Open Cluster NGC 225

NGC 225
NGC 225: Section of DSS2. Here could be your picture. [147]


On 27 September 1783 Caroline Herschel discovered the open clusters NGC 225 along with NGC 189 using her 4.2-inch comet-seeker reflector. She described it as follows: «about 2° from Gamma Cas, making an isosceles triangle with Gamma and Kappa, a small cluster of stars, seeming to be intermixed with nebulosity.» [364]

William Herschel first observed the cluster on 12 March 1784, recorded it as VIII 78 and noted: «A cluster of very coarsely scattered large stars. Take up 15 or 20. Caroline Herschel discovered it 1784. [464]

In 1962 the American astronomer Beverly T. Lynds published her «Catalogue of Dark Nebulae» that she found on the blue and red photo plates of the «National Geographic Palomar Observatory Sky Atlas». She identified several patches of dark nebulosity around cluster NGC 225. [473] In 1965 she published then her catalog of bright nebulae where she identified a small H II region with LBN 604. [270]

In 1966 the Canadian astronomer Sidney van den Bergh published his «Catalogue of Reflection Nebulae», which wa based on a survey on the photographic plates of the «Palomar Observatory Sky Survey». There he identified the reflection nebula vdB 4 with strong absorption around the star BD +61°154 (V594 Cas), but with the identification he was uncertain. [255]

Physical Properties

NGC 225 is a small loose open cluster with an estimated age of 130 million years. [138] It is embedded in some molecular dark clouds that partially reflect the light of cluster stars, which can be seen on photographs with very long exposure.

Revised+Historic NGC/IC Version 22/9, © 2022 Dr. Wolfgang Steinicke [277]
Designation NGC 225
Type OCL (III1p)
Right Ascension (J2000.0) 00h 43m 36.0s
Declination (J2000.0) +61° 46' 00"
Diameter 15 arcmin
Visual magnitude 7.0 mag
Metric Distance 0.657 kpc
Dreyer Description Cl, L, lC, st 9…10
Identification, Remarks WH VIII 78; h 52; GC 120; OCL 305

Finder Chart

The open cluster NGC 225 is located in the constellation Cassiopeia and is on 4 October in opposition to the Sun. From Switzerland it can best be seen in the months July to January.

Finder Chart Open Cluster NGC 225
Open Cluster NGC 225 in constellation Cassiopeia. Charts created using SkySafari 6 Pro and STScI Digitized Sky Survey. Limiting magnitudes: Constellation chart ~6.5 mag, DSS2 close-ups ~20 mag. [149, 160]

Objects Within a Radius of 15°