Sunday, September 06, 2020

imaged HD 202073 (Halifax)

Ordered the BGO bot to image double star HD 202073 aka BU 270 / S 781. In the backyard in with the C8 on 16 Jun '20 I had tried to spot the companions. Saw D but not C. In the image, A is dead centre with D below, south, equally bright.

double star HD 202073

Luminance stacked image was corrupted. This is the red filtered stack. 6 seconds, 12 exposures. FITS Liberator, GIMP. North is up; left is east.

C is obvious, zoomed in, barely visible zoomed out. It is at the 11 o'clock position to A, quite close. Very dim. SkyTools says it is magnitude 12.7. I think it looks as bright as mag 13 and 14 stars in the field... [ed: Stella Doppie says the C element is 14.1! Explains why I didn't see it...]

There's a B star in the mix, a fast-period binary, in this Equuleus multi-star system. But at 0.5", it is too close to A to split.

Lots of faint doubles in the 'hood...

No comments: