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

Today's issue status: done

• Perseids report by Marco Langbroek
• News briefs – occultation news, extrasolar news, unusual object + bits & pieces,
• Risk monitoring – JPL has posted 2004 PU42

Cover: The Visnjan School of Astronomy (VSA) NEO group last night helped confirm the discovery of 2004 PT42, bright and fast enough (moving toward image bottom) to appear as separate beads on the students' string of 18 20-second exposures spanning 18.43 minutes when stacked on the background stars. A standard brightness-to-size formula puts 2004 PT42 at roughly a mile (1.62 km.) wide. JPL shows that this object will be at 63.8 lunar distances on August 16th, the closest it comes to Earth. For more about the VSA NEO group, which is using a remote-controlled Observatorio Astronomico de Mallorca (OAM) 0.3m telescope, see a report from Tuesday.

Perseids report   by Marco Langbroek

We had a beautiful Perseid 11-12 August night here that we will long remember. At first we were afraid to lose the night, as it seemed a front would pass right over. But it didn't, at least not for several hours after midnight. We saw the pre-frontal cirrus coming in south of us, but most of it dissolved before it was over us. I calculated a limiting magnitude varying between +6.5 and +6.8, with a few short breaks in observations because of patches of clouds drifting over, but mostly we had it clear. We observed from our dark location in Biddinghuizen, in the central polders of the Netherlands.

And what a show it was! In about 3.5 hours of effective observing between 2033 and 0030 UTC, I observed 223 meteors, of which 182 were Perseids. (Then we quit, as heavier clouds moved in, and my observing mate Robert had to work today.)

This night was memorable for the really unusual number of bright Perseids, especially in the magnitude zero to -3 range. I counted 31 Perseids of magnitude zero or brighter (up to -3). Being an experienced meteor observer, I can absolutely say this was unusual for an August 11-12 night. It suggests that something unusual was going on, even though I cannot make out any presence of the predicted 2054 UTC peak of dust

from 1862 in my data (but we still had twilight then, as this was near the start of our local night). IMO data suggest some sort of peak was present, but certainly not every observing group will second that. If it was present, it was not very pronounced. Anyway, this was one of the best Perseid shows I've seen in years (have to go back to 1993 to surpass it). So we feel very very happy to have seen it!

We had a reporter from one of the major Dutch newspapers with us in the field. Today the front page of the Volkskrant opened with a large picture of our team member Robert Haas setting up his camera equipment in twilight.

Marco Langbroek is a professional archaeologist and an amateur meteor astronomer active with the Dutch Meteor Society. He is published scientifically on topics as diverse as Neanderthals and comet dust trails. Previously he told A/CC readers about the June Bootids.

Occultation news:  David Dunham's preliminary report is that a 1685 Toro stellar occultation early Tuesday was apparently missed due to problems with path prediction, weather, and equipment. This large NEO, which almost qualifies as potentially hazardous, is in “a 5:8 resonance with Earth's orbit.” It occults another star today with the shadow running across Taiwan and South Korea, and yet another at 1123 UTC tomorrow crossing Kansas, New Mexico, Arizona, and Baja California (see Steve Preston's prediction).

Extrasolar news:  The University of Hawaii Institute for Astronomy has a news release today, “Sharpest Image Ever Obtained of a Circumstellar Disk Reveals Signs of Young Planets,” about an article by Michael Liu in today's journal Science (preprint). It shows observation of the dust disk surrounding the nearby red dwarf, AU Microscopii (AU Mic), which you may recall from April 24th news. Using the 10m infrared Keck II Telescope with the ability to resolve “features as small as 0.4 Astronomical Units” in the disk, clumps were found corresponding “to the regions where Neptune and Pluto reside” in our Solar System. Physics Web has a report, and Space.com has an article today, “Comets, Asteroids and Planets around a Nearby Star.”

Unusual object:  MPEC 2004-P48 today announces the discovery of 2004 PY42 by CINEOS in Italy Tuesday night and confirmed by four observatories through this morning. The first orbit calculation for this distant object (estimated to be 12.2 AU from the Sun now, out beyond Saturn) is noted as having assumed eccentricity and “is essentially indeterminate. Near-parabolic solutions are not excluded.”

Bits & pieces:  The Scotsman has an article today encouraging readers to participate in the great U.K. meteorite hunt (news thread). Meteorite hunter/dealer Rob Elliot is interviewed about how he spotted the last meteorite pieces found in Scotland while fishing in 1998. Chances are good for finding more, he says. “You get 30 meteorites hitting the UK every year. The survival rate is about 200 years, so that’s 6000 waiting to be found.”

Russian and French news agencies, and some credible as well as tabloid news outlets around the world, have been reporting creduously in recent days that Russian UFO advocates have returned from Siberia after a brief search with evidence that the 1908 Tunguska event was caused by a UFO rather than a large meteor. Space.com reports today, “Russian Alien Spaceship Claims Raise Eyebrows, Skepticism.”

Risk monitoring 12 August

JPL today posted 2004 PU42, an object it estimates to be on the order of 20 meters/yards wide that was announced today in MPEC 2004-P47 as discovered yesterday morning by LINEAR in New Mexico and confirmed last night by KLENOT in the Czech Republic and this morning by Table Mountain Observatory in southern California.

Francesco Manca at Sormano Observatory, which maintains a list of small close-approaching asteroids, tells A/CC that 2004 PU42 “will pass from the Earth on August 15, 2004 at 0.005429 AU, or 812,166 km., at about 0700 UT.” This is about 2.1 lunar distances.