Omicron Scorpii, a white bright giant star in Scorpius
Omicron Scorpii is a white bright giant star in the constellation Scorpius. At 573 light years away, it shines at an apparent visual magnitude of 4.57.
Omicron Scorpii (HIP 80079)
Omicron Scorpii is a white bright giant star in the constellation Scorpius. At 573 light years away, it shines at an apparent visual magnitude of 4.57. It is moving through the Galaxy at a speed of 20.6 km/s relative to the Sun.
Sky position: RA 16h 20.6m, Dec -24° 10.2'
Common designations: Omicron Scorpii, 19 Scorpii, HR 6081, HD 147084, HIP 80079, Gaia DR3 6050060708908632960
Omicron Scorpii has the spectral type A5II. A-type stars are white stars with surface temperatures of roughly 7,500 to 10,000 K. Their spectra are dominated by strong hydrogen lines, and many of them rotate rapidly. Its luminosity class II marks it as a bright giant, more luminous than ordinary giants.
How to find Omicron Scorpii in the sky
Omicron Scorpii lies in Scorpius. With a declination of -24° 10.2', it is visible from the entire Southern Hemisphere and from the Northern Hemisphere up to about latitude 66° N. It is bright enough to see with the naked eye under dark skies. It is highest in the sky at local midnight around June, which makes the weeks around that month the best time to observe it.
Tabulated data for Omicron Scorpii
Astrometry and spectroscopy
| Right Ascension (J2000) | 245.15905738° (16h 20.6m) |
| Declination (J2000) | -24.16930430° (-24° 10.2') |
| Galactic Longitude | 352.32792331° |
| Galactic Latitude | 18.05029558° |
| Proper motion RA | -2.35 mas/yr |
| Proper motion Dec | -22.53 mas/yr |
| Parallax | 5.69 ± 0.24 mas |
| Spectral Type | A5II |
| Radial Velocity | -8.20 km/s |
Photometry
| Band | Magnitude | Abs. Mag. |
|---|---|---|
| U | 5.99 | -0.23 |
| B | 5.40 | -0.82 |
| V | 4.57 | -1.65 |
| R | 3.69 | -2.53 |
| I | 2.93 | -3.29 |
| J | 2.23 | -3.99 |
| H | 1.85 | -4.37 |
| K | 1.63 | -4.59 |
Colour index B-V: +0.83
Derivations
- Heliocentric distance: 175.69 pc (573 light years) (4.2% margin of error)
- Absolute visual magnitude: -1.65
- Transverse velocity: 18.9 km/s
- Space velocity relative to the Sun: 20.6 km/s
- Galactic position (X, Y, Z): 165.5 pc, -22.3 pc, 54.4 pc
- Galactic velocity (U, V, W): -6.3 km/s, -14.5 km/s, -13.1 km/s
Data: Extended Hipparcos Compilation (XHIP) and SIMBAD.