Solar System - Comets
February 22, 2009
Comet Lulin caused a buzzed in late winter by brightening substantially and for a time appeared to have two tails. On this evening the comet was on the border of the constellations Virgo and Leo. It was also within 5 degrees of Saturn. This image reveals the bright coma and ion tail. The ion tail is composed of charged particles swept away from the coma but the solar wind. The ion tail always points directly away from the Sun. Here the tail points to the east-southeast. The anti-tail is made up of dust. From what I've read it doesn't always flow with the solar winds and instead lags slightly behind the coma. The appearance of two tails is an illusion. Looking very closely at the coma using my imaging processing software I was able to see what appear to be spikes ahead of the coma. They may be processing artifacts or they could be signs of the dust tail. I'm hoping to revisit Lulin for another round of imaging using a technique pioneered by Richard Bennion at Ewell Observatory.
January 2, 2008
8P/Tuttle was passing through Aries only a few degrees from the spiral galaxy M74. The 4 minute single shot exposure was taken with my Canon 350D with a 300mm telephoto lens piggy backed on my larger scope. I was hoping to catch both M74 and the coment in the same frame but it was not to be. There was a cloud bank approaching quickly from the northwest which cut short my imaging plans for the evening. Before quitting I swung my camera around to image the Andromeda Galaxy rising in the east.
October 29, 2006
A new lunar cycle began this week. I decided to take one more set of images of Comet SWAN before the brightening moon bleached out the comet's
faint tail structure. Messier 13 is still in view at lower right. Compare this evening's image with the one from October 13th. Note
the change in SWAN's position relative to Messier 13. While reviewing the images I took this evening I noticed a change in the comet
s position over 15-30 minutes. Using PhotoShop Elements I layered (overlaid) 3 images, taken a few minutes apart, and saved the result as an
animation which reveals the comet's motion relative to distant stars. Be forewarned: If your Internet connection is dialup beware that the
following link loads a large file Swan in motion (723K) .
October 27, 2006
This evening, Comet SWAN's path took it close to the famous Hercules Globular (Messier 13). Using the same equipment as October 13, I took a
series of 2-3 minute exposures. Since the 13th, the comet's position had moved well above the horizon into darker skies. I was hoping to
record more of its tail structure than my previous outing but the results exceeded my expectations. I was very surprised by how extensive the comet's
tail appears. I compared this image to my sky catalog and estimated the tail at 3.5-4 degrees! Upon close inspection of the greenish-hued coma (head of the comet)
you will notice a bright background star giving the illusion of bug-eyes. Follow the tail to the upper right and you will find another fuzzy
patch of light speckled with bright stars. This is the Hercules Globular cluster. It is 23,400 light years distant and may harbor 300-500,000
stars.
April 23, 2006
Comet 73P/Schwassman-Wachman is returning to the inner solar system for the first time since 1995. During its last pass the comet broke
into three fragments. After posting information about this image to the Cedar Amateur Astronomers Yahoo Group I've learned there are
many fragments. One, known as Fragment B, broke into yet another fragment in the days previous to this image. I'm actually not sure which
fragment I have here. I will research it more and post and update. Watch for more images and information on this comet as I monitor it
over the next few weeks.
December 21, 2004
During mid-December I routinely checked CCD imaging forums on Yahoo to see what the experts were producing. The forums were strangely void of any Machholz discussion or images. Things changed quickly a few nights after 12/14. Stunning images of a 1 degree long sinewy comet tail were posted from Schmidt cameras and large 20” Ritchey-Chretien telescopes. After some correspondence I received advice to shorten my image exposure times. The comet’s tail structure was changing so rapidly that long exposures blurred the details. Being used to “slow-motion” celestial events this was something new for me. I was anxious to try more images.
Iowa skies were miserably overcast in December so I had to wait until 12/21 for another opportunity at Machholz. The sky had cleared from the zenith north but a thin band of clouds persisted to the south. Machholz appeared to be hovering in and out of this cloud band. At about 10:30pm I headed to the observatory hoping for a break. I planned to image the coma and then slew the telescope along the comet’s tail gathering more images. With any luck I could assemble a mosaic of the images showing the extent of the tail. The first image of the coma had very good contrast. Then the clouds swung back into the field of view and stayed there for the remaining images of the tail structure. The following assembled mosaic resulted. My next opportunity on 12/28 under bright moonlit hazy skies proved futile.
December 14, 2004
My next check on C/2004 Q2 occurred on 12/14. The comet relocated some 9 degrees to the northwest of its 12/3 location to the constellation of Eridanus. The dark skies and steady atmosphere were perfect for CCD imaging. The following image revealed a bright coma and a bit of tail structure towards the northeast. Note how the tail orientation had changed since the 12/3 images above.
December 3, 2004
This evening, I readily located the faint fuzzy glow of the comet with 7x35 binoculars approximately 5 degrees southwest of Epsilon Lepus. Soon after my 10” LX200 telescope configured at f/4 was grabbing CCD images of Machholz and the surrounding star field. The first images weren’t very exciting - at least I thought that at the time. I had a fuzzy object showing a smudge of a tail towards the north. The images showed very little tail structure towards the northwest (north is top). The comet’s tail was directed away from Earth at that time. After 30 minutes I noticed something pretty fascinating in the images. The comet was moving noticably against the background stars. The sequence of images from 12/3 was taken at 11:40pm, 12:25am (12/4) and 12:39am. Note in each successive image how Machholz traveled northwest between two stars: GSC 6468:639 and 6468:655 at magnitude 14.5 and 15.5 respectively.
Comet Lulin caused a buzzed in late winter by brightening substantially and for a time appeared to have two tails. On this evening the comet was on the border of the constellations Virgo and Leo. It was also within 5 degrees of Saturn. This image reveals the bright coma and ion tail. The ion tail is composed of charged particles swept away from the coma but the solar wind. The ion tail always points directly away from the Sun. Here the tail points to the east-southeast. The anti-tail is made up of dust. From what I've read it doesn't always flow with the solar winds and instead lags slightly behind the coma. The appearance of two tails is an illusion. Looking very closely at the coma using my imaging processing software I was able to see what appear to be spikes ahead of the coma. They may be processing artifacts or they could be signs of the dust tail. I'm hoping to revisit Lulin for another round of imaging using a technique pioneered by Richard Bennion at Ewell Observatory.
