Contents  on 23 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 23 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 23 December '09

Minor Planet Electronic Circulars

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

MPEC 2009-Y46 - "15:53 UT" - 2007 YV56

<< DOU on 23 Dec. '09 >>  MPEC 2009-Y45 - "07:12 UT" - Daily Orbit Update

MPEC 2009-Y44 - "06:17 UT" - 2002 NE71

Observers  on 23 December '09

Ten observing facilities appear in today's MPECs.

CodeObserver / observatory
703Catalina Sky Survey in Arizona, 1 in MPEC 2009-Y45 -- 2009 WC26
J95Great Shefford Obs. in England, 1 in MPEC 2009-Y45 -- 2009 YR
379Hamamatsu-Yuto Obs. in Japan, 5 in MPEC 2009-Y45 -- 2009 XD, 2006 UR, 2005 MC, 2002 XN14, 2002 WP
5682David Tholen's team on Mauna Kea in Hawaii, 1 in MPEC 2009-Y46 -- 2007 YV56
932McCarthy Obs. in Connecticut, 4 in MPEC 2009-Y45 -- 2009 XT6, 2009 WZ104, 35396, 162998
474Mt. John Obs. in New Zealand, 7 in MPEC 2009-Y45 -- 2009 XP7, 2009 WM139, 2009 WM1, 2009 UX17, 2009 UW2, 2009 UN3, 2009 QY33
644NEAT's Mt. Palomar telescope in southern California, 1 in MPEC 2009-Y44 -- 2002 NE71
H23Pear Tree Obs. in Florida, 2 in MPEC 2009-Y45 -- 2009 WZ104, 35396
H36Sandlot Obs. in Kansas, 1 in MPEC 2009-Y45 -- 2009 YS
691Spacewatch 0.9m telescope in Arizona, 9 in MPEC 2009-Y45 -- 2009 XT6, 2009 UN, 2009 RN, 2009 BP58, 22753, 190166, 163252, 154300, 5836
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 23 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 YRJPL Sentry15522060-210666.8e-06-6.89-7.150JPL: "Analysis based on 26 observations spanning 3.6068 days (2009-Dec-19.27429 to 2009-Dec-22.88105)." Diameter approximately 0.008 km. from mean, weighted H=28.0.
NEODyS15522064-208054.45e-06-7.13-7.420NEODyS: "Based on 26 optical observations (of which 0 are rejected as outliers) from 2009/12/19.275 to 2009/12/22.882."
2009 XT6JPL Sentry1552R E M O V E DJPL: Risk listing removed at 1053 UTC.
2009 WM1JPL Sentry1552207913.4e-08-5.35-5.350JPL: "Analysis based on 82 observations spanning 35.161 days (2009-Nov-17.4641 to 2009-Dec-22.625)." Diameter approximately 0.280 km. from mean, weighted H=20.4.
NEODyS15522078-207951.28e-07-4.76-5.100NEODyS: "Based on 82 optical observations (of which 0 are rejected as outliers) from 2009/11/17.465 to 2009/12/22.626."

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 23 December '09

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

1653Grabbed MPEC 2009-Y46 - 2007 YV56 - see above
1552Noted that JPL Sentry has reposted 2009 WM1 as an impact risk - see above
Noted that NEODyS has updated its 2009 WM1 risk assessment - see above
Noted that JPL Sentry has removed 2009 XT6 as an impact risk - see above
Noted that JPL Sentry has updated its 2009 YR risk assessment - see above
Noted that NEODyS has updated its 2009 YR risk assessment - see above
Grabbed MPEC 2009-Y44 - 2002 NE71 - see above
Grabbed MPEC 2009-Y45 - Daily Orbit Update - see above