NGC 6357

NGC 6357 is a diffuse nebula near NGC 6334 in the constellation Scorpius. The nebula contains many proto-stars shielded by dark disks of gas, and young stars wrapped in expanding "cocoons" or expanding gases surrounding these small stars. It is also known as the Lobster Nebula.[4][5]

NGC 6357
Emission nebula
H II region
Cosmic ‘Winter’ Wonderland.jpg
NGC 6357 composite image
Credit: X-ray: NASA/CXC/PSU/L.Townsley et al.; Optical: UKIRT; Infrared: NASA/JPL-Caltech
Observation data: J2000 epoch
Right ascension 17h 24m[1]
Declination−34° 20′[1]
Distance~5900±450[2] ly   (1800±140 pc)
ConstellationScorpius[3]
DesignationsWar and Peace Nebula,[1] Lobster Nebula [4] Sharpless 11, RCW 131, Gum 66
See also: Lists of nebulae

This nebula was also given the name War and Peace Nebula by the Midcourse Space Experiment scientists because of its appearance, which, in infrared images the bright, western part resembles a dove, while the eastern part looks like a skull.[6]

It is located about 5500 light years away from Earth.[7]

Associated Open ClustersEdit

Pismis 24Edit

 
A Hubble Space Telescope (HST) image of Pismis 24-1, the "core" of NGC 6357.

This nebula includes the open cluster Pismis 24, which is home to several massive stars. One of the brightest stars in the cluster, Pismis 24-1, was thought possibly to be the most massive on record, approaching 300 solar masses, until it was discovered to be a multiple system of at least three stars; component stars would still remain near 100 solar masses each, making them among the more massive stars on record.[8][9]

G353.2+0.7Edit

The young stellar cluster G353.2+0.7 lies east of Pismis 24 and was revealed by a Chandra X-ray image showing approximately 800 stars.[10]

G353.1+0.6Edit

The young stellar cluster G353.1+0.6 lies southeast of Pismis 24 and also contains approximately 800 stars detected by X-ray.[10] The region includes several O-type stars, including [BDSB2003] 10.[11]

Massive starsEdit

NGC 6357 is one of the most prominent sites of massive-star formation our neighborhood of the Milky Way. A variety of early O-type stars reside in this nebula, blowing the bubbles around the stars clusters that can be seen in the molecular cloud.

Prominent stars in Pismis 24[12]
Star
(Pismis 24-#)
Spectral type Magnitude
(Mbol)
Temperature[13]
(K)
Radius
(R)
Mass
(M)
1NE O3.5 If* −10.0 42,000 17 74
1SW O4 III −9.8 41,500 16 66
2 O5.5 V(f) −8.9 40,000 12 43
3 O8 V −7.7 33,400 9 25
10 O9 V −7.2 31,500 8 20
12 B1 V −5.3 30,000 4 11
13 O6.5 III((f)) −8.6 35,600 12 35
15 O8 V −7.8 33,400 10 25
16 O7.5 V −9.0 34,000 16 38
17 O3.5 III −10.1 42,700 17 78
18 B0.5 V −6.4 30,000 6 15
19 B0.5 V −5.4 30,000 4 11

ReferencesEdit

  1. ^ a b c "NGC 6357". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2007-05-03.
  2. ^ Kuhn, Michael A.; Hillenbrand, Lynne A.; Sills, Alison; Feigelson, Eric D.; Getman, Konstantin V. (2018). "Kinematics in Young Star Clusters and Associations with Gaia DR2". The Astrophysical Journal. 870 (1): 32. arXiv:1807.02115. Bibcode:2019ApJ...870...32K. doi:10.3847/1538-4357/aaef8c.
  3. ^ R. W. Sinnott, ed. (1988). The Complete New General Catalogue and Index Catalogue of Nebulae and Star Clusters by J. L. E. Dreyer. Sky Publishing Corporation and Cambridge University Press. ISBN 978-0-933346-51-2.
  4. ^ a b Sample, Ian (20 February 2013). "Lobster Nebula – birthplace of stars – revealed in infrared". the Guardian.
  5. ^ "Lobster Nebula Seen with ESO's VISTA Telescope Space Wallpaper".
  6. ^ "2MASS Picture of the Week Archive Captions".
  7. ^ "Winter Wonderland' Glows in Space as Nebula Is Wreathed in Wintry Colors". Space.com.
  8. ^ "ESA Science & Technology: Star on a Hubble diet NGC 6357". Archived from the original on 2007-04-04. Retrieved 2007-04-11.
  9. ^ Nemiroff, R.; Bonnell, J., eds. (19 December 2006). "NASA: Massive Stars in Open Cluster Pismis 24". Astronomy Picture of the Day. NASA.
  10. ^ a b Townsley, L. K.; et al. (2014). "The Massive Star-Forming Regions Omnibus X-Ray Catalog". Astrophysical Journal Supplement. 213 (1): 1. arXiv:1403.2576. Bibcode:2014ApJS..213....1T. doi:10.1088/0067-0049/213/1/1.
  11. ^ Damke, G.; et al. (2006). "The open cluster G353.1+0.7 in NGC6357". Revista Mexicana de Astronomía y Astrofísica. 26: 180. Bibcode:2006RMxAC..26..180D.
  12. ^ 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.
  13. ^ Martins, F.; Schaerer, D.; Hillier, D. J. (2005). "A new calibration of stellar parameters of Galactic O stars". Astronomy and Astrophysics. 436 (3): 1049–1065. arXiv:astro-ph/0503346. Bibcode:2005A&A...436.1049M. doi:10.1051/0004-6361:20042386.

External linksEdit

  1. Star Forming Region NGC 6357 showing complex interactions between interstellar winds, radiation pressures and magnetic fields.
  2. A Massive Star in NGC 6357 with a close-up of Pismis 24.
  3. NGC 6357: Cathedral to Massive Stars
  4. A Massive Star in NGC 6357
  5. NGC 6357: Cathedral to Massive Stars
  6. NGC 6357: The Lobster Nebula