T Coronae Borealis

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Double star
T Coronae Borealis
T-CrB-Lightcurve-AAVSO.gif
Fluctuations in brightness of T CrB between January 2008 and November 2010
AladinLite
Observation
dates equinox :  J2000.0 , epoch : J2000.0
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

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
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
Bonn survey BD + 26 ° 2765
Bright Star Catalog HR 5958 [1]
Henry Draper Catalog HD 143454 [2]
Hipparcos catalog HIP 78322 [3]
SAO catalog SAO 84129 [4]
Tycho catalog TYC 2037-1144-1 [5]
2MASS catalog 2MASS J15593015 + 2555126 [6]
Other names T Coronae Borealis, Nova CrB 1866, Nova CrB 1946

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

  1. ^ T CrB. In: SIMBAD . Center de Données astronomiques de Strasbourg , accessed on November 2, 2018 .
  2. ↑ a b Hipparcos catalog (ESA 1997)
  3. ↑ a b T CrB. In: VSX. AAVSO, accessed November 2, 2018 .
  4. ↑ a b Bright Star Catalog
  5. ^ Hipparcos, the New Reduction (van Leeuwen, 2007)