Observing Report Part 2

[lunator]

24/10/2008 Seeing II/V Transparency III/V No Moon present.

My aim for this session was to observe some doubles in Lacerta and Pegasus. My guide was the excellent ‘A Visual Atlas of Double Stars’ written by Mike Ropelewski and produced by The Webb Deep Sky Society and the doubles pages from Burham’s Celestial Handbook.

All the doubles from Mike’s book are suitable for small scopes and the OMC 250 was probably too much scope for the pairs.

The first target was 16 Lac a pair about 1 degree South West of Omicron Andromeda. Both stars are white and are very wide. The difference in magnitude is about 4 and if you have a larger scope there is also a small 12^th magnitude star close by making this a visual triple. The 5^th magnitude primary is a variable but the variations are slight.

The next target is h1823 another degree South West. In a small scope the star is a visual triple and the field is rich with background stars. In a larger scope a 4^th component is also visible. All of the brighter stars appear as white.

Moving 4 degrees South West is another 4 star group of 8 Lacerta. A quadruple star that consists of a pair of 6^th magnitude white stars easily visible in a small scope. If you raise the magnification a pair of 9^th and 10^th magnitude pair are revealed.

Very close by is the uneven pair of 10 Lacerta. This pair of white and blue stars is very similar to 16 Lacerta but the back ground field is very rich and well worth a visit.

The final pair I observed in Lacerta is the colur contrast pair STF 2894. It is located about 1 degree East of 1 Lacerta. I found the pair to be easily split at a medium magnification and show’s a nice colour contrast of Yellow/Orange. Mike states in the Atlas they appear pale blue & green!! One to double check. J

I moved onto Pegasus to view a few more Struve doubles.

The 1^st target was STF2905. A double about 10 degrees West of Alpha Pegasi. At x125 in the orthoscopic eyepiece appeared as a nice double. Both stars were creamy-white. In the 24mm at x94 they could be just separated when the seeing settled down.

I moved onto a nice triple STF 3041 A-BC. The A-B pair is wide and can be split at the lowest magnification the BC component can be split at x150 or better and the 3 stars combined show a subtle colour contrast of White/Cream/Yellow.

The next target was the unequal pair STF3055. The separation of around 6” makes this a target that can be split at moderate magnifications, but due to the difference in magnitude of 3 magnitudes the pair shows best at higher magnification. The Primary was white and the secondary grey and could disappear from view sometimes.

The final target was STF3060/3061. I found STF3061 1^st and as I was observing I noticed that STF 3060 was in the same field of view in the 24mm but was not clear split. When I used the 18mm (x125) both pairs would just fit in the field and the 2 pairs were split. STF3061 is a pair of evenly matched 8^th magnitude white stars, STF3060 is a pair of evenly matched 9^th magnitude yellow stars. This is definitely worth a look and can considered comparable to the other double-double in Delphinius (Gamma Del & STF 2725)

[Doc]

Wow what a great report.

I love looking at double stars and yours are going to be added to my list.

I've seen 8 Lacerta before.

[asteria]

Nice work - thanks for the report.

Ed