Comet 103P Hartley may surprise us in mid-October and become visible with the naked-eye. It is currently at 10th magnitude and expected to slowly brighten over the next two months. Current estimates place its brightness at less than magnitude 4.5 on the night of October 20th.
Tonight, 103P Hartley lies between Pegasus and Lacerta around 10 p.m. and should be visible in most telescopes and binoculars. Of course, it goes without saying that the darker the sky, the better the view of the comet will be.
By mid-October the comet will lie in Perseus, a few days later, when the comet is at its brightest, it will lie in Aurigae. By the weekend of October 22nd, it will rise a few minutes after 10 p.m. and will be high enough to easily view by midnight.
Here are the orbital parameters you will need for your sky mapping program to display the comet:
|Epoch||2010 October 28.2673|
|Closest approach to Sun (q)||1.058678 AU|
|Argument of Pericenter (ω)||181.1969°|
|Ascending Node (Ω)||219.7661°|
|Magnitude Parameter H||8.5|
|Magnitude Parameter G||8|
Keep Looking Up