GRS 1915+105

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Template:Short description

GRS 1915+105
File:V1487AqlLightCurve.png
A near-infrared (K band) light curve for V1487 Aquilae, adapted from Neil et al. (2007)[1]
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Aquila
Right ascension Template:RA[2]
Declination Template:DEC[2]
Characteristics
Evolutionary stage Microquasar[3]
Spectral type KIII[4]
Astrometry
Parallax (π)0.120±0.009 mas[3]
Distance28,000 ly
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Details
Black hole
MassScript error: No such module "val".[3]Template:Contradiction-inline Template:Solar mass
Metallicity [Fe/H]{{{metal_fe2}}} dex
Other designations
V1487 Aquilae, Granat 1915+105, Nova Aquilae 1992, Granat 1915+10, INTEGRAL1 112
Database references
SIMBADdata

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GRS 1915+105 or V1487 Aquilae is an X-ray binary star system containing a main sequence star and a black hole. Transfer of material from the star to the black hole generates a relativistic jet, making this a microquasar system. The jet exhibits apparent superluminal motion.

It was discovered on August 15, 1992 by the WATCH all-sky monitor aboard Granat.[5] "GRS" stands for "GRANAT source", "1915" is the right ascension (19 hours and 15 minutes) and "105" reflects the approximate declination (10 degrees and 56 arcminutes). The near-infrared counterpart was determined by spectroscopic observations.[6]

The binary system lies 11,000 parsecs away[7] in Aquila. The black hole in GRS 1915+105 is 10 to 18 solar masses[8]Template:Contradiction-inline. The black hole rotates at least 950 times per second, giving it a spin parameter >0.82 (1.0 is the theoretical maximum).[9][10]

Galactic superluminal source

File:Merlin-GRS1915.gif
A sequence of MERLIN observation of the X-ray binary GRS 1915+105 taken over a few days.

In 1994, GRS 1915+105 became the first known galactic source that ejects material with apparent superluminal motion velocities.[11]

Observations with high resolution radio telescopes such as VLA, MERLIN, and VLBI show a bi-polar outflow of charged particles, which emit synchrotron radiation at radio frequencies. These studies have shown that the apparent superluminal motion is due to a relativistic effect known as relativistic aberration, where the intrinsic velocity of ejecta is actually about 90% the speed of light.[7]

Growth regulation

Repeat observations by the Chandra X-Ray Observatory over the period of a decade have revealed what may be a mechanism for self-regulation of the rate of growth of GRS 1915+105. The jet of materials being ejected is occasionally choked off by a hot wind blowing off the accretion disk. The wind deprives the jet of materials needed to sustain it. When the wind dies down, the jet returns.[12]

See also

References

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External links

Template:Sky

Template:Stars of Aquila