Pictured from left to right are exploding Comet LINEAR X1, sungrazing Comet ISON, short-period Comet Encke, and the brightest of them all, Comet Lovejoy.
Image credits: Sormano Astronomical Observatory (Nov. 7, 2013)
The discovery of C/2013 R1 Lovejoy by Australian amateur astronomer Terry Lovejoy, was announced on Sept. 9, 2013.
All four are visible in binoculars or backyard telescopes, and Comet Lovejoy (mag. +6.0) is visible to the naked eye from dark-sky sites. Comet ISON is actually one of the faintest of the group; only expanding Comet LINEAR X1 (mag. +8) is more difficult to see.
An apparition of so many comets at once is a rare thing, and amateur astronomers are encouraged to wake up early for a tour of the pre-dawn sky.
Dates of special interest include Nov. 15-18 when Comet LINEAR X1 passes by the bright star Arcturus, Nov 17-18 when Comet ISON has a close encounter with Spica, and Nov. 18-20 when Comet Encke buzzes Mercury.
These stars and planets make excellent naked-eye guideposts for finding the comets.
Meanwhile, bright Comet Lovejoy is approaching the Big Dipper; if you can't see it with your unaided eye, a quick scan with binoculars will reveal it.
Sky maps: Nov. 10:
Sky Maps: Nov 11, 12, 13, 14, 15, 16, 17, 18, 19
via and credits SpaceWeather