SU Aurigae
Star in the constellation Auriga
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SU Aurigae is a T Tauri-type variable star in the constellation Auriga. It is located about 500 light-years (150 parsecs) away in the Taurus-Auriga Star Forming Region. Its apparent magnitude is 9.30, which is dim enough that it cannot be seen with the unaided eye.
Diagram of SU Aurigae's magnetic field | |
| Observation data Epoch J2000 Equinox ICRS | |
|---|---|
| Constellation | Auriga |
| Right ascension | 04h 55m 59.38669s[1] |
| Declination | +30° 34′ 01.4996″[1] |
| Apparent magnitude (V) | 9.30[2] |
| Characteristics | |
| Spectral type | G2IIIne[2] |
| Apparent magnitude (G) | 9.25[1] |
| B−V color index | +0.74[3] |
| Variable type | T Tauri |
| Astrometry | |
| Radial velocity (Rv) | 8.31±2.71[1] km/s |
| Proper motion (μ) | RA: 4.185±0.031[1] mas/yr Dec.: −24.304±0.022[1] mas/yr |
| Parallax (π) | 6.3700±0.0303 mas[1] |
| Distance | 512 ± 2 ly (157.0 ± 0.7 pc) |
| Absolute magnitude (MV) | +2.83[3] |
| Details[4] | |
| Mass | 2.22+0.02 −0.05 M☉ |
| Radius | 2.61+0.20 −0.23[3] R☉ |
| Luminosity | 12.9±0.3 L☉ |
| Surface gravity (log g) | 3.65±0.01 cgs |
| Temperature | 5680+40 −20 K |
| Metallicity [Fe/H] | +0.48±0.06 dex |
| Rotation | 2.68+0.15 −0.14 days |
| Rotational velocity (v sin i) | 58±3 km/s |
| Age | 2.92+0.19 −0.41 Myr |
| Other designations | |
| SU Aur, BD+30° 743, HD 282624, HIP 22925, SAO 57509, Gaia DR3 157010573981545344 | |
| Database references | |
| SIMBAD | data |
In 1907, Henrietta Swan Leavitt discovered that SU Aurigae is a variable star.[5]
SU Aurigae's spectral type of G2IIIne means that it is a G-type star with an effective temperature similar to the Sun. The III in the spectral type refers to its luminosity, which is much higher than normal G-type main sequence stars and would put it in the giant star class.[6] However, it is only about 4 million years old, which is relatively young for a star - young protostars like SU Aurigae are luminous because they are larger, not condensing into a normal size until they are older.[7]
SU Aurigae is known to have a circumstellar protoplanetary disk surrounding it, which is typical of many T Tauri stars.[7] SU Aurigae's disk has a high inclination of 62° and is nearly perpendicular to the plane of sky, so orbiting protoplanets or comets may be the cause of why there are drops in the amount of light detected.[3] SU Aurigae's proper motion and distance is similar to AB Aurigae,[10] a better known pre-main-sequence star, meaning that the two may form a very wide binary system;[6] if not, they are still in the same star association.