Friends, Comet, Telescope...

Pat is a buddy and former workmate from seemingly a previous life. He is shown at left when he still worked at the Mirror Lab with one of our safety interns Delayne, standing next to the rear surface of the LSST 8.4 meter mirror substrate. Anyway, I was at his house tonight - I was thinking that his new 10" telescope would be perfect for a close-up view of Comet PanSTARRS. He recently bought my former G-11 mounting, and put his Meade 10" SN LXD75 on it - an F/4 Schmidt-Newtonian telescope that has a 1,000mm focal length.  He wants to get more into astro-imaging, so would be a good learning experience!

I arrived well before sunset and met Pat and his next-door astronomy buddy Byron, and we hauled the mount and telescope 50 yards down the street to a street corner where we had better horizons to spot the Comet. Byron had to leave, but Pat and I met the family who had just moved into the corner house and made new buddies as they observed with us.

First up was the moon, visible even with the sun still above the horizon. We were still uncertain that Pat's camera would focus with the telescope as its lens (Pat is new at this stuff), We were just short of being able to reach focus (the Moon is good as a test object for that). We were able to adjust the collimation screws to push the focus out a few more millimeters - that was all we needed. Pat was amazed at the view of the Moon in the camera's screen in magnified "live view" mode. We took a few quick snapshots, a full-disk shot at left and a cropped view at right. One thing before we move on, though... There are so many craters on the moon, it is always tough to establish scale. In the full-resolution shot at right, I labelled a couple craters with their known diameters to give an idea of what can be easily seen. Generally, the smallest craters or details seen in a moderate telescope is about a half mile or kilometer in diameter... Pat's scope seemed to work fine at resolving small details, though the triangular-shaped moons of Jupiter had us loosening the collimation screws to improve the images... But time to move on - we had bigger fish to fry!

The sun dropped down below the horizon and we searched for the comet. I'm used to a wider expanse of horizon to search, and here we had a narrow gap between houses. Did we pick the right scope location to pick it up? We finally spotted it in binoculars over the house diagonally across the intersection. With only about 10 minutes before dropping below the roofline, we moved quickly, getting it centered in the telescope. We could even focus on the comet's nucleus in "live view" mode - the starlike coma was that bright! Again, imaging in twilight required short exposures, only a few seconds, and just before setting behind the house we tried our longest at 10 seconds. Stacking 5 frames we got the image at left, approximately the same scale as the moon, so about a half-degree shown here. You can see that using the nucleus of the comet to align the images, the comet's motion trailed the stars - it moves a couple degrees per day, visible even in the few minutes we photographed it tonight... Sorry I don't know the exact orientation - the tail is approximately vertical seen in the sky, so North is off the upper right corner somewhere.

The moon is brightening, so will likely take a bit of a break from comet observing - give you a chance to recover from too many astronomical posts! I'm looking forward to seeing it in a darker sky in a couple weeks!