Zeta2 Scorpii

For other stars with this Bayer designation, see Zeta Scorpii.
ζ2 Scorpii

Reddish ζ2 Scorpii alongside the fainter ζ1 Scorpii to the south of NGC 6231
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Scorpius
Right ascension 16h 54m 35.00503s[1]
Declination −42° 21′ 40.7370″[1]
Apparent magnitude (V) 3.59 to 3.65[2]
Characteristics
Spectral type K4 III[3]
U−B color index +1.65[4]
B−V color index +1.37[4]
R−I color index +0.68[4]
Astrometry
Radial velocity (Rv)−18.7±0.9[5] km/s
Proper motion (μ) RA: −126.721 mas/yr[1]
Dec.: −228.837 mas/yr[1]
Parallax (π)24.2353 ± 0.1985 mas[1]
Distance135 ± 1 ly
(41.3 ± 0.3 pc)
Absolute magnitude (MV)0.30±0.09[6]
Details
Mass1.19±0.14[6] M☉
Radius21.0±1.6[6] R☉
Surface gravity (log g)1.84±0.10[6] cgs
Temperature4,169[6] K
Metallicity [Fe/H]+0.06[6] dex
Rotational velocity (v sin i)2.30[7] km/s
Age5.80±2.26[6] Gyr
Other designations
ζ2 Sco, Zeta2 Scorpii, Zeta2 Sco, CD−42 11646, CPD−42 7549, GC 22751, HD 152334, HIP 82729, HR 6271, LTT 6737, NLTT 43744, PPM 322371, SAO 227402.[8]
Database references
SIMBADdata

Zeta2 Scorpii (Zeta2 Sco, ζ2 Scorpii, ζ2 Sco) is a K-type orange giant star in the constellation of Scorpius.[8] It has an apparent visual magnitude which varies between 3.59 and 3.65,[2] and is located near the blue-white supergiant star ζ1 Scorpii in Earth's sky. In astronomical terms, ζ2 is much closer to the Sun and unrelated to ζ1 except for line-of sight co-incidence. ζ1 is about 6,000 light-years away and probably an outlying member of open star cluster NGC 6231 (also known as the "northern jewel box" cluster), whereas ζ2 is a mere 135 light-years distant and thus much less luminous in real terms. ζ2 can also be distinguished from its optical partner, ζ1, because of its orangish colour especially in long-exposure astrophotographs.

  1. ^ a b c d Cite error: The named reference GaiaDR3 was invoked but never defined (see the help page).
  2. ^ a b Cite error: The named reference nsv1 was invoked but never defined (see the help page).
  3. ^ Cite error: The named reference LandiDessy1966 was invoked but never defined (see the help page).
  4. ^ a b c Cite error: The named reference bsc2 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference rgcrv was invoked but never defined (see the help page).
  6. ^ a b c d e f g Cite error: The named reference aaa458_2_609 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference jofre was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference SIMBAD was invoked but never defined (see the help page).