RCW 38

RCW 38
Nebulosity around the embedded star cluster in RCW 38
Observation data (J2000 epoch)
Right ascension	08h 59m 05.52s [1]
Declination	−47° 30′ 39.2″ [1]
Distance	5,500  ly (1.7  kpc) [1]
Physical characteristics
Associations
Constellation	Vela
See also: Open cluster, List of open clusters

RCW 38 is a star-forming region in the southern constellation of Vela (known as the Sails). ^[2] It includes an embedded HII region and a super star cluster. This region is located at a distance of approximately 5,500 light-years from the Sun. ^[1]

This is the youngest super star cluster in the Milky Way galaxy, with age estimates ranging from 0.1 to 1.0 Myr. It has around 10,000 member stars. ^[3] The cluster member stars are still enshrouded within the dark cloud in which they were born. ^[4] The star cluster is surrounded by clouds of brightly glowing gas and includes many protostars. ^[4] Observations by the Chandra X-ray Observatory have revealed more than 800 X-ray emitting young stellar objects in the cluster. ^[5] 139 infrared sources have been identified as variable, of which 47% are candidate young stellar objects. ^[6] Jets emerging from young protostars drive further star formation in the surrounding cloud. ^[7]

The cluster includes about 20 massive O-type stars concentrated in a volume a few parsecs across. The latter stars are having a dissipative effect on the surrounding molecular gas. ^[3] Five bow shocks have been identified coming from these objects, driven by strong stellar winds. ^[7] When these massive stars die, likely before the dispersal of the cluster, they will explode as supernovae. ^[2] It is hypothesized that these O-type stars were formed by a collision of two molecular clouds. ^[8] The primary cloud has a mass of 3×10⁴ M_☉, while the secondary cloud has 2×10³ M_☉. ^[3]

In the infrared, the brightest star in this region is designated IRS 2. ^[9] This is a binary star system consisting of two spectral type O5.5 stars. It is located at the heart of the cluster, ^[10] and appears to lie at the center of the H II region. ^[11] The second brightest source is a dust ridge designated IRS 1, positioned about 0.1 pc to the west of IRS 2. Both sources are surrounded by a dust-free cavity about 0.1 pc across. ^[3]

RCW 38 includes Gum 22, Gum 23, and Gum 24. ^{[12] [ clarification needed ]}

Gallery

• 
  The location of RCW 38 (circled in red)
• 
  An X-ray view of the dense central star cluster
• 
  Central part of RCW 38, showing some of the brown dwarf candidates detected within the cluster ^[13]
• 
  The wider region surrounding RCW 38

References

1. Wolk, Scott J.; et al. (September 2006). "X-Ray and Infrared Point Source Identification and Characteristics in the Embedded, Massive Star-Forming Region RCW 38". The Astronomical Journal. 132 (3): 1100–1125. arXiv: astro-ph/0605096 . Bibcode:2006AJ....132.1100W. doi:10.1086/505704.
2. "Star cluster RCW 38". ESO. Retrieved 2025-03-16.
3. Torii, Kazufumi; et al. (February 2021). "ALMA view of the Galactic super star cluster RCW 38 at 270 au resolution". Publications of the Astronomical Society of Japan. 73 (1): 205–219. arXiv: 1907.07358 . Bibcode:2021PASJ...73..205T. doi:10.1093/pasj/psaa115.
4. Turner, Calum (July 11, 2018). "Colourful Celestial Landscape". Garching bei München, Germany: ESO Public Information Office. Retrieved 2025-03-16.
5. Broos, Patrick S.; et al. (2013). "Identifying young stars in massive star-forming regions for the MYStIX project". The Astrophysical Journal Supplement Series. 209 (2): 32. arXiv: 1309.4500 . Bibcode:2013ApJS..209...32B. doi:10.1088/0067-0049/209/2/32. ISSN   0067-0049. S2CID   67827240.
6. Dörr, M.; et al. (May 2013). "Near-infrared variability in the star-forming region RCW 38". Astronomy & Astrophysics. 553. id. A48. Bibcode:2013A&A...553A..48D. doi:10.1051/0004-6361/201220311.
7. Winston, E.; et al. (January 2012). "Spitzer Observations of Bow Shocks and Outflows in RCW 38". The Astrophysical Journal. 744 (2). id. 126. arXiv: 1111.4413 . Bibcode:2012ApJ...744..126W. doi:10.1088/0004-637X/744/2/126.
8. Fukui, Y.; et al. (March 2016). "The Two Molecular Clouds in RCW 38: Evidence for the Formation of the Youngest Super Star Cluster in the Milky Way Triggered by Cloud-Cloud Collision". The Astrophysical Journal. 820 (1). id. 26. arXiv: 1504.05391 . Bibcode:2016ApJ...820...26F. doi: 10.3847/0004-637X/820/1/26 .
9. Ascenso, Joana (June 2022). "Hidden power of near-infrared data for the study of young clusters: Illustrative case of RCW 38". Astronomy & Astrophysics. 662. id. A31. arXiv: 2203.01064 . Bibcode:2022A&A...662A..31A. doi:10.1051/0004-6361/202142582.
10. Winston, E.; et al. (December 2011). "The Structure of the Star-forming Cluster RCW 38". The Astrophysical Journal. 743 (2). id. 166. arXiv: 1110.2660 . Bibcode:2011ApJ...743..166W. doi:10.1088/0004-637X/743/2/166.
11. Wolk, S. J.; et al. (2008). "The Embedded Massive Star Forming Region RCW 38". In Reipurth, B. (ed.). Handbook of Star Forming Regions, Volume II: The Southern Sky ASP Monograph Publications. Vol. 5. Astronomical Society of the Pacific. p. 43. Bibcode:2008hsf2.book..124W. ISBN   978-1-58381-670-7.
12. Lang, Kenneth R. (December 6, 2012). Astrophysical Data: Planets and Stars. Springer Science & Business Media. ISBN   978-1-4684-0640-5.
13. "Billions of new neighbours?". www.eso.org. Retrieved 17 July 2017.

Further reading

• Pandey, Paarmita; et al. (November 2024). "Constraining the Diffusion Coefficient and Cosmic-Ray Acceleration Efficiency Using Gamma-Ray Emission from the Star-forming Region RCW 38". The Astrophysical Journal. 976 (1). id. 98. arXiv: 2404.19001 . Bibcode:2024ApJ...976...98P. doi: 10.3847/1538-4357/ad83bc .
• Ge, Ting-Ting; et al. (May 2024). "GeV γ-ray emission in the field of young massive star cluster RCW 38". Monthly Notices of the Royal Astronomical Society. 530 (1): 1144–1150. arXiv: 2403.19362 . Bibcode:2024MNRAS.530.1144G. doi: 10.1093/mnras/stae930 .
• Fukushima, Aoto; et al. (February 2023). "Suzaku and Chandra study of diffuse X-ray emission from the massive star-forming region RCW 38". Publications of the Astronomical Society of Japan. 75 (1): 187–198. Bibcode:2023PASJ...75..187F. doi:10.1093/pasj/psac100.
• Izumi, Natsuko; et al. (February 2021). "Observations of the [C I] (³P₁-³P₀) emission toward the massive star-forming region RCW 38: Further evidence for highly-clumped density distribution of the molecular gas". Publications of the Astronomical Society of Japan. 73 (1): 174–196. arXiv: 2012.01330 . Bibcode:2021PASJ...73..174I. doi:10.1093/pasj/psaa113.
• Mužić, Koraljka; et al. (November 2017). "The low-mass content of the massive young star cluster RCW 38". Monthly Notices of the Royal Astronomical Society. 471 (3): 3699–3712. arXiv: 1707.00277 . Bibcode:2017MNRAS.471.3699M. doi: 10.1093/mnras/stx1906 .
• Kaneda, H.; et al. (August 2013). "Large-scale mapping of the massive star-forming region RCW38 in the [CII] and PAH emission". Astronomy & Astrophysics. 556. id. A92. arXiv: 1307.0263 . Bibcode:2013A&A...556A..92K. doi:10.1051/0004-6361/201321614.
• Bik, A.; et al. (April 2010). "Sequential Star Formation in RCW 34: A Spectroscopic Census of the Stellar Content of High-Mass Star-Forming Regions". The Astrophysical Journal. 713 (2): 883–899. arXiv: 1002.2571 . Bibcode:2010ApJ...713..883B. doi:10.1088/0004-637X/713/2/883.
• DeRose, K. L.; et al. (July 2009). "A Very Large Telescope/NACO Study of Star Formation in the Massive Embedded Cluster RCW 38". The Astronomical Journal. 138 (1): 33–45. arXiv: 0904.3279 . Bibcode:2009AJ....138...33D. doi:10.1088/0004-6256/138/1/33.
• Wolk, S. J.; et al. (December 2008). "The Embedded Massive Star Forming Region RCW 38". In Reipurth, Bo (ed.). Handbook of Star Forming Regions, volume II. The Southern Sky ASP Monograph Publications. Vol. 5. p. 124. arXiv: 0808.3385 . Bibcode:2008hsf2.book..124W.
• Gyulbudaghian, A. L.; May, J. (January 2008). "Investigation of the conspicuous infrared star cluster and star-forming region "RCW 38 IR Cluster"". Astrophysics. 51 (1): 18–28. Bibcode:2008Ap.....51...18G. doi:10.1007/s10511-008-0003-8.
• Wolk, Scott J.; et al. (December 2002). "Discovery of Nonthermal X-Ray Emission from the Embedded Massive Star-forming Region RCW 38". The Astrophysical Journal. 580 (2): L161 –L165. Bibcode:2002ApJ...580L.161W. doi:10.1086/345611.
• Smith, Craig H.; et al. (February 1999). "Mid-infrared imaging and spectroscopy of the southern HII region RCW 38". Monthly Notices of the Royal Astronomical Society. 303 (2): 367–379. Bibcode:1999MNRAS.303..367S. doi: 10.1046/j.1365-8711.1999.02241.x .
• Ligori, S.; et al. (1994). "Near infrared imaging of the southern HII region RCW 38". Memorie della Societa Astronomica Italiana. 65: 815–818. Bibcode:1994MmSAI..65..815L.
• Mizutani, K.; et al. (October 1987). "Brackett-gamma mapping observation of RCW 38". Monthly Notices of the Royal Astronomical Society. 228 (3): 721–727. Bibcode:1987MNRAS.228..721M. doi: 10.1093/mnras/228.3.721 .
• Takami, H.; et al. (August 1987). "Far-infrared O III fine-structure lines and ionization structure of RCW 38". Publications of the Astronomical Society of the Pacific. 99: 832–835. Bibcode:1987PASP...99..832T. doi:10.1086/132043.
• Muzzio, J. C.; Celotti de Frecha, M. B. (October 1979). "Faint early-type stars in the neighbourhood of the H II region RCW 38". Monthly Notices of the Royal Astronomical Society. 189 (2): 159–162. Bibcode:1979MNRAS.189..159M. doi: 10.1093/mnras/189.2.159 .

External links

• "RCW 38", SIMBAD , Centre de données astronomiques de Strasbourg , retrieved 2025-03-16.