clear sky chart

Job 9:9

Job 9:9-10
9 He is the Maker of the Bear and Orion,
the Pleiades and the constellations of the south.
10 He performs wonders that cannot be fathomed,
miracles that cannot be counted.

Sunday, May 20, 2012

OTAA Scenic Vista Stargaze

This was my first star party and this was also my darkest sky location which I have imaged from.  Unfortunately there were some thin high clouds that turned into haze as the night progressed.  We had the best sky just after sundown until around 11pm.

It was well attended, quite a few guests came by to look through the eyepieces of various telescopes.  I did a short demonstration to some curious onlookers just before total darkness of Saturn, went through the entire process from acquiring to processing.

There were telescopes there of all sizes.  The largest was what I believe to be a 25" f/5 motorized dob.

There were probably 20 - 25 scopes set up of all different sizes, from about 4 inches to the 25 inch pictured above.

Unfortunately I didnt take any pictures until late, and most didnt come out very well.  There were a lot of scopes behind me when I took this picture, but they didnt come out well enough to post.

Once darkness fell, I started imaging, and I chose M51 for my first target.  I wanted to image familiar things to compare with what I had taken at home to see what the difference having a dark sky made.  The following image of M51 was the best image of the evening as the sky steadily worsened as the evening progressed.  I am rather happy with this image, but there was a nasty diffraction spike which kept it from being absolutely perfect coming from the star Alkaid (Eta Ursa Majoris) which was just outside of the field of view.  This image consists of a composite of 20 120 second frames at iso 1600 stacked.  The telescope was my 6" f/5, 40 minutes total exposure.

This one came out so well (except for the diffraction spike), that it is the only one which I uploaded as a png to preserve the sharp appearance.  Sky transparency, when this was taken was about 6/10, and progressively got worse after this was shot.

While this was imaging, I walked around the grounds and had a look at M81 thru the big dobsonian that was set up.  Climbing up on the 8' stepladder to look through the eyepiece gave me a real nice view of the galaxy.  It was quite bright.

When I got back to my scope, the imaging sequence was finishing up with M51.  I then slewed over to M57, the Ring Nebula in Lyra.  I was shooting through substantial haze, but it seemed to come out OK.  I was not able to capture the dimmer red halo around the object, due to the haze.  Knowing that this was not going to be as good, I only shot 9 - 1 minute frames at iso 1600.

There is somewhat of a red halo present, but its not as pronounced as in my earlier photo.

My next attempt was the Owl Nebula, M97 and M108, which share the same frame.  By this time, the haze was getting worse, and I believe I could have done better under clearer skies, as the Owl is somewhat dim to begin with.  There was some gradient and sky noise showing up in the background which I tried to remove as best I could.

The final image of the evening was M101.  I got about 10 frames before a car's headlights shining on the scope degraded the remainder of the frames.  I probably should have imaged this object first, but I was hoping the sky would improve, as it often does, as the evening progressed.  Unfortunately that didnt happen, so my M101 was not the greatest.

Not bad, but I'm sure it could have been better.

All of the images taken were unguided, and the maximum exposure per sub was 120 seconds.  The scope tracked very well with very little star streaking.  The worst case, and visible in the images were slightly egg-shaped stars.

Overall, I would say I had a successful evening, and with the quality of the images, I look forward to imaging from more dark sky sites.

Saturday, May 12, 2012

M57 - The Ring Nebula in Lyra

As an experiment, I thought I would attempt the Ring Nebula in Lyra the Lyre.  This is a really small object, which I knew before I started imaging.  The reason I wanted to attempt this is because it is one of the most difficult objects that I have  seen long ago, visually with a 60mm refractor back in the 1980's.  I wanted to see if I could photograph it, as I wished that I had the ability to photograph it then.

This image was not the easiest thing to get a decent picture of.  I wish I had taken more frames, only 9 out of 30 were useable.  This is a really bright object to image compared to other nebulae and galaxies.  The frames were only 2 minutes in length, and even then, they were almost to the point of saturation.

My autoguiding was not perfect, and I had a fair amount of declination inaccuracy when this was shot.  This is why my frames were not of good quality.  The good thing is, this is an early morning object right now, and it will position itself better in the sky as the summer progresses.  This object is only 2 arcminutes in diameter, and would be a target for a longer focal length.  Guiding is far more critical on an object this small.  As the object gets higher in the sky, I believe the images will improve as I'll have better polar alignment on the object in the future.

Even with the problems I had, I dont think the image came out that bad.  I'll post 2 images, a somewhat rich field view and a close up of the nebula.

The nebula is located right on the edge of the Milky Way, so the star field is somewhat rich.  I wanted to post a wide field view to show the star density in the frame.

This is a cropped frame so that you can see the detail of the nebula.  The colors are pretty close to accurate.  The center is blue, the middle of the ring should probably be a little more green, but the red along the outer part of the ring is showing up nicely.  I was able to capture the central star, which I was unable to see in the little 60mm refractor years ago.

M101 at Near Zenith

Its been weeks since I've had clear skies without a bright moon getting in the way, it was a Friday night and I could stay up all night if I needed to to get some good imaging in. Needless to say, I took advantage of my excellent sky conditions. The target for tonight was M101 in Ursa Major, the Great Bear. Imaging started a little later than I'd liked, as I had some trouble aligning the mount. I'm getting rusty, being I wasnt able to use the scope in some time. Finally I got it aligned, got the autoguider running and started snapping off frames. I took 20 frames, each 5 minutes in duration. I ended up with this image, after processing.

This is a full frame image.  Only the edges have been cropped out due to stacking noise.

After I had finished imaging M101, I opted to try a different object, M57, the Ring Nebula in Lyra the Lyre. I will post an image in a separate post.

Wednesday, May 9, 2012

The Sun

I had ordered some Baader solar film and I received it yesterday, and made a solar filter for the 6" last night.    It's been raining and cloudy, but I was able to take a snapshot using the Canon Rebel T3 during a break in the clouds.  I was in a bit of a hurry, so the focus might not be real good.

This actually came out better than the projection I did last week.  I think with a little practice and better sky conditions, I should be able to resolve more detail.

The large sunspot (AR1476) is sending out flares in our direction.  Keep an eye out for aurora the next few days.
This sunspot is so large that it is visible at sunrise with the naked eye.

I am not sure of the orientation, but I think south is up.