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Sterope I, 21 Tauri

Proper NamesAsterope, Sterope I
Bayer DesignationNone
Flamsteed Number21 Tauri
HR (BSC)1151
Right Ascension3h 45m 54s
Declination+24° 33' 16"
Distance440 light years
135 parsecs
MagnitudeApparent: +5.8
Absolute: +0.5
Spectral ClassB8 Blue Dwarf
Optimum VisibilityNovember / December
NotesAsterope forms a double star with its near neighbour to the southeast, though the two stars do not form a binary system. This neighbour is designated 22 Tauri, or Sterope. Confusingly, Asterope itself was also traditionally known as Sterope, and the pair are therefore sometimes dessignated as Sterope I (Asterope or 21 Tauri) and Sterope II (22 Tauri).

The northernmost of the named Pleiades is, like all the members of this cluster, a young and hot blue dwarf star. Asterope's magnitude of +5.8 puts it on the edge of naked eye visibility.

Imagery provided by Aladin sky atlas


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