Gacrux

γ Crucis
Location of Gacrux, γ Crucis (circled)
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Crux
Right ascension 12h 31m 09.960s[1]
Declination −57° 06′ 47.568″[1]
Apparent magnitude (V) +1.64[2]
Characteristics
Evolutionary stage Red giant branch
Spectral type M3.5 III[3]
Apparent magnitude (J) −1.99
U−B color index +1.78[2]
B−V color index +1.59[2]
Variable type SRV[3]
Astrometry
Radial velocity (Rv)+20.6[4] km/s
Proper motion (μ) RA: +28.23 mas/yr[1]
Dec.: −265.08 mas/yr[1]
Parallax (π)36.83 ± 0.18 mas[1]
Distance88.6 ± 0.4 ly
(27.2 ± 0.1 pc)
Absolute magnitude (MV)−0.68±0.01[5]
Details
Mass1.5±0.2[6] M☉
Radius73[7] R☉
Luminosity830[6] L☉
Surface gravity (log g)0.75±0.02[6] cgs
Temperature3689±125[6] K
Other designations
Gacrux, γ Crucis, CD−56 4504, HD 108903, HIP 61084, HR 4763, SAO 240019, LTT 4752
Database references
SIMBADdata

Gacrux is the third-brightest star in the southern constellation of Crux, the Southern Cross. It has the Bayer designation Gamma Crucis, which is Latinised from γ Crucis and abbreviated Gamma Cru or γ Cru. With an apparent visual magnitude of +1.63,[8] it is the 26th brightest star in the night sky. A line from the two "Pointers", Alpha Centauri through Beta Centauri, leads to within 1° north of this star. Using parallax measurements made during the Hipparcos mission, it is located at a distance of 88.6 light-years (27.2 parsecs) from the Sun.[1] It is the nearest M-type red giant star to the Sun.[9]

  1. ^ a b c d e Cite error: The named reference aaa474_2_653 was invoked but never defined (see the help page).
  2. ^ a b c Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues. 2237: 0. Bibcode:2002yCat.2237....0D.
  3. ^ a b Cite error: The named reference mnras400_4_1945 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference scfs was invoked but never defined (see the help page).
  5. ^ R., Neuhäuser; G., Torres; M., Mugrauer; L., Neuhäuser, D.; J., Chapman; D., Luge; Matteo, Cosci (2022). "Colour evolution of Betelgeuse and Antares over two millennia, derived from historical records, as a new constraint on mass and age". Monthly Notices of the Royal Astronomical Society (in Italian). 516 (1). doi:10.1093/mnra (inactive 2024-06-21). hdl:10278/5003332. ISSN 0035-8711.{{cite journal}}: CS1 maint: DOI inactive as of June 2024 (link) CS1 maint: multiple names: authors list (link)
  6. ^ a b c d Cite error: The named reference kallinger was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Nielsen2023 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference clpl4 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference mnras350_1_365 was invoked but never defined (see the help page).