Thursday, December 01, 2011
Star light, star bright
While perusing Biography of a Planet the other day for the illustration of bacterial symbiosis, I was jogged into reverie by the drawing above: The night sky above the administration building of Stonehill College. If you are a star-gazer, see if you can recognize the stars and constellations before I tell my story.
You probably worked it out. The constellations of summer: Lyra (the Lyre), Cygnus (the Swan) and Aquila (the Eagle). The "Summer Triangle" stars: Vega, Deneb and Altair. And, of course, the Milky Way and the Great Rift.
But what is that star near the top, nearly as bright as nearby Deneb?
Late one Friday night in 1975, my pal Mike Horne called me at home to say a naked-eye nova had appeared in Cygnus. I rushed outside. It took but a second to recognize the intruder.
Deneb is the Arabic word for "tail." The star represents the fanned tail of a long-necked swan that wings its way south along the stream of the Milky Way. On that particular evening it looked as if a tail feather had been plucked from the swan as it flew by.
Nova means "new," but of course the nova is not a new star. It is the sudden brightening of an old star near the end of its life when its energy balance goes askew, a star thousands of light-years away in our arm of the Milky Way Galaxy, too far away to be seen even telescopically.
The nova was short lived. By the following evening it had dimmed noticeably. Within a week it was visible only with binoculars. But while we had it, every night was a thrill. I remember the tingle in the spine and we watched its fading apparition night-by-night.
Nova Cygnus 1975 was the brightest nova of my lifetime, except for a southern hemisphere nova in 1942 (I was six years old). It was the only nova to reach the first magnitude of brightness. And it appeared at the very peak of my lifelong interest in the night sky.
I look back on those moments of celestial punctuation with gratitude and delight: nova, comets, fireballs, meteor storms, auroras. Unexpected gifts of beauty, scattered by the goddess Urania like banknotes from a royal carriage.