SDSS J090745.0+024507

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]

ConstellationHydra

Right ascension09^h 07^m 44.9925^s[1]

Declination+02° 45′ 06.877″^[1]

Apparentmagnitude(V)19.84^[2]

Quick facts Constellation, Right ascension ...

SDSS J090745.0+024507

SDSS image of SDSS J090745.0+024507 (blue dot in the center)
Observation data Epoch J2000      Equinox 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
Distance	230000 ly (71000[3] pc)
Details
Temperature	10,500[3] K
Other designations
SDSS J090744.99+024506.8[5]
Database references
SIMBAD	data

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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]