Coma Berenices is a constellation that had a hard time establishing its identity.
There it sits in the eastern sky in the spring, a simple triangle framed by the Big Dipper to the north, Leo to the southwest, Bootes to the east, and Virgo to the southeast. In such august company, Coma always had a hard time making a name for itself.
In April, I usually find it by looking in the southern sky almost straight overhead for the constellation Leo. Then I look just to the northeast for the faint patch of about half a dozen stars that define the western corner of the triangular shape of Coma.
Coma’s greatest attribute is that scattered cluster of naked-eye stars, marked MEL 111 on most star maps. This cluster gives the constellation its name, which means “Berenice’s hair.”
In binoculars it expands to many more than the 6 or 7 naked-eye stars.
The stars look so spread out because MEL 111 is one of the closest star clusters to Earth. It is, of course, in our Milky Way galaxy, at only 250 light years away, about 1,500 trillion miles. (One light year is equivalent to about 6 trillion miles.)
By contrast, the other galaxies that make up our universe are much more distant. Just to the left of the bottom-most star in the cluster is one of the most interesting galaxies in the sky, marked as NGC 4565 on a decent star map. It is about 20 million light years away, about 800,000 times more distant than the star cluster.
Galaxies are lens-shaped collections of billions of stars. Seen from the top, they look a lot like a whirlpool or child’s pinwheel. Seen from the side, they look like two plates pressed top to top.
NGC 4565 is the best and brightest example of a galaxy viewed from the side, or “edge-on.” In a medium-sized scope, it is the most beautiful splinter of light you will ever see.
In fact, the whole area is littered with galaxies of various sizes, shapes and brightnesses. Sweep the area carefully with a telescope and you’ll see what I mean.
Most of them are members of the Coma-Virgo Galaxy Cluster, which is about 65 million light years away, which begins to sound pretty far away. However, many astronomers believe that our own Milky Way galaxy is part of the Coma-Virgo Cluster. In a sense, we are outliers. We live in the far suburbs of the vast metropolis of which the Coma-Virgo cluster is the central city.
Coma’s identity problem is that it has almost always been thought of as part of another constellation.
The ancients thought of it as a sheaf of wheat or ivy being held by Virgo to the southeast.
Arab astronomers named it Al Dafirah, “the tuft of hair” at the end of Leo the lion’s tail, which seems to indicate that Coma was associated with Leo.
An astrologer by the name of Conon (with an “o” – no relation to the famous barbarian) changed all that. Since Conon, Coma Berenices has become forever famous as the patron constellation of liars and con men the world over.
Here’s what happened:
Berenice was the wife of Ptolemy III, divine ruler of Egypt around 240 B.C. Ptolemy was always off on some war or another, and Berenice sat home worrying about him.
She offered her beautiful, amber-colored hair to the Greek goddess of beauty Aphrodite (called Venus by the Romans) to ensure her husband’s safe return.
But the hair mysteriously disappeared, and Ptolemy and Berenice weren’t too happy about it. Their wrath fell upon court astrologer Conon, whose responsibility it must have been to keep the “amber tresses” safe.
Let’s transport back to 240 BCE and imagine the scene.
Setting: Conon, Ptolemy and Berenice are standing just outside the temple of Aphrodite at Zephyrium. It is a brilliant starlit night in early spring.
Berenice: Where’s my hair, dude? The bald look won’t come in for at least 2,000 years.
Conon: Er, ah, um.
Ptolemy: (pensively, to himself) Now let’s see … tortures … hmmm.
Berenice: It had better not be stolen, Conon, baby. I don’t want locks of my hair sold in paperweights with “Souvenir of your glorious trip down the Nile” stamped all over them.
Ptolemy: The rack? No, not painful enough. Water torture? Too messy. Iron maiden? No, that hasn’t been invented yet.
Conon: (rolls his eyes up to heaven and has an inspiration) Well, of course, there’s your hair, my queen. Up in the sky, just to the west of Bootes, the herdsman. Yeah, that’s it. That patch of stars. Aphrodite so loved your sacrifice that she took your amber tresses and put them among the stars. Yeah, that’s the ticket.
So Conon saved his skin, and Berenice became the only real, non-mythological person to have a constellation named after her.