Stephenson 2 DFK 49

Stephenson 2 DFK 49
Observation data
Epoch J2000      Equinox J2000
Constellation Scutum
Right ascension 18h 39m 05.586s[1]
Declination −06° 04′ 26.58″[1]
Characteristics
Evolutionary stage Red supergiant[2] or post red supergiant[3]
Spectral type K4[2]
Apparent magnitude (K) 7.324[1]
Astrometry
Radial velocity (Rv)101[4]-109.4[2] km/s
Details
Radius1,074[2] – 1,300[3] R☉
Luminosity245,000[2] – 390,000[3] L☉
Temperature3920±112[2] – 4,000[3] K
Other designations
Stephenson 2 DFK 49, St2-11,[5] DENIS J183905.5-060425 2MASS J18390558-0604265, MSX6C G026.1215-00.0345 TIC 7759844
Database references
SIMBADdata

Stephenson 2 DFK 49 or St2-11 is a putative post red supergiant[3] star in the constellation Scutum, in the massive open cluster Stephenson 2. It is possibly one of the largest known stars with a radius estimated to be between 1,074 solar radii (747,000,000 kilometres; 4.99 astronomical units)[2] to 1,300 solar radii (900,000,000 kilometres; 6.0 astronomical units),[3]. If it was placed at the center of the Solar System, its photosphere would potentially approach or engulf Jupiter's orbit. It loses mass at a very high rate, resulting in large amounts of infrared excess.

  1. ^ a b c Cutri, Roc M.; et al. (2003). "VizieR Online Data Catalog: 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)". CDS/ADC Collection of Electronic Catalogues. 2246: II/246. Bibcode:2003yCat.2246....0C.
  2. ^ a b c d e f g Cite error: The named reference Davies2007 was invoked but never defined (see the help page).
  3. ^ a b c d e f Humphreys, Roberta M.; Helmel, Greta; Jones, Terry J.; Gordon, Michael S. (2020). "Exploring the Mass Loss Histories of the Red Supergiants". The Astronomical Journal. 160 (3): 145. arXiv:2008.01108. Bibcode:2020AJ....160..145H. doi:10.3847/1538-3881/abab15. S2CID 220961677.
  4. ^ Cite error: The named reference Masers was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference deguchi2010 was invoked but never defined (see the help page).