AI overview
Messier 23 is a collection of young stars held together by gravity, located about 2,150 light-years away in the constellation Sagittarius. Studying open clusters like this one helps astronomers understand how stars form and age over time.
AI-generated from the Wikipedia summary — may contain errors.
Key facts
- Right ascension
- 17 57 04
- Declination
- −18 ° 59 ′ 06 ″
- Distance
- 2,050 ly (628 pc )
- Apparent dimensions v
- 35 ′
- Mass
- 1,206 M ☉
- Radius
- 8 ly
- Estimated age
- 330 ± 100 myr
- Other designations
- M 23, NGC 6494, Cr 356, C 1753-190
- Constellation
- Sagittarius
via Wikipedia infobox
Article
Messier 23, also known as NGC 6494, is an open cluster of stars in the northwest of the southern constellation of Sagittarius. It was discovered by Charles Messier in 1764. It can be found in good conditions with binoculars or a modestly sized telescope. It is in front of "an extensive gas and dust network", which there may be no inter-association. It is within 5° the sun's position (namely in mid-December) so can be occulted by the moon.
The cluster is centered about 2,050 light years away. Estimates for the number of its members range from 169 up to 414, with a directly-counted mass of 1,206 M☉; 1,332 M☉ by application of the virial theorem. The cluster is around 330 million years old with a near-solar metallicity of [Fe/H] = −0.04. The brightest component (lucida) is of magnitude 9.3. Five of the cluster members are candidate red giants, while orange variable VV Sgr in the far south, is a candidate asymptotic giant branch star.