Mount Lemmon SkyCenter

A couple weeks ago, Adam Block, a well-known local astro-imager, e-mailed me about the December sunset alignment from the Mount Lemmon Highway. He mentioned that the Mount Lemmon SkyCenter, where he works, had just finished installation of a new 32" telescope, the largest telescope I know of available routinely for public observing. After expressing an interest in checking it out sometime, he invited Melinda and me to come up and assist with a large group he had coming up the next night for an evening program. How could we say no?!

Even though I work for Steward Observatory, I know little about the crop of telescopes atop Mount Lemmon. Working at Kitt Peak decades ago, I was more familiar with that site, and more recent telescope projects on Mount Hopkins and Mount Graham. I did know Mount Lemmon had several in the 60" range, and I also know that a 30" Schmidt and another 60"telescope is used by the Lunar and Planetary Lab for the Catalina Sky Survey, which discovers a large percentage of new comets and asteroids every month. The SkyCenter, opening a couple years ago with a 24" telescope, is open for public observing, as well as an advanced imaging program both with the new Schulman 32" telescope. Adam is the program coordinator for both, and from what we saw that weeknight, does an outstanding job of bringing the universe to those taking part in the program.

The SkyNights program actually starts late in the afternoon, well before sunset. Upon arrival, the visitors are escorted into the telescope for a daytime orientation. On this date they got to observe the bright star Vega, the planet Venus, and also observe the sun with a specialized solar telescope. Arriving a bit before the crowd, Adam also showed Melinda and me the double star Albireo. I wasn't expecting the couple hundred magnification that the "low power" provides and was stunned by how wide the double star appeared, and also how pinpoint sharp the images were in broad daylight. I couldn't wait for the night time viewing!

From the telescope, the 20+ visitors were escorted to the Learning Center, part classroom, part dining hall and part living quarters for overnighting astronomers. We all had a dinner (sandwiches, chips, salad, cookies and a variety of snacks and drinks) along with a slide show orienting us to the universe, using some of the spectacular images Adam has gained a reputation for taking. Binoculars were distributed, as well as planispheres to find our way around the sky later. As sunset approached, we walked 150 meters or so to an overlook with a western view. There were some clouds blocking the sunset, but we did get some nice colors, and Kitt Peak National Observatory, a flat-topped mountain to the southwest, was pointed out for binocular viewing. On our stroll back to the Learning Center, Adam pointed out the shadow of the Earth being cast into the sky - often observed but rarely noticed!

Finally darkness came and all of us returned to the telescope dome (all transit atop the mountain is by bus, to prevent exertion at the 9160 foot elevation of the site). Adam definitely had an agenda for the sky tour - showing the ghostly glow of a planetary nebula from a dying star, to the clouds of gas where they are born. Between those were views of open and globular star clusters with hundreds of thousands of stars. In the photo at left, visitors lined up to look at M13 a globular in Hercules with the Summer Milky Way visible through the dome slit. After a few objects, Adam lead the group outside where everyone found their way around the sky using the planispheres. In a "final exam" Adam used his laser pointer to point to a few objects, and visitors needed to identify the star or asterism. In the photo at right, the group uses their red lights to read the starmaps as Adam uses his green laser pointer (faintly visible at center).

Saving it for the final viewing highlight, Adam waited for Jupiter to rise as high as possible to improve the view. While claiming that "the seeing could be better", there was an abundance of detail in the cloud bands, and even in a few minutes of observing, the motion of the innermost moon Io could be detected. Unfortunately, the planet's permanent anticyclonic Great Red Spot was not visible, but still the view was a suitable climax to a great night of observing. Many thanks to Adam for the invitation to join the group, and no doubt we'll be returning to the SkyNights Program, both as visitors and helpers if our efforts are needed again.