After a night of astrophotography challenges, awe and wonder at the night sky
It was night of multiple problems getting the telescope, laptop and other equipment set up and synced, but it yielded images of the ancient stars in M13
Editor’s note: A version of this has been previously published on the author’s website.
I drove to a dark-sky site near Vernon, Tooele County, Utah, on May 27 to do some astrophotography.
This was a patch of U.S. Forest Service land, one of several cleared of native brush for the benefit of campers. It was bordered on three sides by a rail fence and had a fire pit edged with rocks. Far-off mountains were blue in the shadows and pink-gray where the late afternoon sunlight shone. I leisurely set up my equipment, sometimes resting on a cot and watching the clouds — at first ranges of scattered white puffballs, then thin, moving horsetails. What a relief to get out of the city.
Through the night, I dealt with more than the usual difficulties. Using a compass in my iPhone, I thought I had aligned the telescope on due north while setting up in daylight, but when Polaris shone through the dusk, I found the telescope was impossible to aim at the star without shifting the tripod.
In the midst of this, my flashlight batteries gave out. All of them. The only light I could rely upon was the beam from the iPhone, and its battery was low, too. Fortunately, I had brought a charger, and I plugged it into my AC line to keep the phone charged.
Meanwhile, coyotes — which I love to hear — ripped out only a couple of yips before they stopped abruptly. People camping a fifth of a mile from me had begun playing music loud enough to spook them — I presumed that’s why they quieted — and loud enough to intrude on my sense of solitude.
Mercifully, the music shut off at 1 a.m. Now I had a new obstacle — the laptop balked at simultaneously running the photography program and the guiding program. Also, the latter needed to make a new set of “dark” images to cope with bad pixels produced by the guide telescope. Several tries were needed to get both programs to cooperate.
Then the telescope halted and groaned. This required shutting it down and going through the alignment procedure from scratch.
My main goal was to photograph the spring galaxy Messier 106, where a new supernova had exploded. However, by the time I was ready, 3 a.m. or then-abouts, the galaxy was too low on the horizon to provide a good image. I decided to go for Messier 13, the most magnificent globular cluster in the northern hemisphere.
In the finder, it was a vague patch as seen with light-bothered eyes, but I was able to start tracking and photographing.
Globular clusters are dense groups of stars bound together by gravity and orbiting a galaxy. Several are bright enough to see with the naked eye, although without a telescope or binoculars you can’t distinguish the individual stars. Some — like Omega Centauri, which is easily visible in the southern hemisphere and at times can be glimpsed from parts of the northern — are so bright that they were once mistaken for stars. Omega Centauri means the cluster is the omega, or 24th, brightest “star” in the Centaurus constellation.
The Hubble Heritage Team, NASA and the European Space Agency report on spacetelescope.org that “stars (are) moving about in the globular cluster M13,” 25,000 light-years away. The more than 100,000 stars “are packed so closely together in a ball, approximately 150 light-years across, that they will spend their entire lives whirling around in the cluster.”
NASA’s Goddard Space Flight Center in Greenbelt, Maryland, adds on nasa.gov that at magnitude 5.8, M13 is one of the brightest globulars visible from the Northern Hemisphere. According to the flight center: “Because they are so densely packed together, the cluster’s individual stars were not resolved (shown as separate objects in the telescope) until 1779. Near the core of this cluster, the density of the stellar population is about a hundred times greater than the density in the neighborhood of our sun. These stars are so crowded that they can, at times, run into each other and even form a new star. The resulting ‘blue stragglers’ appear to be younger than the other stars in their immediate vicinity and are of great scientific interest to astronomers.”
As mentioned in a blog almost two years ago, around 150 globular clusters orbit the center of our galaxy, plunging into and out of the Milky Way’s plane. Researchers at Georgia State University say these stellar concentrations number “hundreds of thousands, and sometimes millions of stars” and are thought to have populated a sphere around the early galaxy before it flattened into a disk. “Star formation would have stopped in these clusters maybe 13 billion years ago, so only old stars are expected to be found there.”
Stars in the galaxy’s disk sweep up dust and gas and continue to change. “The objects in the Galactic Halo are at least 10 billion and perhaps as old as (nearly) 14 billion years old,” they note. Astronomers’ latest calculations place the age of the universe as close to 13.7 billion years, according to NASA.
It was so cold that morning that I would have the telescope start taking 30 to 60 images, get in my Jeep and huddle under blankets, stumble out again and have it take another series; this continued until the predawn light interfered. While they were appearing on the laptop I was pleased to see that most photos looked sharp and that the tracking kept the pointing accurate. I was too uncomfortable to think about them beyond that.
At home, when I processed and stacked the photos, I saw that they weren’t as good as I would like. But looking at the final version, I am moved by the cluster’s age, history and beauty.
Fifty-five years ago, I was snorkeling in about 20 feet of water above the dropoff of the Kwajalein Atoll in the Marshall Islands when a large marlin cruised past from the ocean, rapier bill pointed straight ahead, stripes on its body, the sail on its back bent toward the tail. I floated nearby, suspended in surprise and awe. Its sleekness let it glide almost effortlessly, a perfectly adapted big predator. It grew dimmer as it moved farther into the lagoon. I watched until it disappeared. That took only a few seconds.
Completely independent of our species, like nothing on land, it radiated a powerful natural beauty that the visitor from the dry world sensed immediately. I was granted a look into another reality.
That feeling of awe and wonder comes over me now, thinking about the beautiful M13, its 100,000-plus stars circling around in a ball and orbiting our galaxy for 12 billion years — so far.
Joe Bauman, a former Deseret News science reporter, writes an astronomy blog at the-nightly-news.com and is an avid amateur astronomer. His email is firstname.lastname@example.org.