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Evan
01-20-2009, 10:14 AM
A while ago I made new drive gears for my telescope to improve the tracking performance.
http://metalshopborealis.ca/pics5/ww1.jpg

Since then the weather has not cooperated until last night when it was only about -10C. Conditions were clear, the moon was down and all my equipment actually worked.

This is another image of my target of choice this winter, M42. Also known as the Great Nebula in Orion, it is a feature rich target with a wide range of detail and colors. It is also huge, spanning about 24 light years across so even though it is 1500 light years distant it still has an apparent size in the sky of twice the width of the full moon. It is barely visible to the unaided eye in good observing conditions as a very dim patch of mist in the middle of the 3 stars that make up the sword of Orion the Hunter in the southern sky during winter.


http://metalshopborealis.ca/pics5/m42.jpg

This is my best photo so far of this object. There is room for improvement though.

Willy
01-20-2009, 10:35 AM
Beautiful image Evan! Nice work on the gears as well.
I'm sure most people don't realize how many different things have to come together in order to produce an image such as this.
At least you have some control over the quality of the equipment, but you are still bound by the opportunities that nature extends.

japcas
01-20-2009, 10:52 AM
That is a neat picture Evan. I don't understand much about how the tracking equipment is setup but I do know enough about night sky photography to know that you need it for all but the fastest of exposures. What was the exposure time on that picture and what was the focal length?

Bill in Ky
01-20-2009, 10:55 AM
Very nice shot!

JBL37
01-20-2009, 11:09 AM
Thanks for the photo's. Would like to see more of your gear cutting. JIm

Evan
01-20-2009, 11:11 AM
It was several 2 minute exposures combined taken with a six inch f4.5 telescope and my Canon 300D at prime focus (no lens). Most astrophotos taken now are a composite (known as a stack) of more than one image. This technique was impractical with film but is now standard practice with digital. It increases the apparent resolution by adding new information from each stacked frame and reduces noise buildup because of the short exposure times.

tony ennis
01-20-2009, 11:24 AM
That's amazing. I never knew that nebula was so large. How large of a portion of the sky does your image show?

shoprat
01-20-2009, 11:26 AM
that is a beautiful picture evan... would make a nice poster
shoprat

aostling
01-20-2009, 11:41 AM
There is room for improvement though.

Not much room, I'd say. The nebula is beautifully captured.

Those star spikes, are they images from your curved secondary mirror spider?

Evan
01-20-2009, 11:41 AM
That entire image is about a 3 degree x 3 degree field. If you stick a quarter on a post and look at it from 9 feet away that is the apparent size of the moon or sun which is 1/2 degree. So, this image is an area of the sky about the size of a 6x6 array of quarters 9 feet away. The sky is full of very large extended objects. The problem is that they are much too dim to see with your eyes.

Allan,

Those are the diffraction spikes from my six blade spider. It is so thin that it only produces spikes on the brightest stars. It's also a unique signature of my telescope as that spider is the only one like it as far as I know.

gfphoto
01-20-2009, 11:42 AM
Nice M42! You must have great skies up there (drooling). I'd also like to know more about the mount and scope. Either/both homemade?

Gary

Evan
01-20-2009, 11:52 AM
Gary,

You will find links to the telescope and related items on this page:

http://metalshopborealis.ca/

Peter N
01-20-2009, 12:05 PM
Fantastic picture Evan, thanks for posting it.

Peter

Evan
01-20-2009, 12:26 PM
I should mention that all here are free to use my photos that I post here in any way that doesn't involve money or profit. I do reserve copyright including moral copyright which is different from legal copyright. Moral copyright is also spelled out in law and cannot be transferred, disposed or sold. It means that if you use a photo of mine in a way that may reflect badly on me then I may tell you to stop even if I sold the rights.

dp
01-20-2009, 12:44 PM
It's a beauty, Evan. I got a call from my wife last night who wondered if we were having clear skies in Eastern Washington (nope) because there was a brilliant star to the south that seemed to leap out of the sky (Sirius). I asked if she could see a reddish star a bit higher in the sky near three very bright stars strung in a row. And she did see it and noticed it was fuzzy. I sent her a link to Orion so she could see it in it's full splendor.

These cold dry nights are good for something!

And nice work on the gears.

tony ennis
01-20-2009, 01:06 PM
Any pics of Andromeda Evan? I saw it once, in my youth, without aid. I was at the lake and we had gone out to the sticks for the weekend. It was very dark.

Evan
01-20-2009, 04:47 PM
Andromeda is another of those deep sky objects that is huge and covers quite a bit of sky if only our eyes were sensitive enough to see. It makes me wonder what the night sky looks like to an owl.

http://metalshopborealis.ca/pics5/m31b1.jpg

aostling
01-20-2009, 06:49 PM
Andromeda is another of those deep sky objects that is huge and covers quite a bit of sky if only our eyes were sensitive enough to see. It makes me wonder what the night sky looks like to an owl.


I think you posted this photo once before, but now that I see it again I want to see M31 for myself. Phoenix has light pollution, but I can escape it by driving south onto the Gila Indian Reservation.

I've acquired my first telescope. It is a 4.5" Orion StarBlast, an inexpensive altazimuth reflector which I gave to my brother a few years ago so that he could show the skies to his grandchildren. At Christmas he offered it back to me, admitting that it no longer gets any use under his California skies. It has a red-dot finder, which is a treat to use. I really like that there is no color fringing with a reflector (unlike my spotting scope, which does show some CA).

I have the 17mm (26X) plossl eyepiece. Do you think this is enough pupil for a visual sighting of M31? I guess I'll find out, but I may not get out for an observation for a few days.

rode2rouen
01-20-2009, 07:45 PM
Very nice work!
Both the gears and the photo!


Rex

DFMiller
01-20-2009, 08:22 PM
Nice pictures Evan
Its been foggy down here recently. Must be nice to get clear skies.
Dave

Evan
01-20-2009, 08:41 PM
Clear skies are nice but this time of year it means cold. The night sky temperature summer and winter is about -70C. Space has a temperature of about 3 kelvin but the radiant energy from the atmosphere and it's greenhouse gasses make the night sky seem much warmer. Good thing too.

rockrat
01-20-2009, 08:48 PM
Andromeda is another of those deep sky objects that is huge and covers quite a bit of sky if only our eyes were sensitive enough to see. It makes me wonder what the night sky looks like to an owl.



Down here the poor critter would see nothing but light pollution. Columbus lights wash out our sky badly.

Which brings me to my compliment. That has a nice dark background. I only wish our sky's were that dark. Nice gathering of photons you have there.

rock~

gfphoto
01-21-2009, 02:35 PM
Gary,

You will find links to the telescope and related items on this page:

http://metalshopborealis.ca/

Thanks Evan,

Neat projects. I especially like the milling attachment.

Gary