Indus Constellation: The Ultimate Guide

Indus is one of the 88 modern constellations. It has no associated history in ancient occidental cultures because it was not visible in those regions.

In the case of Greek culture, when Ptolemy wrote the Almagest, it did not mention the constellation Indus nor did it appear on the celestial maps of the time.

Indus is one of the faintest constellations. Most of its stars cannot be seen with the naked eye, so it was necessary to wait for telescopes to be invented to see them.

Indus was one of twelve constellations named by cartographer and astronomer Petrus Plancius from observations made by navigators Pieter Dirkszoon Keyser and Frederick de Houtman in 1592.

The constellation Indus first appears publicly on a celestial globe 35 centimeters in diameter (14 inches), published in 1597 in Amsterdam by Plancius and Jodocus Hondius.

Plancius depicted the constellation with the figure of a naked man with three arrows in one hand and one in the other, as a native of the tribes of southern Africa, later given the name Indius because the figure also resembled the natives of India.

In 1922 the International Astronomical Association added the constellation Indius to the 88 official night sky constellations. Since then, it has not undergone significant changes in its boundaries or name.

Indius currently occupies an area of 294 degrees from the sky. This places it 49th in size among the 88 constellations in the night ice.

Indius resides in the fourth quadrant of the Southern Hemisphere (SQ4) between latitudes 15° N and 90° S, which means that we can see the constellation in the night sky from all countries of the southern hemisphere of the earth and some countries of the northern hemisphere.

The constellation Indius is visible in America, Europe, Africa, Australia, and Antarctica.

Indius is not visible in regions above 15° N such as Canada, most of Europe such as Italy, France or Germany, Russia, Greenland, Japan, and Alaska.

The best month to visualize the Indius constellation is in September, which is visible during the fall in the northern hemisphere. In the southern hemisphere, it is visible throughout spring and summer.

The constellation Indius has no stars of the first or second magnitude; that is to say that it is very faint. However, it is very close to two stars of the first magnitude, Alnair and Peacock.

The easiest way to locate the constellation Indus is by drawing an imaginary straight line from the star Peacock of the constellation Pavo towards the star Alnair of the constellation Grus. The constellation Indus is located right in the middle of the two.

The constellations bordering Indus are Microscopium, Sagittarius (corner), Telescopium, Pavo, Octans, Tucana, and Grus.

In addition, Grus belongs to the Johann Bayer family of constellations; these include Apus, Chamaeleon, Dorado, Grus, Hydrus, Musca, Pavo, Phoenix, Tucana, and Volans.

The constellation Indus officially contains 42 stars, of which 5 form the central figure of the constellation; these are The Persian, Beta Indi, Delta Indi, Theta Indi, and Eta Indi.

It is the brightest star in the constellation of Indus, the Indian, with an apparent magnitude of +3.11. Alpha Indi is 98 light-years from the solar system.

It is an orange giant star of spectral type K0III-IV with a surface temperature of 4860 K. Its radius is 11 times larger than the solar radius. Its luminosity is equivalent to 62 times that of the Sun.

With an apparent magnitude of +3.66, it is the second brightest star in the constellation Indus. It is 611 light-years from the earth.

Beta Indi is a luminous orange giant of spectral type K1II whose effective temperature is 4383 K.

Indus is also home to several deep-sky objects. Deep-sky objects often mean star clusters, nebulae (interstellar cloud bodies), or galaxies.

In the case of Indus, because it is a small constellation only has nebulae and galaxies, the most notable of them are:

It is a spiral-like galaxy (like the milky way) located about 31 million light-years away. The combined mass of the stars in this galaxy is 5.5 billion times the mass of the Sun.

This galaxy presents a transversal view, that is to say, that we see it from the side, that is why it is difficult to determine its total mass; it is the most notable deep sky object in the constellation Indus.

It is a lenticular galaxy that spans about 150,000 light-years and is located about 100 million light-years from Earth. It has a very bright nucleus produced due to a prominent ring of dust in the form of a string that stands out against the light of the stars behind it.

• Indus is a constellation located primarily in the southern hemisphere. Its name comes from Latin and means "The Indian."
• The constellation Indus is visible mainly during autumn in the northern hemisphere and spring in the southern hemisphere.
• The constellation Indus lies between latitudes 15° N and 90° S. The best month to observe the constellation is in September.
• The easiest way to locate the constellation Indus is by drawing an imaginary straight line from the star Peacock of the constellation Pavo to the star Alnair of the constellation Grus. The constellation Indus is located right in the middle of the two.
• The brightest star in the Indus constellation is Alpha Indi (α Ind/HD 196171/HR 7869), with an apparent magnitude of +3.11.
• The most notable deep sky body in the constellation Indus is spiral galaxy NGC 7090.

1. https://www.constellation-guide.com/constellation-list/indus-constellation/
2. http://www.seasky.org/constellations/constellation-indus.html
3. https://theplanets.org/constellations/indus-constellation/
4. https://www.universeguide.com/constellation/indus