A fortunate dozen spent a night on Thursday with one of the largest telescopes in the United States, happy to be gazing at some great deep-sky objects.
The Lowell Discovery Telescope (LDT), a 4.3-meter optical telescope operated by Lowell Observatory, is pictured on a clear winter day near Happy Jack, Arizona. Credit: SSR2000/Wikimedia Commons (CC BY-SA 3.0)
When you become a young observer of the skies, happy to be out in a dark field at night with a 6-inch or 8-inch scope, you never dream of the kind of night of observing I experienced on Thursday, June 5. I am in Flagstaff, Arizona, during part of this week, spending some time at the annual meeting of Lowell Observatory, a member of its advisory board. On Thursday, a fortunate group of a dozen of us journeyed for an hour south and a little east of the city to the institution’s largest telescope, the 4.3m Lowell Discovery Telescope. We spent an evening looking at deep-sky objects in what was a deep-sky observer’s dream.
The distinguished astronomer Gerard van Belle drove us in a Lowell van, and we arrived at the summit of this great telescope in early evening. A bright Moon was out, and the sky cleared pretty nicely after a couple of days of mostly cloudy weather in the area. Our guide for the evening was another Lowell astronomer, Stephen Levine, who operated the telescope and chose targets we would observe. For an enthusiastic sky observer, it was like being struck by lightning and going to heaven.
Our guides could not have been better. Stephen is the Lowell Discovery Telescope’s chief scientist, and his research interests are many, including astrometric surveys and the numerical simulation of the dynamics of astrophysical disk systems. He also conducts stellar occultation studies of outer solar system objects. Gerard is the observatory’s director of science, and his research areas include unique expertise in optical telescope arrays for carrying out observations at high spatial resolution.
Once we were settled in and discussed matters in the observatory’s control room, our group made its way up into the dome and prepared for observing. I’ve observed a few times with some very large telescopes, at Mount Wilson Observatory, Yerkes Observatory, and McDonald Observatory, but this was at the top of the list for aperture and a modern, cutting-edge facility.
It’s absolutely astonishing to see a mammoth, 4.3m telescope looming over you, fitted with a visual back and a 30mm Explore Scientific 2-inch eyepiece. Just amazing. It was like being transported into a wonderful episode of The Twilight Zone. The field of view of this huge telescope, at relatively low power, was only about 3 arcminutes across, so of course we were looking at small objects.
First up was the globular cluster M3 in Canes Venatici, and of course we saw essentially just the core of the cluster, nicely resolved all the way across its face into individual, yellowish stars. At its distance of 34,000 light-years, the cluster was incredibly bright in such a large telescope. Next, we turned to a guessing game. Stephen asked me, as a deep-sky nut, to guess what galaxy we were looking at. Of course being inside the dome, you really couldn’t see where the telescope was aimed, very accurately, although it was near the zenith. Well, I didn’t know, and it turned out to be a close-up view of the Whirlpool Galaxy in a way that was completely different than I had ever seen it before. We saw just the bright central hub of M51 (the companion, NGC 5195, was well outside the field), with a few sparkling field stars and with the start of large, glowing, spiral arms emanating from the hub, with stark, dark areas of the field between the start of the arms. It was absolutely amazing.
We then went on to a planetary nebula (small and with high surface brightnesses, they are perfectly made for such small fields of view). It was the Cat’s Eye Nebula in Draco, NGC 6543, and looked incredible — just completely different than I had ever seen it before. It presented a strong blue color, rather like a robin’s egg blue, and a prominent disk surrounding the central star, with some hints of “spiral” structure throughout the disk, and easily showing the bright central star, which glows a little fainter than 11th magnitude.
The whole experience was beset with great and funny discussions with the astronomers and other guests, and we arrived back on Mars Hill late at night, far richer for the experience, and very glad to have gazed visually through such a large telescope. I hope this is an experience that every fan of astronomy has the chance to do at some time in their lives.
