Celaeno, designated as 16 Tauri, is a star in the zodiacal constellation of Taurus, the celestial bull. It is a member of the Pleiades open star cluster.
Key Facts & Summary
- Celaeno is among the nine brightest stars of the Pleiades cluster. It is located at around 430 light-years away from the Sun.
- The Pleiades cluster is comprised out of at least 1,000 confirmed stars, and many other fainter and unresolved stars.
- The cluster’s tidal radius is about 43 light-years, however, its core radius is only 8 light-years across.
- The brightest members of the Pleiades cluster, including Celaeno, are young, hot B-type stars that formed in the last 100 million years or so.
- Celaeno is a blue-white subgiant with an apparent magnitude of +5.45 and an absolute magnitude of -0.76.
- Celaeno’s spectral classification is B7IV, indicating the spectrum of a subgiant, however, its other properties suggest that it may still be in the late stages of the main sequence.
- This star is bigger than our Sun, having 4.0 solar masses and 4.4 solar radii.
- Celaeno is approximatively 344 times brighter than our Sun, having surface average temperatures of around 12,800 K.
- This star is also a fast spinner, having a rotational velocity of 185 km / 114.9 mi per second.
- With this speed, Celaeno might have a surrounding disk around it, as most fast-rotating stars, however, it is yet unconfirmed.
- The surface gravity of Celaeno is around 3.9 cgs.
- The zodiacal constellation of Taurus and the Pleiades open cluster was known to humanity for thousands of years.
- The Pleiades cluster is very bright, though, it cannot be seen during May and June since the Sun blocks our view of the cluster in that period.
- Celaeno has a radial velocity of +2.9 / + 1.8 mi per second.
The star Celaeno was named after one of the Pleiades, the seven daughters of the sea-nymph Pleione and the Titan Atlas, in Greek mythology.
The name Celaeno derives from the ancient Greek word Kelaino – translating to “the dark one.” In the Greek mythos, Celaeno had four children with the sea god Poseidon, and two with the Titan Prometheus.
The star’s name as “Celaeno” was officially approved by the IAU in 2016. Celaeno was also called “the Lost Pleiad” by the Greek scholar Theon of Alexandria.
Other sources gave this title to the Pleiades stars Merope and Electra, even though they are brighter and appear less “lost” than Celaeno. Celeno though would appear brighter to us if it weren’t for the 0.05 magnitudes of interstellar extinction.
Celaeno, along with its neighboring stars in the Pleiades cluster, formed between 75 and 150 million years ago. This open cluster is among the closest star clusters to Earth.
All the stars in the Pleiades cluster have a common origin, they formed through a gigantic molecular cloud of dust and gas. Gravity pulled the swirling gas and dust together and formed the Pleiades cluster.
The Pleiades cluster is overall dominated by very hot blue and luminous stars.
Distance, Size, and Mass
Celaeno is located at around 430 light-years / 130 parsecs away from the Sun. It is much more massive than our Sun, having 4 solar masses, or 400% the Sun’s mass.
Celaeno is also bigger than our Sun, having 4.4 solar radii or 440% the Sun’s radius. It is thus, at least 8 times bigger than our Sun.
Celaeno is a blue-white star of spectral type B7IV, this indicates that it is a subgiant star, however, some of its properties suggests that the star is still in its late stages of the main sequence.
Celaeno has an apparent magnitude of +5.45 and an absolute magnitude of -0.76. It is 344 times brighter than our Sun. The average surface temperatures on Celaeno are estimated to be at around 12,800 K, or 2.2 times hotter than our Sun.
Like many other stars in the Pleiades, Celaeno is a fast spinner having a rotational velocity of 185 km / 114.9 mi per second. At this speed, the star should have a scattered disk surrounding it, similarly to the brightest star in the Pleiades, Alcyone. However, this is yet unconfirmed. This star doesn’t appear to be gravitationally bound to other stars.
Celaeno is located in the zodiacal constellation of Taurus, the celestial bull. It is among the nine brightest stars of the famous Pleiades open cluster. The Constellation of Taurus is also home to another great open cluster named Hyades.
This constellation is among the largest in the night sky, and also one of the most prominent of the northern constellations occupying an area of 797 square degrees.
The constellation of Taurus, apart from the two mentioned clusters, also has many interesting stars such as Aldebaran, Elnath, and also other fascinating deep-sky objects such as the Crab Nebula, Crystal Ball Nebula, merging galaxies and many more open clusters.
These celestial objects are best observed and studied during January. The nine brightest stars in the Pleiades cluster are Alcyone, Asterope, Celaeno, Electra, Maia, Merope, Taygeta, Atlas, and Pleione.
Celaeno is among the nine brightest stars of the famous Pleiades open cluster. From October to April, these stars can be observed and studied, however, May and June are not suitable for observation since the cluster is too close to the Sun.
The Pleiades open cluster is among the closest star clusters to Earth, and one of the brightest in our vicinity. Though the cluster is very bright and easy to find, you may also draw an imaginary line from the stars of Orion’s Belt – Alnitak, Alnilam, and Mintaka – past Aldebaran – and find the cluster.
The Pleiades cluster is also known as Messier 45. The majority of the brightest and hottest stars here are of spectral class B, and they formed between 75 and 150 million years ago.
Most of them are far apart from each other, and at around 444 light-years away from us. The most documented and famous stars are all named after the mythological Seven Sisters and their parents from Greek mythology.
The mythological story depicts the sisters as they caught the eye of Orion, a giant huntsman. Atlas, being condemned for his battles against the gods, was condemned to carry the heavens on his shoulders while Orion, the giant, pursued his daughters.
However, the Greek god Zeus stepped in and transformed the sisters into doves, and then into stars to console their father. Even so, Orion, the giant, is still pursuing the Pleiades sisters across the sky, represented by the Orion constellation.
Alcyone will continue to exist for many millions of years however, the Pleides star cluster has been studied closely and many computer simulations predict a grim future.
Most simulations suggest that the cluster will continue to survive for 250 million years before it will start to disperse due to gravitational interactions with its galactic neighborhood.
Did you know?
- The USS Celeno (AK-76) was a U.S Navy Crater class cargo ship named after Celaeno.
- The Pleiades star cluster is believed to have been formed from a compact configuration that resembled the Orion Nebula.
- Many cultures throughout the world knew of the Pleiades cluster since ancient times. One of the earliest depictions of the Pleiades cluster and its stars resides in the Nebra sky disk – a Bronze Age artifact dating to 1.6000 BCE, uncovered in Germany.
- Many famous and ancient texts mention the cluster, such as Homer’s Illiad and Odyssey, Hesiod’s Works and Days, the Bible, the ancient Egyptian Calendar of Lucky and Unlucky Days, and the Japanese Kojiki – An Account of Ancient Matters – the 8th-century chronicle of myths, oral traditions, and legends.
- The Pleiades are mentioned in the Kojiki as the Mutsuraboshi – translating to “six stars.” In modern Japan, the cluster is now known as Subaru – the same name used by the famous automobile company that depicts the six brightest stars in their logo.
- One of the first telescopic observations conducted on the Pleiades was during the 1610s. Galileo Galilei observed the bright stars and the cluster and it is noted that he may well be the first to have done so.