The Indus Constellation

Indus is a constellation in the southern sky created in the late sixteenth century. The constellation was created by Petrus Plancius from the observations of Pieter Dirkszoon Keyser and Frederick de Houtman. The first depiction of this constellation in a celestial atlas was in Johann Bayer’s Uranometria of 1603. Plancius portrayed the figure as a nude male with arrows in both hands but no bow. Indus takes up 294.006 sq. degrees of the night sky which equates to 0.71% of the night sky. Indus is the 49th largest in terms of size in the night sky and can be seen at latitudes between +15° and -90°. The neighbouring constellations are Grus, Microscopium, Octans, Pavo, Sagittarius,  Telescopium and Tucana. Indus belongs to the Johann Bayer family of constellations, along with Apus, Chamaeleon, Dorado, Grus, Hydrus, Musca, Pavo, Phoenix, Tucana and Volans.

Indus does not contain any bright stars. Alpha Indi, the brightest star in the constellation, is an orange giant of magnitude 3.1, 101 light-years from Earth. Beta Indi is an orange giant of magnitude 3.7, 600 light-years from Earth. Delta Indi is a white star of magnitude 4.4, 185 light-years from Earth. Epsilon Indi is one of the closest stars to Earth, approximately 11.8 light years away. It is an orange dwarf of magnitude 4.7, meaning that the yellow dwarf Sun is slightly hotter and larger. The system has been discovered to contain a pair of binary brown dwarfs and has long been a prime candidate in SETI studies. Indus is home to one bright binary star. Theta Indi is a binary star 97 light-years from Earth. Its primary is a white star of magnitude 4.5 and its secondary is a white star of magnitude 7.0. T Indi is the only bright variable star in Indus. It is a semi-regular, deeply coloured red giant with a period of 11 months, 1900 light-years from Earth. Its minimum magnitude is 7 and its maximum magnitude is 5.

The constellation contains several notable galaxies, including NGC 7049, NGC 7064, NGC 7083, NGC 7090, NGC 7140, NGC 7041, and IC 5152. NGC 7049 is a galaxy located about 100 million light-years from Earth. It spans approximately 150,000 light years. The galaxy has a prominent dust ring and relatively few globular star clusters. It has characteristics of both a spiral galaxy and an elliptical galaxy. The galaxy’s unusual appearance is believed to the result of several recent collisions with other galaxies. NGC 7064 is a barred spiral galaxy, also discovered by John Herschel on July 8, 1834. It has an apparent magnitude of 12.2. NGC 7083 is a magnitude 12 barred spiral galaxy. It is considered a grand design spiral galaxy. A supernova, SN 2009hm, was observed in the galaxy in 2009. NGC 7090 is a spiral galaxy in Indus. It has an apparent magnitude of 10.51 and is about 30 million light years distant. It was discovered by the English astronomer John Herschel on October 4, 1834. NGC 7140 is another spiral galaxy in Indus. It was discovered by the British astronomer John Herschel at the Cape of Good Hope in October 1834. The galaxy has a visual magnitude of 11.7 and is approximately 122 million light years distant from Earth. NGC 7041 is an elliptical galaxy. It was discovered by John Herschel on July 7, 1834. The galaxy has a visual magnitude of 11.1. C 5152 is an irregular galaxy in Indus. It was first discovered by the American astronomer DeLisle Stewart in 1908. It is uncertain whether or not the galaxy is an outlying member of the Local Group of galaxies.

All Sky Automated Survey for Supernovae (ASAS-SN) in 2015 detected a superluminous supernova, named ASASSN-15lh (also designated SN 2015L). Based on the study conducted by Subo Dong and a team from the Kavli Institute for Astronomy and Astrophysics (KIAA) at Peking University, ASAS-SN-15lh was two times more luminous than any supernova previously discovered, and at peak was almost 50 times more luminous than the entire Milky Way galaxy. Credit: Constellation Guide, Universe Guide, Wikipedia.