View Full Version : Another astrophoto

08-28-2011, 07:05 PM
Last night was spectacularly clear with a very transparent sky. No haze and no light pollution from town. The Milky Way stood out like a banner of distant flame across the sky. I used my Cannon 1000D with an old 28mm lens adapted to take some long exposure of the sky. This image is a composite of two sets of stacked images. Each stack is 4 exposures x 5 minutes for a total of 20 minutes per final frame. The images have been adjusted to increase contrast and saturation but all colour hues came from the actual exposures. If only our eyes were more sensitive, especially to colour, this is how it might look.

This first is a thumbnail with a larger image below. Even the large image sacrifices a lot of quality since the full size image has 4 times the resolution.

These images didn't use the telescope but they were made possible by the accuracy of the drive. The camera was mounted on the front of the telescope.


In this larger image there are major regions of ionized hydrogen visible as reddish pink areas. There are also numerous open star clusters. An open cluster is a group of stars that are at approximately at the same distance from earth and are to some degree gravitationally bound to each other. The image is warmer near the bottom because it is closer to the horizon, just like a sunset. The tree is blurred because the camera was following the sky as it appears to rotate relative to the Earth.

This image of the Milky way is looking away from the center along the spiral arm which is our address. The dark areas are not holes, but clouds of dust composed of the very same materials as our planet. Galaxies are for the most part very dirty places. Many of the stars we see in our galaxy are third and fourth generation stars. The previous generations have either sputtered out to dim dwarf stars or have exploded in novas and super novas. It is in the super novas that all the elements heavier than iron are produced. Eventually some of that material is gravitationally aggregated to form later generations of stars and planets, including our own.


08-28-2011, 07:57 PM
Who needs a telescope when you can get images like this!

On the next cloudy night, you can amuse yourself by estimating how many pinpoints of light you captured with your 28mm.

08-28-2011, 09:07 PM
Reminds me of how the sky looked when I was at Ayers Rock in Australia in 1986. It could look that way around here, if there wasn't so much light pollution. We're missing a lot.

08-28-2011, 09:07 PM
Evan, Spectacular & educational, thank you for posting. Regards, Earl

08-28-2011, 09:21 PM
Thanks Evan,
That's a great picture. Hopefully you will get a few good nights to wring out your scope.

08-28-2011, 11:28 PM
What's the large open area extending up from the bottom? Is that really the edge of the milky way?

Also, what's that really prominent light source seen at the righthand edge of the big open area?

08-29-2011, 12:47 AM
The open area is a very blurred tree. It gives a good reference for black in the images and demonstrates that the rest isn't noise. The very bright light is the star Vega. Straight above the tree is another slightly less bright blue star. That is Deneb and out of view to the lower left is Altair. These form the "Summer Triangle" and also serve well as pointers to a variety of objects in the region. These images were taken at about 3 am. Earlier in the night the same part of the sky is directly overhead.

08-29-2011, 01:30 AM
Taken with just a camera- that's impressive.

Just above Deneb, and about an inch to the left, there's a dim star with a planet orbiting it. I think that's the planet I came from :)

A.K. Boomer
08-29-2011, 08:46 AM
That is amazing --- it looks like a close up shot of diamond powder taken with the flash on:)

Its always great to see the pics you take from up there Evan, Thanks for posting

08-29-2011, 12:21 PM
The open area is a very blurred tree.

A tree huh?
Gosh, I didn't even know trees grew out in space! :)

Must be giant Sequoia.

08-29-2011, 12:48 PM
great photos there Evan. Be sure to keep them coming.


08-29-2011, 01:11 PM
On the next cloudy night, you can amuse yourself by estimating how many pinpoints of light you captured with your 28mm.

That was last night. According to a program I have the count is about 117,000 for the complete image. Of course, when you zoom in with a longer lens more become resolvable. The majority of stellar systems are double stars as well as triple or more.

08-29-2011, 01:32 PM
According to a program I have the count is about 117,000 for the complete image.

That is only about one star out of every million in the Milky Way. Your telescope is needed after all!