As one of the brightest, Aldebaran is also one of the most mythologized stars in the night sky. Ancient astronomers in the Middle East, India, Greece, Mexico and Australia all had stories to explain Aldebaran’s reddish glow, which is actually a product of its large size and relatively cool surface temperature.
Even today, if you attend an astronomy stargazing session — especially in the winter, since that’s when Aldebaran and its home constellation are visible — you’ll likely learn about Aldebaran and the most common stories that are told about this eye-catching star.
Despite our fascination with the brightest stars in the sky, astronomers continue to learn about them — Aldebaran included. Here are some of the basics about this luminous orange star.
What’s in a Name?
Like many stars, the roots of the name “Aldebaran” are found with the Arabic astronomers whose star nomenclature is so prominent in early star catalogs. “Aldebaran” comes from the Arabic phrase “al Dabarān,” which translates as “the follower.” This is because Aldebaran follows the open star cluster Pleiades across the sky; both are in the constellation Taurus. Speaking of Taurus, Aldebaran is also named Alpha Tauri, as it is the brightest star in the constellation.
Aldebaran also holds a special place in the graphical depictions of Taurus, the bull. In most drawings, Aldebaran takes its place as the bull’s bright, orange-red eye. This makes sense as the bull charges at the neighboring constellation of Orion.
Starlight, Star Bright
Aldebaran is not just the brightest star in the constellation Taurus, it’s also the 14th brightest star in the sky. This makes it roughly as bright as Antares, also called Alpha Scorpii, and Pollux, which is part of the pair of bright stars in Gemini (along with Castor).
What makes Aldebaran so bright is both its size and luminosity. The orange giant is about 44 times the size of our sun and over 400 times more luminous. This is how we are able to spot it so brightly in our sky despite its being over 66 light-years from Earth.
Stories of a Star
Because it is so eye-catching, Aldebaran features prominently in the mythologies of many cultures who can see it in the night sky.
The Seris people of northwestern Mexico call Aldebaran by other names, including Hant Caalajc Ipápjö, Queeto and Azoj Yeen oo Caap (“star that goes ahead”). In Hindu astronomy, Aldebaran is identified as the lunar mansion Rohini (“the red one”) and as one of the 27 daughters of Daksha and the wife of the god Chandra (the moon). The ancient Greek astronomers called it “Lampadias,” literally “torch-like” or “torch-bearer,” which is astonishingly similar to the Seris myth that Aldebaran provides light to the seven women giving birth as the Pleiades.
Through different cultures, Aldebaran’s brightness and proximity to other notable stars has played into the role it has taken in various astronomy mythologies.
Host to Exoplanet
Aldebaran is orbited by at least one exoplanet — or planet outside our solar system. Known as Aldebaran b, the primary exoplanet orbiting Aldebaran is roughly 6.5 times larger than Jupiter.
Aldebaran b was initially detected in 1993, but it took until 2015 for its existence to be confirmed; new data in 2019 cast doubts on the existence of Aldebaran b again, so it is still considered a candidate exoplanet until better data can provide a clearer answer on whether or not it exists.
Unfortunately, even if Aldebaran b exists, it is an unlikely candidate for carbon-based life. Its surface temperature is roughly 2,240 degrees Fahrenheit (1,500 degrees Kelvin or 1,227 degrees Celsius) and it receives large amounts of radiation from its host star, Aldebaran. So even if we could reach it in a timely fashion once confirming its existence, don’t expect to hear about colonies on Aldebaran b for a while.