It's now 1999. For the next 12 months, we'll no doubt be subjected to varied Y2K warnings, numerous dire predictions, and endless chatter over whether we should celebrate in 2000 or 2001. (By the way, the only sensible solution is this: celebrate both!) Admittedly, the roll-over of the century is a notable event in anyone's lifetime. I think I have a handle on a century, having been alive for almost half of one. But a millennium? That one still has me stumped. It turns out that the Crab Nebula, or M1, has been around for a millennium. Well, more like 950 years, but that's close enough for astronomers. Can it provide some cosmic perspective? Its first thousand years go something like this:

July 4, 1054: Chinese astronomers note a "guest star" near the star Zeta in the constellation of Taurus The Bull. It was as bright as Venus, seen in the daylight for three weeks, and visible at night for two years. Changes in the sky were vitally important: human destiny was determined by the "cosmic winds." Native Americans may have recorded the supernova's appearance near the crescent Moon in pictographs in the American Southwest. There are no known European sightings.

1731: John Bevis discovers the nebula (Latin for cloud) with his telescope, recording its position on The Bull's right horn in his celestial atlas Uranographia Britannica (1745). August 28th, 1758: While observing the Comet of 1758, Charles "Ferret of Comets" Messier noted a "whitish light, elongated in the form of a candle flame." This object became Messier's first entry in his 1771 catalog of comet look-alikes. 1844: Lord Rosse observed and sketched M1, calling it for the first time the "Crab Nebula." Later sketches by Rosse, Mitchell and Lassell were far more accurate representations. It became apparent that it was a true nebula, not resolvable into stars even at high magnification. 1892: Isaac Roberts photographs M1, showing it elongated with an irregular outline, dark embayments, mottlings and rifts. 1913: V.M. Slipher's spectrographs reveals doubled, Doppler-shifted emission lines: the nebula is an expanding shell of gas. 1921: Astronomers recognize that the 1054 guest star and M1 were one in the same. The M1 nebula was what remained of the "guest" star that exploded, a supernova remnant. 1963: The first identified X-ray star, detected by a rocket-borne telescope was the Crab Nebula. 1964: By comparing photographs made in 1950, Virginia Trimble was able to visualize the growth of the nebula in the intervening 14 years. 1969: Discovery of radio pulsar in the Crab Nebula, then the fastest know, pulsing every 33 thousandths of a second. Later this year, optical flashes from the pulsar were seen on the television monitor at the Lick Observatory.

Over the last thirty years, study of the Crab Nebula supernova remnant has played a pivotal role in astronomy, bearing on everything from archaeoastronomy, stellar evolution and radio astronomy, to x-rays and neutron stars and to even more bizarre objects. Best of all, you can see it for yourself in the winter sky. November 28, 1998: My CCD image: 20-cm S-C, Cookbook 245 CCD, 4 x 60 s. February 1999: Why not make your own observations?

Perhaps it's too far ahead to begin planning a millennial celebration for 2054--assuming we survive Y2K, there's plenty of time! Even today, we think of the heavens as permanent and unchanging. True, by far most of a star's existence quiet. But the first thousand years of M1's stellar afterlife have been as dramatic out there as they have been momentous down here. And who knows what the next millennium will bring?

For more about the M1 and other supernova remnants: Paul Murdin and Lesley Murdin, Supernovae. Cambridge University Press, 1985 and Paul Murdin, End in Fire. The supernova in the Large Magellanic Cloud. Cambridge University Press, 1990. Moondark is written by Doug Miller and published in the Delmarva Star Gazers' Star Gazer News and in the Delaware Astronomical Society's FOCUS. Please address comments and suggestions to dmiller@udel.edu. This document was last revised on 24 January 1999. All text and images copyright © 1999 Douglas C. Miller, All Rights Reserved. This material may not be reproduced in any form without prior permission.