Blue-white star · Andromeda

Alpheratz

Also known as: α Andromedae (α And), HIP 677

mag 2.197 light-years

About

Alpheratz (α Andromedae) is a blue-white star of magnitude 2.1 in Andromeda, about 97 light-years away.

Alpheratz is in the constellation Andromeda.
Best evenings: around early November 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 51° S.
Star patterns: Great Square of Pegasus.

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.

EyesEasy, even from town.
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	Alpheratz
Designation	α Andromedae (α And)
Hipparcos number	HIP 677
Type	Blue-white star
Spectral type	B9p
Colour	WhiteB−V colour index −0.04
Magnitude	2.1The smaller the number, the brighter.
Distance	97 light-yearsThe light you see left it around 1929.
Proper motion	0.21″ per year across the sky
Constellation	Andromeda
Right ascension (J2000)	00h 08m 23.3s
Declination (J2000)	+29° 05′ 25″