12 September 2005 - Monday
Hayabusa arrives: Alan Fitzsimmons brings to our attention to the fact that "the Japanese Institute of Space and Astronautical Science (ISAS) has been posting regular images of 25143 Itokawa as the Hayabusa spacecraft approaches. The latest image from 20 km. away can be found here." Earlier images and reports are archived here.
Risk monitoring: (2137 UTC report) Someone has reported to NEODyS and JPL observation of 99942 Apophis (2004 MN4) at 1516 UT last Sunday, adding 55.462 days to the observation arc. The two risk monitors updated their assessments today, with NEODyS very, very slightly raising its overall risk ratings for five impact solutions in the years 2036 to 2069, and JPL cutting to a single slightly lower-rated solution in 2036.
Update: David Tholen tells A/CC that, "The 'someone' was us. I realized that it would be observable during our Subaru run, so I had Fabrizio Bernardi add it to the list. It was at 39 deg. solar elongation. Solar conjunction therefore lasted less than two months, as we were the last to see it during the previous apparition from Kitt Peak in July" (report).
Today's Daily Orbit Update MPEC reports observation of 2005 RR6 from Farpoint Observatory in Kansas yesterday morning, and today NEODyS and JPL cut to a single lower-rated impact solution for this object, which is estimated to be bit more than 600 meters/yards wide.
11 September 2005 - Sunday
Bits & pieces: The time has come for this overstretched reporter to cut back to my bottom-line commitment to minor object news coverage, which is to keep A/CC's semi-automated CRT page functioning, which has the functions of watching the status of all objects with impact solutions that are under current observation, and giving public credit to those doing the observing. In place of the once daily risk monitoring narratives to put observers' work on permanent record, the CRT news section will now scroll off onto a quarterly archive page with all the details. This A/CC News page probably will have something new posted only occasionally, which has been increasingly the case in recent months, anyway.
There are some important points to note in risk monitoring news since A/CC's August 31st report. Over the past 11 days, there were objects reported in the Daily Orbit Update MPECs of only September 1st, 3rd, 4th, and 9th. On the 4th, NEODyS removed its last impact solution for 2005 QP87, which was discovered by FMO Project online volunteer Stefan Kurti of Slovakia. On the 1st, NEODyS joined JPL from the previous day in posting another small object and Spacewatch discovery, 2005 QK76. Only one further observation has been reported, from the SZTE Asteroid Program in Hungary, adding half a day to the 1.127-day observation arc, and this object is now out of view for most telescopes. Yet another Spacewatch discovery, 2005 QG88, was posted by both risk monitors on September 2nd and removed the next day.
Currently in need of follow-up are Siding Spring Survey discovery 2005 RQ6, announced two days ago, which is when JPL posted it, followed by NEODyS the next day, and 2005 RR6, announced yesterday, which is when it was posted by both monitors.
2005 RR6's discovery MPEC, 2005-R44, does not specify exactly who discovered it or with which of two cited telescopes on Mauna Kea in Hawaii. A/CC inquired and was told that this half-kilometer-plus object was discovered last Sunday by Fabrizio Bernardi using the Japanese 8.2m Subaru Telescope. He followed it up with the same telescope Tuesday, and it was further confirmed Friday morning by Gary Hug at Farpoint Observatory in Kansas and several hours later by Mary Laychak and T. Georges, operating the 3.6m Canada-France-Hawaii Telescope (CFHT) at the direction of David Tholen.
In comet news, Rainer Kracht has found four comets in the U.S. Air Force SOLWIND satellite image archives, as he tells about on his My Solwind Comets page: C/1981 W1, C/1983 N2, C/1984 Q1, and C/1984 R1.
Comet C/2005 P3 (SWAN) was first noted in late August by people watching images from SOHO's SWAN instrument, which can't be used to obtain astrometry, but this object was subsequently picked up with ground-based telescopes. Suno Observatory in Italy has posted an animation of ten 10-sec. frames with this object from the night of August 29th.
And before this next news gets any older, let's note that MPEC 2005-P44 of August 9th formally announced the discovery of inside-Earth orbit object (IEO), 2004 XZ130. It was found last December 13th by David Tholen's team, which tracked it on 14, 16, 18, and 20 December, and also caught it on January 9th and February 1st and 8th, all using three different telescopes on Mauna Kea in Hawaii. This is only the third confirmed IEO discovery, and the first since May of last year (news), but actually has been known to the astronomical community since late February (report).
FMOP news, by Marco Langbroek:
The most recent discoveries are
Aug 31 2005 QQ87 Su Shan Ding, China, MPEC 2005-R04
Aug 31 2005 QP87 Stefan Kurti, Austria, MPEC 2005-R03
Both discoverers are new volunteers in the project. Stefan joined in July and discovered 2005 QP87 in his 50th image review!
And there were also two recent recoveries of the same object discovered earlier by Spacewatch's own observer (see MPEC 2005-Q46):
Aug 30 2005 QP11 Quanzhi Ye, China, Disc. 2 days earlier by SW
Aug 29 2005 QP11 Josep Gomez, Spain, Disc. 1 day earlier by SW
A remarkable coincidence, is that all three asteroids have their aphelion within Mars' orbit, not between Mars and Jupiter. 2005 QP87 is very small (about 10 meters), and 2005 QP11, too (about 14 meters).
4 September 2005 - Sunday
Special FMO: Urgent follow-up observations are needed for this small object, and Marco Langbroek explains in E-mail to A/CC why it is of special interest:
On our FMO Project mailing list, Jun Yu noted that the period of the August 31st discovery, 2005 QQ87, which was discovered by FMOP online volunteer SuShan Ding from China, is very close to the orbital period of Earth.
I have produced a few diagrams by integrating the discovery orbit of 2005 QQ87 (MPEC 2005-R04) 50 years backward and forward with Pasquale Tricarico's ORSA integration package. Note, as the orbit currently is still very preliminary, caution should be exercised with regard to these results. Nevertheless, the object appears clearly to be in resonance with Earth. Currently it is in a phase where it makes relatively close encounters each year (!) to within 0.08 AU. See sunper.gif, earthdis.gif, and earthper.gif.
As Yun Ju noted, if there ever was a small NEA with good prospects for
recoveries during future passes, this one is it!
Based on its H-value of 23.0 and assuming an albedo 0.15, 2005 QQ87 is about 86 meters in diameter.
Checking with MPC's Ephemeris Service (MPES), the current orbit calculation would make it appear that recovery opportunities for 2005 QQ87 are very, very good in 2006. Of course, that current orbit is far from well established.
During August 23 to September 1 of next year, the object is predicted to be magnitude +19.5 or brighter (brightest face value prediction is +18.9 August 26-28), and there will be a new moon on August 23! 2005 QQ87 will be located very high in the sky for Kitt Peak, culminating in the zenith for the early part of the observational window. It moves from Cygnus to Capricorn. The only snag (apart from the still very preliminary orbit parameters) might be the weather, if the infamous Arizona monsoon lingers to the end of August like it did this year.
After some communications with Josep Gomez, he showed me that the uncertainty in RA is rather large (larger than I had thought in my enthusiasm). This is a function of the observational arc still being very small. Recovery will therefore be tricky, especially if the arc remains as short as it is now, so I hope that 2005 QQ87 gets enough follow-up. Unfortunately, Spacewatch is currently out of service because of bad weather.
If the orbit can be properly fixed, this could in the near future be a very interesting target for a dedicated space mission, as the annual close encounters would provide a number of launch opportunities.
The current MPES prediction is for 2005 QQ87 to be technically in view through the night of 13-14 September, but as an increasingly difficult target.
Risk monitoring: Of several recent PHA discoveries, only the small 2005 QK76 remains listed with impact solutions, and it hasn't been reported observed outside of its discovery arc.