STARLOG

DOUBLE DIPPING IN THE MOONLIGHT

MAY 6, 2017

Observer: Tom Campbell
Location: College Station, Texas (Long: 96°17'W Lat: 30°37'N)
Telescope: Zhumell 12" f/5 Dobsonian
Eyepieces: Explore Scientific 18mm (83x)
Explore Scientific 11mm (136x)
Lenses: Celestron Luminos Barlow (2.5x)
Weather: The sky was clear. Temperature was in the low 70s (F), with a feeling of moisture in the air.

OBSERVING SUMMARY:
BOÖTES: Alkalurops (μ Boö), Izar (ε Boö), Pi (π Boö), Xi (ξ Boö)
CANCER: Σ1327
CANES VENATICI: Cor Caroli (α CVn), 2 CVn
CORONA BOREALIS: Zeta (ζ CrB)
CORVUS: Delta (δ Crv)
LEO: Algieba (γ Leo), 6 Leo, 54 Leo, 88 Leo, Σ1360
SCORPIUS: M4
URSA MAJOR: Σ1321

Tonight was beautifully clear and calm, a rarity these days. The Moon was in a waxing gibbous phase, meaning she'd be bright and in the sky all evening long. Her glare would prevent me from tracking down faint galaxies or nebulae, but I didn't want to let such a good night go to waste.

I decided to play around with some double stars. Using a list of colorful doubles from the Royal Astronomical Society of Canada (RASC), I set up my telescope and began my evening.

Delta (δ) Corvus Double Star 9:30pm CDT

This is a nice double, best viewed at 208X. The primary is very bright and white, while the secondary is much fainter and orange. To me, it resembles a star with a planet orbiting it.

 
Cor Caroli (α CVn) Canes Venatici Double Star 9:40pm CDT

This double is easily split at 83X. The primary is a bright white and the secondary is a pale yellow. Very nice.

 
2 CVn Canes Venatici Double Star 9:45pm CDT

NEW! The best view was at 136X. This has a gorgeous orange primary and the secondary is pale blue and a couple of magnitudes fainter.

 
Σ1321 Ursa Major Double Star 10:05pm CDT

I couldn't find this one in the Pocket Sky Atlas, so I had to go to my computer and look it up. As it turns out, the star was plotted in PSA, but not labelled. Both stars are of about equal magnitude, nicely separated at 83X. Both appear to be orange and remind me of 61 Cygni.

 
54 Leo Leo Double Star 10:10pm CDT

This pair is easy to find by using Denebola (β Leo) and Zosma (δ Leo) as pointer stars. Both stars are bright, with the primary being a magnitude or two brighter and is pale yellow, where the secondary is an even paler yellow-white.

 
Algieba (γ Leo) Leo Double Star 10:15pm CDT

This is a very bright double, with the primary being about a magnitude brighter than its companion. The main star is yellow-white, and the secondary is a slightly deeper yellow.

 
6 Leo Leo Double Star 10:25pm CDT

NEW! This double is wide and fairly faint. I found this easily by pointing at nearby Omicron (ο) Leonis. 6 Leo was in the same field of my finderscope. The primary is a couple magnitudes brighter and a pale yellow, while the secondary is blue. Nice, but not overly impressive.

 
88 Leo Leo Double Star 10:30pm CDT

NEW! This is easily found about halfway between Denebola (β Leo) and Chertan (θ Leo). The best view was at 83X, where the primary was a nice yellow color and the secondary was orange and a couple of magnitudes fainter.

 
Σ1360 Leo Double Star 10:40pm CDT

NEW! This one is faint enough to not even show up in my finder scope, at least with the gibbous Moon high overhead. It was still easy to find, being not far from 6 Leo. Both stars are about the same magnitude and appear pale orange.

 
Σ1327 Cancer Multiple Star 11:20pm CDT

NEW! I had to do a bit of starhopping with my finder scope to get this one, which was made more difficult by the bright moonlight. I started at ε Leo, hopped to λ Leo, then κ Leo, and finally found it about halfway between κ Leo and τ Leo. The faintest of the three is very close to the primary, with the third star being just a bit brighter than the secondary and about 4-5 times farther away. The primary is a nice milky white, but the other two stars were too faint to detect much color in them, and they appeared gray. The 3 stars are almost, but not quite, in a line.

 
Alkalurops (μ Boö) Boötes Double Star 11:30pm CDT

This is a nice wide double, easily split at 83X. The primary star is white and a magnitude or two brighter, while the secondary is a pale yellow.

 
ζ CrB Corona Borealis Double Star 11:35pm CDT

The best view was at 208X. The stars are similar in magnitude and look like a pair of bright white headlights.

 
Izar (ε Boö) Boötes Double Star 11:40pm CDT

I had to crank this one up to 341X because the stars are pretty close together and the secondary was right on a diffraction spike from the primary. The primary is bright white and the secondary is a few magnitudes fainter and also white. Together, they look like a little snowman.

 
Pi (π Boö) Boötes Double Star 11:45pm CDT

The primary is a bluish white and the slightly fainter companion is slightly yellow-white.

 
Xi (ξ Boö) Boötes Double Star 11:50pm CDT

This pair is pretty. They are fairly close, but can be separated nicely at 136X. The primary is pale yellow and the secondary is orange.

 

Things were starting to dew up to the point of affecting my viewing and it was getting late, so I decided to pack it in. But as I looked up, I saw Scorpius rising in the southeast, with bright Antares beckoning to me. I couldn't resist a peek at one of my favorite clusters before I ended the night.

M4 Scorpius Globular Cluster 11:55pm CDT

Although called a globular cluster, this group of stars appears more like a tight open cluster, and is a very elongated oval in appearance. This is probably due to its extreme age, which is nearly three times older than our own sun. At a glance, it's an elongated fuzzy patch with a few stars along the edges, but the longer you look, the more stars you see resolving at the core. Even in the washed out glow of the Moon tonight, it's still a beautiful sight.