Eridanus is the sixth largest constellation in the sky, and it is located in the southern hemisphere. Its name translates to "the river."
Key Facts & Summary
- Eridanus is quite a prominent constellation, stretching for 1138 square degrees, being the sixth largest constellation out of the 88 modern constellations in the sky.
- There are no Messier objects located in Eridanus.
- There are only two meteor showers associated with Eridanus, the Nu Eridanids and Omicron Eridanids.
- The brightest star in Eridanus is Achernar, designated as Alpha Eridani. It has an apparent magnitude of 0.46, being among the brightest stars in the night sky.
- Achernar is actually the ninth brightest star in the sky, and many consider it the least spherical star in our galaxy.
- Thirteen stars in Eridanus are confirmed to host planets.
- A Supervoid is located in this constellation, and it is known as the Eridanus Supervoid.
- This void is the second-largest ever discovered.
- Only four stars are brighter than magnitude four in this constellation.
- Many stars that form Eridanus are situated quite close to us. Thirteen of them are within 32 light-years from Earth.
- The majority of stars in Eridanus cannot be seen from China.
- Many of the stars in the constellation of Fornax were once part of Eridanus.
- Eridanus is surrounded by Caelum, Cetus, Fornax, Horologium, Hydrus, Lepus, Orion, Phoenix, Taurus, and Tucana.
- Eridanus belongs to the Heavenly Waters family of constellations, together with Carina, Columba, Delphinus, Equuleus, Piscis Austrinus, Puppis, Pyxis, and Vela.
- The best time to observe Eridanus' constellation and all of its components is during December.
- Many interesting deep-sky objects besides the supervoid reside in Eridanus.
The Constellation of Eridanus for Kids
The constellation of Eridanus is represented like a celestial river, and it lies in the southern celestial hemisphere, occupying an area of 1138 square degrees (2.8% of the sky). It's the sixth-largest constellation in the sky and one of the 88 modern constellations.
Eridanus was cataloged by the Greek astronomer Claudius Ptolemy as it was one of the first 48 Greek constellations. Let us see what does this constellation represent.
What Does the Constellation of Eridanus Represent?
Eridanus represents a celestial river, and it's usually described as flowing from the waters poured by Aquarius. The name has Greek origins, and it came from the river Po in Italy.
The Eridanus Constellation is associated in Greek Mythology with the story of the son of the Sun-god Helios and the Oceanid Clymene - Phaeton.
The story goes that Phearton was eager to drive his father's chariot across the heavens, and after long requests, he received Helios's permission. However, the father advised his son to follow the beaten track.
Lacking experience and with too much self-confidence in his driving skills, Phaeton flew up into the sky but lost control of the reins. So the chariot plunged close to the Earth, and the lands burst into flames.
Zeus, learning about the events, struck Pheaton with a thunderbolt. His hair burned, and he leaped from the chariot and fell into the Eridanus. Deeply grieved by his son's deeds, Helios did not drive his chariot for days, leaving the world in darkness.
Where Can You See the Constellation of Eridanus?
The 6th largest constellation in the sky can be seen at latitudes between +32° and -90°. Eridanus is located in the first quadrant of the southern hemisphere (SQ1). It is best seen in December.
Together with Carina, Columba, Delphinus, Equuleus, Piscis Austrinus, Puppis, Pyxis, and Vela, Eridanus is part of the Heavenly Waters family of constellations.
Fun Kids Facts About the Constellation of Eridanus
- The constellation of Eridanus represents the celestial river that runs from Cursa (Beta Eridani) near Rigel in Orion all the way to the ninth brightest star in the sky - Achernar (Alpha Eridani), in the far southern sky.
- Eridanus has no Messier object, but it has 32 stars with known planets, only 19 with names approved by the International Astronomical Union.
- Achernar (the brightest star in the Eridanus Constellation) is the hottest and bluest in color out of the ten most luminous stars in the night sky.
- Eridanus Constellation hosts many interesting deep-sky objects like possibly the second-largest known void – the Eridanus Supervoid, the Eridanus Group of galaxies, and the Witch Head Nebula.
- The Eridanus Constellation doesn't have any Messier object but has recently been associated with two meteor showers - The Nu Eridanids and Omicron Eridanids.
Size and Comparison
The Eridanus Constellation spreads on 1138 square degrees, being the sixth largest constellation in the night sky among the 88 modern constellations.
What Are the Major Stars in the Constellation of Eridanus?
Eridanus Constellation has 32 stars with known planets, but only 19 stars have official names.
Acamar, Achernar, Angetenar, Ayeyarwady, Azha, Beemim, Beid, Chaophraya, Cursa, Keid, Koeia, Montuno, Mouhoun, Ran, Sceptrum, Theemin, Tojil, Zaurak, and Zibal are the stars with names approved by the International Astronomical Union.
There are seven important stars in the constellation of Eridanus: Achernar (the brightest star in Eridanus), Cursa, Acamar, 39 Eridani, 40 Eridani, p Eridani, or Ran.
What is the Brightest Star in Eridanus?
The brightest star in Eridanus is Achernar, designated as Alpha Eridani, and it's also the ninth most luminous star in the night sky, sometimes sharing the title with Betelgeuse.
Achernar is a binary star system, containing one blue main-sequence star Achernar A, and an A-type star designated as Achernar B. Achernar is the hottest and bluest in color out of the ten brightest stars in the night sky.
Because of its very fast spin, having a rotational velocity of around 250 km/155.3 mi per second, the primary star is the least spherical star in the Milky Way, which causes Achernar to have an equatorial diameter, which is 56% greater than its polar diameter. This star is located at 139 light-years away from us.
Are There Any Messier Objects in the Constellation of Eridanus?
Eridanus Constellation doesn't have any Messier object, and only recently, two meteor showers were associated with it - The Nu Eridanids and Omicron Eridanids.
However, Eridanus contains several notable deep-sky objects and stars. For example, the second-largest void known - the Eridanus Supervoid, the Witch Head Nebula, and the Eridanus Group of Galaxies, are some famous deep-sky objects located here.
Eridanus Constellation Notes
- Eridanus is among the 88 modern constellations and the sixth most prominent constellation, occupying around 1138 square degrees.
- This constellation has no Messier objects, and only two meteor showers were recently associated with it – the Nu Eridanids and Omicron Eridanids.
- Achenar, a blue main-sequence star, is the brightest star in Eridanus and also the ninth most luminous star in the night sky.
- Around 32 stars host planets in this constellation, but only 19 have recognized names.
- The Eridanus Constellation is home to the second-largest known void, a supervoid - the Eridanus Supervoid.