Astronomy Class - AM

Students from this spring's second session of three-week intensive astronomy course visited Stephens Memorial Observatory this morning to take a look at our Sun. This class was luckier than the previous course's students for we were blessed with mostly-clear skies, reasonably steady seeing, and a sunspot (#1072). Using the big Cooley Telescope and a modern white light solar filter over the objective, we looked at the solar disk as a whole with the low-magnification eyepiece and could see traces of, I suspect, "supergranules" and the lonely sunspot floating in the lower left-hand portion of our field of view. At about 122X granulation wasn't apparent but good detail could be observed in the sunspot! When seeing was best we could easily make out the shape of the umbra (dark central portion of the spot) and the filaments of the penumbra. Interestingly it seemed almost as if the entire assembly was encircled by a solid line cleanly separating the spot from the rest of the solar atmosphere. There have been very few sunspots to observe and (seemingly) fewer clear days during which to observe them so the morning session was a real treat. The visit lasted from about 9:00 to 10:00 when the students returned to their classroom... for mid-term exams! If they survive their tests and the sky is clear, we plan to have a nighttime visit from the astronomy class with the Moon and Saturn as featured attractions.

Image credit: SOHO/MDI - image "flipped" side-to-side to illustrate telescope view.

A break in the weather

I had a public open night scheduled for July 12. The weather forecasts and the weather conditions called for mostly cloudy skies all night with a high chance for rain. Reality set in, however, with breaks appearing in the clouds at about 8:00 PM. I headed to Stephens and arrived a little after 9:00 --our announced start time-- to find a family of four waiting at the door. No sooner had I uncovered the telescope and opened the dome than the clouds began to break. At first we grabbed a few seconds of viewing at a time through passing holes in the clouds. Soon, however, the clouds scudded away to the east and we had a clear view of the waxing gibbous Moon -- our main subject for the night. After the family left there was a quiet period when I played with my camera once again to grab a few afocal shots of the Moon as I did a month earlier.

I put the camera away as more people began to arrive. We viewed the Moon at about 30X through the excellent vintage eyepiece and again at about 100X through a modern Plossl eyepiece. Later we waited for Jupiter to rise in the southeast above the neighbor's trees. Those were awkward moments waiting but those who stayed were rewarded with very good views of the huge planet. At 100X we could make out two major cloud bands, perhaps a bit of detail in the atmosphere around the bands, and the four Galilean satellites arranged to one side --on the right, as seen through the eyepiece-- in two pairs.

In all 29 visitors came to the Observatory. The clear sky was a welcome surprise and I was glad I trusted my instincts and made the trip to Hiram; I was going to cancel. The last visitors left at about 11:10 and I, sweating profusely in the warm (~ 80 F) and extremely muggy atmosphere (ground haze and mists, heavy dew on everything), was happy to close the dome and head home in an air conditioned car! By midnight the sky had become 100 percent overcast once more and rain developed overnight ... that part followed the experts' predictions!

Images: The waxing gibbous Moon as seen through the eyepiece of the Cooley Telescope of Stephens Memorial Observatory. Fuji Finepix S7000 digital camera: ISO 400, 1/200 sec., f/4.5, July 12 at about 8:37 PM Eastern Daylight Time. Large image is in color; detail shows color removed. South is up. Photo by James Guilford.

19th and 2st Centuries meet

I went to Stephens Observatory and was able to use the 2-inch adapter to mount my Canon Digital Rebel XT camera to the century-old Warner and Swasey telescope with its 9-inch Brashear objective. All of the photos are a bit softer than I'd like but not surprising but two were fairly good. Quality suffered in part because of trees surrounding the site, the photos were all made in bright twilight. And the atmosphere was unsteady. I was at the limit of inward motion on the eyepiece holder so I couldn't experiment with focus. Still, this first success pleases me and I can hardly wait to try again under better conditions! Moon images were all made between about 8:40 and 8:45 PM when Luna moved behind high trees to the south-southwest of the dome. Didn't try Jupiter because it just didn't look good enough -- details barely distinguishable by eye. I did learn, however, that placing a neutral density filter at the eyepiece improved the quality of Jupiter's appearance to the point where, instead of a brilliant blank disk, I could visually make out the two major cloud bands. I took a long break and then went into my continuing efforts to learn aiming the telescope by celestial coordinates. I believe I succeeded in finding M22 by this method but had trouble with other objects. So there is a lot of work remaining. Spotted M9 with binoculars though dim objects were hard to spot this night. Saw one fast-moving satellite in the telescope's field of view. Surprising and delightful was seeing the Milky Way span the sky nearly overhead -- a wonderful way to end the evening (really the night) at about midnight. Came home and had to view my photographic efforts and that kept me up til about 2:00 AM. My favorite image is seen here. There's chromic aberration at the edge of the lunar disk but it isn't bad considering the optics of this 9-inch achromatic doublet are 107 or so years old -- uncoated and no filters! I sent a copy of this photo to a local newspaper to see if they'll use it and give us a bit of added publicity.

Reinstalled Cooley clock drive

Spent the evening at Stephens Memorial Observatory (SMO) tonight and finally got the mechanical clock drive reinstalled. I still must hang the drive weights and test the system (especially running speed) but I believe the hard part is done. To celebrate I took a look at Saturn. That was a little difficult because it was very high in the sky. I wound up kneeling on the floor to observe. Skies were clear but not the most transparent. Still the view was very good at around 100X. There was a hint of banding in the body of the planet and I could make out the shadow of the planetary sphere falling across the ring plane. Too uncomfortable to view for long, though! The Moon had risen so I used the brilliant --BRILLIANT-- full disk to better align the finder scope. It will probably take two hands to do that job right, but aim is better than it was. I had two visitors: a man with his son who saw lights on and decided to see the telescope. They arrived just after I did so they got no observing and apologized for dropping in and distracting me from my work. Hey, it is great to have such interest in the reawakening of SMO! Closed up the dome at 9:45 PM and headed for home. The sky went from clear to overcast during my trip home so I guess things timed out just fine.