NGC 110
DSS image of NGC 110
Overlaid DSS image of NGC 110, 30' x 30' with north at top and west to the right

Aladin viewer for the region around NGC 110
h 22, GC 55, C 0024+711

Type  Open Cluster
Magnitude  
Size  19'
Right Ascension  0h 27' 25"  (2000)
Declination  71° 23' 26" N
Constellation  Cassiopeia
Description  Cl, pR, lC, st 9...12
Classification  IV1p
Observing Notes

Captain William Henry Smyth
Nov 25, 1838    No. 6 The Crescent, Bedford, England (map)
150mm f/17.6 refractor by Tully 1827

A large and straggling group of small stars, between the Lady's footstool and the knee of Cepheus; a line from the γ of one asterism to the γ of the other, and ⅓ the distance from that of Cepheus, hits 22 H. The place here given is that of a coarse double star, the components of which are of the 8½ and 11 magnitudes, both greyish, in the following portion of the mass; and which is, in a manner, insulated. It was first registered by Sir John Herschel, and described as a very loose but pretty rich cluster. On the whole, this object offers a fair test for trying the light and defining power of a telescope.
― A Cycle of Celestial Objects Vol II, The Bedford Catalogue, William Henry Smyth, 1844

Harold Corwin

Is this a true cluster, or just a part of the northern Milky Way that is randomly richer? John Herschel found the grouping in late October 1831, and described it as "A very loose, pretty rich cluster; stars 9th to 12th magnitude; 9th magnitude star in the middle taken." Assuming that John Herschel's position is correctly reduced and printed, the 9th magnitude star is GSC 4303-1643 at 00 27 25.4, +71 23 27 (J2000.0; I've adopted this position -- rounded off -- as the position of the cluster).

Looking at the object on the POSS1 does not show much beyond a group of 50-60 stars scattered over an area about 20 x 15 arcmin across. Had this not been included in the Alter-Ruprecht catalogue, I suspect that it would have been one of the RNGC's "nonexistent" clusters.

There is the possibility of a mistake in John Herschel's single position, but I don't see any other grouping in the area that would fit his description as well. I think this is a candidate for visual observation.

Note added in October 2003. Bob Erdmann and I examined the cluster a couple of weeks ago under good skies in Prescott, AZ with 8-inch and 16-inch telescopes. John Herschel's description from the eyepiece is more appropriate than mine from the POSS. The "cluster" is just a bit more than a random scattering of 15-20 stars from the 9th to the 12th magnitudes in an area about 20 arcmin across. It doesn't stand out very well from the field, but we can still see why John Herschel recorded it.

Looking at the DSS2 red image in December 2016 simply confirms what I say above about this "cluster". However, I put the center of the cluster about three arcminutes northwest of the GSC star.

The recent cluster compilations based on proper motions and photometry (e.g. Dias et al 2014 and online at http://www.wilton.unifei.edu.br/ocdb/; Karchenko et al 2013, available through SIMBAD) make the cluster a bit smaller (12 to 14 arcminutes) and put the center close to the GSC star that John Herschel noted. So, as before, I've simply adopted that position for the object
NGC Notes by Harold Corwin
Other Data Sources for NGC 110
Nearby objects for NGC 110
No nearby objects within 120'
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NGC 110