Gama Crux

[jsmoraes]

Nearest red giant star to the Sun, distant 88.6 light years. 30% more massive than the Sun, has expanded to 84 times the Sun's radius. 1,500 times luminosity with 3,626 K of temperature. Reddish-orange and semi-regular variable

The binary system is only optical, the companion is about 400 light years distant from Earth
The CDC tells separation of 125.4 arcsec and 26 degrees at 1991. Wikipedia tells about 120.0 arcsec and 128 degress (?!)

CDC shows the last two positions and with different proper movement they will leave the optic binary appearance.

blue companion star:
RA movement: 0.005
DEC movement: -0.013

Gama Crux :
RA movement: 0.028
DEC movement: -0.264

GSO 305 mm - Canon T3 - Skyglow filter - 15 seg ISO 1600 - detalhe: 5 seg ISO 100

note: Taking the 2 stars on detail as reference to find the scale, we will have 0.766 arcsec/pixel. So, a bigger separation than showed in the photo.

Did I registered a new position of the companion stars , or it is only an error of scale ?

Normally the scale 0.65 arcsec/pixel work fine, with good math aproximation.

[xtreemchaos]

great image mate,nice imfo,thanks for sharing.  charl.