Coma Berenices, The Constellation Named For A Real Woman

Queen Berenices flowing locks now form the constellation Coma Berenices (KO-muh Bear-en-EYE-ceez), well-placed in the southeastern sky in late March and April. Urania’s Mirror / Sidney Hall

There are 88 constellations. All are named for mythological characters, animals and even machines. Except one — Coma Berenices. It’s the only constellation named for a real person. The name means “Berenice’s Hair” and refers to the locks of Queen Berenice II of Egypt. She lived in Cyrene near the modern-day city of Shahhat, Libya from 266-221 B.C.

Bust of Berenice II of Egypt.

When her husband, Ptolemy III Euergetes, went off to war in Asia, the queen made a vow to cut off her hair and offer it up to Aphrodite, the goddess of love, beauty and passion, should he return safely. A year later the king arrived home, Berenice got a haircut and the tresses were placed in a temple associated with the goddess. Only the next day, the hair went missing.

The whodunit tale is unrecorded, but Conon of Samos, an astronomer and mathematician living in Alexandria, offered up an ingenious explanation to the king — Berenice’s hair had ascended to the sky as a nebulous mass of stars behind the constellation Leo, an area that used to represent the lion’s tail. A darker reading of the tale suggest a more likely motivation: that the disappearance and supposed “reappearance” of the hair was cooked up to glorify the king and queen in the eyes of their subjects, proving once again there’s no escaping politics.

This map shows the sky looking southeast around 9:30 p.m. local time in late March. Coma Berenices lies between Leo’s tail and brilliant Arcturus lower down in the eastern sky. Regulus is another bright star you can use to star-hop to Coma. Stellarium

Much later, 16th and 17th century astronomers included the “hair of Berenices” in their catalogs and atlases, establishing Coma Berenices as an official constellation. Spring is a best time to find the group, located between Leo and the bright star Arcturus. Since “Coma” has no stars brighter than 4th magnitude, it’s rather faint, so be sure to look for it when the moon is either out of the sky or no thicker than a crescent.

The Coma Star Cluster is a big star cluster visible with the naked eye and binoculars. Stellarium

Three stars connect to form a right-angle triangle 10° (one fist) to a side, but what really catches the eye is the spray of faint stars — the “hair” — a little more than a fist to the upper left of Denebola in Leo. This swarm is a true, gravitationally-bound star cluster. All of its members lie within a few dozen light years of one another and hang together as a unit in space as they orbit the center of the Milky Way galaxy.

Called the Coma Cluster or Mel 111 it contains more than 40 stars spread across 7° of sky. That’s big! Bigger than the Seven Sisters (Pleiades) and Hyades. But the stars are also more spread out. To see it best use the technique called averted vision, where you scan around the cluster rather than stare directly at it. You’ll see more stars that way. The Coma cluster has an unmistakable hazy, dare I say hairy, appearance.

You get a better sense of how many stars fill the cluster in this time exposure photo. The cluster is lies 280 light years from Earth. Bob King

Any pair of binoculars will show many more stars and fit about two-thirds of the cluster in the field of view. Don’t bother with a telescope — too much magnification will spread the stars out too much. Sometimes the lowest magnification is best. I wouldn’t go higher than 7x on this pretty object.  Coma Berenices and cluster stand almost halfway up in the southeastern sky by 9:30 p.m. local time and reach their greatest height around 1 a.m.

Given the great sacrifice of Berenice II, I hope you’ll only consider it but a small sacrifice of your time to find the hair of hope that still flutters behind the lion’s tail the next clear night.

2 Responses

  1. Richard Keen

    Bob says:
    “There are 88 constellations. All are named for mythological characters, animals and even machines. Except one …. It’s the only constellation named for a real person.”
    I’ve told the same story at trivia fests, dinner, and such, except my answer is a different constellation – Scutum. From Wikipedia:
    “Scutum was named in 1684 by Polish astronomer Johannes Hevelius (Jan Heweliusz), who originally named it Scutum Sobiescianum (Shield of Sobieski) to commemorate the victory of the Christian forces led by Polish King John III Sobieski (Jan III Sobieski) in the Battle of Vienna in 1683. Later, the name was shortened to Scutum.”
    Being a bit Polish myself, I always took pride in this tidbit, especially since Sobieski is a national hero.
    Now I can change the trivia question to “What do Poles and Egyptians have in common?”,
    now that two constellations fit the description!
    BTW, I’m sure glad I went back to check on the spell check. It changed the constellation name to “Sputum”. Yuk.

    1. astrobob

      Right you are, Richard. I was thinking of an actual person rather than an implement, but I see your point. There’s a historical connection there.

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