V1073 Scorpii
Variable star in the constellation Scorpius
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V1073 Scorpii is a variable star in the constellation Scorpius. It has a non-Greek Bayer designation of k Scorpii. The star has a blue-white hue and is visible to the naked eye with an apparent visual magnitude that fluctuates around +4.8. Parallax measurements yield a distance estimate of approximately 2,920 ly (896 pc) from the Sun, and it is drifting further away with a radial velocity of +7 km/s.[6] It has an absolute magnitude of −6.8[7]
  | |
| Observation data Epoch J2000.0 Equinox ICRS | |
|---|---|
| Constellation | Scorpius |
| Right ascension | 17h 04m 49.35254s[1] |
| Declination | −34° 07′ 22.5483″[1] |
| Apparent magnitude (V) | +4.82 to 4.88[2] |
| Characteristics | |
| Spectral type | B0.7 Ia[3] |
| U−B color index | −0.69[4] |
| B−V color index | +0.26[4] |
| Variable type | α Cyg[5] |
| Astrometry | |
| Radial velocity (Rv) | 7.00[6] km/s |
| Proper motion (μ) | RA: +0.600[1] mas/yr Dec.: −2.015[1] mas/yr |
| Parallax (π) | 1.1161±0.2097 mas[1] |
| Distance | approx. 2,900 ly (approx. 900 pc) |
| Absolute magnitude (MV) | −6.8[7] |
| Details | |
| Mass | 28[8] 19.7±1.0[9] 27.11±8.39[10] M☉ |
| Radius | 36.0[7][3] R☉ |
| Luminosity | 302,000[7] L☉ |
| Surface gravity (log g) | 2.70[8] 2.65[3] cgs |
| Temperature | 20,800[10] 22,500[3] K |
| Rotational velocity (v sin i) | 47[8] km/s |
| Age | 4.2±0.3[9] Myr |
| Other designations | |
| k Sco, V1073 Sco, CD−33°11706, HD 154090, HIP 83574, HR 6334, SAO 208377[11] | |
| Database references | |
| SIMBAD | data |
This object is a massive supergiant star with a stellar classification of B0.7 Ia.[3] It was found to be a variable star in 1996, when the Hipparcos data was analysed. It was given its variable star designation in 1999.[13] It is an α Cygni variable;[14] a supergiant that pulsates erratically on a timescale of days to weeks with an amplitude of less than a tenth of a magnitude. A simplistic fitting of Hipparcos data suggests a periodicity of 1.6 days.[15][12] The star is around 4.2[9] million years old and is a member of the Upper Scorpius subgroup of the Sco OB2 association.[16] V1073 Scorpii is considered a "runaway" star, showing a peculiar velocity of more than 37 km/s relative to its neighbourhood.[9] No bow shock has been detected from its motion through interstellar space.[17]
V1073 Sco has a 14th magnitude visual companion,[18] which is an unrelated background object according to its Gaia Data Release 2 parallax.[19]