Some Astrophotography for Your Long Wait
It’s crazy how easy it is to get distracted from writing. All it takes is one day to go by without writing, then you go a week without writing. A week turns int two weeks, which becomes a month. Before you know it you haven’t posted anything on your blog since August! I’ve done many things worthy of writing about since August including trying my hand at astrophotography for the first time, attended to two star parties, almost been killed by someone spotlighting deer while observing in southern Maryland, and failed to observe comet ISON several times before its unfortunate demise on Thanksgiving. There has also been loads of astronomy news since my last post as well.
I’m mad at myself for slacking off so much over the last five plus months but I’m back and better than before! To make up for the absence of posts since the summer I will share with you all the (best) astrophotos I managed to take during the summer. Back in July I borrowed 80mm refractor telescope and an German equatorial mount from my astronomy club to assist with a star party I was planning on hosting for my friends. The star party never worked out due to weather and other factors but I got to try my hand at proper astrophotography for the first time. I had absolutely no prior experience using an EQ mount so this was all very new to me. The key part of deep sky photography is aligning the mount with the celestial north pole, or CNP. Since long exposures are needed to collect the light from faint deep sky objects, what you’re imaging moves across the sky while your camera’s shutter is open. To compensate for the Earth’s rotation and keep the stars “still” in your telescope the mount you’re using has to be aligned with the celestial north pole, or the Earth’s polar axis. For people in the northern hemisphere the CNP is about 3/4 of a degree away from the star Polaris in Ursa Minor. That’s why Polaris is known as the North Star, or the Pole Star. Everything else in the sky appears to rotate clockwise around Polaris.
I was never good at polar aligning the mount so that severely limited what I was able to image. I was stuck with exposures of 30-40 seconds. Nevertheless, that’s still good enough for a couple familiar objects such as the Andromeda Galaxy, the Orion Nebula, and the Dumbbell Nebula. I had assistance from the Reddit community of astrophotographers. Their collective knowledge and wisdom was invaluable in my novice attempts to photography things many light years away.
The first object I imaged was the Andromeda Galaxy. Known by astronomers as Messier 31, on Charles Messier’s famous list of faux comets. M31 is best known as the Milky Way’s twin galaxy. The galaxy has roughly the same mass as the Milky Way but is 2.5 million light years away. Andromeda is the closest spiral galaxy to the Milky Way and is so bright it can be seen with the naked eye from darker skies. A small telescope reveals a giant bright and elongated fuzzy patch. Larger telescopes under dark skies may even reveal dust lanes on the north side of the galaxy. I chose M31 as my first target because of its brightness which would require shorter exposures.
Once the mount as telescope was set up and the mount polar aligned (as best I could do) I attached my camera to the focuser and began shooting away. The image below is a stack of 30 :40 images. I used Deep Sky Stacker to combine the images and Photoshop to process it. I did a poor job of framing the image so the bottom part of the galaxy is cut off. I hope to revisit M31 later on and do a better job. There are actually three different galaxies visible in the image! The obvious one is M31 but fuzzy oval located top left of M31 is another galaxy called M110 and at bottom right is M32. Both are elliptical galaxies, meaning they have no spiral structure, and are satellite galaxies of M31. They are both gravitationally bound to M31 and are, like M31, part of the Local Group of galaxies. These three galaxies are all next-door neighbors to the Milky Way.
The next object I imaged was M27, known as the Dumbbell Nebula. The Dumbbell Nebula is what astronomers call a planetary nebula. They actually have nothing to do with planets despite their name. A planetary nebula is what happens to massive stars right before they die. As the star ages it begins to shed its layers of gas as the nuclear fission in its core slows down. Our own sun will eventually do this as it begins the final stage of its life. M27 is the most well-known and studied planetary nebulae because of its brightness and close distance to Earth. For this target I used the same exposure settings, 30×40 sec and stacked in DSS.
One final image I’ll share is perhaps my favorite, for two reasons. One because of its aesthetic beauty and because of its difficulty to process in Photoshop. You’ll no doubt recognize the Great Orion Nebula. This giant cloud of gas and dust is where stars are formed. In fact, the Hubble Space Telescope has imaged many newborn stars within the nebula over the past twenty years. Known as Messier 42, the Orion Nebula is visible to the naked eye even in light polluted skies. The nebula is located in the sword of Orion that hangs from the Hunter’s belt. The nebula itself appears as the middle star is the sword but closer inspection with binoculars reveals something more than a star, but a bright greyish glow which is actually the nebula.
Just like as in the M31 image, there are actually three separate nebulae present in this image. The largest, and brightest is M42, an emissions nebula and its intricate knots of gas and dust in brilliant colors. Next to it is M43, also an emission nebula like M42. Emission nebula are named as such because they emit their own light from ionized gas that glows in an array of colors. The third nebula is the one in the upper left of the image. It is called NGC 1977, or the “Running Man Nebula.” NGC 1977 is what is called a reflection nebula, meaning the gas and dust doesn’t emit any light of its own, but rather reflects the light of stars inside or around the nebula. See if you can notice the running man pattern.
All these images were taken with a Nikon D3100 with a SkyWatcher ED80 refractor mounted on an Orion SkyView Pro EQ mount. The mount and scope were borrowed from the Harford County Astronomical Society (HCAS). My thanks to the club! Check out their website at http://www.harfordastro.org.
That’s it for now. I hope to be able to share more deep sky objects in the future. Until then clear skies and keep looking up!
Posted on December 9, 2013, in Astrophotography and tagged Andromeda Galaxy, Astrophotography, Dumbbell Nebula, M27, M31, M42, Milky Way, NGC 1973 NGC 1975 and NGC 1977, Orion Nebula. Bookmark the permalink. Leave a comment.