Wednesday, January 10, 2018

HD 62679 in M93 (Halifax)

HD 62679 is a double-star inside the open cluster Messier 93 (M93). It was on my View Again list with a note "consider imaging." BGO to the rescue (with the minimum altitude setting decreased to 20). Happily, I spotted the B companion of the pair in Puppis.

double-star HD 62679 with Messier 93 luminance

Luminance only, 5 seconds subexposures, 20 stacked shots. FITS Liberator, Paint.NET. North is up; east is left.

First viewed on 21 Mar '12 from the Overlook deck in Toronto. Split on 7 Apr '12 from Carr Astronomical Observatory atop the Blue Mountains.

HD 62679 is arguably the brightest in the cluster, south-west of centre. The B element, while much dimmer, is clearly visible to the north-west of A. An issue from the visual attempts in 2012 was that the companion was much fainter than what the software SkyTools said. Certainly the B star is dimmer than GSC 06540-3094 to the east and it is magnitude 11.9. B is very similar in brightness to GSC 06540-2578 to the south-east which is mag 12.4. So, we can put this one to bed.

South-east of the parallelogram of stars and the right-angle triangle of stars is a faint wide pair, vertical oriented, i.e. arrange north-south. This is ARA 2069. SkyTools says they are both magnitude 10.1 but B is fainter by about 1 unit.

There are other doubles within M93 but I cannot split them.

And there are other pairs and triples that look obvious but are not marked in the software.


Wikipedia link: Messier 93.

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