Heavily obscured star cluster on the far side of the Milky Way
H-band infrared image of 1806−20 cluster 1806−20 (originally named the SGR 1806−20 cluster) is a heavily obscured star cluster on the far side of the Milky Way , approximately 28,000 light-years distant.[ 3] soft gamma repeater SGR 1806−20 and the luminous blue variable hypergiant LBV 1806−20 , a candidate for the most luminous star in the Milky Way. LBV 1806−20 and many of the other massive stars in the cluster are thought likely to end as supernovas in a few million years, leaving only neutron stars or black holes as remnants.
The cluster is heavily obscured by intervening dust, and mostly visible in the infrared . It is part of the larger W31 H II region and giant molecular cloud . It has a compact core of ~0.2 pc in diameter with a more extended halo of ~2 pc in diameter containing the LBV[ 1] Wolf–Rayet stars (of types WC8, WN6, and WN7) and an OB supergiant , plus other young massive stars.[ 4]
See also
References
^ a b c SIMBAD/Aladin plot, of r=30 asec region around SGR B18054117-20251165
^ H. E. S. S. Collaboration; et al. (2018). "Extended VHE γ-ray emission towards SGR1806-20, LBV 1806-20, and stellar cluster Cl* 1806-20". Astronomy and Astrophysics . 612 : 612. arXiv :1606.05404 Bibcode :2018A&A...612A..11H . doi :10.1051/0004-6361/201628695 . S2CID 118345803 . ^ Bibby, J.; Crowther, P.; Furness, J.; Clark, J. (2008). "A downward revision to the distance of the 1806-20 cluster and associated magnetar from Gemini Near-Infrared Spectroscopy" . Monthly Notices of the Royal Astronomical Society . 386 (1). arXiv :0802.0815 Bibcode :2008MNRAS.386L..23B . doi :10.1111/j.1745-3933.2008.00453.x S2CID 14466990 . ^ Figer, Donald F.; Najarro, Francisco; Geballe, T. R.; Blum, R. D.; Kudritzki, Rolf P. (2005). "Massive Stars in the SGR 1806-20 Cluster". The Astrophysical Journal . 622 (1): L49 – L52 . arXiv :astro-ph/0501560 Bibcode :2005ApJ...622L..49F . doi :10.1086/429159 . S2CID 14696048 .
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