Horologium Constellation: The Ultimate Guide

Horologium is one of the 88 modern constellations. It does not appear or have associated histories in ancient Western cultures because it was not visible in those regions.

Horologium 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.

Having observed and cataloged nearly 10,000 southern stars for two years in 1756, the French astronomer Nicolas Louis de Lacaille first described the constellation as <<l'Horloge à pendule & à secondes>> meaning Clock with pendulum and seconds.

Lacaille devised fourteen new constellations in previously unexplored regions of the celestial southern hemisphere, which were not visible from Europa. All but one honored scientific instruments and thus symbolized the Age of Enlightenment.

The constellation's name was Latinized to Horologium in an updated catalog and chart published posthumously in 1763.

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

Horologium currently covers an area of 49 square degrees, thus ranking 58th in size among the 88 constellations in the night sky.

Horologium resides in the first quadrant of the Southern Hemisphere (SQ1) between latitudes 30° 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.

Horologium is visible in Europe, Africa, Australia, and Antarctica.

Horologium is not visible in regions above 30°N such as the USA, Canada, and most of Europe, such as Italy, France or Germany, Russia, Groenlandia, Japan, and Alaska.

The best month to visualize the Horologium constellation is in December, which is visible during the winter in the northern hemisphere, and during the summer in the southern hemisphere.

The constellation Horologium is very faint and difficult to locate, so you can support yourself using the bright stars nearby, such as the star Achernar or Canopus.

The easiest way to locate the constellation Horologium is to locate the second brightest star in the sky, Canopus, then draw a straight line towards the star Achernar Eridanus. The constellation Horologium is located right in the middle of the two.

The constellations bordering Horologium are Eridanus, Hydrus, Reticulum, Dorado, and Caelum.

In addition, Horologium belongs to the family of constellations discovered by Lacaille; these include Antlia, Caelum, Circinus, Fornax, Mensa, Microscopium, Norma, Octans, Pictor, Reticulum, Sculptor, and Telescopium.

The Circinus constellation officially contains 30 stars, of which 7 form the central figure of the constellation; these are Alpha Horologii, R Horologii, Beta Horologii, Mu Horologii, Zeta Horologii, Eta Horologii, and Iota Horologii.

It is the brightest star in the constellation Horologium with an apparent magnitude of +3.86. It is located 117 light-years away from the Solar System.

Alpha Horologii is an orange giant of spectral type K2III with a surface strength of 4650 K. Its spectral type is almost the same as that of the well-known Arthur (α Bootis). However, with a luminosity equivalent to 47 suns, it is less luminous than this one.

With an apparent magnitude of +4.93, Delta Horologii is the second brightest star in the constellation Horologium. It is 175 light-years away from the Solar System.

Delta Horologii is a white main-sequence star, generally classified as spectral type A9V. However, it has also been classified as a subgiant of type F2IV.

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

Horologium is a small constellation; because of that, it has a small number of deep objects, mainly galaxies and globular cumulus. The most notable are:

A distant galaxy located 38 million light-years away, NGC 1512 is almost as large as the Milky Way. It is Horologium's most notable deep sky object.

On its inside, intense star-forming clusters have been observed. These clusters either appear bright in visible light.

A magnitude +8.0 is the globular cluster that can be well seen with a large telescope. It has an approximate age of 10.24 billion years and is located about 53,500 light-years from Earth.

• Horologium is a constellation located primarily in the southern hemisphere. The name of the constellation Horologium comes from Latin and means "Pendulum Clock."
• The name of the constellation is only taken from the Greek language. Still, it is not related to the culture since, in ancient Greece, there were no pendulum clocks.
• The constellation Horologium is located between 40° N and 90° S. The best month to observe the constellation is in December.
• The easiest way to locate the constellation Horologium is to locate the second brightest star in the sky, Canopus, then draw an imaginary straight line towards the star Achernar Eridanus. The constellation Horologium is located right in the middle of the two.
• The brightest star in the constellation Horologium is Alpha Horologii (α Hor/ HD 26967 / HR 1326), with an apparent magnitude of +3.86.
• The most notable deep sky body in the constellation Horologium is the barred spiral galaxy NGC 1512.

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