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

Today's issue status: done

• June Bootids by Marco Langbroek
• Small objects – report for 21-27 June
  Observation summary
• News briefs – New Zealand event, rocket re-entry & fireball reporting
• Risk monitoring – NEODyS has posted 2004 ME6

Cover: Confirmation imagery of small object 2004 MO3 from June 22nd from Krisztian Sarneczky using the SZTE Asteroid Program 0.6m Schmidt telescope at Piszkesteto Station in Hungary. This is a composite of three 20-second exposures stacked at A/CC on the stellar background to show the object's motion. North is up, east is left, and, after cropping, the field of view is 7.6'x7.6'.

June Bootids   By Marco Langbroek

Rainer Arlt of the International Meteor Organization (IMO) has issued a shower circular (posted on the IMO News Mailing List) about the return of the June Bootid meteor shower last week. Based on a preliminary analysis of early reports to the IMO, the zenithal hourly rate (ZHR) curve suggests that rates briefly surged to a ZHR of perhaps 50 on June 23rd, only slightly less than the maximum ZHR (80) of the well known Perseids in August.

Zenithal hourly rate is the number of meteors a “standard” observer would see if he or she was observing with the radiant at zenith (directly above the observer) and a limiting magnitude of +6.5. As this is rarely the case, ZHR values are obtained by correcting observed rates for deviations in real limiting magnitude and radiant altitude.

The usual ZHR for the June Bootids is below a value of 2 per hour. From the diagram it can be seen that rates were well over that for several hours spanning 22-23 June, therefore classified as an "outburst" at an unusual high level for this stream, which also displayed this kind of behavior in 1916 and 1998.

The possibility of enhanced activity in 2004 was predicted by Sergey Shanov and Sergey Dubrowsky, Mikiya Sato, and Jeremy Vaubaillon. The outburst was due to the Earth meeting a dust trail left by the parent comet, 7P/Pons-Winnecke, with dust contributions from perihelion passages during 1819-36.

Marco Langbroek is a professional archaeologist and an amateur meteor astronomer active with the Dutch Meteor Society. He is published on topics as diverse as Neanderthals and comet dust trails. See the news Index for more of his writing.

Small objects
Discovery & follow-up for 21-27 June

This last week was another in which only recently discovered small asteroids (defined at right) were tracked — four announced this week and four from last week. That's eight of the 555 small NEAs currently listed by JPL, which speaks of the difficulty in keeping tabs on Earth's nearest and smallest neighbors, which have an average observation arc of 44 days. And the importance of keeping tabs is underscored by the fact that, of these eight, one has impact solutions, as did two others, and all but one would be classified as “potentially hazardous” if larger. One will fly past Earth at 3.7 lunar distances (LD) on Tuesday, the 29th.

Two of this past week's discoveries came from Spacewatch. The first was from its 0.9m telescope and FMO Project, and the second from its 1.8m telescope. Another was caught by the Observatory of Rome's CINEOS project at Campo Imperatore, and LINEAR found one.

Twenty-four observatories participated in this work, with KLENOT playing the most active role.

<< previous report | skip table | Small objects table >>

New Zealand event:  Newstalk ZB reports that Port FM radio on New Zealand's South Island “has taken dozens of calls . . . from Christchurch to Timaru” about “a bright light streaking across the sky” at around 9:30pm local Saturday night. That exact report has also been repeated here and here. Marco Langbroek notes that no space debris decay was expected that would explain the sightings.

Stuff.co.nz has more details in a report dated tomorrow, saying it happened “just after 9pm” heading east-to-west with remarkable colors, and was seen also from the North Island. According to Alan Gilmore, it was “likely to have been ‘at least’ 200km to 300km west of the South Island's east coast.”

Rocket re-entry:  Marco Langbroek reports that a Russian booster rocket re-entered over the eastern U.S. at around 10:53pm EDT Saturday (0252-0254 UTC), resulting in reports of multiple fireballs to the Satobs mailing list.

SpaceWeather.com today makes note of this event — “probably fragments of a Russian rocket motor,” and links to an Aerospace Corporation re-entry report.

Fireball reporting:  A/CC has received an uncorroborated eyewitness account of a fireball seen from San Mateo, California at 11:30pm Saturday night. If you saw this or know of news reports, please tell us.

Formal fireball reports should be filed using the International Meteor Organization online form, and, for reports in the U.S., also use the American Meteor Society form. For Colorado and west-central U.S., please also use the form at Cloudbait Observatory.

Risk monitoring 27 June

NEODyS has posted 2004 ME6, which was announced yesterday in MPEC 2004-M59 as discovered Friday morning Spacewatch 1.8m telescope in Arizona and confirmed that night by KLENOT in the Czech Republic and with the discovery telescope yesterday morning. From its absolute magnitude (brightness), it is roughly estimated to be 100 meters/yards wide.

The Sunday Daily Orbit Update MPEC has no further observations for 2004 ME6, nor for 2004 MX2, which is the only other object currently in view that that has impact solutions. The Minor Planet Center Last Observation page, however, is showing that Camarillo Observatory in southern California caught 2004 MX2 this morning.