T Cephei

Region of NGC 7023, with T Cephei marked on the full-size image Credit: NASA, ESA and Digitized Sky Survey 2
Observation data Epoch J2000       Equinox J2000
Constellation	Cepheus
Right ascension	21h 09m 31.78348s [1]
Declination	+68° 29′ 27.2311″ [1]
Apparent magnitude (V)	5.2 - 11.3 [2]
Characteristics
Evolutionary stage	AGB [3]
Spectral type	M6-9e [4]
U−B color index	+0.33 [5]
B−V color index	+1.49 [5]
Variable type	Mira [3]
Astrometry
Radial velocity (Rv)	−8.03 [6] km/s
Proper motion (μ)	RA: −44.210 [1]  mas/ yr Dec.: −44.921 [1]  mas/ yr
Parallax (π)	5.4400 ± 0.3476  mas [1]
Distance	600 ± 40  ly (180 ± 10  pc)
Details
Mass	0.55 [7]  M☉
Radius	329+70 −50 [8]  R☉
Luminosity	5,700 [9]  L☉
Temperature	2,400 [9] - 3,347 [10]  K
Other designations
T Cephei, HR 8113, HD 202012, HIP 104451, BD+67°1291, GC 29611, SAO 19229, GSC 04460-02400
Database references
SIMBAD	data

T Cephei is a Mira variable star in the constellation Cepheus. Located approximately 600 light-years (180 parsecs) distant, it varies between magnitudes 5.2 and 11.3 over a period of around 388 days. ^{[9] [2]}

T Cephei is a red giant of spectral type M6-9e with an effective temperature 2,400 K, a radius of 329 R_☉, a mass of 0.55 M_☉, and a luminosity of 5,700 L_☉. If it were in the place of the Sun, its photosphere would at least engulf the orbit of Mars. This star is believed to be in a late stage of its life, blowing off its own atmosphere to form a white dwarf in a distant future.

• VV Cephei
• R Cancri
• Mira
• S Cassiopeiae

• T Cephei in VizieR