k Scorpii, a blue-white supergiant star in Scorpius
k Scorpii is a blue-white supergiant star in the constellation Scorpius. At 3,532 light years away, it shines at an apparent visual magnitude of 4.87.
k Scorpii (HIP 83574)
k Scorpii is a blue-white supergiant star in the constellation Scorpius. At 3,532 light years away, it shines at an apparent visual magnitude of 4.87. It is moving through the Galaxy at a speed of 14.2 km/s relative to the Sun.
Sky position: RA 17h 4.8m, Dec -34° 7.4'
Common designations: k Scorpii, V1073 Scorpii, HR 6334, HD 154090, HIP 83574, Gaia DR3 5978207447948294016
k Scorpii has the spectral type B2Iab. 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 I marks it as a supergiant, among the most luminous and largest stars known.
How to find k Scorpii in the sky
k Scorpii lies in Scorpius. With a declination of -34° 7.4', it is visible from the entire Southern Hemisphere and from the Northern Hemisphere up to about latitude 56° N. Observers poleward of latitude 56° 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 July, which makes the weeks around that month the best time to observe it.
Tabulated data for k Scorpii
Astrometry and spectroscopy
| Right Ascension (J2000) | 256.20563190° (17h 4.8m) |
| Declination (J2000) | -34.12292824° (-34° 7.4') |
| Galactic Longitude | 350.82871459° |
| Galactic Latitude | 4.28504245° |
| Proper motion RA | 1.27 mas/yr |
| Proper motion Dec | -2.05 mas/yr |
| Parallax | 0.92 ± 0.11 mas |
| Spectral Type | B2Iab |
| Radial Velocity | 7.00 km/s |
Photometry
| Band | Magnitude | Abs. Mag. |
|---|---|---|
| U | 4.44 | -5.73 |
| B | 5.13 | -5.04 |
| V | 4.87 | -5.30 |
| R | 4.59 | -5.58 |
| I | 4.42 | -5.75 |
| J | 4.25 | -5.92 |
| H | 4.19 | -5.98 |
| K | 4.13 | -6.04 |
Colour index B-V: +0.26
Derivations
- Heliocentric distance: 1,082.84 pc (3,532 light years) (11.4% margin of error)
- Absolute visual magnitude: -5.30
- Transverse velocity: 12.4 km/s
- Space velocity relative to the Sun: 14.2 km/s
- Galactic position (X, Y, Z): 1066.0 pc, -172.1 pc, 80.9 pc
- Galactic velocity (U, V, W): 7.0 km/s, -5.6 km/s, -11.0 km/s
Data: Extended Hipparcos Compilation (XHIP) and SIMBAD.