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Comet Hale-Bopp's Light Curve Is Rising Faster Than Ever


Mark Kidger

As visual observers will be aware, Comet Hale-Bopp has just passed magnitude 0 and seems to be increasing in brightness faster than ever. The light curve which I have compiled now has over 800 observations, nearly half of them made during the last 4 weeks. This allows the recent trends to be defined very accurately and is a tribute to the excellent quality of the observations that so many people are making.

The latest light curves are at

Around about 10 days ago the light curve gave another small jump upwards and far from the rate of rise slowing as the comet's geocentric and heliocentric distances stabilise, it appears to be brightening faster than ever. Because we are now so close to perihlion this probably will not mean too much in terms of the peak brightness, although I am now optimistic that the peak may be slightly brighter than magnitude -1.

This is the first time I can remember that a long period comet has ever consistently run above the predictions in this way, so close to perihelion.

Recent data shows that the observers who go to Mongolia for the weekend's eclipse may be in for a spectacular experience. Recent tail length estimates have also exceeded most predictions with observers even in poor sites reporting decent tails. As of this week, with the comet's phase angle, a 16 degree tail was equivalent to around 80 million kilometers of true length. There have even been some reports of much longer tails, although these imply quite amazing true lengths.

Mark Kidger - March 7, 1997 comethome.gif Comet Hale-Bopp Home Page