Open Cluster NGC 2509
History
This open cluster was discovered by William Herschel on 3 December 1783 during one of his early sweeps. He discovered it again on 15 February 1786, listed it as VIII 1 and noted: «A cluster of coarsely scattered stars. The place is that of the most compressed part, which is not the middle.» [463]
John Herschel listed it only in his «General Catalogue» as GC 1613 with four total observations and the description: «Cluster; bright; pretty rich; little compressed; stars small.» [467]
Physical Properties
| Designation | NGC 2509 |
| Type | OCL (II1p) |
| Right Ascension (J2000.0) | 08h 00m 47.8s |
| Declination (J2000.0) | -19° 03' 02" |
| Diameter | 12 arcmin |
| Visual magnitude | 9.3 mag |
| Metric Distance | 2.900 kpc |
| Dreyer Description | Cl, B, pRi, lC, st S |
| Identification, Remarks | WH VIII 1; GC 1613; OCL 630; ESO 561-SC7 |
Finder Chart
The open cluster NGC 2509 is located in the constellation Puppis. On 19 January it in opposition with the Sun and is therefore highest in the sky at local midnight.
