Watching the Stars Come Out
Mars!
Deep Sky
The Gas Giants

Watching the Stars Come Out

I like to arrive at SCAC's Bonny Dune observing site as the sun sets. I like to setup Argo as the last vestiges of dusk illumine the western sky. I like to bid adieu to the few remaining veil-like clouds as they drift eastward - bathed in the final rays of a lowering solar orb. I like to watch as the first few bright stars of the season take resident in a deep blue darkening sky.

I like to turn Argo (or the Pup) on the brightest star in the skies middle third. I like to assess the quality of the seeing, whether a "heat plume" has taken temporary residence in the optic tube and whether the alignment is spot on. I like swinging the scope around on the nearest bright double star, or whatever planet that might be accessible at the time.

I like doing all these things because they create a "moodus observatum". They help me establish momentum. They are part of my own private ritual and are a big part of my observing experience.

But these operations are not essential. I can of course, arrive late and assemble the scope in darkness. I can of course, miss the descent of the blanket of night. I can of necessity, attend a star party on speculation - speculation that the thin clouds encroaching on the preserve of the stars will part and a fine night will reveal itself.

During last night's SCAC Bonny Dune star party the latter set of conditions prevailed and not the former. For you see, it was already well into dusk before I rolled up to the closed fences guarding the entrance. And it was nearly skydark before I had Argo assembled in the solitude enclosed within. And it was beneath variable translucent clouds - clouds that ever so slowly came and went revealing the high thin clouds and stars to magnitude 5.0 above them.

But my, how still was that sky? Absolutely and wonderfully still.

Mars!

Initially, a lowering Northern Cross lay in an exposed region of the sky. Turned a 70x Argo on Sadr. Then swept one field north and east to the now easily identified "bird of prey" asterism that marks the locale of (7.4 magnitude 10 arc-minute apparent sized) NGC6910. This little jewel of an open cluster revealed two dozen stars faintly sprinkled between a close set pair of 7th magnitude stars. The dimmest that could be held direct (magnitude 11.2) was far short of the 12.5 magnitudes Argo is capable of under more transparent conditions. Looking up, I saw why: Translucent clouds had gravitated to the region - magically drawn by Argo's carefully aimed optik-tube...

Ah, but what was that "bright star" high to the south, southwest? Could this still be "The God of War"'s world, that fiery Red Planet Mars?

Why, of course!

And how dim you are?

Magnitude .6 according to some.

And how small?

6.8 arc seconds.

Take a chance...

As I wrapped up my view of NGC6910, SCAC club president Dwight pulled up. Together we turned Argo on Mars. At 180x, a very small, slightly gibbous, sharply defined disk was presented. Not only a disk - but stretched across the north temperate region, "maria presentia". But could this be small image scale contrast effect? No, again this particular maria was horizontal - not vertical. And higher magnifications (360x) confirmed it. The finest, most contrast laden, view of maria seen on the Red Planet by these eyes ever. But, how is such a thing possible?

I followed the planet throughout the early Summer and into maria obscura (dust storm season) and never saw maria with as much presence and contrast. Why?

Truly, there wasn't a whole lot of it to be seen. No fine detail. Nothing like that - but what was seen was very present and evident. Again why?

Surely, the planets improved sky position is a factor - but that in itself can not possibly account for it.

Dwight may have given the answer though: The late summer storms had scoured the maria and redeposited the fine, lightly-colored dust in various basins. Thus dark basaltic "maria" was exposed and increased the overall contrast.

Further mysteries awaited me. As I write this I learn that Syrtis Major should have rotated in at the time of this observation - 20:00 hours PST. But it was nowhere to be seen. Only a very contrasty horizontal region - probably Mare Tyrrhenium and Syrtis Minor - plus hints of Mare Australe ringing Zen Lacus to the south. Neither polar cap was in plain evidence either.

Mars last night: Questions, shrouded in enigma, veiled by mystery...

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Deep Sky

The evening before last night's "star party" had been especially successful from Backyard Boulder Creek. Though skies were marginal stability-wise, they were deep enough to unequivocably track down two faint members of the Andromeda Galaxy Clan (NGC185 and 147 - a backyard first). However, I remained unconvinced that Argo had revealed the huge star-forming region NGC206 in M31's southwestern spiral arm. Last autumn, had experienced a great deal of difficulty locating this small (2x1 arcmin) thirteenth magnitude knot. And may very well have mistaken it for a small group of faint stars the previous evening.

The sky above cleared. And although Dwight and I had a difficult time turning Argo away from such a fine view of a miniature-Mars, we broke off and turned the scope on M31. At the time transparency may have approached 5.0 ULM - but it certainly wasn't any better than the previous evening. Our search for NGC206 remained unfulled, for we both concluded that, if anything, the knot was on the edge and therefore unconfirmable.

Another mystery I've been pursuing as of late was a holdover from a previous star party. On that occasion fellow-SCAC member Dan had turned his FS102 APO on M76. We were both rewarded with a nicely defined view of two distinct planetary nebulae - joined at the hip. A true "hourglass resolved double planetary". The view was as fine a one as I'd ever seen - irrespective of aperture.

And this remark includes Argo. For you see, last night it required extreme averted vision to get the kind of view the 4 inch Tak gave direct on that one occasion. And I don't think I can attribute all the difficulty to sky conditions alone...

Another concern arising out of the previous week's observing had to do with the three Aurigaen Messier clusters. From experience, I'd come to know them as "the Cross", the "Pyramid", and the "Beauty". Each description relates to either my own sense of the clusters shape - or the impact it has on my psyche. At risk of sounding judgmental, the Beauty is far superior to the other two aesthetically. Hundreds of uniformly bright stars spill across the center of this particular cluster. Neither Cross nor Pyramid are so well graced with stars. They simply lack the "fullness" of their confrere. Neither gives that "truly there is a God" experience that Beauty does.

One thing nice about Argo (compared to the 80mm Pup) is the quality of the 7X35 finderscope. For as a nice big swath of dark sky opened northwest, it was extremely easy to locate each cluster in turn. And in so doing, get a sense of their relationship one to another and to nearby starfields.

In the finder, Cross and Pyramid form right angles: Cross to north and Pyramid, east. Beauty can be found much further east (and slightly south). Several dozen stars are visible direct in both the Cross and the Pyramid at 70x. Neither showed the amount of central concentration displayed by Beauty - which also appears somewhat "cruciform" but includes all those 11th magnitude stars at the crux.

There is a certain virtue however to the other clusters. One degree east of Pyramid is faint, "globular-esque" NGC1931. This 11.3 magnitude 3 arc-minute bright nebula gives a "globular-like" appearance due to it's "roundness" and the fact that a small cluster of stars may be seen in its midst. Last night Dwight and I could resolve two of the stars at 120x with a third hinted at on the border of perceptibility. Interestingly, Dwight and I both agreed that although the nebula was quite distinct, it lacked the kind of "presence" that would make it an excellent study for a six inch scope. To my eye though, it is a much finer study than M76. Again I am surprised that Monsiour Messier never tracked this one down. It certainly has to be placed on anyone's "Missed Messier's" list of deepsky studies.

Not to be outdone by Pyramid, Cross also has a neighboring study of some note. 30 arcmins north is a fine spray of about 2 dozen stars covering a region of 5 arcmins. As of yet, I've found no reference to this cluster. It is simply one of those pleasing, serrendipitous discoveries. One I suspect anyone who looks it up will take great enjoyment in marveling at.

Later in the evening, Orion achieved the skies middle third. Turned Argo on Alnitek and got a splendid, clean, wide open split between the 2.5 arc second wide, second/fourth magnitude pair. Transparency was limited, BUT hints of the Flame Nebula (NGC2024) were seen and Alnitek's 9.5 magnitude come could occasionally be held direct. Of course, my next stop could be none other than the Great Nebula.

Within M42 the beginnings of a bright open cluster is in formation. Four superbright "progenitor" stars can easily be seen by even the most modest scopes. Two others should be accessible to scopes 4 inch or larger on better nights of stability AND transparency. On this particular night, stability was superb - although transparency varied considerably. Given the advantages of six inches in aperture, transparency should not be as much an issue as stability. But this is only a pet theory. Would Argo be able to reveal other members of the cluster on such a night?

I settled in with the Great Nebula at 120x. Both the "Eagle's Head" dark nebulae and 'Darkness Cliff" nicely framed the Trapezium. Nebulosity showed a distinctive "robbin's egg blue" hue. Trapezium stars were pointlike and compactly luminous. There was no difficulty holding the 11.1 magnitude E member of the cluster direct. But it was quite dim and I suspected the 11.5 magnitude F member would prove illusive.

I have yet to see the F member - through any scope. Because of this I tend to doubt seeing it when I do through Argo. But tonight "there" it was. Trailing the brightest member of the group across the sky. Faint, but easily seen with the slightest amount of aversion. Now that I have "real-world" experience in tracking it down, I look forward to revisiting frequently. maybe one of these times I'll be as confident in seeing F as I am E now...

NOTE: Subsequent research on an AstroTalk thread published by Cor Berrevoet's (and based on an HST image of the Trapezium Neo-Cluster) revealed that I had in fact seen 11.5 magnitude Theta Orionis "F" on this occasion.

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The Gas Giants

Throughout the evening, Dwight and I found Saturn irresistable. As the sky alternately opened and closed above us, The Ringed Wonder (and nearby Aldebaran) remained a constant. Early on Jupiter could be seen peeking between the foliage to the west. Then it cleared the treeline and also became the subject of frequent visits and slack-jawed appreciation.

Saturn was, in a word, "exquisite". The entire litany of vaunted "Ringed Wonder" features (save one) were paraded before our eyes: Cassini, Encke, Dusky, Ring B Gradient, Equatorial Zone, South Equatorial Belt along with South Temperate Zone, and Blue Mottling (fainter than usual) above that. Cor Berrevoet's "Frosty the Snow Ring Anti-Division" could easily be picked out between a razor-sharp Cassini Division and Encke Minima. On the planet itself the SEB was quite distinct (although less so at 540x) and hints of irregularities along its northern frontier could be made out.

What was missing was the planetary shadow on the posterior ring. But this was no flaw in either seeing or optics. The Ringed Wonder is in "the opposition zone" and any shadow falls precisely behind the planets disk. This was made up for by one rarely seen vista - the sweep of the dark Cassini Division all the way around the planet - only to be hidden by the very southernmost cap of the disk. A most extraordinary view.

Even with Jupiter only 20 degrees above the northeastern horizon, it too gave extraordinary views. All belts (but one) were visible. (Even the wispy equatorial belt.) SEB cleanly rifted. NEB showed internal barges and edge irregularities. NTB a nice thin, high contrast dark band with clear variations in width and depth of contrast. STB and SSTB directly discernable. Variagated polar regions. All but the NNTB easily seen at 180x. 210x. 360x. 540X!

It had been a long time since I'd viewed Jupiter at this extraordinary magnification - but there it was: Quarter-dollar sized disk racing across a 5 arcmin field of view. All belts visible - along with obvious variations in equatorial details. At 360x the view was not improved over 540x (though the planet appeared less in a rush to avoid scrutiny).

Early on Dwight noticed a disturbance along the trailing edge of Jupiter's SEB. We speculated that it might very well be the GRS rotating into view. In fact this did happen - but well after Dwight had bid the eving adieu. As it rotated in, I realized the nature of the disturbance seen earlier - it was the beginnings of a series of "pinches" in the SEB rift. Pinches that gave rise to a series of "oval brightenings" - remnant regions of the rift as it deteriorates near the GRS.

The view of the GRS itself was quite dramatic - everything one might want - except color. All that really remains of the GRS is a "dark-rimmed hollow". The color outside the hollow (the "socket") is tannish brown while within it is simply tan - the color of the rift in the SEB.

Speaking of color, the NEB seems to be losing the distinct ruddyness noted earlier this autumn. This may coincide (as fellow observer Otto Piechowski remarked) with an increase in the number and density of barges embedded in the NEB. Possibly all the dark-colored material erupted from the planets icy surface is coelescing under the pressure of relentless corriolus forces at work in the atmsophere.

Recently, added a "Gas Giant" drawing gallery to Astro.Geekjoy. Last night was my opportunity to include a new Jupiter sketch to the collection. The plan last night was to make the drawing just before heading home. And this is exactly what I did - but perhaps a little later than anticipated. For just as I was about to begin that drawing a car pulled into the lot. Family of three emerged and we spent some time observing the Gas Giants and The Great Nebula through Argo. I can think of absolutely no better occasion to have shared the Gas Giants with visitors. A subdued but distinct sense of awe hung over us all. The family carried that mood with them as they departed.

Later as I completed the drawing (around 22:00 PST), a fourth vehicle arrived. A fellow SCAC member pulled up with a homemade F8 6 inch, sixties-era Newtonian. Despite the frailties of the overburdened mount, the view of Jupiter was very good and the GRS stood out admirably. This surprised me because I had observed through this scope (briefly) on other occasions. The proud owner went on to explain that he had lavished considerable time and expense on the scope. Replaced the secondary, and purchased new eyepieces. The results spoke well of his efforts...

Before this last arrival there had been a considerable shift in air and sky. Temperatures dropped noticeably, and sky cleared considerably. Despite the temptation to stay, I chose to leave - bearing a rich load images and experiences.

The sky and adventures thereof were left in the capable hands of another...

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