Chi Aurigae, a blue-white supergiant star in Auriga
Chi Aurigae is a blue-white supergiant star in the constellation Auriga. At 3,589 light years away, it shines at an apparent visual magnitude of 4.79.
Chi Aurigae (HIP 25984)
Chi Aurigae is a blue-white supergiant star in the constellation Auriga. At 3,589 light years away, it shines at an apparent visual magnitude of 4.79. It is moving through the Galaxy at a speed of 18.5 km/s relative to the Sun.
Sky position: RA 5h 32.7m, Dec +32° 11.5'
Common designations: Chi Aurigae, 25 Aurigae, HR 1843, HD 36371, Gaia DR3 3448691754658000640, HIP 25984
Chi Aurigae has the spectral type B4Ia. B-type stars are hot (about 10,000 to 30,000 K), luminous and blue-white. They are massive, short-lived stars, typically only tens of millions of years old, and are common in young clusters and OB associations. Its luminosity class I marks it as a supergiant, among the most luminous and largest stars known.
How to find Chi Aurigae in the sky
Chi Aurigae lies in Auriga. With a declination of +32° 11.5', it is visible from the entire Northern Hemisphere and from the Southern Hemisphere down to about latitude 58° S. Observers poleward of latitude 58° N see it as circumpolar: it never sets. It is bright enough to see with the naked eye under dark skies. It is highest in the sky at local midnight around January, which makes the weeks around that month the best time to observe it.
Tabulated data for Chi Aurigae
Astrometry and spectroscopy
| Right Ascension (J2000) | 83.18197657° (5h 32.7m) |
| Declination (J2000) | 32.19202237° (+32° 11.5') |
| Galactic Longitude | 175.76636659° |
| Galactic Latitude | -0.61202337° |
| Proper motion RA | -0.81 mas/yr |
| Proper motion Dec | -3.15 mas/yr |
| Parallax | 0.91 ± 0.19 mas |
| Spectral Type | B4Ia |
| Radial Velocity | 7.27 km/s |
Photometry
| Band | Magnitude | Abs. Mag. |
|---|---|---|
| U | 4.68 | -5.53 |
| B | 5.15 | -5.06 |
| V | 4.79 | -5.42 |
| R | 4.42 | -5.79 |
| I | 4.15 | -6.06 |
| J | 4.25 | -5.96 |
| H | 4.08 | -6.13 |
| K | 4.00 | -6.21 |
Colour index B-V: +0.36
Derivations
- Heliocentric distance: 1,100.47 pc (3,589 light years) (21.0% margin of error)
- Absolute visual magnitude: -5.42
- Transverse velocity: 17.0 km/s
- Space velocity relative to the Sun: 18.5 km/s
- Galactic position (X, Y, Z): -1097.4 pc, 81.2 pc, -11.8 pc
- Galactic velocity (U, V, W): -8.0 km/s, -10.9 km/s, -12.6 km/s
Data: Extended Hipparcos Compilation (XHIP) and SIMBAD.