Tuesday, September 30, 2008

Newly acquired Astrophotography mount

I enjoy astrophotography, and one of my main tools is my AstroTrac TT320. The TT320 is a lightweight, easy to set up, and very accurate tracking mount. I was fortunate to own one of the first three TT320 mounts in the US. I have since become a constant user of the TT320. Recently, Richard Taylor, owner of AstroTrac notified me that he would soon be releasing an updated version of his mount, called the TT320X. I immediately put in an order for one, and it arrived from the UK the other day. It has a host of new features, such as solar and lunar tracking, to go along with sidereal tracking (stars). It has been redesigned to carry a 50% increase in load capacity. There were other improvements made as well. I am looking forward to testing out this new mount, and you will see the results here on this blog in the future, as well as my astrophotography website at:
www.darkskyphotos.com

The image above shows the two mounts. The one on the left is the new AstroTrac TT320X. The mount on the right is the AstroTrac TT320. The AstroTracs are the silver long arms with the tracking system at right angles to the arms at the bottom of the arms. Simple, yet elegant.
In case anyone wants to know, the camera on the left is a Canon 40D, with a Sigma 300mm f2.8 telephoto lens. The camera on the right is a Canon 30D, with a Tamron 300mm f2.8 lens.


The image above shows the two mounts from the side, so you can see the design layout of the AstroTrac TT320 mounts. The small telescopes facing upward on each mount are the polar alignment scopes. These are used to align the mount with the north so the unit will track the cameras to counteract the rotation of the earth. Improper alignment of the mounts results in poor images with stars trailing through the photograph.

Friday, September 19, 2008

Newer Images from the Roanoke Night Sky

Earlier this month, the skies around Roanoke cleared up for a stretch of several days, and I took advantage of the offer. I shot over 20 hours of images, and have just now had the opportunity to process some of them. Here are the latest images of the objects in the light sky above Roanoke. As in other posts, details of the image is printed below the image.


The image above is the Helix Nebula (NGC 7293) in the constellation Aquarius. It has low surface brightness, which makes it a tougher target, but it is a large object. If it were bright enough to see the whole object with the naked eye, it would be close to the size of the full Moon in the sky. It is one of the closest planetary nebulae, at a distance of about 450 light years. The rings are the gases of the central star, at they were blown away from the star in a series of stellar events. Now those gases fluoresce, or glow, as they are exposed to the radiation from the now exposed core of the star.

Camera - Hap Griffin Modified Canon EOS 350D

Lens - Sigma 300 MM f2.8 Lens, set at f2.8 - ISO 800 - (480MM effective focal length)
26 Minutes of exposure (13 x2 minutes)
AstroTrac TT320 Astrophotography mount for tracking


The image above is the Andromeda Galaxy (M31) in the constellation Andromeda.

Camera - Canon EOS 40D

Lens - Sigma 300 MM f2.8 Lens, set at f2.8 - ISO 1600 - (480MM effective focal length)
28 Minutes of exposure (14 x2 minutes)
AstroTrac TT320 Astrophotography mount for tracking


The image above is the Pleiades (Messier 45) in the constellation Taurus. It is a young, open cluster of stars. It is sometimes mistaken as the little dipper, due to the fact that the brighter stars form an asterism that does look like a dipper. This cluster is called Subaru in Japan. If you look at the logo for the Subaru automobile, you will see a representaion of this star cluster. It is one of the closest recognisable open clusters, at a distance of about 400 light years. The stars are exciting the gases in the area of the cluster, causing the blue-colored glow around the stars.

Camera - Canon EOS 40D
Lens - Sigma 300 MM f2.8 Lens, set at f2.8 - ISO 1600 - (480MM effective focal length)
18 Minutes of exposure (9 x2 minutes)
AstroTrac TT320 Astrophotography mount for tracking


The image above is the Lagoon Nebula (Messier 8) in the constellation Sagittarius. This image is at a focal length that is pushing the capability of my tracking mount.

Camera - Hap Griffin Modified Canon EOS 350D

Lens - Sigma 300 MM f2.8 Lens, set at 600 MM f5.6 - ISO 1600 - (960MM effective focal length)
28 Minutes of exposure (14 x2 minutes)
AstroTrac TT320 Astrophotography mount for tracking


The image above was shot last June, and I just had the opportunity to process it. It was photographed using a digital SLR camera with special filtration to highlight Hydrogen alpha (Ha) emissions. This is the area of Cygnus, the Swan. It is what many people call the northern cross. If you look closely at the stars, the cross looks like it is laying down, with the top pf the cross to the left. The intense red color of this image is due to the Ha emissions, which are not very visible to the naked eye.

Camera - Hap Griffin Modified Canon EOS 350D - Filtered
Lens - Canon 18-55 MM f3.5-5.6 Zoom Lens, set at 28MM f3.5 - ISO 400 - (45MM effective focal length)
10 Minutes of exposure (10 x1 minutes)
Kenko SkyMemo Astrophotography mount for tracking

Friday, September 5, 2008

Working on Images

The past few evenings have been pretty clear, and I took advantage of it with several nights of imaging. I now have about 20 hours of astrophotos that I need to stack and process. So, be looking here in the near future for some new astro images, taken from right here, in the Roanoke area.

Also, a new astronomy group has formed in the Roanoke Valley. the Star City Astronomy Network (SCAN) is a small group of astronomy enthusiasts that are dedicated to teaching astronomy and doing astronomy outreach. Feel free to contact SCAN here, or at www.starcityastronomy.org .