Tuesday, June 18, 2019

imaged LDS 4781 region (Halifax)

I tried to capture LDS 4781 in Lyra. This entry in the Washington Double Star catalogue shows it has been viewed once, back in 1960.

WDS ID: 18150+3840LDS4781
last observed: 1960
observations: 1
position angle: 0
separation: 4.0
magnitudes: 13.6 and 13.7
precise coords: 181503.48+383931.5

Oops. A bit too tight for BGO. I forgot to filter on rho greater 4...

In SkyTools 3 Professional, a single star shows at this location: GSC 03103-1706. Magnitude 12.84 (poor quality).

The BGO catalogue did not include this designation so I programmed the 'bot to aim at GSC 03103-1510, the dimmer star just to the north.

region surrounding double star LDS 4781

Luminance only, 2 seconds subexposures, 12 stacked shots. FITS Liberator, Paint.NET. North is up; east is left.

There are weird artefacts all through the image.

The star in question, the slightly brighter star below or south of centre, does appear to be rod shaped, in a nearly vertical orientation. But this is very near the resolution limit of this system and with the degraded quality in this shot, it is difficult to know for certain. But, to me, it looks like something is there.

When I examine the blue channel stretched, two peaks emerge...

Also in this image are a couple of obvious doubles.

To the south-east, there's the fainter pair, tight, unequal. This is ALI 869. ST3P says these stars were separated by a 8.8 arc-second gap. Magnitudes 11.4 and 13.6. Oriented at a 36° angle.

To the east, slightly north, is a brighter pair, nearly equal, about double the separation of 869. This is ALI 871. 13.3", 180°. Mag 10.9 and 12.8, according to the Object Information box. When I hover over the B companion in the chart, it shows as mag 11.9; that's better.

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