Rosette once more

Yesterday, I managed to polar adjust the mount a bit better. Autoguiding still acted a bit weird. Have to look into that. But with a proper poar adjustment, I was able to take longer exposures at lower ISO. This would mean higher dynamic range on the camera. I actually haven't tried setting the ISO to its lowst and see what happens, but maybe next time.
The Rosette nebula. I never really payed any attention to this one, since The Orion nebula and the Horsehead was nearby. And the elusive Simeis-147 has been on my list of things I wanted to image. But it is by no means a boring nebula. Beautiful in itself, and quite large. So imaging with even the tiny 71mm f/4.9 telescope, it fills large parts of the frame. It probably could do with twice the exposure, but that will have to wait until I get a few nights of clear sky a little bit earlier in the season. Now it goes too low at midnight or thereabouts. Still getting back into processing. But getting better and rmembering more of the tricks. But still have a long way to go. The image is cropped slightly. Also, minimized the stars to make the nebula stand out more from the background.

Tecch specs : Pentax K5, ISO800, 54x2m30s unguided exposures, Astronomik CLS filter, Zenithstar 5-element apo, Celestron AVX mount. Stacked in DSS, processed in PS and Irfanview.

I also added the red channel here to show how much nebulosity has been recorded. If I could just get this out more precicely and smoother.

Flaming Star nebula

I never tried this before, and when the skies cleared yesterday night, I decided to give it a go. Didn't know how much exposure it needed, and the other objects I wanted to image were already too low for any longer integration. It is obvious the image needs some more exposure, and maybe could use some narrowband imaging. It has been a while since I last did any processing of tricky images, so I will probably need some time to get the hang of it again. And an image like this needs som careful processing. That much is clear. And it probably also needs a lot more exposure to get the dynamics of the nebula right.

Tech specs : Pentax K5, ISO 1600, 120x1min unguided exposures, 20 flats, WO 71mm Zenithstar 5-element apo, Astronomik CLS filter, Celestron AVX mount. Stacked in DSS, processed in PS and Irfanview. Cropped from original image.

Virgo-cluster

It is amazing browsing through the Virgo cluster in the sky. It feels like no matter where you point your telescope, you can find at least a couple of galaxies. Makes you feels small and insignificant. What I glorious feeling. :-)
I shot this image halfway centered around M87. The big elliptical galaxy almost in the centre of this image a bit below the middle. Up to the right is the Markarian Chain. A chain of galaxies like pearls on a string. And dottet around in the image are several Messier-galaxies, NGC-galaxies and probably some PGC-galaxies as well. I haven't checked properly, but I guess there are a couple of dozen galaxies in this single image.

Tech specs : Pentax K5, 150x1min unguided exposures, 24 flats, Williams Optic 71mm Zenithstar 5-element apo, Astronomik CLS-filter. Celestron AVX mount. Stacked in DSS, processed in PS and Irfanview. As always : Click on the image for a full version.

O joy! Lovejoy!

Last night was finally a clear night. And I had to exploit it. I drove out of town and brought with me my two refractors. Wanted to use one as the guider for the other. When I arrived, I found that I was unable to reach focus with the guider camera... And I managed to fail the all star polar alignment several times. So in the end I had to settle for 1 minute exposure with the 71mm Zenithstar. One of the objects I tried my luck on, was comet Lovejoy. I missed it slightly (couldn't remember properly its coordinates. When checking the image afterwards, I see that this was a good thing, since I got a few other interesting objects in the same field of view. Down to the left, a weak red nebulosity can be seen. This is Simeis-22. And almost in the middle of the image, lower half, we can see NGC457, the Owl Cluster. And just up to the right from this, the small cluster NGC436. The tail of the comet didn't excactly show up well, but it is there up to the left on the comet. Click on the image for full size.

Tech spec : Pentax K5, ISO 1600, 10x1 minute unguided exposures, 24 flats, 71mm Zenithstar 5-element APO. Celestron AVX mount. Stacked in DSS, processed in PS and IrfanView.

Rosette nebula with new gear

The total solar eclipse of 2015 is coming up, and I'm going to Svalbard to watch it. So, I needed some new gear that would be easy to bring on a plane. I ended up buying a complete new set of everything. A Berlebach wooden tripod, a SkyWatcher Star Adventurer, and the crown jewel of the pack : A William Optics ZenithStar 71mm f/4.9 5-element flatfield apochromat. As always with WO : Beautiful piece of art and engineering.
The weather has been terrible for astronomy this season. Mostly cloudy or partly cloudy. And if there has been any opening in the clouds, it has been for a short while. On wednesday, the clouds finally departed, and I got a chance to try the setup out for a short while. before the clouds came pulling in again. I opted for the Rosette nebula. The Star Adventurer without autoguider was able to give me up to 30 sec exposures without star trails. I could probably have gone a bit higher, but I settled for that. I managed to collect about two hours of exposures. Some of the frames had to be discarded due to clouds, and some due to satellite tracks or airplanes crossing the line of sight. In the end, I had about 1h45m of imaging data. I tried pulling out as much as possible. Not the best result, for sure. But it is OK for testing the telescope and the tracking performance.

Tech details : Pentax K5, ISO 1600, Astronomic CLS filter, WO Zenithstar 71mm F/4.9, Skywatcher Star Adventurer. Stacked in DSS, processed in Maxim, PS and Irfanview.

Lovejoy is in the air again

A new Lovejoy comet is flying across the sky this month. The weather has been dismal to say the least this season, so I have been waiting and waiting for a break in the weather. Tuesday the 13th, the clouds finally parted in the evening. But this night, I had people over, so I didn't have much time to set up the gear. So I opted for real wide field. I originally thought I'd use my 85mm lens, but ended up using my 180mm telephoto lens. It is not as sharp, but I guessed it would show the comet better. I didn't take my time adjusting the polar axis. And I didn't calibrate the Goto. I probably should have. Cause I spent some time trying to find the comet from maps I had on my phone. But eventually I had it in sight. I set my camera timer to take 70 images of 30 second lengths. I forgot to take flats (it has been a while since last time, so I forgot my routine), so I have had some problems digging the tail out from the background. Since I am shooting from the middle of the city of Oslo, there is some light pollution to take into account. I am not very happy with my result, but considering the effort, I guess I cannot expect more. Hopefully, the weather will clear soon so I can make a REAL shot of this comet. BTW : The reason for the "double star" appearance is that there were some clouds that drifted through the field in the middle of the stack, so I removed those frames...

Tech details : Pentax K5, Carl Zeiss Jena Sonnar 180/2.8 @5.6, ISO 400, 50x30 sec exposures. Stacked on comet in DSS, processed in PS.

Pluto - a "wandering star"

I know that Pluto is no longer defined as a planet, but for most of my life, Pluto captured my imagination as a planet. So far out. So cold. I remember seeing artists' impressions of what it would be like to stand on the surface. Looking back at the bright star 5 billion km away. But I have never been able to see it with my eyes. Only in pictures. It moves slowly across the sky. Barely visible to the eye in a large amateur telescope. But with a short exposure, it is possible to spot. Not in itself, but by the very definition of the word planet. The word comes from Greek "Planetes aster", or "wandering star". The old Greeks didn't have telescopes, so to them, everything on the night sky, save from the Moon, where stars. And some of them moved. These are what we now know as planets. I decided a week ago to try to capture the movement of Pluto, the planet, on three days. To see it moving against the stars in the background.
The following image shows Pluto on November 11th. Try to find it! It is literally finding the "needle in the haystack".

And it is no wonder that nobody found it until 1937. First of all, it is very faint. Around magnitude 14 (which is more than 1000x fainter than the faintest star we can see with an unaided eye). But even when you use a long exposure like above, it looks just like a star in the image. It is impossible to discern it from the stars. But if you compare images taken a few days apart, it becomes apparent. Clyde Tombaugh compared the images taken a few days apart using a blink comparator. One of the stars moved. Today, we can use a computer to create an animation, and suddenly, it stands out from the background.
I added three images, taken a few days apart, and it is obvious that one of the "stars" is moving. It is a "wandering star", "planetes aster". A planet. The planet Pluto. Click on the image to get a bigger version.