Category Archives: Astronomy

The Joys of Country Living

People often ask me, “Doug, why do you live so far out in the country? Wouldn’t it be easier if you lived closer to campus?” Well, sure my commute would be a bit shorter, but then I’d never see night skies like this from my driveway.

Our Milky Way Galaxy extending up above my barn. This was taken on Friday, August 17th around 10pm-ish.

During late summer and early fall, if you look to the south in the evening, around 9-10ish, you’ll see the constellation Sagittarius, or more likely a subset of it the asterism of The Teapot. When you’re looking at The Teapot, you’re also looking toward the central core of our galaxy and the disc of our galaxy will extend almost straight upward from it. If you live in the city, this magnificent view will be denied to you by the copious amounts of light pollution from street lights and security lights. In order to get the view I get to see every clear night, you have to drive away from the reach of all those city lights. Getting to see the night sky like this is well worth the extra commute time for me!

This photo is a combination of 28 images each taken at a focal length of 18mm with an aperture f/5.6 and a shutter speed of 6 seconds at ISO 3200. I simply sat the camera on a tripod, locked down the shutter button, and walked away for a while. The images were combined using Deep Sky Stacker, a piece of freeware that automatically rotates and aligned a stack of individual images. It doesn’t take a fancy camera, just patience and good skies.

Imaging the Night Sky in Motion

So I’ve been meaning to try something new for a while now and I just got it worked out (sorta) this past week. I’ve always enjoyed photographing the night sky, but I really wanted to work on taking images that showed the sky in motion. It’s so easy to go outside, glance up at the sky, and think of it as static and unchanging, but if you look carefully enough, you’ll see that it’s in constant motion. I did a lot of work last year imaging the sky in a static way, either by shooting through a telescope with a clock drive, or by stacking a succession of individual images. While I really enjoyed some of the images that I captured through those methods, they didn’t really portray how rapidly things move around in our night sky.

In thinking of ways to demonstrate this motion, the first obvious choice was to do a typical “star trails” image. I’ve attempted these type of images before, but this past week, I tried to up my game a bit. My trails images before were only about 10 to 15 minutes in length, but the one I took last Thursday was approximately an hour-long exposure. The resulting image turned out pretty good, all things considered. I have a dusk-to-dawn light (that I need to put on a switch!) that’s great for security, but not so great for viewing the night sky. To combat its effects, I set my camera up on its tripod on the far side of my barn so that the barn blocked most of the light. The trees and surrounding ground, as you can see in the image, were still fully illuminated. My light and others around the area also light up the sky, so rather than a deep, dark background sky, I got a kinda pink-ish background. The star trails themselves, came out great.

Here’s the EXIF data for the image.

Camera Nikon D7000
Exposure 3099
Aperture f/5.0
Focal Length 18 mm
ISO Speed 200
Exposure Bias 0 EV

Even if you don’t have a tripod, you can still try this type of shot for yourself. You will need something to keep the camera steady. A beanbag or a bag of rice will work just fine. You will also need a remote shutter release. Find either a bright star or planet and manually focus on it, then set your camera to manual mode and set the shutter speed to “bulb”, and your aperture to your lens’ sweet spot. For the lens I was using, that happens to be about f/5.0. Even though it’s night, don’t use a high ISO. The length of the exposure will gather all the light you need. Once it’s ready, lock the shutter button down and go back inside where it’s warm and wait. 🙂

Practice, practice, practice, and share your star trails pics, tips, and suggestions in the comments section below.

Astrophotography FTW!

I had hopes of doing a LOT more astrophotography than I actually did over the summer. It seemed like every time I was home and free, it was either cloudy or so humid that dewfall was a constant problem. This weekend, I finally had time and good skies to go out and take some deep sky images. Some pics turned out, some didn’t. …I really need to work on my planetary photo skills.

I was able to capture a decent image of The Andromeda Galaxy, M31, and the Dumbell Nebula, M27. In both cases, I used JCCC’s 8″ Meade SCT on LX200 base mounted on an equatorial wedge with my Nikon D7000 mounted on the back. My alignment wasn’t great, so I couldn’t integrate any longer than 10-15s per image, but I took a few dozen images of each object and stacked them to produce a single long-exposure equivalent image.



I’m hoping to get some solar images today, so check back later for some new shots.

Beware of People Wearing Tin Foil Hats – Comet Elenin

As an astronomer, I hear all kinds of crazy conspiracy theories about what the government and scientists are trying to hide from the general public. I can’t speak about what the government may or may not hide, but I can say that by and large scientists don’t much care about the opinion of the general public when it comes to their assessment of data and the analysis of what those data imply about our Universe. First and foremost, we are beholden to data collected through methods that can be replicated and verified by others. This is where the “Comet Elenin is a space ship” or “Comet Elenin is a dwarf star” or “Comet Elenin is going to strike the Earth” conspiracies fail.

Comet Hale-Bopp imaged by my predecessor Paul Tebbe.
As with many other conspiracy manifestos and ramblings, the YouTube videos I’ve seen regarding Comet Elenin have been more like Star Trek technobabble than science. It seems as though people pull a word from here, a piece of jargon from there, and try to stitch together the biggest gloom-and-doom story imaginable. The fact is, there are a lot of highly trained and skilled eyeballs on this comet. It was originally hoped that since it was to come reasonably close to Earth, 90 Lunar orbital radii, that it might provide a nice show in our night skies much like Comet Hale-Bopp did in 1997. Unforutunately, Elenin appears to have fragmented and faded in intensity. No awesome comet show for us. However, there won’t be any world-ending catastrophe, either!

Comet Elenin is a space ship:
Ok, if someone actually believes this, I don’t think there’s anything that can be said to dissuade them short of actually taking them to the comet and letting them stand on its surface themselves. …but then perhaps even that won’t do it. All I can say is that it looks like a comet, acts like a comet, and orbits like a comet.

Comet Elenin is a dwarf star:
A comet is an icy body which appears to us as a fuzzy ball with an extending tail as the comet approaches the Sun. The sunlight heats up the sunward side of the comet causing the ice to vaporize creating a temporary atmosphere of sorts for the comet nucleus. The dust and gas released from the surface of the comet as the volitiles (water, carbon dioxide, cyanogen) vaporize are blown back by the solar wind, creating the tail structure. A dwarf star by comparison is a …well… STAR. Its a ball of incandescent gas made hot by thermonuclear fusion of hydrogen at its core. The smallest of these, a brown dwarf, although small by stellar standards are still at least 80x the size of Jupiter. Comet Elenin is most definitely NOT a dwarf star.

Comet Elenin is going to impact the Earth:
While having an extraterrestrial impactor strike our planet, either a comet or asteroid, will likely occur at some time in the future, it’s not going to happen with Comet Elenin. Comet and asteroid strikes are a large concern to the scientific community and NASA’s Jet Propulsion Laboratory (JPL) has a Near-Earth Object (NEO) program in place to identify and track potentially hazardous objects. You can read more about Comet Elenin’s trajectory on JPL’s Asteroid Watch.