C/2001 Q4 (NEAT)


Image was captured on May 22, 2004 near San Bernardino, Ca. Three exposures of 4 minutes, ISO of 400, and 200mm Lens. The images were stacked in Adobe photoshop. The camera was piggybacked on telescope in Alt-AZ mode. Notice the field rotation.


Several observatories in the United States and elsewhere search the sky every clear, moonless night to look for asteroids which might eventually pose a threat to Earth; however, with such a systematic search of the sky come other interesting discoveries as well. S. H. Pravdo, E. F. Helin, and K. J. Lawrence (Jet Propulsion Laboratory) announced that the 1.2-m Schmidt telescope at Palomar Observatory (California, USA) had found a comet on 2001 August 24.40 in the course of the Near Earth Asteroid Tracking (NEAT) program. The comet was found on CCD images and the astronomers were able to confirm the discovery on August 26 and 27. The comet was described as a round nebulosity measuring about 8 arc seconds across. The total magnitude as given as 20.0. Confirmations also came from other observatories on August 27 and these indicated a brighter total magnitude. J. Ticha, M. Tichy, and P. Jelinek (Klet Observatory) gave the magnitude as 17.8, while P. J. Shelus (McDonald Observatory, Texas, USA) gave it as 17.3.

Historical Highlights
* This comet was first announced on IAU Circular No. 7695 (2001 August 28), when Daniel W. E. Green gave the discovery details, as well as a "very uncertain" orbit by Brian G. Marsden. The orbit indicated the comet might pass perihelion on 2005 August 25, with the closest distance to the sun being just over 4 AU. The reason for the orbit's uncertainty was because the comet was moving very slowly due to its rather great distance from the sun. Marsden's orbit indicated the comet was probably over 11 AU from the sun when discovered. Kazuo Kinoshita published an orbit for this comet on his website on September 5. This orbit used 25 positions spanning the period of August 24 to 31 and indicated a perihelion date of 2004 May 23 and a perihelion distance of 0.99 AU. Such an orbit indicated a potentially bright apparition for this comet, but little excitement was generated as more observations were needed to firmly establish an orbit. Confirmation of Kinoshita's calculations came on September 10, when IAU Circular No. 7711 included new positions, as well as an orbit by Green which was based on 38 positions from the period of August 24 to September 10. This orbit indicated a perihelion date of 2004 May 26 and a perihelion distance of 1.00 AU. Green wrote that the perihelion date "is still uncertain by several weeks, but it appears that this comet may become an easy binocular (and possibly naked-eye) object in May-June 2004." As it turned out, the comet was discovered when 10.1 AU from the sun.