As February opens, Comet PANSTARRS (C/2011 L4)
is acting the way many comets do — unpredictably. Astronomers at the University of Hawaii discovered this object June 7, 2011. By now, it should have reached a brightness that would let observers from a dark site see it without optical aid. And although the comet is visible through even small binoculars, it unfortunately isn’t living up to predictions.
Comet PANSTARRS currently glows at approximately magnitude 7. Astronomers use the magnitude system to describe the brightness of any celestial object; the smaller the number, the brighter the object. Most people can see a magnitude 6 star from a dark site without optical aid. But, unlike a star, a comet is an extended object, so its brightness spreads out a bit. To reach naked-eye visibility, Comet PANSTARRS will have to rise fivefold in brightness, which, hopefully, will happen in about a week.
For complete coverage of Comet PANSTARRS, visit www.astronomy.com/panstarrs.
On February 1, the comet lies in the obscure constellation Telescopium
, and it is visible only to those who live in southern latitudes. On that date, from latitude 30° south (the approximate position of Santiago, Chile, and Perth and Sydney, Australia), Comet PANSTARRS will stand 15° above the southeastern horizon at the start of morning twilight. And it will lie 10° or more above the horizon through the 13th. Unfortunately, the comet will remain invisible to Northern Hemisphere observers throughout February.