- Gamma Crucis
Starbox begin
name = Gamma CrucisStarbox observe
epoch =J2000.0
equinox =J2000.0
constell =Crux
ra = RA|12|31|9.9
dec = DEC|-57|06|48
appmag_v = 1.59Starbox character
class = M4III
r-i =
v-r =
b-v = 1.60
u-b = 1.77
variable = Starbox astrometry
radial_v = +20.6
prop_mo_ra = 27.94
prop_mo_dec = -264.33
parallax = 37.09
p_error = 0.67
parallax_footnote =
dist_ly =
dist_pc =
space_v_u =
space_v_v =
space_v_w =
absmag_v = -0.56Starbox detail
source =
mass = 3
radius = 113
gravity =
luminosity = 1,500
luminosity_bolometric =
luminosity_visual =
temperature = 3,400
metal =
rotation =
age = Starbox catalog
names = CD-56°4504, Gacrux, Gamma Crucis, GJ 470, HD 108903, HIP 61084, HR 4763, LTT 4752, SAO 240019Starbox reference
Simbad = HD 108903
ARICNS =Gamma Crucis (γ Cru / γ Crucis), often named Gacrux, is a
red giant star approximately 88light-year s away in theconstellation ofCrux . The star is the third-brightest star in Crux (the Southern Cross) and one of the brightest stars in the nighttime sky. A line from the two "Pointers",Alpha Centauri throughBeta Centauri leads to within a few degrees of this star.Physical Properties
Gamma Crucis is a
binary star , 88light year s distant from Earth. The main star is ofapparent magnitude +1.6 and spectral classification M4 III. Its +6.4 magnitude white companion star (spectral classification A3) lies about 2 arcminutes away at an angle of 128 degrees from the main star, and can be observed withbinoculars . But it is only an optical companion, who is about 400 light years distant from Earth. The colour of Gamma Crucis A is a prominent reddish-orange, well in keeping with its spectral classification.Gacrux has evolved off of the
main sequence to become ared giant star, and may even be evolving past thehelium -burning stage. It is also semi-variable with a period of about 90 days. The atmosphere is enriched withbarium , which is likely due to neutron emission from an undetectedwhite dwarf companion.Etymology
Since Gamma Crucis is at roughly −60°
declination , it is only visible south of theTropic of Cancer and likely never received an ancient traditional name. Thus, "Gacrux" is simply a combination of the "Ga" in Gamma plus Crux. It is known as 十字架一 ('First Star of the Cross') in Chinese.See also
*
Aldebaran
*Alpha Crucis
*Beta Crucis
*Betelgeuse External links
*
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