Wednesday, August 24, 2016

imaged 70 Ophiuchi (Halifax)

I asked the BGO robot to image the fast-moving double star 70 Ophiuchi (by centering on GSC 00434 02340).

multi-star system 70 Ophiuchi luminance

Luminance only, 5 seconds subexposures, 10 stacked shots. FITS Liberator, Paint.NET. North is up; left is east.

70 Oph aka Σ2272 (Struve) is a multi-star system. Part of the reason I was interested in imaging it was to identify some of the other members.

Also, the AB pair is a binary system with a 88 year period. If I image the pair periodically, I might see the motion.

Curiously, SkyTools 3 Pro shows pairs such as VX and AY but in the end there seem to be 11 or so pairs. From the image, I'm having no trouble seeing P, Q, R, S, T, U, W, and Y. V and X are interesting. I think I can identify V without difficulty but it looks like the X star has moved dramatically—it is heading to the south-east. Anyway, it's very neat seeing all the elements!

There looks to be a double well away to the north-north-west in the image. Not identified in ST3P.

The 5 second exposure time is blowing out the A and B stars. If, in fact, I want to record the binary motion, I'll have to use a faster exposure time. Maybe I'll try around 2 or 3 seconds...


Processed in colour on 18 May '17.


Redid the stretching to pull out the B star. Cropped to zoom in.


Reshot faster on 10 Jul '17.


Annual image log:

2016 Aug < you are here
2017 Jul
2018 May
2019 May
2020 May

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