The Constellations Octans, Indus, and Pavo
South Circumpolar Constellations Including the South Celestial Pole
Sep 29, 2009
Octans the Octant, Indus the Indian, and Pavo the Peacock are all constellations deep in the Southern Hemisphere with mostly dim stars.
The Constellation Octans the Octant
The most important fact about Octans is that it contains the South Celestial Pole. In the Northern Hemisphere, a star marks the location of the North Celestial Pole. Polaris is the Pole Star and helps outdoorspeople navigate at night. But in the Southern Hemisphere there is no star to mark the location around which all the stars seem to revolve. Nevertheless, the constellation Octans the Octant is named for an old-time navigational instrument. The constellation Crux points toward the pole and most use that as a guide instead.
In Octans, however, there is a galaxy that is pretty nearly at the location of the South Celestial Pole. It's just not very bright. The galaxy is given the fitting name of Polarissima Australis and it shines at magnitude 13.5.
The brightest star in Octans is only magnitude 3.73 and is known as Nu Octantis. It lies 69 light-years away.
The Constellation Indus the Indian
Indus was created in the 16th century by Petrus Plancius. The name "The Indian" may have referred to either people of Asia or the Americas. The constellation itself has no discernible shape. It has only dim stars and is made up of the dark sky in between the constellations Tucana and Pavo. It also borders Octans.
Indus's brightest star in magnitude 3.11. The star, named Alpha Indi, lies 101 light-years away.
The Constellation Pavo the Peacock
Pavo the Peacock is found next to Octans and Indus. Pavo has one bright star and a handful of moderately bright stars. Its brightest star is Alpha Pavonis, sometimes also called Peacock. Alpha Pavonis is magnitude 1.94 and lies 183 light-years away. Beta Pavonis is magnitude 3.42 and lies 138 light-years away. Delta Pavonis is 3 1/2 degrees from Beta and shines almost as bright, at magnitude 3.55. Delta is a double star, with the brighter member lying 20 light-years away and its optical partner lying a whopping 1,144 light-years away.
Near the border with the constellation Ara is Eta Pavonis at magnitude 3.61 and a distance of 371 light-years. Near the border with Octans is Epsilon Pavonis at magnitude 3.97 and a distance of 106 light-years.
Pavo contains part of the Milky Way and therefore is home to many nebulae. However, most of these are quite dim. One beautiful exception to the many dim deep-sky objects in Pavo is NGC 6752. This globular cluster shines at a bright magnitude 5.4, making it easily reachable with binoculars. NGC 6744 is a decent galactic target for telescopes. This spiral galaxy shines at magnitude 9 from a distance of 25 million light-years.
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