updated Friday, March 21, 2008

       
       
       

 

The reddish color during totality (middle row) is caused by refracted sunlight striking the moon after first having passed through the Earth's atmosphere.  
It's much like the effect we see in the evening as skies turn reddish after sunset.

Transit of Venus
June 8, 2004

The picture below shows the Sun just after is rose on June 8th with Venus located at about the 4 o'clock position.
It was visible to the unaided eye because of haze near the horizon.

I am also using a webcam to obtain images through the telescopes.  The webcam allows for a little more flexibility in getting the images I want, that is, lunar and planetary images.  I use a low-light PC-164C videocamera for occultation work.  This camera can "see" stars that are dimmer than can be seen through the telescope with the eye alone.  Last, I have a Meade Deep Sky Imager I which can be used for images of galaxies, clusters, comets, etc.

ALPO
As a member of ALPO, I work most with the Solar Section.  At one time I was involved in full-disk pictures of the sun taken through a Tuthill Solar Skreen filter over the 12.5" Newtonian stopped down to 6 inches.  Exposures normally were 1/500 sec on Tech Pan 2415 developed in a modified POTA formula I mixed from scratch.  That film is no longer available, so the darkroom has been retired. 

Now, I am looking to take high resolution digital images of sunspot groups and active regions using the Meade imager and Astrovid video camera. 

I have written a computer program to provide physical details about the sun ( RA, Dec, Rotation Number, Heliographic coordinates, etc.)  These data are provided for the ALPO webpage as well as for a new book out shortly on how to observe the Sun.

I may now expand my observing to include the planets.  I believe that the new equipment will allow me to record important surface details.  This new work is definitely in its infancy.

IOTA
As a member of IOTA, I am involved in timing lunar and asteroidal occultations.  I am also the Northeast United States, Southeast Canada occultation computar ( yes, with an "a" ).  I am the person who, using geographic information supplied by IOTA members, uses a computer program to calculate lunar total and grazing occultations and asteroidal appulses.  This information is generated on a yearly basis and sent (via regular mail or email) to each observer.  Updates are available on IOTA's own web page.

I have also become deeply involved with the observation and analysis of asteroid occultations.  Steve Preston provides predictions for events in which more distant stars are occulted, or blocked from our view, by asteroids in orbit around the Sun.  His website provides maps and star field maps to aid in timing these events.  There are thousands of asteroids, but most are so small that the chance of an event being visible from any one location during the course of a year is quite small.  Many observers travel great distances to observe these events.  I've been quite lucky in having see 2 occultations during the last few months of 2006.  One of them, involving the asteroid Phocaea, produced a grazing occultation.  I actually saw the star reappear in a valley on the asteroid for a split second!   Details of that unique observation, including a video clip of the event, can be found on this Phocaea Occultation Page.  A second occultation, by the asteroid Melpomene, proved a bigger challenge.  The asteroid was brighter than the star.  The combined light of the two during the occultation would not decrease all that much.  A program called Registax is able to combine odd numbers of frames of a video into integrated frames.  This has the effect of reducing noise and increasing the signal-to-noise ratio.  Some time resolution is lost, but the ability to pick events such as this one out of the background noise far overrides the slight decrease in timing accuracy.  A new tool, LiMovie, allows one to read in a video file and create a graph of star/asteroid intensities.  The exact moment of the occultation can then be read with high accuracy.  Finally, a program called Occular has been developed to take the files created by LiMovie and further analyze them to extract data from a set of data that might otherwise be too noisy.

I also am the webmaster for a new set of pages devoted to the science of asteroid occultations.  On these pages I provide observers with observing templates for each event and a detailed summary of the results of each event.  These results are forwarded to Dave Herald who then sends them to the official Minor Planets office.  The page for North America, with links to all other pertinent pages, can be found here.

The PC164C camera I own is proving to be invaluable in this work.  I used to record the video signal along with WWV time signals onto a VCR tape for later playback.  That has been improved with the acquisition of a KIWI OSD time insertion module.  This device uses a GPS receiver to determine accurate location information as well as precise time information.  This is then written to the video being provided by the camera so that everything can be seen on the video at the same time.  You can literally step through the video one frame at a time to get an event time accurate to 1/30 of a second!