Blue-white main-sequence star · Taurus

Asterope

Also known as: 21 Tauri (21 Tau), HIP 17579

mag 5.8370 light-years

About

Asterope (21 Tauri) is a blue-white main-sequence star of magnitude 5.8 in Taurus, about 370 light-years away.

Asterope is in the constellation Taurus.
Best evenings: around early January 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 55° 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	Asterope
Designation	21 Tauri (21 Tau)
Hipparcos number	HIP 17579
Type	Blue-white main-sequence star
Spectral type	B8V
Colour	WhiteB−V colour index −0.04
Magnitude	5.8The smaller the number, the brighter.
Distance	370 light-yearsThe light you see left it around 1650.
Proper motion	0.049″ per year across the sky
Constellation	Taurus
Right ascension (J2000)	03h 45m 54.5s
Declination (J2000)	+24° 33′ 16″