Copyright 2009 Glen Ward and Starry Mirror
Astronomy From West Virginia
COMET HARTLEY 2 DISAPPOINTED IN THE FALL OF 2010
Flemington, WV - Comet Hartley 2 disappointed us in the Fall of 2010, as the comet's diffuse appearance made it difficult to see during its close pass by the Earth.
I first spotted the comet back in September. It was brightening and appeared at about magnitude 8. It was already looking overly fuzzy, though, and this diffuse appearance is what made it such a let down when it made its close pass a few weeks later.
In early October, I managed to look right at the comet without seeing it. It was then passing very near the Double Cluster in Perseus, yet it was so dim and diffuse that it was not noticed in the ten inch telescope I was using to show my sister the clusters. When we checked the coordinates of the comet later that night with the hope of observing it, we felt a little silly...
By the time of the comet's close pass by the Earth in late October, its angular size had greatly increased, but the apparent surface brightness was so weak that many friends were reporting an inability to see it in binoculars. The comet was like a ghost, because while the coma was reported by imagers to be twice the size of a full Moon, it was possible to track down its exact position with charts and still not see it.
The best instruments for observing the comet were very high contrast refractors. This was very similar to the Comet Macholz of 2004, which was nearly invisible in larger reflectors but which was easy to see in a four-inch refractor. With the small refractor, I was able to show the comet to two visitors from China. Though they had a hard time making it out, they did eventually see the visitor. - GW