Open Cluster Messier 93
History
Charles Messier discovered his number 93 on 20 March 1781 and noted: "A cluster of small stars, without nebula, between the big dog and the bow of the ship." [281]
Physical Properties
M 93 is an open cluster of the Trumpler type IV1p and contains about one hundred stars, spread over an area of about 22 arc minutes. At an estimated distance of around 3600 light years, it must be around 20 to 25 light years long. The brightest stars in the main sequence in the cluster are of the spectral type B9, which suggests that the cluster is about 100 million years old. [196]
| Designation | NGC 2447 |
| Type | OCL (IV1p) |
| Right Ascension (J2000.0) | 07h 44m 30.0s |
| Declination (J2000.0) | -23° 51' 24" |
| Diameter | 10 arcmin |
| Visual magnitude | 6.2 mag |
| Metric Distance | 1.037 kpc |
| Dreyer Description | Cl, L, pRi, lC, st 8…13 |
| Identification, Remarks | M 93, OCL 649, ESO 493-SC7 |
Finder Chart
The open star cluster is located in the constellation Puppis about 1.5 degrees northwest of the 3.3 mag bright star Asmidiske (ξ Puppis). The best time to observe is around January, when the constellation is highest above the southern horizon at night.
