White subgiant · Cancer

Asellus Borealis

Also known as: γ Cancri (γ Cnc), HIP 42806

mag 4.7180 light-years

About

Asellus Borealis (γ Cancri) is a white subgiant of magnitude 4.7 in Cancer, about 180 light-years away.

Asellus Borealis is in the constellation Cancer.
Best evenings: around mid-March it is highest at about 9 pm (10 pm in summer time); a month earlier, two hours later.
Where on Earth: it is seen well, at least 10° up, from north of 59° S.

When it rises and sets tonight, how high it climbs and how much the Moon gets in the way are worked out in your browser for your place.

EyesNeeds a dark sky away from city lights.
Binoculars (10×50)A sharp point; binoculars bring out its colour and the fainter stars around it.
Telescope (6–8 inch)Still a point of light at any magnification — stars are too far away to show a disc. Low in the sky, bright stars twinkle and flash colours.

Stars look the same in any instrument: brighter and sharper, but never bigger.

Proper name	Asellus Borealis
Designation	γ Cancri (γ Cnc)
Hipparcos number	HIP 42806
Type	White subgiant
Spectral type	A1IV
Colour	WhiteB−V colour index 0.01
Magnitude	4.7The smaller the number, the brighter.
Distance	180 light-yearsThe light you see left it around 1850.
Proper motion	0.11″ per year across the sky
Constellation	Cancer
Right ascension (J2000)	08h 43m 17.2s
Declination (J2000)	+21° 28′ 07″