A visual band light curve for RY Tauri, shawing variability on three different time scales, adapted from Ismailov and Adygezalzade (2012),[1] Ismailov et al. (2011)[2] and Siwak et al. (2011)[3] | |
Observation data Epoch J2000 Equinox J2000 | |
---|---|
Constellation | Taurus |
Right ascension | 04h 21m 57.4133s[4] |
Declination | +28° 26′ 35.5340″[4] |
Apparent magnitude (V) | 9.5 - 11.5[5] |
Characteristics | |
Evolutionary stage | pre-main-sequence star |
Spectral type | F7[6] |
Apparent magnitude (G) | 10.706[7] |
Variable type | T Tau[8] |
Astrometry | |
Radial velocity (Rv) | 24.3±1.9 km/s |
Proper motion (μ) | RA: 8.744[7] mas/yr Dec.: −27.002[7] mas/yr |
Parallax (π) | 7.2349 ± 0.2031 mas[7] |
Distance | 450 ± 10 ly (138 ± 4 pc) |
Absolute magnitude (MV) | +2.11 (at magnitude 9.55)[5] |
Position (relative to RY Tauri)[9] | |
Component | 2MASS J04215810+2826300 |
Angular distance | 10.83″ |
Position angle | 122.41° |
Projected separation | 1500 AU |
Details | |
Mass | 2.0[10] M☉ |
Radius | 3.2[10] R☉ |
Luminosity | 11.6[10] L☉ |
Surface gravity (log g) | 3.8[10] cgs |
Temperature | 5,945[10] K |
Age | 4.7+1.00 −0.90[5] Myr |
Other designations | |
Database references | |
SIMBAD | data |
RY Tauri is a young T Tauri star in the constellation of Taurus about 450 light years away, belonging to the Taurus Molecular Cloud. It is more massive than typical T Tauri stars, and may be an intermediate between this class and the Herbig Ae/Be star type.[11]
There was one suspected stellar companion to RY Tauri, a 14.81 magnitude object 2MASS J04215810+2826300 discovered in 2008 at a projected separation of 1500 AU.[9] It was proven to be a background star not related to RY Tauri with Gaia data though.[12]
The star is surrounded by a protoplanetary disk discovered in 2006.[11] The disk is massive at 0.3M☉ and consists mostly of gas.[13] The existence of a protoplanetary disk is disputed; the signal can also be attributed to the birth envelope partially disrupted by the young star. Also, polar jets were detected.[14] The jets contain detectable amounts of oxygen and sulfur.[6] A superjovian planet on a 0.2 AU orbit is suspected since 2021.[15]
Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
---|---|---|---|---|---|---|
protoplanetary disk | 0.21–80 AU | 65° | — |
RY Tauri varies in brightness. It is a highly (by 1.5 magnitudes)[14] obscured Orion variable, producing fluctuations of brightness as the star shines through the inhomogeneities of the inner part of the protoplanetary disk.[13] It also produces irregular brightening events with a duration of about a month and amplitude of one magnitude.[16] The light curve of RY Tauri varies by 2-3 magnitudes over a decade and by roughly one magnitude over a year. The star was gradually brightening during the 20th century, possibly changing the variability mechanism in the process.[17]