6-Aug-2000 image of Comet Tempel 1

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The image below was taken by Cynthia Gustava and Bill Dillon on the morning of 6-August-2000. The image is a stack of the best 6 of 10, one-minute images starting at 07:57:20 (UT). An attempt was made to centroid on the comet.

The images were taken with an ST-7 camera in 2×2 binning mode, using the Fort Bend Astronomy Club’s 18 inch (46 cm) f/4.5 reflector, located at the George Observatory.

Also noted is the asteroid discovery we made while imaging Comet Tempel 1, 2000 PO8, which we originally designated FBAC55. Thanks again to all the observers Stephanie McLaughlin alerted (and Teammate Keith Rivich) who provided astrometry from their own images!


Trans-Neptunian Object 2000 EB173 imaged by FBAC


After a year and half of trying (off and on), we finally managed to image a Trans-Neptunian Object (also known as Kuiper Belt Objects) — thanks to a suggestion from Paul Comba that 2000 EB173 would be a good object to attempt.

The first image below was made by FBAC members Joe Dellinger, Bill Dillon, and Cynthia Gustava. The image is the result of stacking six, four-minute exposures taken with our club’s “Cookbook” CCD camera and 18 inch (46 cm) reflector on 22 June 2000, at 03:45:00 UT (average time of the images). The object is bracketed by vertical and horizontal bars above and to the right of the object.


The second image was taken by Alex Cruz, Len Casady, and Randy Pepper on the following night, using the same equipment and number of exposures. Average time of the exposure set was 03:47:30 UT, 23 June 2000. Randy’s program was used to flat field, hot-cold pixel remove, and stack the images. Note the slight shift in position. Astrometric positions were reported to the Minor Planet Center using the programAstrometrica.


2000 EB173 was 29.6 A.U. (Astronomical Units = mean earth-sun distance) from the earth when the images were taken, or 4.4 billion kilometers (2.75 billion miles). 2000 EB173 is approximately 300-700 kilometers in diameter.

2000 EH26


JPL astronomers requested help in refining the orbit of the earth-crossing asteroid 2000 EH26 for radar studies at Arecibo. We responded and were able to image and do astrometry on this fast-moving, faint object!

Below are two motion-compensated image stacks of the NEO asteroid 2000 EH26. The images were taken out at the George Observatory, using the Fort Bend Astronomy Club’s 18-inch (46 cm) reflector and Cookbook CCD camera. Each stack was made from 10, 30-second images. The stars are streaked as the images were shifted to follow the rapid motion (about 6 arcseconds/min) of the asteroid.

Observers were Joe Dellinger, Bill Dillon, and Cynthia Gustava. Images were processed by Randy Pepper and converted from fts to gif. Randy and Russ Wicker developed our motion-compensation code. The small red arrow points to the faint asteroid (~19th magnitude). Certainly one of the most challenging asteroids we’ve ever imaged!

Postscript: JPL astronomers succeeded in making radar contact with this asteroid!
B image stack, 02:41:08 UT, 25-April-2000
C image stack, 02:47:53 UT, 25-April-2000