The bright multiple is known as BU 1 (00 52 49.22 +56 37 39.5) although this was not actually the earliest Burnham discovery. The accepted distance to the cluster is 2.94 ± 0.15 kiloparsecs whereas the parallax of star A in Gaia DR2 corresponds to a distance of 2.80 ± 0.38 kpc. The WDS lists 16 components altogether with most of the stars lying between magnitudes 12 and 16. It is not clear where this group ends and the cluster begins. There is a magnitude 9.3 star at 1.5 arc-seconds distance, whilst star C is magnitude 8.9 is 4 arc-seconds away with another 9.7 (D) at 9 arc-seconds distance. He found that the brightest star in the cluster (V = 8.6) is a close double. Burnham soon after he obtained his 6-inch Clark refractor.Ī finder chart for the double star BU 1 in Cassiopeia created with Cartes du Ciel. The cluster is dominated by a group of 9th and 10th magnitude stars which attracted the attention of S. Some 90 arc-minutes to the east of alpha Cas is the open cluster IC 1593 which is inside the nebulosity NGC 287. The stars are magnitudes 7.2 and 7.7 and easily seen in smaller apertures.īob Argyle - Double Star Section Director I measured this pair with the Cambridge 8-inch three times with the following results: 2000 - 153 degrees, 5".97, 2005 - 151 degrees, 6". This is certainly an optical pair but is noticeable for the measurable change in aspect over a number of years. It can be found as the faint point about one degree north following the three stars marked psi, and also, incidentally, one degree due west of the spiral galaxy NGC 7606.Ī finder chart for the double star STF 3008 in Aquarius created with Cartes du Ciel. One of the double stars which William Herschel included in his last list of discoveries is H N 112, better known as STF 3008 (23 23 45.3 -08 27 36) which lies in Aquarius and is again included in CDSA2 but again is unlabelled. The faint companion is 33 light-years further out, but with a significantly greater error. Gaia EDR3 has pinned down the distance to all three stars, in the case of the main pair to better than 1% - the mean value is 803 light-years. There is a third star, V = 11.0, at 99" and 291 degrees. I have not measured this pair, possibly because the high declination makes access using a German-mounted refractor awkward.
This is an easy object for the small aperture with the components of magnitudes 6.0 and 7.2 currently separated by 15".2 in PA 70 degrees, although the separation has decreased from 18" over 200 years. It is marked on the Cambridge Double Star Atlas 2nd Edition (CDSA2) but not labelled.Ī finder chart for the double star STF 3053 in Cassiopeia created with Cartes du Ciel. The fine pair STF 3053 (00 02 36.1 +66 05 56) is located on the border between Cassiopeia and Cepheus and is about 1 degree south of the large emission nebula Cederblad 214.
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