Events

An opportunity to see a comet without a telescope occurs this month. Comet C/2007 N3 Lulin is currently in the morning sky, near the center of the constellation Libra. It is slowly brightening as it nears the Earth. Perihelion, close approach with the Sun, occurred January 10th.

The comet is expected to reach fifth magnitude in late February, just bright enough to be seen from a dark location without the use of a telescope of binoculars. Mag 5 is not very bright and will require some effort to locate and see as a small fuzzy star. The view will certainly be much better with some form of optical aid, binoculars should show the comet well.

Comet Lulin was discovered by Asian astronomers in July 2007.¹ Chinese astronomer Quanzhi Ye, a student at Sun Yat-sen University (Guangzhou, China), found the comet on images obtained by Chi-Sheng Lin (Institute of Astronomy, National Central University, Jung-Li, Taiwan) at the Lulin Observatory. The discovery was a product of the Lulin Survey, an project to map small bodies in the solar system.

Because of the geometry of our view of this comet has two tails. The odd part is that one tail points in one direction and the other is seen in the completely the opposite direction, an anti-tail. Contrary to most expectations comet tails do not point behind the comet as it moves. The dust tail is buffeted by the solar wind and always points away from the Sun from the comet's nucleus. The second tail in this case is cometary dust in the plane of the comet's orbit. As the comet orbits in nearly the same plane at the Earth this dust is seen edge-on and becomes bright enough to be visible.

The photo at the right is processed to show both tails by inverting the image. Astronomers often use inverted images to more readily show faint structure that might otherwise go unnoticed. The normal tail is seen to the right of the coma, while the dust plane anti-tail is seen to the left.

The comet should be easily observable through much of February. An ephemeris of the comet can be found at the Minor Planet Center. For finder charts and magnitude estimates go to Seiichi Yoshida's comet page for Comet Lulin.



1) Discovery announcement in IAUC8857 published by the MPC, 18 Jul 2007