NGC 6441
| NGC 6441 | |
|---|---|
| Apparent magnitude (V) | 7.2[3] |
| Apparent dimensions (V) | 9.6′[3] |
| Physical characteristics | |
| Mass | 1.6×106[4] M☉ |
| Radius | 4.8[5] |
| Tidal radius | 88.8 ly (27.23 pc)[6] |
| Metallicity | = −0.53 |
![{\displaystyle {\begin{smallmatrix}\left[{\ce {Fe}}/{\ce {H}}\right]\end{smallmatrix}}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/4c0821bd80891e071c08e7c7ee8e022baedf522c)
NGC 6441 is a
arc minutes east-northeast of the star G Scorpii,[3] and is some 43,000 light-years from the Sun.[2]
This is one of the most massive and luminous globular clusters in the Milky Way, with an estimated 1.6 million
arc minutes, compared to the half-mass radius of 0.64 arc minutes. The density of stars in the core region is indicated by the luminosity density: 5.25 L⊙ pc−3.[5] The cluster has a half-light radius of 7.1 ly (2.18 pc).[6]
This cluster has an abnormally large number of
color-magnitude diagram suggests that there are at least two and possibly three distinct populations in the cluster. The brightest and higher temperature members of the red clump stars are more concentrated toward the center of the cluster. This group may be a helium-enriched second generation of stars.[10]
The cluster contains at least four millisecond pulsars, of which two are in binary systems. One of these binaries, PSR J1750−37A, is in a highly eccentric orbit with an eccentricity of 0.71.[5] The cluster has an X-ray burster, X1746-370, which has the longest period known in any globular cluster and is consistent with the galaxy as a whole.[11] Finally, there is a planetary nebula, JaFu 2,[12] one of only four planetary nebulas known to inhabit globular clusters in the Milky Way.[3]
References
- ^ S2CID 119183070.
- ^ S2CID 239998638.
- ^ ISBN 978-1139851541
- ^ S2CID 119235389, 32.
- ^ S2CID 2507922.
- ^ S2CID 15709239.
- S2CID 118634071, 183.
- ^ "NGC 6441". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2021-02-19.
- S2CID 49969831.
- S2CID 119208738, L27.
- S2CID 3217284.
- doi:10.1086/118671.
External links
Media related to NGC 6441 at Wikimedia Commons
