HR 4803, a yellow-white subgiant star in Hydra
HR 4803 is a yellow-white subgiant star in the constellation Hydra. At 111 light years away, it shines at an apparent visual magnitude of 5.41.
HR 4803 (HIP 61621)
HR 4803 is a yellow-white subgiant star in the constellation Hydra. At 111 light years away, it shines at an apparent visual magnitude of 5.41. It is moving through the Galaxy at a speed of 20.2 km/s relative to the Sun.
Sky position: RA 12h 37.7m, Dec -27° 8.3'
Common designations: HR 4803, HD 109799, HIP 61621, Gaia DR3 3496266901235127808
HR 4803 has the spectral type F2IV. F-type stars are yellow-white stars of about 6,000 to 7,500 K, slightly hotter and more massive than the Sun. Their hydrogen lines are weaker than in A stars and metal lines become prominent. 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 HR 4803 in the sky
HR 4803 lies in Hydra. With a declination of -27° 8.3', it is visible from the entire Southern Hemisphere and from the Northern Hemisphere up to about latitude 63° N. It is bright enough to see with the naked eye under dark skies. It is highest in the sky at local midnight around April, which makes the weeks around that month the best time to observe it.
Tabulated data for HR 4803
Astrometry and spectroscopy
| Right Ascension (J2000) | 189.42616407° (12h 37.7m) |
| Declination (J2000) | -27.13888553° (-27° 8.3') |
| Galactic Longitude | 299.17233305° |
| Galactic Latitude | 35.63259072° |
| Proper motion RA | 79.90 mas/yr |
| Proper motion Dec | -95.92 mas/yr |
| Parallax | 29.28 ± 0.08 mas |
| Spectral Type | F2IV |
| Radial Velocity | 0.61 km/s |
Photometry
| Band | Magnitude | Abs. Mag. |
|---|---|---|
| B | 5.74 | 3.07 |
| V | 5.41 | 2.74 |
| J | 4.76 | 2.09 |
| H | 4.63 | 1.96 |
| K | 4.54 | 1.87 |
Colour index B-V: +0.33
Derivations
- Heliocentric distance: 34.15 pc (111 light years) (0.3% margin of error)
- Absolute visual magnitude: 2.74
- Transverse velocity: 20.2 km/s
- Space velocity relative to the Sun: 20.2 km/s
- Galactic position (X, Y, Z): 13.5 pc, -24.2 pc, 19.9 pc
- Galactic velocity (U, V, W): 16.6 km/s, -1.1 km/s, -11.5 km/s
Data: Extended Hipparcos Compilation (XHIP) and SIMBAD.