Open Cluster NGC 2304
History
This open cluster was discovered by German-British astronomer William Herschel on 30 December 1783 using his 20 foot Speculum reflector with 18.7-inch aperture. He listed it as VI 2 and noted: «A very compressed cluster of extremely small stars of irregular figure, 5 or 6' diameter.» [463]
His son John Herschel listed the cluster as h 415, made two observations and described it on 18 December 1830 (sweep 313): «Pretty rich cl; acutangular, the acute angle precedes; the p side is bounded by a remarkably definite line.» [466]
Physical Properties
| Designation | NGC 2304 |
| Type | OCL (II1p) |
| Right Ascension (J2000.0) | 06h 55m 11.8s |
| Declination (J2000.0) | +17° 59' 19" |
| Diameter | 3 arcmin |
| Visual magnitude | 10.0 mag |
| Metric Distance | 3.991 kpc |
| Dreyer Description | Cl, pL, Ri, mC, st vS |
| Identification, Remarks | WH VI 2; h 415; GC 1467; OCL 484 |
Finder Chart
The open cluster NGC 2304 can be found in the constellation Gemini. On 4 January it in opposition with the Sun and is therefore highest in the sky at local midnight.
