IU Aurigae
Triple star system in the constellation Auriga
From Wikipedia, the free encyclopedia
IU Aurigae is a triple star[6] system in the constellation Auriga, consisting of an eclipsing binary pair orbiting a third component with a period of 335 years.[7] This system is too faint to be viewed with the naked eye, having a peak apparent visual magnitude of 8.19.[3]
| Observation data Epoch J2000 Equinox ICRS | |
|---|---|
| Constellation | Auriga |
| Right ascension | 05h 27m 52.40539s[2] |
| Declination | +34° 46′ 58.3435″[2] |
| Apparent magnitude (V) | 8.19 to 8.83[3] |
| Characteristics | |
| Spectral type | B0p + B1Vp[3] + ? |
| U−B color index | −0.66 |
| B−V color index | +0.18 |
| Variable type | Eclipsing binary[4] |
| Astrometry | |
| Radial velocity (Rv) | 9±5 km/s |
| Proper motion (μ) | RA: −4.479[2] mas/yr Dec.: −9.049[2] mas/yr |
| Parallax (π) | 0.4786±0.5765 mas[2] |
| Distance | 6,500 ly (2,000 pc)[1] |
| Details[1] | |
| A | |
| Mass | 21.4±2.5 M☉ |
| Radius | 7.8±0.8 R☉ |
| Luminosity | 57,500 L☉ |
| Surface gravity (log g) | 3.99±0.17 cgs |
| Temperature | 32,000 K |
| B | |
| Mass | 14.5±2.0 M☉ |
| Radius | 7.1±0.8 R☉ |
| Luminosity | 26,300 L☉ |
| Surface gravity (log g) | 3.89±0.19 cgs |
| Temperature | 27,540±290 K |
| Other designations | |
| IU Aur, BD+34°1051, HD 35652, HIP 25565, SAO 58059, PPM 70395[5] | |
| Database references | |
| SIMBAD | data |
Pavel Mayer discovered that the star's brightness varies in 1964.[8] The eclipsing pair form a Beta Lyrae-type semidetached binary of two Bp stars[3] with a period of 1.81147435 days.[4] During the primary eclipse, the visual magnitude of the system drops to 8.89, while for the secondary it decreases to 8.74.[3][9] The third component is a massive object with 17–18 M☉, and may actually be a binary – which would make this a quadruple star system.[7]