Right ascension 10 11 00.8 Redshift 324 ± 2 km/s Apparent size (V) 5′.9 × 4′.9 Constellation Sextans | Declination −04° 41′ 34″ Type IBm Magnitude 11.9 Apparent magnitude (V) 11.9 | |
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Distance 4.31 ± 0.13 Mly (1.32 ± 0.04 Mpc) Similar Sextans B, NGC 3109, Wolf–Lundmark–Melotte, Leo A, IC 1613 | ||
Sextans A (also known as UGCA 205) is a tiny dwarf irregular galaxy. It spans about 5000 light-years across, and is located at 4.3 million light-years away, in the outskirts of the Local Group of galaxies, which includes the Milky Way galaxy, and to which Sextans A may or may not belong.
Sextans A has a peculiar square shape. Massive short-lived stars exploded in supernovae that caused more star formation, triggering yet more supernovae, ultimately resulting in an expanding shell. Young blue stars now highlight areas and shell edges high in current star formation, which from the perspective of observers on Earth appears roughly square.
References
Sextans A Wikipedia(Text) CC BY-SA