If you're a Harry Potter fan, have you noticed that the Black family likes star names for their children? Here you can find out more about these stars. There's also a bit of background on the characters for those who aren't familiar with the J.K. Rowling books.
Bellatrix and her sisters
Evil and completely crazy Bellatrix Lestrange was devoted to Lord Voldemort.
The star Bellatrix is a blue giant in Orion that is more than six thousand times as luminous as our Sun, and is commonly called the Amazon star. The Greek Bellatrix, meaning female warrior, fits the bellicose [warlike] character J.K. Rowling created. It's certainly more fitting than a thirteenth century Arabic name that means huge left shoulder.
Bella was born to the Black family - wealthy, descending from a long line of wizards, and very racist about those who weren't born wizards. The family disowned Bella's sister Andromeda for marrying a wizard of mixed parentage (and perhaps just for being sane). The constellation Andromeda represents the Greek heroine who was rescued from a sea monster by Perseus. The most famous object in the constellation is M31, a great spiral galaxy which is approaching the Milky Way at high speed. The two galaxies will merge in a few billion years.
The other sister, Narcissa, married Lucius Malfoy and named their son Draco. Draco had the arrogance of both sides of his family, but turned out not to have his aunt Bella's stomach for murder. The constellation Draco (the Dragon) is an ancient constellation in the far northern sky. Its bright star Thuban was the pole star for nearly two thousand years from 3942 BCE onward.
Draco Malfoy named his own son Scorpius. Scorpius is a zodiac constellation which lies in the southern hemisphere. It does resemble a scorpion for southern observers who can see the whole thing. If you live in Canada, northern USA or Europe, you can see only part of the constellation, but its bright reddish star Antares is visible low in the sky.
Cygnus Black and Orion Black
Bellatrix and her sisters are the daughters of Cygnus Black III. Cygnus the swan represents the myth of Leda and the swan in which the god Zeus was disguised as a swan to seduce Leda. Five of the bright stars also make the star pattern known as the Northern Cross.
Cygnus's sister Walburga, who was not named for anything astronomical, married her second cousin Orion Black. Orion the hunter is a very recognizable constellation. Bellatrix represents his left shoulder, but his right shoulder is the better known red supergiant star Betelgeuse. The row of three bright stars that make his belt are easy to pick out in the sky. The Great Nebula of Orion is a nearby stellar nursery.
Sirius Black and Regulus Arcturus Black
Orion and Walburga had two sons, Sirius and his younger brother Regulus Arcturus.
Sirius, in the constellation Canis Major (Greater Dog), is the brightest star in the sky. It's known as the “dog star.” The name Sirius came from a Greek word meaning scorching. In ancient Greece, Sirius became visible just before the hot dry days of early summer. The period of about five weeks from the start of July are still sometimes called the Dog Days. Sirius Black was also an “animagus” which was a wizard that could transform into an animal – his animal was, of course, a dog.
Sirius was a friend of the Potter family and godfather to Harry. Eventually, his cousin Bella killed him. (She also killed her niece, Andromeda's daughter.) However his brother Regulus was a delight to the family, following the family traditions of arrogance and bigotry. As a teenager he became a follower of evil Lord Voldemort. However when he became disgusted by Voldemort's actions, he died while sabotaging one of the Dark Lord's schemes.
The star Regulus is the brightest in the constellation Leo (the Lion). It means little King, but to the Arabs it was known as the heart of the lion. Regulus is actually a system of four stars, though Regulus A, a blue-white star nearly three hundred times brighter than the Sun, dominates.
Regulus Black's middle name was Arcturus. Arcturus is the brightest star in Boötes (the Shepherd), a red giant that appears an attractive yellow color. It has had a cultural importance to many peoples throughout history, including being an important navigation star for the Polynesians.
The Dark Lord's mother
The final celestial name is not a member of the Black dynasty, but Merope Gaunt, mother to Tom Riddle Jr who became known as Lord Voldemort (or the Dark Lord or not named at all). Merope came from a long line of wizards, but her family got the bigotry without any money. She was mistreated by her family and didn't even have the good looks to escape them through marriage. But Merope did manage to enchant a handsome, wealthy muggle (non-magical human) named Tom Riddle. They married, but he deserted her. She died giving birth to their son. And the rest isn't history, but it provided the chief villain for the Harry Potter books.
The star Merope is a star in the Pleiades star cluster, also known as the Seven Sisters. The sisters were immortals, the daughters of a Titan and an ocean nymph. There are hundreds of stars in the cluster, even though tradition names seven. In fact, without binoculars few people can see more than six, so many cultures have legends of a missing Pleiad. In one of the Greek tales Merope hid away because of her shame at marrying a mortal.