Y Tauri

Not to be confused with Upsilon Tauri.

Y Tauri is a carbon star located in the constellation Taurus. Parallax measurements by Gaia put it at a distance of approximately 2,170 light-years (670 parsecs).^[2]

A visual band light curve for Y Tauri, plotted from ASAS data^[11]

Y Tauri

Location of Y Tauri (circled)
Observation data Epoch J2000      Equinox J2000
Constellation	Taurus[1]
Right ascension	05h 45m 39.4101s[2]
Declination	+20° 41′ 42.149″[2]
Apparent magnitude (V)	6.5 - 9.2[3]
Characteristics
Evolutionary stage	AGB[4][5]
Spectral type	C6.5,4e(N3)[3]
Variable type	SRb[3]
Astrometry
Radial velocity (Rv)	17.00[6] km/s
Proper motion (μ)	RA: 0.039[2] mas/yr Dec.: −4.532[2] mas/yr
Parallax (π)	1.5006±0.0592 mas[2]
Distance	2,170 ± 90 ly (670 ± 30 pc)
Absolute magnitude (MV)	−1.1 (near max.)[7]
Details
Mass	4.3[8] M☉
Radius	219[9] R☉
Luminosity	6,025[5] L☉
Surface gravity (log g)	0.228[8] cgs
Temperature	3,217[10] K
Metallicity [Fe/H]	−0.106[8] dex
Other designations
Y Tau, BD+20°1083, HD 38307, HIP 27181, HR 1977
Database references
SIMBAD	data

Y Tauri is a semiregular variable star. Its class is SRb, and its primary pulsation cycle lasts 241.5 days.^[3] No long secondary period has been identified.^[12] It has a radius of 219 R_☉, an effective surface temperature of 3,217 K, and a bolometric luminosity of 4,489 L_☉. Its mass is calculated to be 4.3 M_☉.

Y Tauri is losing mass at 4×10⁻⁷ M_☉/yr, and is surrounded by dust at a temperature of 1,900 K.^[4]