The Asteroid/Comet Connection's
daily news journal about
asteroids, comets, and meteors

Today's issue status: done

• News briefs – occultation news & cover story
• Risk monitoring – JPL has posted 2004 JR

Cover: Comet C/2001 Q4 (NEAT) from Gary Hug Saturday night at Sandlot Observatory in Kansas. See "Cover story" below for more info.

Occultation news:  David Dunham's stellar occultation news includes Main Belt asteroids with some indication of having companions. The latest is 559 Nanon. An account tells of one succesful "long occultation" observation May 5th. From another location, a "miss" was accompanied ahead of the occultation by a dimming that "represents over 30 Nanon diameters from the object, a distance unlikely to be stable enough for satellites, virtually all of the known ones of which are within 10 asteroid diameters." 559 Nanon will occult another star July 1st, viewable from southern California.

An account of an April 18th occultation by 772 Tanete reports that its cross-section was measured at 141 km., and there was indication of "a possible satellite about 40 km in diameter 1260 km (a plausible 9 diameters) from Tanete." An opportunity comes quickly to follow up, with an occultation May 20th visible from the southeastern U.S., Mexico, New Zealand, and Australia.

Cover story: Gary Hug, member of NEKAAL and a regular at chasing NEOs, writes that “C/2001 Q4 makes a good target while waiting for the sky to completely darken. This image is 10 seconds in length and was imaged with a 12" LX-200 working at f/6 and a SBIG ST9E CCD camera. I processed the image with dark and flat field, then used a soft sharpen routine, auto-log scaling, and DDP with CCDOPS software. The FOV is about 20 minutes square.” (Full-size but cropped above.)

Ian Shelton's video of an occultation last December 7th by 757 Portlandia shows fading and then a brief brightening "probably due to a deep depression along the midsection of the circa-30 km diameter asteroid," or possibly due to it having a companion.

David Dunham notes that a record was set in 2002 with 85 asteroid occultation events known to have been observed, and again in 2003 with 113.

Risk monitoring 11 May

The Tuesday Daily Orbit Update MPEC reports two positions for 2004 HQ1 from Saturday from David Tholen's team at the University of Hawaii 2.2m Telescope on Mauna Kea. Today NEODyS slightly lowered its low assessment for this small object.

NEODyS announced today that its host computer at the University of Pisa in Italy "is undergoing an OS upgrade," so its main Web site will be offline, and users are referred to the duplicate site at the University of Valladolid in Spain during the interim. (A/CC's Consolidated Risk Tables page for objects of current concern provides NEODyS links as both main and backup alternate.)

Update:  JPL has posted 2004 JR with a single low-rated impact solution eight years from now. This object, which JPL estimates at 790 meters/yards wide, was announced today in MPEC 2004-J42 as discovered by LINEAR in New Mexico Sunday morning. It was confirmed yesterday morning by Table Mountain and Tenagra II observatories, last night by Herrenberg

Observatory, and this morning by Sabino Canyon and Tenagra II observatories.