Albireo is unquestionably one of the finest examples of a wide bright double of color visible from northern hemisphere skies. This dblCalc view renders the brighter 3.1 magnitude primary as "gold" while treating the 5.1 magnitude secondary as pure blue. The combination, as can be seen at right is rapturously stunning!
Designation: Beta Cygni
Right Ascension: 16h:29.2m
Declination: 27d:57.6m
Primary Magnitude: 3.1
Secondary Magnitude: 5.0
Separation: 34"
Position Angle: 54d
Lovers of doubles of color frequently turn to "Charles' Heart" during the late winter and spring to recapture the wonder of Albireo - itself seen best in late summer and early fall. Cor Coroli's 2.9 magnitude primary however has a whitish - as opposed to golden cast to it - although the fainter 5.5 magnitude secondary displays the same enigmatic qualities seen in Albireo-B.
Designation: Alpha Canes Venatici
Right Ascension: 12h56.0m
Declination: 38d19.0m
Primary Magnitude: 2.9
Secondary Magnitude: 5.5
Separation: 19"
Position Angle: 228d
Autumn's Almach comes very close to capturing the same splendour of the lights as Albireo and Cor Coroli. However, the tighter separation of the pair and the increased brightness of the primary tends to diminish the strong sense of color contrast seen in its confrere.
Designation: Gamma Andromedae
Right Ascension: 02h03.9m
Declination: +42d20m
Primary Magnitude: 2.5
Secondary Magnitude: 5.0
Separation: 10"
Position Angle: 63d
Ras Algethi is not the brightest star in the Greater Hero - but it is certainly the prettiest double... Like autumn's Almach, early summer's Ras Algethi shows a lovely color contrast (orange and green) along with tightish pair spacing. Any amateur scope will resolve the pair and this - joined with the relative brightness of both components - allows any amateur scope to reveal the lovely contrast in coloration...
Designation: Alpha Herculus
Right Ascension: 17h14.7m
Declination: +14d:23m
Primary Magnitude: 3.0
Secondary Magnitude: 5.5
Separation: 4.6"
Position Angle: 104d
Rigel IS the Great Hunter's brightest star and - under better than unusual observing conditions - a scope possessed of modest aperture but decent optics - will reveal that "Rigel is not alone" in the universe. On such occasions - when the usual atmospheric shenaningans settle out - the image to the right gives us more than a hint of the "two kind of blue" view revealed to the patient eye of the questing observer...
Designation: Beta Orionus
Right Ascension: 05h:14.5m
Declination: -08d:11m
Primary Magnitude: 0.3
Secondary Magnitude: 7.0
Separation: 9.4"
Position Angle: 202d
Designation: Alpha Centauri
Right Ascension: 14h39.6m
Declination: -60d50m
Primary Magnitude: 0.1
Secondary Magnitude: 1.3
Separation: 17.9"
Position Angle: 217d
Some tight southern sky disparate pairs are susceptible of resolution from even temperate northern hemisphere locales. At 37 degrees north, the view at right however is about as good as it gets!
Designation: Alpha Scorpii
Right Ascension: 16h:29.2m
Declination: -26d:12:36m
Primary Magnitude: 1.0
Secondary Magnitude: 5.4
Separation: 2.9"
Position Angle: 270d
Designation: Delta Cygni
Right Ascension: 19h45m
Declination: +45°08'
Primary Magnitude: 2.9
Secondary Magnitude: 7.9
Separation: 2.5"
Position Angle: 229d
There are, of course, numerous double stars of all types liberally distributed about the starry expanse of the heavens. Why just poking around in the Queen's Thrown you might notice a wide, disparate pair of color such as this beauty...
Designation: Eta Cassiopeia
Right Ascension: 0h 49.1m
Declination: +57°49'
Primary Magnitude: 3.4
Secondary Magnitude: 7.5
Separation: 12.2"
Position Angle: 315d
Designation: Trapezium
Right Ascension: 5h35m
Declination: -05°23'
Primary Magnitude "C": 5.1
Other Components: D=6.7,A=7.2(v),B=7.9,F=10.2,E=10.3
Separation: CD=13.3",CA=12.9,CB=16.6,CF=4.3,CE=16.3
Position Angle (estimated): CD=125,CA=240,CB=210,CF=55,CE=220