18 Scorpii

18 Scorpii
Diagram showing star positions and boundaries of the Scorpius constellation and its surroundings
Location of 18 Scorpii (circled)
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Scorpius
Right ascension 16h 15m 37.27028s[1]
Declination –08° 22′ 09.9821″[1]
Apparent magnitude (V) 5.503[2]
Characteristics
Spectral type G2 Va[3]
U−B color index +0.18[4]
B−V color index +0.64[4]
Variable type Sun-like[5]
Astrometry
Radial velocity (Rv)11.71±0.12[1] km/s
Proper motion (μ) RA: 232.230 mas/yr[1]
Dec.: −495.378 mas/yr[1]
Parallax (π)70.7371 ± 0.0631 mas[1]
Distance46.11 ± 0.04 ly
(14.14 ± 0.01 pc)
Absolute magnitude (MV)4.77[2]
Details[6]
Mass1.03±0.03 M☉
Radius1.010±0.009 R☉
Luminosity1.0438±0.0120 L☉
Surface gravity (log g)4.448±0.012 cgs
Temperature5,817±4 K
Metallicity [Fe/H]0.04±0.024[7] dex
Rotation22.7±0.5 d[8]
Age2.9±0.5[9] Gyr
5.64 or 7.18 Gyr
Other designations
BD−07°4242, GC 21864, GJ 616, HD 146233, HIP 79672, HR 6060, SAO 141066, CCDM 16156-0822[4]
Database references
SIMBADdata
Exoplanet Archivedata

18 Scorpii is a solitary star located at a distance of some 46.1 light-years (14.13 parsecs) from the Sun at the northern edge of the Scorpius constellation. It has an apparent visual magnitude of 5.5,[2] which is bright enough to be seen with the naked eye outside of urban areas. The star is drifting further away with a radial velocity of +11.6.[2]

18 Scorpii has some physical properties in common with the Sun, a G-type star. Cayrel de Strobel (1996) included it in her review of the stars most similar to the Sun,[10] and Porto de Mello & da Silva (1997) identified it as a younger solar twin.[11][12] Some scientists therefore believe the prospects for life in its vicinity are good.

  1. ^ a b c d e Cite error: The named reference GaiaDR3 was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference aaa418_989 was invoked but never defined (see the help page).
  3. ^ Cite error: The named reference Keenan1989 was invoked but never defined (see the help page).
  4. ^ a b c Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference aj138_1_312 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference Bazot2018 was invoked but never defined (see the help page).
  7. ^ Meléndez, Jorge; Ramírez, Iván (2007). "HIP 56948: A Solar Twin with a Low Lithium Abundance". The Astrophysical Journal. 669 (2): L89–L92. arXiv:0709.4290. Bibcode:2007ApJ...669L..89M. doi:10.1086/523942.
  8. ^ Cite error: The named reference baas42_333 was invoked but never defined (see the help page).
  9. ^ "Identification of oldest solar twin may help locate rocky exoplanets". NASA. August 28, 2013. Retrieved 2020-11-10.
  10. ^ Cite error: The named reference aar7_3_243 was invoked but never defined (see the help page).
  11. ^ "The life cycle of a Sun-like star (annotated)]". ESO. 28 August 2013. Retrieved 2020-11-10.
  12. ^ Cite error: The named reference apj482_2_L89 was invoked but never defined (see the help page).