Delta2 Gruis

For other stars with this Bayer designation, see δ Gruis.
Delta2 Gruis

A light curve for Delta2 Gruis, plotted from Hipparcos data[1]
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Grus
Right ascension 22h 29m 45.43402s[2]
Declination −43° 44′ 57.1968″[2]
Apparent magnitude (V) 3.99 - 4.20[3]
Characteristics
Spectral type M4.5 IIIa[4]
U−B color index +1.71[5]
B−V color index +1.57[5]
Variable type LB?[3]
Astrometry
Radial velocity (Rv)+2.7±0.8[6] km/s
Proper motion (μ) RA: −14.08[2] mas/yr
Dec.: +2.57[2] mas/yr
Parallax (π)9.1556 ± 0.1885 mas[7]
Distance356 ± 7 ly
(109 ± 2 pc)
Absolute magnitude (MV)−0.90±0.05[4]
Details
Radius97[8] R☉
Luminosity1,359[8] L☉
Surface gravity (log g)+0.45[8] cgs
Temperature3,560[8] K
Rotational velocity (v sin i)+4.5±0.8[9] km/s
Other designations
δ2 Gru, CD−44° 14935, HD 213080, HIP 111043, HR 8560, SAO 231161, WDS J22298-4345A[10]
Database references
SIMBADdata

Delta2 Gruis, Latinized from δ2 Gruis, is a solitary,[11] red-hued star in the southern constellation of Grus. It is visible to the naked eye with an apparent visual magnitude of about 4. Based upon an annual parallax shift of 9.88 mas as seen from the Earth, the star is located around 330 light years from the Sun. It is moving further away from the Sun with a radial velocity of +3 km/s.[6]

This is an evolved red giant star with a stellar classification of M4.5 IIIa.[4] It is a pulsating variable with multiple periods, including 20.6, 24.1, 24.5, and 32.3 days. The strongest period is 33.3 days with an amplitude of 0.043 magnitude.[12] It has a magnitude 9.71 visual companion at an angular separation of 60.4 arc seconds along a position angle of 210°, as of 2013.[13]

  1. ^ Cite error: The named reference CDS was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference vanLeeuwen2007 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference gcvs was invoked but never defined (see the help page).
  4. ^ a b c Cite error: The named reference park2013 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Nicolet1978 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. ^ Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
  8. ^ a b c d Cite error: The named reference McDonald2017 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference Zamanov2008 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference tabur2009 was invoked but never defined (see the help page).
  13. ^ Cite error: The named reference WDSC2014 was invoked but never defined (see the help page).