Eta2 Coronae Australis

For other stars with this Bayer designation, see η Coronae Australis.
η2 Coronae Australis
Location of Eta2 CrA (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Corona Australis
Right ascension 18h 49m 34.99649s[1]
Declination −43° 26′ 02.7522″[1]
Apparent magnitude (V) 5.59±0.01[2]
Characteristics
Evolutionary stage main sequence star[3]
Spectral type B9 IV[4]
B−V color index −0.08[5]
Astrometry
Radial velocity (Rv)−23.0±4.3[6] km/s
Proper motion (μ) RA: −2.963 mas/yr[1]
Dec.: −25.374 mas/yr[1]
Parallax (π)4.25 ± 0.1158 mas[1]
Distance770 ± 20 ly
(235 ± 6 pc)
Absolute magnitude (MV)−0.24[7]
Details
Mass3.23±0.08[3] M☉
Radius5.82±0.31[8] R☉
Luminosity171+20
−18[3] L☉
Surface gravity (log g)3.47[9] cgs
Temperature10,940±255[3] K
Metallicity [Fe/H]+0.06[9] dex
Rotational velocity (v sin i)30[10] km/s
Age213[11] Myr
Other designations
Eta2 CrA, 26 G. Coronae Australis[12], CD−43°12854, CPD−43°8779, GC 25766, HD 173861, HIP 92382, HR 7068, SAO 229307[13]
Database references
SIMBADdata

Eta2 Coronae Australis (Eta2 CrA), Latinized from η2 Coronae Australis, is a solitary star[14] located in the southern constellation of Corona Australis. It is visible to the naked eye as a dim, blue-white hued star with an apparent visual magnitude of 5.59.[2] Gaia DR3 parallax measurements imply a distance of 770 light years from the Solar System,[1] but it is drifting closer with a radial velocity of −23 km/s.[6] At its current distance Eta2 CrA's brightness is diminished by 0.27 magnitudes due to stellar extinction from interstellar dust[15] and it has an absolute magnitude of −0.24.[7]

This object has a stellar classification of B9 IV,[4] indicating that is a slightly evolved a B-type subgiant star. However, Zorec & Royer (2012) model it to be a dwarf star that has completed 80.4% of its main sequence lifetime.[3] It is estimated to be 213 million years old[11] and it has a mass that is 3.23 times that of the Sun.[3] The star is radiating 171 times the luminosity of the Sun[3] from its photosphere 5.82 times the radius of the Sun[8] at an effective temperature of 10,940 K.[3] Eta2 CrA has a near-solar metallicity at [Fe/H] = +0.06[9] and spins modestly with a projected rotational velocity of 30 km/s.[10] Some earlier catalogues listed the object as a chemically peculiar star but that status is now considered to be doubtful.[16]

  1. ^ a b c d e Cite error: The named reference GaiaDR3 was invoked but never defined (see the help page).
  2. ^ a b Cite error: The named reference Tycho2000 was invoked but never defined (see the help page).
  3. ^ a b c d e f g h Cite error: The named reference Zorec2012 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Houk1978 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference Corben was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Gontcharov2006 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference Kervella2004 was invoked but never defined (see the help page).
  9. ^ a b c Cite error: The named reference Anders2019 was invoked but never defined (see the help page).
  10. ^ a b Cite error: The named reference Levato2004 was invoked but never defined (see the help page).
  11. ^ a b Cite error: The named reference Gontcharov2012 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference Gould1879 was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  15. ^ Cite error: The named reference Gontcharov2017 was invoked but never defined (see the help page).
  16. ^ Cite error: The named reference Renson2009 was invoked but never defined (see the help page).