T Cephei

from Wikipedia, the free encyclopedia
Star
T Cephei
Telescope image of T Cephei
Telescope image of T Cephei
AladinLite
Observation
dates equinox :  J2000.0 , epoch : J2000.0
Constellation Cepheus
Right ascension 21 h 09 m 31.78 s
declination + 68 ° 29 ′ 27.2 ″
Apparent brightness 7.33 mag
5.2 to 11.3 mag
Typing
B − V color index +1.49 
U − B color index −0.33 
Spectral class M5.5e to M8.8e
Variable star type M. 
Astrometry
Radial velocity (−8.03 ± 0.49) km / s
parallax (5.69 ± 0.40)  mas
distance (570 ± 40)  ly
175  pc
Proper movement 
Rec. Share: (−44.15 ± 0.69)  mas / a
Dec. portion: (−42.31 ± 0.68)  mas / a
Physical Properties
radius 329  +70−50 R ☉
Luminosity

5.700  L ☉

Effective temperature 2,400  K
Other names
and catalog entries
Bonn survey BD + 67 ° 1291
Bright Star Catalog HR 8113 [1]
Henry Draper Catalog HD 202012 [2]
Hipparcos catalog HIP 104451 [3]
SAO catalog SAO 19229 [4]
Tycho catalog TYC 4460-2400-1 [5]Template: Infobox star / maintenance / specification of the TYC catalog
2MASS catalog 2MASS J21093180 + 6829268 [6]
Other names T Cephei

T Cephei is a Mira star in the constellation Cepheus . It is about 175 parsecs (570 light-years ) away, the apparent brightness varies between +5.2 and +11.3 mag with a period of around 388 days.

The star shows a sinusoidal variation of the period length over decades. In 1881 it was 400 days long; According to E. Zische, evaluations from 1905 to 1982 showed, however, a period length of 379 to 398 days. The BAV calculates with an average of 388.14 days.

The fact that the star is variable was already observed in 1877 by W. Ceraski (Moscow) and published on January 17, 1879. Further early observations are documented by G. Knott in 1882.

Individual evidence

  1. ↑ a b c d e f g T Cep. In: SIMBAD . Center de Données astronomiques de Strasbourg , accessed on November 12, 2018 .
  2. ↑ a b c d T Cep. In: VSX. AAVSO, accessed November 12, 2018 .
  3. ↑ Gerd Weigelt, Udo Beckmann, Jean-Philippe Berger, Thomas Bloecker, Michael K. Brewer, Karl-Heinz Hofmann, Marc G. Lacasse, Victor Malanushenko, Rafael Millan-Gabet, John D. Monnier, Keiichi Ohnaka, Ettore Pedretti, Dieter Schertl, F. Peter Schloerb, Michael Scholz, Wesley A. Traub, Boris Yudin: JHK-band spectro-interferometry of T Cep with the IOTA interferometer . In: SPIE . 4838, 2003, pp. 181-184. bibcode : 2003SPIE.4838..181W . doi : 10.1117 / 12.458659 .
  4. ^ A b T. Danilovich, D. Teyssier, K. Justtanont, H. Olofsson, L. Cerrigone, V. Bujarrabal, J. Alcolea, J. Cernicharo, A. Castro-Carrizo, P. García-Lario, A. Marston : New observations and models of circumstellar CO line emission of AGB stars in the Herschel SUCCESS program . In: Astronomy & Astrophysics . 581, 2015, p. A60. arxiv : 1506.09065 . bibcode : 2015A & A ... 581A..60D . doi : 10.1051 / 0004-6361 / 201526705 .
  5. ^ F. Vohla: T Cep at a glance . In: BAV circular . 1, 2008.
  6. ↑ a b G. Knott: About the variable star T Cephei . In: Astronomical News . 103, 1882, p. 329. bibcode : 1882AN .... 103..329K .
  7. ↑ E. Zische: period change at T Cephei . In: The Stars . 1, 1984, p. 54. bibcode : 1984Stern..60 ... 54Z .
  8. ↑ W. Ceraski: About a new variable . In: Astronomical News . 94, 1879, p. 175. bibcode : 1879AN ..... 94..175C .