Kappa Eridani, a blue-white subgiant star in Eridanus
Kappa Eridani is a blue-white subgiant star in the constellation Eridanus. At 526 light years away, it shines at an apparent visual magnitude of 4.25.
Kappa Eridani (HIP 11407)
Kappa Eridani is a blue-white subgiant star in the constellation Eridanus. At 526 light years away, it shines at an apparent visual magnitude of 4.25. It is moving through the Galaxy at a speed of 29.8 km/s relative to the Sun.
Sky position: RA 2h 27.0m, Dec -47° 42.2'
Common designations: Kappa Eridani, HR 721, HD 15371, HIP 11407, Gaia DR3 4939205900704478592
Kappa Eridani has the spectral type B7IV. 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 IV marks it as a subgiant: it has exhausted hydrogen in its core and is beginning to expand toward the giant phase.
How to find Kappa Eridani in the sky
Kappa Eridani lies in Eridanus. With a declination of -47° 42.2', it is visible from the entire Southern Hemisphere and from the Northern Hemisphere up to about latitude 42° N. Observers poleward of latitude 42° S 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 November, which makes the weeks around that month the best time to observe it.
Tabulated data for Kappa Eridani
Astrometry and spectroscopy
| Right Ascension (J2000) | 36.74634213° (2h 27.0m) |
| Declination (J2000) | -47.70384066° (-47° 42.2') |
| Galactic Longitude | 267.12400591° |
| Galactic Latitude | -62.24034747° |
| Proper motion RA | 19.23 mas/yr |
| Proper motion Dec | -5.72 mas/yr |
| Parallax | 6.21 ± 0.14 mas |
| Spectral Type | B7IV |
| Radial Velocity | 25.50 km/s |
Photometry
| Band | Magnitude | Abs. Mag. |
|---|---|---|
| U | 3.61 | -2.43 |
| B | 4.11 | -1.93 |
| V | 4.25 | -1.79 |
| R | 4.28 | -1.76 |
| I | 4.41 | -1.63 |
| J | 4.53 | -1.51 |
| H | 4.66 | -1.38 |
| K | 4.60 | -1.43 |
Colour index B-V: -0.14
Derivations
- Heliocentric distance: 161.16 pc (526 light years) (2.2% margin of error)
- Absolute visual magnitude: -1.79
- Transverse velocity: 15.3 km/s
- Space velocity relative to the Sun: 29.8 km/s
- Galactic position (X, Y, Z): -3.8 pc, -75.0 pc, -142.6 pc
- Galactic velocity (U, V, W): -7.1 km/s, -24.1 km/s, -16.0 km/s
Data: Extended Hipparcos Compilation (XHIP) and SIMBAD.