Key facts
- Right ascension
- 07 41 46.0
- Declination
- −14 ° 48 ′ 36 ″
- Distance
- 4,920 ± 980 ly (1,510 ± 302 pc )
- Apparent dimensions v
- 22.8 ′
- Mass
- 453 +214, −145 M ☉
- Radius
- 37.8 ly
- Estimated age
- 251.2 Myr
- Other designations
- M46, NGC 2437, Cr 159, C 0739-147, OCl 601.0
- Constellation
- Puppis
via Wikipedia infobox
Article
Messier 46 or M46, also known as NGC 2437, is an open cluster of stars in the slightly southern constellation of Puppis. It was discovered by Charles Messier in 1771. Dreyer described it as "very bright, very rich, very large." It is about 5,000 light-years away. There are an estimated 500 stars in the cluster with a combined mass of 453 M☉, and it is thought to be a mid-range estimate of 251.2 million years old.
The cluster has a very broadest (tidal) radius of 37.8 ± 4.6 ly (11.6 ± 1.4 pc) and core radius of 8.5 ± 1.3 ly (2.6 ± 0.4 pc). It has a greater spatial extent in infrared than in visible light, suggesting it is undergoing some mass segregation with the fainter (redder) stars migrating to a coma (tail) region. The fainter stars that extend out to the south and west may form a tidal tail due to a past interaction.