The asterism of seven stars that make up the constellation Ursa Major - The Great Bear.
The Big Dipper can tell you where north is since it is a circumpolar asterism (from our latitude of about 42° north), all of its stars are visible regardless of the time of night or time of year. When you have located the Big Dipper connect the two outer stars of the bowl opposite of the handle, Merak and Dubhe. With an imaginary line extend that line up and beyond the open end of the bowl, the next star you will encounter (just over five times the height of the bowl away) will be Polaris, the North Star. Polaris is apart of the Ursa Minor constellation.
A lot of people mistake Polaris to be the brightest star in the night sky which is not true. Sirius is the brightest star in the night sky. People also confuse Sirius with the North Star. Polaris, at magnitude 1.97, is only about the 45th brightest star in the sky, and is in fact outshone by three of the stars the Big Dipper.
The constellations we are currently familiar with originate from “Ptolemy’s 48 constellations” compiled from ancient Greek constellations by Claudius Ptolemaeus (from 90 A.D. to about 168 A.D.). He was a Greek astronomer flourishing in Alexandria, Egypt in the second century A. D. In Hindu Astronomy the stars are known as the Seven Great Sages. Ancient Egyptians represented the stars as an ox’s foreleg. The location of these seven stars were very important to the ancient Egyptians and were monitored throughout the night and the course of the year.
1. Vintage Illustration 1800’s
2. Big Dipper (upside down) taken from the ISS in 2003 NASA
3. The Big Dipper above my house. I labeled the stars so you can find Merak and Dubhe.
Bioluminescence Under A Starry Sky One of the things I love about astrophotography is you never know exactly what you may capture on any given night. You may be lucky enough to get a meteor streaking across frame, or even a sky full of intense air glow.
And last night was just one of those unexpected nights which I would rate right up there as one of my best nights of astrophotography to date. The unexpected thing about this night, was not in the night sky, but rather in the ocean in the form of glowing bioluminescence. Every time the waves broke, bioluminescent phytoplankton was stirred up making the wave glow brightly even to the naked eye. This was certainly something I wasn’t expecting, and it looked amazing under the starry night sky!
This image is a single exposure shot on a Canon 6d in Byron Bay, Australia.
My first time photographing Andromeda. I’m pretty impressed with how it came out considering I was using an old, cheap vintage lens I bought earlier this year.
135mm @f/4 // 4 minute exposure // 400 ISO // Sony A7R II
Andromeda Galaxy - Messier 31 by David Baier Via Flickr: My biggest astrophotography project yet.
This image was taken during three nights: 29.11.16 / 30.11.16 / 01.12.16
Telescope: Omegon 126/880 f/7 Triplet APO
Mount: Losmandy G11
Camera: Canon EOS 6D Astrodon mod.
I finally did a little astrophotography again last night, experimenting with my new
Meade LPI-G color Solar System imager. This is the best shot I could manage, though I took four long-ish videos (yes, it takes live vids!) that saved in a weird format I can’t figure out how to open or edit, so that’ll be later.
Talk about a series of challenges, though! I wanted to use my apo refractor, because those are optimal for bright objects like the Moon, but when I pulled it out, I remembered I’d swapped its mount for a much sturdier iOptron… and the seller still hasn’t sent me the new controller and cables to make that function (and the mount is now in use with my solar telescope). OK.
So I put that away and grabbed my handy-dandy 12″ Schmidt-Cassegrain. I’d forgotten that I’d taken it apart to install a big equatorial wedge (so it can better track the night sky), but discovered while trying to install it that the wedge expects a slightly different pattern of holes drilled (too old, perhaps?), so I’d loosely re-assembled it. So I had to reassemble it, then haul it out into the yard. It’s a big puppy, btw.
Anyhow. So now it was set up, and I plugged in the extension cord and power supply, got it aligned properly so it could track the stars, and set it to show the Moon. Handily, the mount tracks for crap, and the Moon slowly drifted across the field of view. Which was WAY too high-magnification (another reason I wanted to use the much-smaller refractor: Without an eyepiece, the focal length of a telescope and its focal-ratio determine the magnification of an object, and a 12″ f/10 SCT acts like a REALLY powerful telephoto lens.
So now I went inside to grab my f/6.3 focal reducer, almost halving the magnification, so the Moon only sort-of overfilled the field of view. Ready to go!
Next, I slid the little astro-camera into the eyepiece holder, plugged it into my laptop, and WOW! Live, streaming images from space! Except it still drifted across the field of view pretty quickly. *sigh* Well, at least Moon shots don’t need very long exposures, so you can get pretty sharp images even when the mount doesn’t properly track.
Forgot to mention it was frakkin’ COLD. What stopped me from continuing to take images or try to improve the mount’s tracking is that my fingers were getting too stiff to work properly.
Anyhow, here’s one of the shots I got. The neat software that comes with the camera has some nice processing tools that also allowed me to sharpen the image a bit.
Oh, and despite the ridiculousness of trying to take a deep-sky photo through a telescope on a problematic drive on a moonlit night,
I also tried my hand at photographing the Great Orion Nebula. I think this little camera will be AWESOME once I get to use it on a properly footed telescope. Check it out!
The Moon shot, at least, is not too bad for my first time doing astrophotography in years, and the nebula shot shows great promise,
especially considering I took this through a telescope that wasn’t tracking correctly while freezing to death and using new
software I don’t really yet know how to use!
(BTW, you can click the images to see higher-resolution versions.)