Monday, January 13, 2014

Names In The Sky

On Twitter, following up from this, Adam Roberts asked 'How many named stars are there in the sky? As few as 70?'

It's a good question. Even the largest star catalogues list only around a billion stars, out of an estimated total of 200 to 400 billion in the Milky Way, but there are only a few hundred stars with proper names. Stars in constellations have Bayer designations - α Cephei, β Cephei and so on - and often have proper names that reflect their position in the constellation.  α Cephei is known by the Arabic name Alderamin, the right arm, and by the Chinese name Tian Gou wu, the Fifth Star of Celestial Hook. And then there are the bright stars, like Sirius or Procyon, or unusual stars like Barnard's Star or Luyten's Star (both red dwarf stars with large proper motions), or Proxima Centauri, the closest star to the Sun. Names that sound like names, rather than a catalogue number such as, say, BD+20°2465.

Actually, I have a fondness for BD+20°2465. It's a red dwarf star that's also known as AD Leonis (which sounds like the name of a character in an Isaac Bashevis Singer story), just sixteen light years away. It was the star of the fictional planet on which I set my first novel, Four Hundred Billion Stars. Even a string of numbers and letters can grow familiar. Can seem like a name, a tag for something known and understood, a local habitation.

On the Twitter thread, Winchell Chung reminded us of this great quote from James Blish's Earthman Come Home:
The entire pack of cities, decelerating heavily now, was entering the 'local group' - an arbitrary sphere with a radius of fifty light years, with Earth's sun at its centre.  This was the galaxy's centre of population still, despite the outward movement which had taken place for the past centuries, and the challenges which were now ringing around the heads of the Okies were like voices from history:  40 Eridani, Procyon, Kruger 60, Sirius, 61 Cyni, Altair, BD+4°4048, Wolf 359, Alpha Centauri . . . To hear occasionally from Earth was no novelty, but these challenges were almost like being hailed by ancient Greece, or the Commonwealth of Massachusetts.

1 Comments:

Blogger Unknown said...

It's strange in a way that the known stars within 50 light years haven't been given individual names by now. It will take our civilisation a long time to spread beyond this sphere. Perhaps the discovery of nearby exo-planets will provide a new impetus. What does that say about us though? Does a thing have to be capable of being claimed and exploited before it's worth naming? I hope we're better than that when the time comes.

January 14, 2014 11:22 am  

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