of the region associated with NGC206 showed that, even some 40 arc-minutes distant from the core of M31, there was considerable background luminosity associated with the spiral arm itself. An object such as NGC206 must somehow "highlight" itself against such brighter background nebulosity. Even though such highlighting was not obvious, there was a suggestion of increased luminosity in the expected location. Only a faint will-o-wisp, undefinable in shape, barely brighter than the sky around it. No edge. No definition. No shape. No neon sign proudly announcing "You've found it!". Dwelling on the threshold of the possible. "Imaginosity".

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The Real Thing

Sometimes, you just gotta do your homework and keep on trying. Take, for instance, NGC206 -- that mass of stars that "brightens" the southwest spiral arm of galaxy M31. NGC206 has been somewhere rattling around in my sub-consciousness ever since I first failed to notice it (as an afterthought) during my Friday, December 15, 2000 observing session.

Early on the problem was simple ignorance. I had no real idea of what I was looking for -- only a brief description in Harrington's "The Deep Sky", and an icon on a star chart (in that self-same reference). Once I added 206 to my observing plan (just before the New Millennium), I was commited to determining whether or not it could be seen with a 6" telescope and the conditions under which such an observation was possible.

Observing sessions on Saturday, December 30, Sunday, December 31st, Sunday, January 14, 2001, Monday, January 15, Friday, January 19, Saturday, January 20, Monday, January 22, Saturday, January 27, and Monday, January 29 (9 dates) all failed to deliver conclusive proof that NGC206 was susceptible to view. Andromeda descending into the western sky quadrant, a waxing moon, and a self-imposed restriction on viewing (from the backyard) conspired to suggest that I would have to wait 'till next fall before finalizing my quest (one way or the other). But things have changed...

First, I spent a little time on the internet grabbing astro-photos of M31 and evaluating asterisms (star configurations) associated with 206. Next, noticing that, despite moonglow, the sky is exceptionally transparent outside (directly overhead and in the flight path of M31) I felt the time was right to make a final conclusive push. So with the Iota Cassiopeia's 12th magnitude field star direct at 70X (5.2 ULTM at Zenith) and enough stability to get a dirty split of the tighter companion (stability fair to good) I turned the scope on M31. Thus began tonight's search for the 10th and 11th magnitude stars that make up my marker asterism:

					  X	



   *		
*			*	    	*

				*	

						   *
				    			*	       
 

As a sweeper, I elected to use the 25mm Ultrascopic. This choice was based on the need to get a dark enough sky to improve contrast (otherwise the 35mm would have been fine for an object said to be about 2X1 arc-minutes in apparent size). After about 10 minutes (and with my eyes fully dark adapted) I could make out all the above members of the asterism. I began scanning for 206. With the FOV centered on the main asterism triangle and employing averted vision, I could just (barely) make out an "ill-defined luminous mound" at the expected location. By shifting the telescope moderately back and forth along the declination axis, I confirmed that the brightening was not "imaginosity".

Following this, I installed the 10mm (180X) ep and began "squinting" for detail. There were two main concerns: First I wanted to know if I was being deceived by any small group of 13th magnitude field stars. (None were visible.) And second, the mound of light detected looked larger than expected and I wanted to pin down the angular dimensions. (The mound did have a "shape" -- unfortunately even at 180X I couldn't really delineate it, only determine that what I was looking at might easily have been "rectangular" and of the expected size.)

So what does all this say about NGC206?

To get an idea of how dim 206 is, we have to assume that it's adjusted surface brightness is right at the 70X threshold limiting magnitude of this particular evening. (LTM=12.1). Assuming NGC206 to be a "globular cluster" (with a susceptibility magnitude of 12.1), it would have a photographic magnitude of 14.2. It's corresponding average surface brightness would therefore be 14.8. (These last two figures seem rather dim to me but given difficulties in finding 206 over the last few months, it's not surprising.) NGC206 could also be evaluated as an "elliptical galaxy". Then using the calculator you would repeat what I've done above (by working everything in reverse) as an elliptical galaxy. Well I'll leave this one up to anyone interested in working through the problem.

Suffice to say that, like NGC604 in M33, there is more to finding the really dim stuff than sweeping the scope around in the expected location. - Sometimes, a lot more...

End of January, 2001 Observations

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