Contents  on 20 February '11


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 20 February '11

The MPC's NEO Confirmation Page is currently empty

The NEOCP is currently empty. There was one listing noted earlier today.

New MPECs  on 20 February '11

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 2011-D19 - "17:43 UT" - 2011 BY59

<< DOU on 20 Feb. '11 >>  MPEC 2011-D18 - "07:06 UT" - Daily Orbit Update

Observers  on 20 February '11

Five observers appear in today's MPECs.

CodeObserver / observatory
H21Astronomical Research Obs. Westfield in Illinois, 7 in MPEC 2011-D18 -- 2011 CL50, 2011 BX10, 2011 BT15, 2011 BJ24, 2011 AN16, 2010 XY82, 2010 WQ7
355Hadano Obs. in Japan, 5 in MPEC 2011-D18 -- 2009 DV42, 1999 TK12, 40267, 4954, 3554
5682David Tholen's team on Mauna Kea in Hawaii, 1 in MPEC 2011-D19 -- 2011 BY59
F51Pan-STARRS 1 in Hawaii, 1 in MPEC 2011-D19 -- 2011 BY59
204Schiaparelli Obs. in Italy, 2 in MPEC 2011-D18 -- 2011 BP24, 1998 HE3
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 20 February '11

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. Both also post impact solutions beyond 100 years for a few special 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
2011 CL50JPL Sentry17442036-2110884.3e-05-5.99-7.050JPL: "Analysis based on 28 observations spanning 7.6547 days (2011-Feb-12.46221 to 2011-Feb-20.116917)." Diameter approximately 0.010 km. from mean, weighted H=27.6.
NEODyS17442043-2090661.8e-05-6.28-6.990NEODyS: "Based on 28 optical observations (of which 0 are rejected as outliers) from 2011-02-12.463 to 2011-02-20.118."
2011 BT15JPL Sentry17442037-21101127.9e-05-2.95-4.000JPL: "Analysis based on 39 observations spanning 26.771 days (2011-Jan-24.28933 to 2011-Feb-20.060534)." Diameter approximately 0.140 km. from mean, weighted H=21.9.
NEODyS17442037-2090583.72e-05-3.21-3.920NEODyS: "Based on 40 optical observations (of which 3 are rejected as outliers) from 2011-01-24.290 to 2011-02-20.061."

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 20 February '11

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

1834Grabbed MPEC 2011-D19 - 2011 BY59 - see above
Noted that the NEOCP has become empty
1744Noted that JPL Sentry has updated its 2011 BT15 risk assessment - see above
Noted that NEODyS has updated its 2011 BT15 risk assessment - see above
Noted that JPL Sentry has updated its 2011 CL50 risk assessment - see above
Noted that NEODyS has updated its 2011 CL50 risk assessment - see above
Grabbed MPEC 2011-D18 - Daily Orbit Update - see above
Noted that the NEOCP has become active