Stephn Paul posted:

What the heck should we be looking at, that's off the beaten path, on an obscure or even non-existent list?

Well, I don't know about obscure, but here are some of my most favorite
color-contrasting double stars:

COMMON DOUBLE STARS WITH SIGNIFICANT COLOR CONTRAST
(positions, separations, and position angles for 2000)

LEGEND: R.A. = Right Ascension (2000.0) Dec. = Declination
mag. = apparent visual magnitude sp. = spectral type
Sep. = separation (in arc seconds) P.A. = position angle
************************************************** ******************

Eta Cassiopeiae, R.A. 0h 49.10m Dec. +57d 49.0'
Primary: mag. 3.4, sp. G0V, Secondary: mag. 7.5, sp. dM0
Sep. 12.8" arc, P.A. 317 deg. (period: 480 years)
Colors seen in 10 inch: Off-white and faint reddish-orange.

ALMACH (Gamma And.), R.A. 2h 3.90m Dec. +42d 19.8'
Primary: mag. 2.2 sp. K3III, Secondary: mag. 4.8 sp. B8V
Sep. 9.8" arc, P.A. 64 deg. (mag. 6.3 companion of Gamma-B at 0.4" arc,
p.a. 103 deg.).
Colors seen in 10 inch: Yellow (Gold) and light blue.

32 Eridani, R.A. 3h 54.29m Dec. -2d 57.3'
Primary: mag. 4.5, sp. G8III, Secondary: mag. 6.1, sp. A2V
Sep. 6.9" arc, P.A. 348 deg.
Colors seen in 10 inch: Yellow and pale blue.

38 Geminorum (STF 982), R.A. 6h 54.64m Dec. +13d 10.7'
Primary: mag. 4.7, sp. F0V, Secondary: mag. 7.7, sp. ?
Sep. 7.1" arc, P.A. 144 deg.
Colors seen in 10 inch: White and faint orangish.

h3945 (ADS 5951, CMa), R.A. 7h 16.61m Dec. -23d 18.9'
Primary: mag. 4.8 sp. K4III, Secondary: mag. 6.8, sp. F0
Sep. 26.6" arc, P.A. 55 deg.
Colors seen in 10 inch: Orange and bluish-white.
"The Winter Albireo"

Iota Cancri, R.A. 8h 46.70m Dec. +28d 45.6'
Primary: mag. 4.0 sp. G8II, Secondary: mag. 6.6 sp. A3V
Sep. 30.5" arc, P.A. 307 deg.
Colors seen in 10 inch: Light yellow and pale blue.

Tau Leonis, R.A. 11h 27.94m Dec. +2d 51.3'
Primary: mag. 4.9 sp. G8II, Secondary: mag. 7.4 sp. ?
Sep. 89.7' arc, P.A. 180 deg.
Colors seen in 10 inch: Yellow and pale bluish-white.
*nice low power pair with double 83 Leonis 20' at P.A. 298 deg.

2 Canum Venaticorum, R.A. 12h 16.13m Dec. +40d 39.6'
Primary: mag. 5.7, sp. M1III, Secondary: mag. 8.7, sp. F7V
Sep. 11.3" arc, P.A. 260 deg (2003).
Colors seen in 10 inch: Yellowish-orange and pale bluish.

24 Comae Berenices, R.A. 12h 35.13m Dec. +18d 22.6'
Primary: mag. 5.0 sp. K2III, Secondary: mag. 6.6 sp. A7V
Sep. 20.3" arc, P.A. 271 deg.
Colors seen in 10 inch: Yellow and pale blue.

Cor Caroli (Alpha CVn), R.A. 12h 56.00m Dec. +38d 19.1'
Primary: mag. 2.9 sp. A0spe, Secondary: mag. 5.6, sp. F0V
Sep. 18.8" arc, P.A. 230 deg.
Colors seen in 10 inch: Bluish-white and off-white (cream).

Izar (Epsilon Bootis), R.A. 14h 44.99m Dec. +27d 4.5'
Primary: mag. 2.4 sp. K0II, Secondary: mag. 5.1, sp. A2V
Sep. 2.8" arc P.A. 339 deg.
Colors seen in 10 inch: Yellow and light blue.

Xi Bootis, R.A. 14h 51.39m Dec. +19d 6.0'
Primary: mag. 4.5, sp. G8V, Secondary: mag. 6.8, sp. K5V
Sep. 6.8" arc P.A. 320 deg.
Colors seen in 10 inch: Pale yellowish white and orange.

Antares (Alpha Sco). R.A. 16h 29.41m Dec. -26d 25.9'
Primary: mag. 1.0v sp. M1I, Secondary: mag. 5.4 sp. B4
Sep. 2.6" arc P.A. 274 deg.
Colors seen in 10 inch: Orange and light blue.

Ras Algethi (Alpha Her) R.A. 17h 14.65m Dec. +14d 23.4'
Primary: mag. 3.2v sp. M5II Secondary: mag. 5.4, sp. F2/G3
Sep. 4.6" arc P.A. 104 deg.
Colors seen in 10 inch: Reddish-orange and pale bluish-white.

Omicron Ophiuchi, R.A. 17h 18.00m Dec. -24d 17.2'
Primary: mag. 5.1, sp. K.. Secondary: mag. 6.6, sp. ?
Sep. 10.3" arc, P.A. 355 deg.
Colors seen in 10 inch: Yellow and pale blue.

SHJ 282 (ADS 11834, Lyra), R.A. 18h 54.90m Dec. +33d 58.0'
Primary: mag. 6.1, sp. G8 Secondary: mag. 7.7, sp. A1
Sep. 45.4" arc P.A. 350 deg.
Colors seen in 10 inch: Yellowish-white and bluish-white.

Albireo (Beta Cyg) 19h 30.72m Dec. +27d 57.6'
Primary: mag. 3.1 sp. K3II Secondary: mag. 5.1 sp. B8V
Sep. 34.3" arc P.A. 54 deg.
Colors seen in 10 inch: Yellow and light blue.

ADS 12900 (Cyg). 19h 45.86m Dec. +35d 0.77'
Primary: mag. 6.1 sp. K2? Secondary: mag. 8.6 sp. A2V
Sep. 37.5" arc P.A. 25 deg.
Colors seen in 10 inch: Yellow and blue.

Gamma Delphini, R.A. 20h 46.73m Dec. +16 deg. 7.8'
Primary: mag. 4.2 sp. G5V, Secondary: mag. 5.2 sp. F8V.
Sep. 9.6" arc P.A. 268 deg.
Colors seen in 10 inch: Yellowish and white (hint of blue)?

Delta Cephei R.A. 22h 29.20m Dec. +58d 25'
Prmary: mag. 4.07 (variable) sp. F5-G3 Secondary: mag. 6.27 sp. B7
Sep. 40.8" arc P.A. 191 deg.
Colors seen in 10 inch: Yellowish-white and light blue.

Clear skies to you.
--
David W. Knisely
Prairie Astronomy Club: http://www.prairieastronomyclub.org
Hyde Memorial Observatory: http://www.hydeobservatory.info/

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* Attend the 13th Annual NEBRASKA STAR PARTY *
* July 23-28, 2006, Merritt Reservoir *
* http://www.NebraskaStarParty.org *
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