Yellow main-sequence star · Cassiopeia

Achird

Also known as: η Cassiopeiae (η Cas), HIP 3821

mag 3.519 light-years

About

Achird (η Cassiopeiae) is a yellow main-sequence star of magnitude 3.5 in Cassiopeia, about 19 light-years away.

Achird is in the constellation Cassiopeia.
Best evenings: around mid-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 22° 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.

EyesVisible from the suburbs on a clear night, but lost in bright city skies.
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	Achird
Designation	η Cassiopeiae (η Cas)
Hipparcos number	HIP 3821
Type	Yellow main-sequence star
Spectral type	G0V SB
Colour	YellowB−V colour index 0.59
Magnitude	3.5The smaller the number, the brighter.
Distance	19 light-yearsThe light you see left it around 2007.
Proper motion	1.22″ per year across the sky
Constellation	Cassiopeia
Right ascension (J2000)	00h 49m 05.7s
Declination (J2000)	+57° 48′ 55″