Comet Neat (C/2001 Q4)

C/2001 Q4 (NEAT) is a comet with an unusual, almost perpendicular retrograde orbit which brings it into the inner solar system by a deeply southward path. It initially emerged from its remote home spending most of its time near the south celestial pole. This comet was discovered on August 24, 2001 by the Near-Earth Asteroid Tracking program (NEAT).

In 2004, residents of the southern hemisphere had the opportunity to watch the comet gradually brighten as it raced toward 
perihelion. On May 6, 2004 the comet approached within 0.32 AU of the Earth.Beginning in early May, the comet started racing north and burst into view in the northern hemisphere when it had reached almost maximum brightness.With a near perihelion orbital eccentricity of 1.00069 (epoch 2004-May-18) that keeps a barycentric epoch 2014-Jan-01 eccentricity of 1.00067, this hyperbolic comet is going to be ejected from the Solar System.
NealCloseup   NeatSmall

Comet Neat was an exasperating comet. I tried in vain to capture it  every night at dusk for 3 weeks. It seems that the clouds enjoyed obscuring a small spot in the southwestern sky each evening.  Many nights the entire sky would be perfectly clear, but that one little cloud remained persistently in the southwest. On two different nights I thought I got a glimpse of the Comet through holes in the clouds, but the glimpse was so brief I wasn't really sure, and did not have enough time to get in a picture.

NEAT51604p                                         Neat5112004  

My luck changed on the night of May 15th.  At dusk the sky was clear except for the southwestern horizon, and it appeared to be clearing.  As twilight progressed, the cloud continued to dissipate and night sky objects began winking into view.  Venus, of course, was first to appear, then Saturn.  A quick glance overhead revealed Jupiter and the constellation, Leo. Back in the southwest conditions were improving. The ominous cloud was gone and the sky actually appeared to be settling quite nicely. Slowly, almost imperceptibly,  old friends began appearing. There was Sirius almost touching the horizon. Up and slightly north came Betelgeuse.  Back to the south and upward came Procyon.  Up a little higher and to the north, near Saturn and Venus were the twins.

Using these familiar guideposts, I picked up my binoculars and looked where I thought the Beehive Cluster should be.  "Ah, there it is." I stopped for a brief second or two  and reveled in the sight.  The Beehive is a large open cluster and  is quite spectacular in  binoculars.  I slowly moved the Beehive to the left side of the view and got my first real glimpse of Comet Neat.   It wasn't dark yet, so the first image was quite poor, but hinted at some nice qualities. The Comet had a bluish-green appearance, the coma was very large and dense and a hint of a tail appeared to be visibly extending outward at about 10:00.

I quickly set up the telescope for photography and began taking the photos which appear on this page.  None are earth shattering views, but I must admit that I was pleased with the results.  This was my first time using my new Canon EOS REBEL Digital SLR camera. And yes, the camera is nice, but is a lot different than my old Olympus OM-1 Astrocamera. It took me almost a half hour to find the right settings to get a picture.

All photos taken 5/16/2004 in Birmingham, Ohio
by John & Dorothy O'Neal
Camera: Canon EOS Digital Rebel
Lenses: Canon EFS 18-55mm
Lenses: Canon EF 75-300 w/2x flat field Doubler
Telescope: Meade 8"


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.
  • The comet slowly brightened during the remainder of 2001 and throughout 2002. As 2003 began, the comet was still fainter than magnitude 15, but it steadily brightened as the year progressed, reaching 14 near the end of May, 13 early in July, and 12 around mid-September. September of 2003 also marked the time that amateur astronomers in the Southern Hemisphere began supplying regular visual observations of this comet. The coma diameter was typically given as 0.6 to 1.2 arc minutes. CCD images by amateurs also began showing a short fan-shaped tail pointing northward in July. By late September, this tail extended about 0.8 arc minutes toward the northwest. As 2003 came to an end, the comet had become slightly brighter than magnitude 10, with a coma diameter of about 2 arc minutes. A faint, fan-shaped tail extended about 4 arc minutes toward the east.
  • Predictions: The comet should be at its brightest during the first half of May. The Central Bureau for Astronomical Telegrams predicts a maximum magnitude of 0.9, although their brightness parameters have not been updated in many months. Several experienced amateur astronomers are keeping close tabs on this comet. Andreas Kammerer (Germany) looked at all available observations obtained up to the end of November 2003, and suggests the comet's total magnitude may reach 2. Seiichi Yoshida (Japan) indicated during the last days of 2003 that the maximum brightness might reach 2.
  • The comet steadily brightened as the year progressed. Observers indicated the brightness attained magnitude 8 in mid-February, 7 in mid-March, 6 as April began and 5 shortly before mid-April. The coma grew in size during this same period, with estimates near 2 arc minutes at the beginning of February, 5 arc minutes around mid-March, 10 arc minutes as April began, and 15 arc minutes around mid-April.
  • The comet finally appeared to amateur astronomers of the Northern Hemisphere on the night of May 3/4. Numerous observers in the United States, from Texas, New Mexico, Arizona, southern California, and Hawaii, were able to spot the comet at a very low altitude just below the star Epsilon Canis Majoris. Most observers described the comet as appearing like a globular cluster between 7 and 10 arc minutes across, while a few noted a tail extension. Around this same time, observers in the Southern Hemisphere were giving the magnitude as between 3.2 and 3.6 on that date. The comet passed closest to Earth on May 6 and quickly attained a higher attained for northern observers during the next week. Naked-eye observations were obtained from dark-sky locations and observers generally noted a magnitude of 2.8 to 3.0. The tail was initially a short stub, but soon became longer and developed a filamentary structure. In addition, many observers noted the sunward side of the coma was abnormally bright, and many specially processed digital images revealed hoods near the nucleus.