Grus Constellation: The Ultimate Guide

Grus is classified as one of the 88 modern constellations. It has no associated history in ancient Western cultures because it was not visible in those regions.

Grus is not a very bright constellation, and most of its stars cannot be seen with the naked eye, so it was necessary to wait for telescopes to be invented.

The stars of the constellation Grus were first defined as a separate constellation by Dutch astronomer Petrus Plancius.

Petrus created 12 new constellations, including Grus, based on observations of the southern sky by Dutch explorers Pieter Dirkszoon Keyser and Frederick de Houtman.

Dirkszoon and Houtman sailed to the East Indies on the first Dutch commercial expedition, known as Eerste Schipvaart. There were no records of stellar observations.

The constellation Grus first appeared on a celestial globe 35 centimeters in diameter, published in 1598 in Amsterdam by the cartographers Plancius and Jodocus Hondius.

His first appearance in a celestial atlas was in the Uranometry of the German cartographer Johann Bayer of 1603. He was depicted with the figure of a Flemish.

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

Currently, Grus covers an area of 366 square degrees. It ranks 45th in size among the 88 constellations in the night sky.

Grus resides in the fourth quadrant of the Southern Hemisphere (SQ4) between latitudes 34° 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.

Grus is visible in South America, Africa, Australia, and Antarctica.

Grus is not visible in regions above 34° N such as Canada, most of Europe such as Italy, France or Germany, or Russia, Greenland, Japan, and Alaska.

Grus is a constellation close to the south pole, so it is visible almost all year round; however, October is the best month to visualize it.

The constellation Grus is visible during autumn in the northern hemisphere and spring in the southern hemisphere.

The constellation Grus is small but has stars of the first magnitude that can be seen with the naked eye.

The easiest way to locate the constellation Grus is with the help of the star Fomalhaut.

If we draw a straight line from the star Fomalhaut towards the south celestial pole, we will find the two brightest stars of Grus, Alnair and Beta Gruis. From here, we can easily recognize the rest of the constellation.

The constellations bordering Grus are Piscis Austrinus, Microscopium, Indus, Tucana, Phoenix, and Sculptor.

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

The constellation Grus officially contains 55 stars, of which 12 form the main figure of the constellation, these are Alnair, Gruid, Aldhanab, Epsilon Gruis, Iota Gruis, Delta-1 Gruis, Zeta Gruis, Delta-2 Gruis, Theta Gruis, Lambda Gruis, Mu-1 Gruis and Rho Gruis.

It is the brightest star in the constellation Grus, with an apparent magnitude of +1.73. It is 103 light-years from the solar system.

Al Nair is a hot bluish-white subgiant of spectral type B7IV, whose effective temperature is 13,500 K. It is as luminous as 380 suns and has a radius 3.3 times larger than solar.

Ees is the second brightest star in the constellation Of Grus with an apparent magnitude of +2.07. It is located at a distance of 170 light-years from the earth.

Beta Gruis is a cold red giant of 3400 K of surface temperature and spectral type M5III. Its luminosity is about 3900 times greater than the Sun and has a diameter of 0.8 AU; that is, in the place of the Sun, it would extend beyond the orbit of Venus.

Grus is also home to a couple of deep-sky objects. Deep-sky objects often mean star clusters, nebulae (interstellar cloud bodies), or galaxies.

In the case of Grus has galaxies and nebulae, some of these are:

It is a barred spiral galaxy located 37.5 million light-years from the solar system. It is the most notable deep-sky object in the constellation Grus. It is about 100,000 light-years in size, similar to the Milky Way galaxy.

It is also called the "grand design" galaxy because of its well-defined spiral arms. A supernova and two ultraluminous X-ray sources have been discovered in NGC 7424.

It is a planetary nebula of colors close to violet located about 3000 light-years away. IC 5148 is expanding at 50 kilometers per second, one of the fastest planetary nebulae.

• Grus Quartet: It is a set of four galaxies (NGC 7552, NGC 7590, NGC 7599, and NGC 7582) that interact. These four galaxies are part of the IC Group 1459.
• NGC 7213: It is a Seyfert type 1 front galaxy located approximately 71.7 million years ago.

• Grus is a constellation located primarily in the southern hemisphere. The name of the constellation Grus comes from Latin and means "Crane."
• The constellation Columba lies between latitudes 34° N and 90° S. The best month to observe the constellation is in October.
• The easiest way to locate the constellation Grus is with the help of the star Fomalhaut.
• If we draw a straight line from the star Fomalhaut towards the south celestial pole, we will find the two brightest stars of Grus, Alnair and Beta Gruis. From here, we can easily recognize the rest of the constellation.
• The brightest star in the constellation Grus is Al Nair (α Gruis /α Gru), with an apparent magnitude of +1.73.
• The most notable deep sky body in the constellation Grus is the spiral galaxy NGC 7424.

1. https://www.constellation-guide.com/constellation-list/grus-constellation/
2. http://www.seasky.org/constellations/constellation-grus.html
3. https://www.universeguide.com/constellation/grus
4. https://earthsky.org/constellations/grus-the-crane-the-bright-one/