Astronomy:8 Herculis

From HandWiki
Short description: Star in the constellation Hercules
8 Herculis
Location of 8 Herculis (circled in red)
Observation data
Equinox J2000.0]] (ICRS)
Constellation Hercules[1]
Right ascension  16h 08m 46.6312s[2]
Declination +17° 12′ 20.292″[2]
Apparent magnitude (V) +6.13[1]
Characteristics
Evolutionary stage main sequence[3]
Spectral type A0Vnn[3]
B−V color index −0.003±0.005[1]
Astrometry
Radial velocity (Rv)−17.0±4.3[1] km/s
Proper motion (μ) RA: −18.098(35)[2] mas/yr
Dec.: −31.408(43)[2] mas/yr
Parallax (π)8.1684 ± 0.0430[2] mas
Distance399 ± 2 ly
(122.4 ± 0.6 pc)
Absolute magnitude (MV)+1.18[1]
Details
Mass2.52[4] M
Radius2.54[4] R
Luminosity55[4] L
Surface gravity (log g)4.03[4] cgs
Temperature9,863[4] K
Metallicity [Fe/H]+0.10[5] dex
Rotational velocity (v sin i)259[3] km/s
Age317[6] Myr
Other designations
8 Her, BD+17°2967, HD 145122, HIP 79102, SAO 101962[7]
Database references
SIMBADdata

8 Herculis or 8 Her is an A-type main-sequence star 399 light-years (122.4 parsecs) away in the constellation Hercules. It is also known as HD 145122. Because of its apparent magnitude, of 6.13 the star can be very faintly seen with the naked eye in excellent conditions.

Stellar properties

8 Herculis is a main-sequence star of spectral type A0Vnn. The nn indicates extremely nebulous spectral lines due to its rapid rotation. The star has about 2.5 times the mass, 2.5 times the radius, and 55 times the luminosity of the Sun. The star appears to have a similar metallicity to the Sun. At 317 million years old, it is modelled to be about 40% of the way through its main sequence life.[3]

References

  1. 1.0 1.1 1.2 1.3 1.4 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode2012AstL...38..331A  XHIP record for this object at VizieR.
  2. 2.0 2.1 2.2 2.3 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940  Gaia DR3 record for this source at VizieR.
  3. 3.0 3.1 3.2 3.3 Zorec, J.; Royer, F. (2012). "Rotational velocities of A-type stars. IV. Evolution of rotational velocities". Astronomy and Astrophysics 537: A120. doi:10.1051/0004-6361/201117691. Bibcode2012A&A...537A.120Z. 
  4. 4.0 4.1 4.2 4.3 4.4 Stassun, Keivan G. et al. (2019). "The Revised TESS Input Catalog and Candidate Target List". The Astronomical Journal 158 (4): 138. doi:10.3847/1538-3881/ab3467. Bibcode2019AJ....158..138S. 
  5. Huson, Dylan; Cowan, Indiana; Sizemore, Logan; Kounkel, Marina; Hutchinson, Brian (2025). "Gaia Net: Toward Robust Spectroscopic Parameters of Stars of all Evolutionary Stages". The Astrophysical Journal 984 (1): 58. doi:10.3847/1538-4357/adc2fa. Bibcode2025ApJ...984...58H. 
  6. Gontcharov, G. A. (2012). "Dependence of kinematics on the age of stars in the solar neighborhood". Astronomy Letters 38 (12): 771. doi:10.1134/S1063773712120031. Bibcode2012AstL...38..771G. 
  7. "8 Her". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=8+Her.