Psi Eridani, a blue-white subgiant star in Eridanus
Psi Eridani is a blue-white subgiant star in the constellation Eridanus. At 907 light years away, it shines at an apparent visual magnitude of 4.78.
Psi Eridani (HIP 23364)
Psi Eridani is a blue-white subgiant star in the constellation Eridanus. At 907 light years away, it shines at an apparent visual magnitude of 4.78. It is moving through the Galaxy at a speed of 22.7 km/s relative to the Sun.
Sky position: RA 5h 1.4m, Dec -7° 10.4'
Common designations: Psi Eridani, 65 Eridani, HR 1617, HD 32249, Gaia DR3 3187058564780234496, HIP 23364
Psi Eridani has the spectral type B3IV. 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 Psi Eridani in the sky
Psi Eridani lies in Eridanus. With a declination of -7° 10.4', it is visible from the entire Southern Hemisphere and from the Northern Hemisphere up to about latitude 83° N. 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 Psi Eridani
Astrometry and spectroscopy
| Right Ascension (J2000) | 75.35977409° (5h 1.4m) |
| Declination (J2000) | -7.17396479° (-7° 10.4') |
| Galactic Longitude | 206.59364898° |
| Galactic Latitude | -27.68912299° |
| Proper motion RA | 1.31 mas/yr |
| Proper motion Dec | 7.00 mas/yr |
| Parallax | 3.60 ± 0.14 mas |
| Spectral Type | B3IV |
| Radial Velocity | 20.70 km/s |
Photometry
| Band | Magnitude | Abs. Mag. |
|---|---|---|
| U | 3.87 | -3.35 |
| B | 4.61 | -2.61 |
| V | 4.78 | -2.44 |
| J | 5.18 | -2.04 |
| H | 5.29 | -1.93 |
| K | 5.28 | -1.94 |
Colour index B-V: -0.17
Derivations
- Heliocentric distance: 278.06 pc (907 light years) (4.0% margin of error)
- Absolute visual magnitude: -2.44
- Transverse velocity: 9.4 km/s
- Space velocity relative to the Sun: 22.7 km/s
- Galactic position (X, Y, Z): -220.2 pc, -110.2 pc, -129.2 pc
- Galactic velocity (U, V, W): -22.1 km/s, -2.7 km/s, -4.5 km/s
Data: Extended Hipparcos Compilation (XHIP) and SIMBAD.