Contents  on 26 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 26 December '09

The MPC's NEO Confirmation Page has 1 listing: 1 new

When last checked at 2359 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had one new listing. So far The Tracking News has counted a total of three listings on the NEOCP at some point today.

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 26 December '09

Minor Planet Electronic Circulars

As of last check at 2359 UTC, there have been two MPECs posted today from the International Astronomical Union's Minor Planet Center in Cambridge, Massachusetts.

MPEC 2009-Y52 - "15:08 UT" - 2009 DO111

<< DOU on 26 Dec. '09 >>  MPEC 2009-Y51 - "07:12 UT" - Daily Orbit Update

Observers  on 26 December '09

Six observing facilities appear in today's MPECs.

CodeObserver / observatory
J95Great Shefford Obs. in England, 5 in MPEC 2009-Y51 -- 2009 YR, 2009 YF, 2009 XT6, 2009 XO, 2009 XF2
695.Lawrence H. Wasserman via Kitt Peak Natl. Obs. in Arizona, 1 in MPEC 2009-Y51 -- 1998 YW5
5682David Tholen's team on Mauna Kea in Hawaii, 2 in MPECs 2009-Y51 & 2009-Y52 -- 2009 DO111, 2002 XY38
A13Naef Obs. in Switzerland, 1 in MPEC 2009-Y51 -- 2006 AO4
691Spacewatch 0.9m telescope in Arizona, 2 in MPEC 2009-Y51 -- 2009 WF, 2009 RN
291Spacewatch 1.8m telescope in Arizona, 10 in MPEC 2009-Y51 -- 2009 YU6, 2009 YQ, 2009 YG, 2009 XV1, 2009 QZ34, 2009 QL8, 2008 GE1, 2006 OU10, 2005 VQ, 190166
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 26 December '09

Summary Risk Table for Risk Assessments Updated Today   (last checks: NEODyS and JPL at 2359 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 Sentry15362060-208769.5e-06-6.75-7.080JPL: "Analysis based on 29 observations spanning 6.5440 days (2009-Dec-19.27429 to 2009-Dec-25.81832)." Diameter approximately 0.008 km. from mean, weighted H=28.0.
NEODyS15362064-208874.09e-06-7.16-7.380NEODyS: "Based on 29 optical observations (of which 0 are rejected as outliers) from 2009/12/19.275 to 2009/12/25.819."
2009 YGJPL Sentry15362033-209992.9e-06-1.92-2.200JPL: "Analysis based on 36 observations spanning 8.0006 days (2009-Dec-17.42051 to 2009-Dec-25.42113)." Diameter approximately 0.827 km. from mean, weighted H=18.1.
NEODyS15362033-208051.98e-06-2.02-2.230NEODyS: "Based on 36 optical observations (of which 0 are rejected as outliers) from 2009/12/17.421 to 2009/12/25.422."
2009 XONEODyS15362083-208823.65e-08-5.27-5.340NEODyS: "Based on 103 optical observations (of which 0 are rejected as outliers) from 2009/12/09.153 to 2009/12/25.948."
JPL Sentry1536R E M O V E DJPL: Risk listing removed at 1052 UTC.

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 26 December '09

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

1700Noted that the NEOCP has become active
1536Noted that JPL Sentry has removed 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 updated its 2009 YG risk assessment - see above
Noted that NEODyS has updated its 2009 YG risk assessment - 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-Y51 - Daily Orbit Update - see above
Grabbed MPEC 2009-Y52 - 2009 DO111 - see above
Noted that the NEOCP has become empty