Triple Tail

On April 8, a friend joined me to observe Hale-Bopp at my nearby and nearly-dark site at Lake Zumbra. We enjoyed watching the very young moon set, then went about preparing to take some pictures. I was hoping to get a shot taken at a smaller lens aperture so the stars would have less distortion than in my earlier photos.

We were able to make three exposures of the comet. Two of the three showed a tracking problem: the weight shifted across the drive gear during the exposure. The result looked like a double exposure with every star appearing twice, once while the motor was "pushing" the gear, and again with the gear pulling the motor. The separation is a measure of the backlash in the system.

Fortunately, one frame turned out. The stars are mostly quite sharp little points. Their relative colors also show up nicely. The comet itself has a broader dust tail than a week earlier; and the ion tail seems to have two parts! Is this the "invisible third tail"?

The stars above the comet belong to the constellation Perseus. Just to the right of the comet's head is a tight grouping of stars. This is M34, an open cluster, the 34th entry in the famous Messier list of "non-comet" objects.