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

Today's issue status: done

• Occultation news – 60 Echo & more
• News briefs – cover observer, meteor news, radar/binary news & PHC news
• Risk monitoring – JPL has reposted 2004 BG121

Cover: Small object 2004 PG20 was discovered on August 9th and the image at left is from Robert Hutsebaut's participation in the confirmation process on the 10th using a rented telescope in New Mexico from his home in Belgium (see more below about his work). This image is a composite of eight 60-second exposures stacked on the object's motion of 4.03"/min. toward 356.0° — a “Difficult object for the 0.25m scope.” 2004 PG20 hasn't been reported seen since August 19th and is currently flagged as “Urgent” on the SCN Priority List, where it is noted as going out of view for most observers on September 19th.

Caught! — see report.

60 Echo occultation:  John Broughton of Reedy Creek Observatory in southeastern Queensland, Australia writes that the above is a “CCD drift image of an occultation of a magnitude 11.9 star by minor planet 60 Echo on [the night of August 28th]. This occurred only 15 degrees from an almost full Moon where more conventional visual and video methods of observation would not have been possible. The image was used to accurately time the event and is my seventh positive result in 14 months. My report on this observation can be found on the RASNZ occultation results page.” There he tells about some rather difficult observation conditions.

Other occultation news:  John Dunham reports that “The occultation of 7.2-mag. SAO 36280 A = HIP 1642 A by the 76-km asteroid (914) Palisana may be the best occultation of 2004 in North America,” running 0506-0518 UT Sunday, September 12th (Saturday night in the west), running from Nova Scotia across Missouri, New Mexico, and central Baja California. A 2 September update tells of a big problem in the path prediction, and mentions that Paul Maley has maps and coordination for the observing effort in New Mexico (search Maley's page for “brightest star,” as, when last checked, Palisana wasn't mentioned by name).

Dunham's site also reports a 21 August occultation by small Main Belt asteroid 1903 Adzhimushkaj, recorded by Ed Morana and Richard Nolthenius in northern California.

Cover observer:  Robert Hutsebaut, who provided today's news “cover” image above, and who recently told about how he got started in NEO observing using remote-controlled telescopes, has a new article telling about his discovery of Main Belt asteroid 2004 QX16.

Meteor news:  The Winnipeg Sun has a brief item from September 4th saying that a “bright fireball . . . hurtled across Manitoba about 10:45 Thursday night” (the 2nd), reported by “several people” to the Manitoba Museum Planetarium.

Radar/binary news:  The Sunday Daily Orbit Update MPEC reports radar observation of 2002 CE26 from Arecibo early on August 27th, for which planning was reported in August 25th “Radar news.” Peter Pravec told the Minor Planet Mailing list (MPML) on Saturday that Michael Shepard's team had found this asteroid to be binary, “one of the largest NEAs known to be binary,” with a satellite that is small relative to the primary's size. “[We] could not detect the small satellite with the photometric technique as its photometric variation in the system's lightcurve is estimated to be <0.01 mag. The photometric technique has a lower limit of ds/dp about 0.15.”

PHC news:  MPEC 2004-R24 yesterday has the discovery and confirmation observations of comet P/2004 R1 (McNaught) (see Sunday “Comet news”) from Australia and southern California. The first preliminary orbit puts perihelion slightly inside Earth's orbit at 0.98775 AU a week ago Monday (August 30th), but 0.691 AU from where we all were at the time. The Minor Planet Ephemeris Service (MPES) presently shows that this comet will be closest this year on 28-29 September, when it will be 0.593 AU from Earth. But it can come to within 0.0259 AU of Earth according to JPL, close enough to be classified as potentially hazardous. Thus it becomes the second PHC discovered this year, after P/2004 CB (LINEAR), which was listed with impact solutions for a time in February, back before its cometary nature was observed (see news Index).

Risk monitoring 7 Sept.

Revised report:  JPL today reposted 2004 BG121 based on nine observations from the original .934-day observing arc during 30-31 January 2004. As is common with an assessment from so little observation, there are many highly preliminary impact solutions, but it happens that the first is less than a year away, on August 1st. And more follow at the same time of year in many years from 2007 to 2099. All 135 solutions have low probabilities, and remember that an impact solution is not a prediction but rather a possibility that hasn't yet been eliminated.

2004 BG121 was discovered by Jim Scotti with the Spacewatch 0.9m telescope in Arizona, was confirmed with the Spacewatch 1.8m telescope and by Tenagra II Observatory, also in Arizona, and was announced eleven days later in MPEC 2004-C38. It had impact solutions posted at JPL, which were soon removed without further observation, while NEODyS has continued to list it under “Lost objects.” It was posted to the SCN Priority List back then as “Urgent” and noted as going out of view on 23 February, but was not reported seen again. From its brightness, it has a diameter on the order of 625 meters/yards.

For an update, see September 10th news.