25 Scorpii

25 Scorpii (abbreviated to 25 Sco) is a star in the zodiac constellation of Scorpius, located about 920 light years away from the Sun. Its apparent magnitude is 6.71,[2] so its apparent brightness is at the limit of human eyesight and can only be seen under excellent conditions, according to the Bortle scale. The object is moving closer to the Earth with a heliocentric radial velocity of −1.3 km/s.[1] It is a proposed member of the Scorpius-Centaurus association.[7]

25 Scorpii

Observation data Epoch J2000      Equinox J2000
Constellation	Scorpius
Right ascension	16^h 46^m 51.34498^s[1]
Declination	−25° 31′ 42.8647″[1]
Apparent magnitude (V)	6.71[2]
Characteristics
Spectral type	K0 II[3]
B−V color index	+1.18[2]
Astrometry
Radial velocity (Rv)	−1.31±0.14[1] km/s
Proper motion (μ)	RA: −4.165[1] mas/yr Dec.: −15.630[1] mas/yr
Parallax (π)	3.5599 ± 0.0433[1] mas
Distance	920 ± 10 ly (281 ± 3 pc)
Absolute magnitude (MV)	0.09[4]
Details
Mass	2.075+0.709 −0.993[5] M☉
Radius	12.719+2.800 −1.943[5] R☉
Luminosity	135[6] L☉
Surface gravity (log g)	2.509+0.135 −0.351[5] cgs
Temperature	4777+76 −133[5] K
Metallicity [Fe/H]	−0.031+0.150 −0.480[5] dex
Other designations
25 Sco, CD−25° 11667, FK5 5482, HD 151179, HIP 82140, HR 6225, SAO 184630
Database references
SIMBAD	data

This is an evolved bright giant with a spectral type of K0 II.[3] It is about two times more massive and over twelve times wider than the Sun.[5] The star is radiating 135[6] times the Sun's luminosity from its photosphere at an effective temperature of about 4,700 K.[5]

References

1. Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
2. Corben, P. M. (1971). "Photoelectric Magnitudes and Colours for Bright Southern Stars". Monthly Notes of the Astron. Soc. Southern Africa. 70: 37. Bibcode:1971MNSSA..30...37C.
3. Houk, N.; Swift, C. (1999). "Michigan catalogue of two-dimensional spectral types for the HD Stars, Vol. 5". Michigan Spectral Survey. 5: 0. Bibcode:1999MSS...C05....0H.
4. Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015.
5. Huber, Daniel; Bryson, Stephen T.; Haas, Michael R.; Barclay, Thomas; Barentsen, Geert; Howell, Steve B.; Sharma, Sanjib; Stello, Dennis; Thompson, Susan E. (2016). "The K2 Ecliptic Plane Input Catalog (EPIC) and Stellar Classifications of 138,600 Targets in Campaigns 1-8". The Astrophysical Journal Supplement Series. 224 (1): 2. arXiv:1512.02643. Bibcode:2016ApJS..224....2H. doi:10.3847/0067-0049/224/1/2.
6. Sartori, M. J.; Lépine, J. R. D.; Dias, W. S. (2003). "Formation scenarios for the young stellar associations between galactic longitudes l $\mathsf{= 280\degr{-}360\degr}$". Astronomy & Astrophysics. 404 (3): 913. arXiv:astro-ph/0304426. Bibcode:2003A&A...404..913S. doi:10.1051/0004-6361:20030581.
7. Murphy, Simon J.; et al. (November 2015). "New members of the TW Hydrae Association and two accreting M-dwarfs in Scorpius-Centaurus". Monthly Notices of the Royal Astronomical Society. 453 (3): 2220–2231. arXiv:1507.08002. Bibcode:2015MNRAS.453.2220M. doi:10.1093/mnras/stv1745.