Phi-2 Orionis, a yellow giant star in Orion
Phi-2 Orionis is a yellow giant star in the constellation Orion. At 114 light years away, it shines at an apparent visual magnitude of 4.09.
Phi-2 Orionis (HIP 26366)
Phi-2 Orionis is a yellow giant star in the constellation Orion. At 114 light years away, it shines at an apparent visual magnitude of 4.09. It is moving through the Galaxy at a speed of 112.4 km/s relative to the Sun.
Sky position: RA 5h 36.9m, Dec +9° 17.4'
Common designations: Phi-2 Orionis, 40 Orionis, HR 1907, HD 37160, HIP 26366, Gaia DR3 3334901543952614528
Phi-2 Orionis has the spectral type G9.5IIIbFe-2.5. G-type stars are yellow stars of about 5,300 to 6,000 K, the same class as the Sun. Their spectra show strong lines of ionized calcium and many metals. Its luminosity class III marks it as a giant: an evolved star that has left the main sequence and swollen to many times its original size.
How to find Phi-2 Orionis in the sky
Phi-2 Orionis lies in Orion. With a declination of +9° 17.4', it is visible from the entire Northern Hemisphere and from the Southern Hemisphere down to about latitude 81° S. 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 Phi-2 Orionis
Astrometry and spectroscopy
| Right Ascension (J2000) | 84.22661905° (5h 36.9m) |
| Declination (J2000) | 9.29067125° (+9° 17.4') |
| Galactic Longitude | 195.84489920° |
| Galactic Latitude | -11.94707491° |
| Proper motion RA | 98.30 mas/yr |
| Proper motion Dec | -305.02 mas/yr |
| Parallax | 28.67 ± 0.19 mas |
| Spectral Type | G9.5IIIbFe-2.5 |
| Radial Velocity | 99.08 km/s |
Photometry
| Band | Magnitude | Abs. Mag. |
|---|---|---|
| U | 5.70 | 2.99 |
| B | 5.04 | 2.33 |
| V | 4.09 | 1.38 |
| R | 3.33 | 0.62 |
| I | 2.78 | 0.07 |
| J | 2.34 | -0.37 |
| H | 1.77 | -0.94 |
| K | 1.68 | -1.03 |
Colour index B-V: +0.95
Derivations
- Heliocentric distance: 34.88 pc (114 light years) (0.6% margin of error)
- Absolute visual magnitude: 1.38
- Transverse velocity: 53.0 km/s
- Space velocity relative to the Sun: 112.4 km/s
- Galactic position (X, Y, Z): -32.8 pc, -9.3 pc, -7.2 pc
- Galactic velocity (U, V, W): -76.8 km/s, -75.6 km/s, -31.8 km/s
Data: Extended Hipparcos Compilation (XHIP) and SIMBAD.