Astronomy:SDSS J090745.0+024507

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Short description: Variable star in the constellation Hydra
SDSS J090745.0+024507
SDSS J090745.0+024507.jpg
SDSS image of SDSS J090745.0+024507 (blue dot in the center).
Observation data
Equinox J2000.0]] (ICRS)
Constellation Hydra
Right ascension  09h 07m 44.9925s[1]
Declination +02° 45′ 06.877″[1]
Apparent magnitude (V) 19.84[2]
Characteristics
Spectral type B9 V[3]
Variable type SPB[3]
Astrometry
Radial velocity (Rv)+853 ± 12[4] km/s
Distance230000 ly
(71000[3] pc)
Details
Temperature10,500[3] K
Other designations
SDSS J090744.99+024506.8[5]
Database references
SIMBADdata

SDSS J090744.99+024506.8 (SDSS 090745.0+024507) is a short-period variable star in the constellation Hydra. It has a Galactic rest-frame radial velocity of 709 km/s.[3]

Its effective temperature is 10,500 K (corresponding to a spectral type of B9) and its age is estimated to be at most 350 million years. It has a heliocentric distance of 71 kpc. It was ejected from the centre of the galaxy less than 100 million years ago, which implies the existence of a population of young stars at the galactic centre less than 100 million years ago.[3]

Christened by the astronomer Warren Brown as the "outcast star", it is the first discovered member of a class of objects named hypervelocity stars.[6] It was discovered in 2005 at the MMT Observatory of the Center for Astrophysics | Harvard & Smithsonian (CfA), by astronomers Warren Brown, Margaret J. Geller, Scott J. Kenyon and Michael J. Kurtz.[4]

See also

References

  1. 1.0 1.1 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode2018A&A...616A...1G. 
  2. Brown, Warren R.; Geller, Margaret J.; Kenyon, Scott J.; Kurtz, Michael J.; Bromley, Benjamin C. (2007). "Hypervelocity Stars. III. The Space Density and Ejection History of Main-Sequence Stars from the Galactic Center". The Astrophysical Journal 671 (2): 1708. doi:10.1086/523642. Bibcode2007ApJ...671.1708B. 
  3. 3.0 3.1 3.2 3.3 3.4 3.5 Cesar I. Fuentes; K. Z. Stanek; B. Scott Gaudi; Brian A. McLeod; Slavko B. Bogdanov; Joel D. Hartman; Ryan C. Hickox; Matthew J. Holman (21 July 2005). "The Hypervelocity Star SDSS J090745.0+024507 is a Short-Period Variable". The Astrophysical Journal 636 (1): L37. doi:10.1086/499233. Bibcode2006ApJ...636L..37F.  Accessed 18 January 2016.
  4. 4.0 4.1 Brown, Warren R.; Geller, Margaret J.; Kenyon, Scott J.; Kurtz, Michael J. (2005), "Discovery of an Unbound Hypervelocity Star in the Milky Way Halo", Astrophysical Journal 622 (1): L33–L36, doi:10.1086/429378, Bibcode2005ApJ...622L..33B 
  5. "[BGK2006 HV 1"]. SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=%5BBGK2006%5D+HV+1. 
  6. Berardelli, Phil (10 February 2005), "In The Stars: Odd Stars, Odder Planets", Space Daily, http://www.spacedaily.com/news/extrasolar-05h.html 

Further reading

External links