Friday, August 16, 2019

returned to gamma Her (Halifax)

The Burke-Gaffney Observatory robot imaged the multi-star system γ (gamma) Herculis in the constellation Ursa Major. aka SHJ 227. I aimed the system at nearby GSC 01513-0543.

multi-star system gamma Her in luminance

Luminance only, 0.1 second subexposures, 12 stacked shots. FITS Liberator, Paint.NET. North is up; east is left.

First viewed this target on 1 Aug '19.

Primary is bright at magnitude 3.8! The second to the bottom-right or south-west is much dimmer. Mag 9.9.

I spotted the C companion visually in the 16-inch reflector two weeks ago.

At the time I wasn't clear about the position of the D element as noted in the Washington Double Star database. 

During the observing session at the Carr Astronomical Observatory, I thought I saw another star... To the north-west.

So, I wanted to dig out the C and D stars with an image.

C is there but extremely faint, to the west, about two or three times the AB separation. [ed: Barely visible at a 1/10th of a second.]

I don't see a D star. It should be very close to A, to the south... [ed: It's 1/5th the AB split. But magnitude 8, while B is 10 and C is 13.]


Wikipedia link: gamma Herculis.

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