Saturday, July 28, 2007

July open night -- Jupiter rules!

Tonight was a scheduled open house at the SMO. The weather (cloud cover) was extremely doubtful but there was enough clear sky that I felt I had to make the drive out and open the dome. Good thing I did! All told about 12 visitors stopped by over the evening with the last leaving after 11 PM -- they were the same two ladies who showed up as my first visitors at about 9:30! We had surprisingly good views of Jupiter considering sky conditions but a long wait for the Moon to climb out from behind the neighbor's trees. Cloud bands were fairly easy to pick out on the planetary disk. The four Galilean moons were also easy to see and point out to guests. No neutral-density filter necessary. When Luna finally rose high enough we had to wait for breaks in the clouds -- most people seemed to think the wait was worth it. Views at around 100X weren't very special --soft details, probably the atmosphere-- so I switched to a low-power, fist-sized antique eyepiece and the entire view was changed. We could see the entire nearly-full Moon in the field of view with good detail overall and excellent seeing at the terminator. Even thin clouds scudding across the lunar disk seemed to add, rather than detract. So not too bad a night. My Moon photo (below) apparently was published in Ravenna's Record-Courier newspaper... I've gotta try and get a copy!

Saturday, July 21, 2007

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.

Monday, July 2, 2007

Solar photo experiment

At Chaunticlair this afternoon I experimented with my AstroZap Baader solar filter and coupling of my Canon Digital Rebel XT to the Meade 390 telescope. I had cobbled together pieces of at least two different camera adapters to come up with a short one that would fit the Canon to the 1.25-inch eyepiece holder of the telescope. The combination focussed easily but the images were a bit disappointing. I had hoped and expected (based on the Cooley Telescope experience) that I would see sunspot and granulation but didn't see any granulation at all! Visually the sunspot showed good detail --today Sunspot 961 was nearly dead-center on the Sun-- but didn't image well (1/1,000th second @ ISO 400). I'll keep trying! Tonight I used the 390 and took a look at the pairing of planets Venus and Saturn in the twilight sky. With the 32mm (about 31X) eyepiece I was just able to fit both planets in the same field of view and got a very nice look at Venus in crescent phase -- the best I've seen it-- with Saturn tiny but distinct. The twilight actually helped by controlling the contrast of brilliant Venus. Swung the telescope around and got a nice look at Jupiter, as well, viewed through openings between the trees here at home. At the end of the brief evening clouds began moving in as I attempted photographs of the Meade 390 pointing towards Venus and Saturn in the fading twilight. The image didn't turn out as well as one I had seen and was imitating but it isn't bad, either.