T Coronae Borealis
Double star T Coronae Borealis |
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Fluctuations in brightness of T CrB between January 2008 and November 2010 | |||||||||||||||||
AladinLite | |||||||||||||||||
Observation dates equinox : J2000.0 , epoch : J2000.0 |
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Constellation | Northern crown | ||||||||||||||||
Right ascension | 15 h 59 m 30.16 s | ||||||||||||||||
declination | + 25 ° 55 ′ 12.6 ″ | ||||||||||||||||
Apparent brightness | 10.08 (2.0 to 10.8) mag
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Typing | |||||||||||||||||
B − V color index | +0.10 | ||||||||||||||||
R − I index | +1.56 | ||||||||||||||||
Spectral class | M3 III + p | ||||||||||||||||
Variable star type | NR + ELL | ||||||||||||||||
Astrometry | |||||||||||||||||
Radial velocity | (−27.79 ± 0.13) km / s | ||||||||||||||||
parallax | (1.21 ± 0.05) mas | ||||||||||||||||
distance | 2,700 ly 800 pc |
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Proper movement | |||||||||||||||||
Rec. Share: | (−4.22 ± 0.07) mas / a | ||||||||||||||||
Dec. portion: | (12.36 ± 0.09) mas / a | ||||||||||||||||
Physical Properties | |||||||||||||||||
Other names and catalog entries |
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T Coronae Borealis ( T CrB for short ) is a recurrent (recurring) nova in the constellation Northern Crown, approximately 2,000 light years away . T Coronae Borealis is normally 10.8 mag , but reached 2.0 in the last two eruptions in 1866 and 1946.
It is a so-called symbiotic star , i.e. a binary star system in which an extensive red giant and a compact white dwarf orbit each other at a relatively close distance. The matter from the gas envelope of the red giant overflows onto the white dwarf. If a critical mass is reached, fusion processes begin , which can be observed as explosive outbursts of brightness.
According to the conventions for naming variable stars , the letter "T" in front of the name identifies this star as the third to be discovered in the constellation Northern Crown.
Individual evidence
- ^ T CrB. In: SIMBAD . Center de Données astronomiques de Strasbourg , accessed on November 2, 2018 .
- ↑ a b Hipparcos catalog (ESA 1997)
- ↑ a b T CrB. In: VSX. AAVSO, accessed November 2, 2018 .
- ↑ a b Bright Star Catalog
- ^ Hipparcos, the New Reduction (van Leeuwen, 2007)