Sunday, June 30, 2013

Sun

It's been a while since I've done any solar imaging. I found that I enjoyed imaging in Hydrogen Alpha when I was preparing for the Venus Transit last year, but I don't have the right equipment. I borrowed a Coronado PST this weekend and managed to get a few images between the clouds.

All three images were made using the Coronado PST. The first two were imaged with a Meade DSI camera, and the third was imaged with a Canon EOS Rebel T3 (1100D). I was able to capture a separate set of images for the solar disk in the first image, which is why the details are more pronounced than in the second image.

Solar Prominences

Solar Prominences

The full disk of the Sun, taken with my DSLR.

Saturday, June 22, 2013

Supermoon 2013

About once every 14 lunar months the Moon reaches perigee with the Earth at about the same time that it enters the Full phase. We call these events Supermoons. There's nothing intrinsically special about this occurrence. The Full Moon appears slightly larger than other Full Moons, and will be noticeably brighter to those who are used to seeing it often. But as far as its effects on Earth are concerned, there is very little to mention except that we humans like to make a big deal out of it.

Still, it's a good excuse to take pictures.

Here are a couple of snapshots taken of the 2013 Supermoon as it rose over the trees in my neighborhood. My neighbor across the street was kind enough to let me use her yard since the Moon is completely blocked from view in mine until it gets about 30 degrees above the horizon.

Supermoon 2013
Canon EOS Rebel T3, f/7.1, 1/400 sec, ISO-3200, 300mm focal length

Supermoon 2013
Canon EOS Rebel T3, f/5.6, 1/100 sec, ISO-200, 300mm focal length

Thursday, June 20, 2013

Lunar Experimentation

I usually avoid taking pictures of the Moon with my ST80 because the scope's short focal length does not provide much magnification. I began experimenting with an adapter to use eyepiece projection, but could not bring anything into focus. I eventually discovered that a 2X barlow lens works fine with the adapter. Here are images of the Moon taken on June 20, 2013:

Moon, June 20, 2013; Canon Rebel T3 (1100D), 2X Barlow, ST80 on Vixen SP mount; 11x1/40 sec at ISO -200

Closeup of Moon, June 20, 2013; Canon Rebel T3 (1100D), 2X Barlow, ST80 on Vixen SP mount; 11x1/40 sec at ISO -200

Sunday, June 9, 2013

Asteroid 1998 QE2

Asteroid 1998 QE2 passed relatively close to Earth back on May 31, 2013. It remained relatively bright for several days after its closest approach, and I was able to capture it with my ST80 on June 3rd.

1998 QE2 is classified as a Potentially Hazardous Object because its orbit may occasionally bring it close to Earth. It is unlikely that 1998 QE2 will ever pose a significant threat, though.

Below is a link to a movie composed of 100 30-second exposures made at ISO-6400 with my Canon EOS Rebel T3 (1100D). The exposures start at approximately 9:47 PM CDT and end around 11:09 PM CDT. The bright star near the bottom is Yed Posterior in Ophiucus. Several satellites can be seen streaking through the video.

1998 QE2 Movie

I had to manually remove the effects of periodic error and bad polar alignment from each frame. The image below illustrates the effects of these errors over time. It is a combination of all 100 images compiled in Startrails. The up/down oscillation is due to periodic error, while the progression from left-to-right is the result of incorrect polar alignment. Autoguiding, Periodic Error Correction and various alignment techniques can reduce or remove these effects. Sadly, my mount does not support autoguiding or PEC.

The effects of periodic error (up/down oscillations) and misalignment (progression from left-to-right).

Thursday, June 6, 2013

Lightning!

I usually use a DSLR to capture lightning images, but this time I set up my Samsung Galaxy S III in the window at my office and caught a couple of strikes on video. I converted the MP4 video file to AVI and used VirtualDub to copy and paste the individual frames with lightning in them to Paint.NET to save them to files. The first strike was split up between a couple of frames, so I combined them using Startrails. Pretty cool for a phone, huh?

Look carefully where the bolt meets the ground and you can see the reflection of my hand in the window.


Sunday, June 2, 2013

Flaming Star Nebula - New Camera

I've held off posting this one for a few months because, frankly, I'm not at all happy with it. This is the Flaming Star Nebula, located in the constellation Auriga.

Flaming Star Nebula; Canon Rebel T3 (1100D), ST80 on Vixen SP mount; 10x120 at ISO-6400
The reason I decided to post it here is to give an example of what a long exposure looks like on my new camera. I've had this camera for a while, but haven't had the opportunity to use it much for astrophotography. It is a Canon EOS Rebel T3 (1100D) that I got for cheap. It's main selling point was its low noise on long exposures. I was never able to separate the Flaming Star Nebula from the ambient noise of the old Rebel XS.

Another advantage of the new camera is that it will take exposures at ISO-3200 and ISO-6400, unlike the old camera that only went up to ISO-1600.

As those of you who keep up with this blog already know, I use an Orion ShortTube 80 on an old Vixen Super Polaris mount when I view and image from home. The Super Polaris is a great little mount, but it does not have autoguiding or any kind of fancy computer control, like GOTO. The polar alignment scope is out of date (it was probably made in the mid-80s), so I have to estimate where to place Polaris in the reticle. As a result, the best I can usually get out of it are 3-minute exposures. Therefore, I figure that the higher ISO and lower noise of the T3 will help me capture more detail.

Here is a portion a single shot from the run that was used to produce the image above. I limited the exposure time to two minutes because the light pollution was swamping the nebula at higher exposures.

Two-minute exposure at ISO-6400. The nebula is barely visible, but can be separated from the relatively even noise.
Here is another example frame. It is a portion of a shot of Messier 101:

Three-minute exposure at ISO-1600 of Messier 101.
I'm looking forward to trying this camera on the astrograph at the observatory.