Saturday, December 29, 2007


My daughter Laurie | Canon EOS 1D | 16-35mm F.2.8 L @ 16mm | 1/160 sec @ F/7.1 | ISO 100 | Two Canon EX550 flashes through 36" Umbrella

Thursday, December 27, 2007

Comet 8P/Tuttle

Tonight I did some test imaging of Comter Tuttle through the 400mm lens with a 2X teleconverter making it a 800mm F/5.6 system. Continous 1 minute exposures were made from 01:54 UT to 02:35 UT on December 27th. Below is the sum of thirty seven one minute exposures. The comet is moving quite rapidly in dec (about 7 arcseconds per minute) thus the image of the comet is trailed against the stellar background.

Details: 37 minutes (effective) @ ISO 1600 | F/5.6 | 800mm | Takahashi EM200 Mount

Details: Comet centered sum of 37 images.

Details: Cropped and inverted version of comet centered image

Sunday, December 23, 2007

Mars and the Moon

This evening a beautiful conjuction bewtween the Moon and Mars took place near moon rise. From my house west of the Catalina mountians - here was the view. Canon EOS 5D | Canon 400mm F/2.8L IS @ F/4.5 | ISO 400 1/20 sec.

Below - a view through a 3.5 inch Questar. Canon EOS 1D | ISO 100 | 1/30 sec @ F/16

Saturday, December 22, 2007

Ursids 2007

The Ursid meteor shower is underway. The parent comet 8P/tuttle is passing near Earth and the Sun next month and there is an anticipated elevation in the number of meteors that could be seen from dust streams left behind by the comet in years past. As part of the SETI research on the stream I photographed the sky Saturday morning and Saturday evening 8 hours before and 5 hours after the anticipated peak. Below is a sum of the images obtained Saturday morning. The image shows about an hour's worth of integration (5 second exposures at f/2.8 and ISO 1600) through a 16mm lens - centered on the radiant. Only one Ursid was captured (frame upper-right at11:37 UT). In addition several satellites were captured (frame center and frame lower left).

Ursid Radiant from 12:25 UT to 13:30 UT December 22, 2007.

Ursid Radiant from 01:15 UT to 03:00 UT December 23, 2007. No meteors but lots of aircraft and a couple of satellites! Its a crowded sky ain't it!?!

Friday, December 14, 2007

Geminids 2007

Well, spent last night on the roof of my house in suburban Tucson watching the sky fall, my feet turn to ice, and my camera lenses repeatedly dew over. Astronomy is too much fun.

The astronomical expedition began by selecting the observing site. With no moon out for the event, I considered a dark site somewhere in the desert or up at Kitt Peak. I wanted to have the cameras mounted on my EQ Mount so I could track the radiant and have a better chance of summing images showing the actual radiant structure of the Shower. Problem was I knew it was going to be cold and the dew point was going to be close to the ambient temperature. Camera and mount drive batteries don't last long in low temperatures and the exposed wide angle lenses I planned on using would most likely suffer from the humidity. I would need AC power to run the mount, camera battery chargers, and a hair dryer.

Kitt Peak observatories were closed the night before the shower maximum with high humidity and temperatures near -3 degrees Celsius and the availability of AC power was limited to areas where domes and building would block a significant portion of the sky.

In town, my home has similar visiblity problems if I setup on the ground. I had significant success from the roof of my house earlier this year during the Aurigids and decided that the convenience of working from home outweighed the drawbacks of the suburban light polution. Home I would stay and after several back-breaking climbs up and down the roof of the house, I finally got the mount and cameras setup just before sunset.

The sky was partly cloudy at sunset and improved prior to my start time of 10:00 pm that evening. No concerted effort was made to temporally count meteors over the course of the night - as I spent most of the time either tending to cameras and lenses or in the house trying to recover from the cold. On the occasions I did observe I noticed that the meteor rates were quite high - typically I would see 5 to 7 in the space of a 5 minute interval and at other times I was able to see 3 or 4 in a single minute. This was noticed rather early in the shower - around 2 am. As it got later - fewer meteors seemed to present themselves.

Visually the shower was quite impressive. Photographically, not so much. Although I had very wide angles of coverage and fairly fast optics (using a f/3.5 8mm circular fisheye and a f/2.8 15mm full frame fisheye) I was only able to capture about a dozen meteors in over 5 hours of effort. Sigh. Bottom line - the Geminids are a wonderful visual treat. Photographically however - its a tough sale. Results are shown below.