Pismis 24-1

Pismis 24-1

Pismis 24-1 is the brightest region of light at the centre of this optical image of the NGC 6357 region.
Credit: ESO/IDA/Danish 1.5 m/ R. Gendler, U.G. Jørgensen, J. Skottfelt, K. Harpsøe
Characteristics
NE
Spectral type O3.5If*
Variable type eclipsing
SW
Spectral type O4III(f+)
Astrometry
Radial velocity (Rv)−2.0 km/s
Proper motion (μ) RA: −0.1 mas/yr
Dec.: −1.3 mas/yr
Distance6,500 ly
(2,000 pc)
Absolute magnitude (MV)−7.50
NE
Absolute magnitude (MV)−6.41
SW
Absolute magnitude (MV)−6.28
Details
NE
Mass74 M☉
Radius18 R☉
Luminosity776,000 L☉
Temperature42,500/41,500 K
SW
Mass66 M☉
Radius17 R☉
Luminosity646,000 L☉
Temperature~40,000 K
Other designations
CD−34°11671, 2MASS J17244349-3411570, CCDM J17247-3412A
NE: Pismis 24-1NE, HD 319718A
SW: Pismis 24-1SW, HD 319718B
Database references
SIMBADdata

Pismis 24-1 (also known as HD 319718) is the brightest star in the Pismis 24 open cluster in the NGC 6357 nebula. It is 6,500 light years away. It was thought to be the most massive star known: actually it is made of three stars. These are still some of the most luminous and most massive stars known.

References

  1. 1 2 3 Maíz Apellániz, J.; Walborn, Nolan R.; Morrell, N. I.; Niemela, V. S.; Nelan, E. P. (2007). "Pismis 24-1: The Stellar Upper Mass Limit Preserved". The Astrophysical Journal. 660 (2): 1480–1485. arXiv:astro-ph/0612012. Bibcode:2007ApJ...660.1480M. doi:10.1086/513098. S2CID 15936535.
  2. 1 2 3 4 Barr Domínguez, A.; Chini, R.; Pozo Nuñez, F.; Haas, M.; Hackstein, M.; Drass, H.; Lemke, R.; Murphy, M. (2013). "Eclipsing high-mass binaries. I. Light curves and system parameters for CPD - 51° 8946, PISMIS 24-1, and HD 319702". Astronomy & Astrophysics. 557: A13. arXiv:1306.5482. Bibcode:2013A&A...557A..13B. doi:10.1051/0004-6361/201321642. S2CID 118623790.
  3. ↑ Crampton, D. (1972). "Radial velocities of southern B stars determined at the Radcliffe Observatory - VI. Stars in H II regions". Monthly Notices of the Royal Astronomical Society. 158: 85–98. Bibcode:1972MNRAS.158...85C. doi:10.1093/mnras/158.1.85.
  4. 1 2 Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P.; Wicenec, A. (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355: L27. Bibcode:2000A&A...355L..27H. doi:10.1888/0333750888/2862.
  5. 1 2 Lima, E. F.; Bica, E.; Bonatto, C.; Saito, R. K. (2014). "Probing embedded star clusters in the HII complex NGC 6357 with VVV". Astronomy & Astrophysics. 568: A16. arXiv:1406.2413. Bibcode:2014A&A...568A..16L. doi:10.1051/0004-6361/201323050. S2CID 56229887.
  6. 1 2 3 4 5 Fang, M.; Van Boekel, R.; King, R. R.; Henning, T.; Bouwman, J.; Doi, Y.; Okamoto, Y. K.; Roccatagliata, V.; Sicilia-Aguilar, A. (2012). "Star formation and disk properties in Pismis 24". Astronomy & Astrophysics. 539: A119. arXiv:1201.0833. Bibcode:2012A&A...539A.119F. doi:10.1051/0004-6361/201015914. S2CID 73612793.