Andrew's Astronomy Blog – Page 16 – Space: There's a lot of it out there!

Andromeda Galaxy

I was originally going to post an image of this galaxy that I took in Yorkshire, but the sub-frames were only 1 minute in length and the galaxy lacked detail in the fainter regions. This is the result I took from home using 180 second exposures. Later images in the series trailed due to my using an unbalanced setup but results have been much improved by replacing the Manfrotto 410 head with an Astrotrac wedge.

Telescope: Zenithstar 70 with WO FF III
Exposures: 13 x 180 seconds ISO 800. Flats and darks not used.

Deep Sky

Kemble’s Cascade

Starting from ? Persei and scanning east with binoculars into Camelopardalis you will find a remarkably straight line of evenly matched stars running roughly north-south and ending at a small open cluster, NGC 1502. This is an asterism, or collection of unrelated stars, numbering about 20 and stretching a distance of about 5 moon widths in the sky.

ZenithStar 70 with WO Field Flattener III
Canon 350D @ ISO 800
6 x 2 minute exposures

Deep Sky Nebula

M17 – The Swan Nebula

I’m slowly working my way through the pictures I took in Yorkshire. This one is of an object I spotted as a bright hazy patch while scanning the Milky Way through binoculars. A long exposure photo confirmed it as the Swan / Omega nebula. To my eyes it looks more like a swan than the uppercase Greek letter omega (?).

M17 is an object very similar to the Orion Nebula – an active star forming region. The cluster of young stars within it have yet to reveal themselves visually as they are largely obscured by dust within the nebula. They can however be studied in infra-red where the dust absorbtion is much less. The bright bar of the nebula is about 20 light years long and the nebula is located in the Sagittarius arm of our Galaxy, 5900 light years away.

This image is comprised of 7 three minute exposures through the ZenithStar 70 at ISO1600 with an unmodified Canon 350D.

Deep Sky Galaxy

The Milky Way

The Yorkshire sky had a much better southern horizon than I get at home so one of the things I wanted to image was the Milky Way. Unfortunately, I was plagued with cloud in this direction so all I managed was 2 3 minute exposures at ISO 800 with the 18-55 Canon lens. Even these frames had some cloud reflecting the sodium lighting of the towns to the south but the results show promise with a dark sky down to the horizon.

Notice that the Coathanger stands out well in this picture, almost dead centre.

Solar System

Jupiter at opposition

Once every year the Earth overtakes Jupiter on the inside track and as Jupiter is opposite to the Sun in the sky this is known as Opposition. As the planetary orbits are not circular, the inter-planetary distance varies each year and this year Jupiter is the closest it’s been since 1963. Additionally, for Northern hemisphere observers it’s also higher in the sky than it’s been for many years and this results in a clearer view as there’s less of our atmosphere in the way. To add additional interest this year, the southern equatorial cloud belt has disappeared although it’s just beginning to make a comeback.

Also in this picture, the moon Ganymede has just re-appeared from behind Jupiter.

This image was taken on Tuesday evening with the club 9.25? Celestron SCT with a 2.5x PowerMate and modified Phillips SPC900 camera. It’s a stack of about 1000 frames processed in Registax.

Deep Sky Nebula

Dark Nebulae

Dark nebulae are clouds of cold gas and dust which only reveal themselves by blocking out the light of more distant stars. Consequently, most of them are to be found in the plane of the Milky Way where stars are most densely packed. The astronomer Edward Barnard catalogued many of them from photographic plates and they are now known by their ‘B’ number.

This image shows B142 & B143, just to the west of ? Aquilae or Tarazed.

As I wasn’t too sure of the exact position of the nebulae I positioned Tarazed at the left hand side of the field and took 11 3 minute exposures which were then combined for the final image. Telescope was the ZS70.

Deep Sky

North Yorkshire Skies

I’ve just got back from a week’s holiday in the North Yorkshire Moors. We were staying at a cottage at Low Garth in Fryup Dale. 3 nights were clear up until about midnight on each night and I took a fair few photographs and as I process them I’ll post them here.

The night sky quality in the Moors is very good as there are no major towns nearby and Teeside was conveniently hidden by the side of the valley we were located in. The only time you were really aware of it was passing clouds reflecting an orange glow.

Equipment was the Astrotrac with Canon 350D and either the ZenithStar 70 or Canon kit 18-55 zoom. I did have a repeat of the issues with the Manfrotto 410 head working loose, I think it’s the other axis this time, so it’ll be back for repair and I need to think about an alternative. While expensive, the Astrotrac TW3100 wedge looks very nice!

While I’m processing some of the images here’s some fun I had with an asterism between Sagitta and Cygnus. CR399, otherwise known as ‘The Coathanger’ is an easy binocular object in Vulpecula. 5x 30 second exposures at ISO 1600 through the ZenithStar 70mm refractor. As usual, click on the image for a larger view.

Deep Sky Nebula

The Little Gem

More formally known as NGC 6818, this planetary nebula in Sagittarius was dicovered in 1787 by William Herschel. Despite it’s relatively low visual magnitude of 9.3, because it is such a small object it can be photographed with quite short exposures and this image is a stack of 52 5 second frames on the club 20″. I used a Canon 350D at ISO800.

It has two distinct components; a spherical outer shell and a brighter core. Size is a diminutive 25″.

Solar System

Jupiter on the 20″

Friday evening at the Observatory was spent showing some visitors around. As it was clear we were able to look at Venus, Mars, Jupiter and Uranus as well as the Moon through the 20?. Although the planets were all very low and suffering from massive amounts of atmospheric dispersion they went away happy.

After that, it was down to the main business of the night, measuring periodic error on the 20? drives. This shows that we have some more work to do to stop drift on the altitude drive and also that we have about 7 arc seconds peak to peak periodic error on the azimuth axis.

By this time, Jupiter was high in the sky so we finished up putting my modified Philips webcam on with a 2.5x PowerMate for some video images. Jupiter is more favourably positioned for Northern hemisphere observers than it has been for many years and it was nice to see it at a decent altitude with lots of detail visible in the eyepiece.

Deep Sky Open Cluster

Messier 103

Discovered by Mechain on the 27th March 1781, M103 became the last entry in Messier’s original catalog. Interstellar extinction of about 1.5 magnitudes makes determining the precise distance difficult but it probably lies about 7200 light years away. The cluster diameter is 17 light years and the bright star in the field is Delta Cassiopeia.

This was the first time that I’d tried out a new piece of software, DSLR_Logger from the AstroTrac Yahoo group. It’s main purpose is for determining precise polar alignment of the mount. I will write more about this program when I’ve had a chance to explore it rather more fully.

This was also the first outing for my new Williams Optics Field Flattener 3 on the 70mm.