Contents  on 25 December '09


The latest A/CC news is available via framed access, RSS news feed RSS news feed, or redirection. - Note: A/CC has a main Web site and also a backup site with its own duplicate RSS news feed.

Navigation tips: Use the << and >> arrows on the menus for each regular section (Observers, Risks, etc.) to move to the previous and next day's news for that section. Use the Index menu item to access specific days through a calendar interface. And use the all-up news archive to access news from any time since A/CC began in early 2002. To keep track of what's new each day, watch the Chronology section.

NEOCP Activity  on 25 December '09

The MPC's NEO Confirmation Page has 2 listings: 2 new

When last checked at 2358 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had two new listings. Both of these were "one nighters."

To learn how observers use the NEOCP, see the Practical guide on how to observe NEOCP object at Suno Observatory by Birtwhistle et al.

New MPECs  on 25 December '09

Minor Planet Electronic Circulars

As of last check at 2358 UTC, there have been two MPECs posted today from the International Astronomical Union's Minor Planet Center in Cambridge, Massachusetts.

MPEC 2009-Y50 - "21:27 UT" - 2006 SV134

<< DOU on 25 Dec. '09 >>  MPEC 2009-Y49 - "07:11 UT" - Daily Orbit Update

Observers  on 25 December '09

Four observing facilities appear in today's MPECs.

CodeObserver / observatory
379Hamamatsu-Yuto Obs. in Japan, 4 in MPEC 2009-Y49 -- 2009 XR2, 2009 XD, 2006 UR, 2002 XN14
5682David Tholen's team on Mauna Kea in Hawaii, 1 in MPEC 2009-Y50 -- 2006 SV134
932McCarthy Obs. in Connecticut, 2 in MPEC 2009-Y49 -- 2009 XV, 2009 XO
291Spacewatch 1.8m telescope in Arizona, 6 in MPEC 2009-Y49 -- 2009 YV6, 2009 YO, 2009 XQ1, 2009 XO, 2009 XJ8, 1998 YW5
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 25 December '09

Summary Risk Table for Risk Assessments Updated Today   (last checks: NEODyS and JPL at 2358 UTC)
See the CRT page for a list of all objects rated recently as risks and our ephemerides page for a list of risk-listed objects under current observation.
The time horizon for JPL is 100 years from today and for NEODyS is usually the year 2090. Beginning Jan. 22nd, both are also posting impact solutions beyond 100 years for a few objects.
For the latest official risk assessments, and for explanations of the terminology, see the JPL NEO Program Sentry and NEODyS CLOMON (backup) risk pages.





Notes for Today's Latest Risk Assessments
2009 YV6JPL Sentry1509R E M O V E DJPL: Risk listing removed at 0949 UTC.
NEODyS1509R E M O V E D-
2009 XOJPL Sentry1509202818.4e-08-4.29-4.290JPL: "Analysis based on 100 observations spanning 16.104 days (2009-Dec-09.152 to 2009-Dec-25.25605)." Diameter approximately 0.320 km. from mean, weighted H=20.1.
NEODyS15092028-208841.81e-07-4.14-4.290NEODyS: "Based on 100 optical observations (of which 0 are rejected as outliers) from 2009/12/09.153 to 2009/12/25.257."

Legend: VI# = VI count, Prob Cum = cumulative probability, PS Cum/Max = cumulative/maximum Palermo Scale, TS = Torino Scale

An impact solution, also known as a "virtual impactor" (VI), is not a prediction but rather a possibility derived from a variant orbit calculation that cannot be eliminated yet based on the existing data. Elimination can come quickly with just a little further observation or may take weeks or months, sometimes years. Once superceded or eliminated, a former impact solution has zero relevance to an object's risk. See Jon Giorgini's "Understanding Risk Pages" to learn more.

Chronology  on 25 December '09

Times are UTC for when items were noted or added by The Tracking News.

2358Grabbed MPEC 2009-Y50 - 2006 SV134 - see above
1509Noted that JPL Sentry has reposted 2009 XO as an impact risk - see above
Noted that NEODyS has updated its 2009 XO risk assessment - see above
Noted that JPL Sentry has removed 2009 YV6 as an impact risk - see above
Noted that NEODyS has removed 2009 YV6 as an impact risk - see above
Grabbed MPEC 2009-Y49 - Daily Orbit Update - see above