| Constellation | |
 | |
| Abbreviation | PsA |
|---|---|
| Genitive | Piscis Austrini |
| Pronunciation | /ˈpaɪsɪs ɒsˈtraɪnəs/ or /ɒsˈtreɪlɪs/, genitive /ˈpaɪsɪs ɒˈstraɪnaɪ/ |
| Symbolism | the Southern Fish |
| Right ascension | 21h 27m 13.8661s–23h 06m 54.6033s[1] |
| Declination | −24.8250446°–−36.4592972°[1] |
| Quadrant | SQ4 |
| Area | 245 sq. deg. (60th) |
| Main stars | 7 |
| Bayer/Flamsteed stars | 21 |
| Stars with planets | 6 |
| Stars brighter than 3.00m | 1 |
| Stars within 10.00 pc (32.62 ly) | 3 |
| Brightest star | Fomalhaut (α PsA) (1.16m) |
| Messier objects | 0 |
| Meteor showers | ? |
| Bordering constellations | Capricornus Microscopium Grus Sculptor Aquarius |
| Visible at latitudes between +55° and −90°. Best visible at 21:00 (9 p.m.) during the month of October. | |
Piscis Austrinus is a constellation in the southern celestial hemisphere. The name is Latin for "the southern fish", in contrast with the larger constellation Pisces, which represents a pair of fish. Before the 20th century, it was also known as Piscis Notius. Piscis Austrinus was one of the 48 constellations listed by the 2nd-century astronomer Ptolemy, and it remains one of the 88 modern constellations. The stars of the modern constellation Grus once formed the "tail" of Piscis Austrinus. In 1597 (or 1598), Petrus Plancius carved out a separate constellation and named it after the crane.
It is a faint constellation, containing only one star brighter than 4th magnitude: Fomalhaut, which is 1st magnitude and the 18th-brightest star in the night sky. Fomalhaut is surrounded by a circumstellar disk, and possibly hosts a planet. Other objects contained within the boundaries of the constellation include Lacaille 9352, one of the brightest red dwarf stars in the night sky (though still too faint to see with the naked eye); and PKS 2155-304, a BL Lacertae object that is one of the optically brightest blazars in the sky.