Contents  on 1 May '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 1 May '11

The Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) was not checked on this day.

New MPECs  on 1 May '11

Minor Planet Electronic Circulars

There were two MPECs posted this day from the International Astronomical Union's Minor Planet Center in Cambridge, Massachusetts.

MPEC 2011-J02 - "23:50 UT" - 2011 HY52

<< DOU on 1 May '11 >>  MPEC 2011-J01 - "07:07 UT" - Daily Orbit Update

Observers  on 1 May '11

Seventeen observers appeared in this day's MPECs.

CodeObserver / observatory
A50Andrushivka Obs. in the Ukraine, 1 in MPEC 2011-J02 -- 2011 HY52
H21Astronomical Research Obs. Westfield in Illinois, 10 in MPEC 2011-J01 -- 2011 HS4, 2011 HS, 2011 HO4, 2011 HL7, 2011 HG, 2011 GQ59, 2011 GO65, 2011 GC55, 2011 FG41, 2011 FB29
703Catalina Sky Survey (CSS) in Arizona, 7 in MPEC 2011-J01 -- 2006 SV134, 85490, 15745, 102873, 8567, 7889, 1864
807|Robert Holmes via Cerro Tololo Inter-American Obs. in Chile, 1 in MPEC 2011-J01 -- 208565
F65%Tim Lister in southern California via Faulkes Telescope North in Hawaii, 2 in MPEC 2011-J01 -- 2011 HO24, 2011 HE24
B86Hagen Obs. in Germany, 1 in MPEC 2011-J02 -- 2011 HY52
704LINEAR in New Mexico, 5 in MPEC 2011-J01 -- 2011 GL62, 260141, 251346, 102873, 4954
B67Mirasteilas Obs. in Switzerland, 3 in MPEC 2011-J01 -- 2010 VN65, 2005 WD1, 138359
474Mt. John Obs. in New Zealand, 3 in MPEC 2011-J01 -- 2011 GQ61, 2011 GH62, 2011 GA62
G96Mt. Lemmon Survey (MLS) in Arizona, 2 in MPEC 2011-J01 -- 2005 LG8, 68031
A13Naef Obs. in Switzerland, 1 in MPEC 2011-J01 -- 2011 GL62
A24New Millennium Obs. in Italy, 9 in MPEC 2011-J01 -- 2008 FT6, 2004 FJ29, 2002 TD60, 2001 QP181, 89958, 53435, 252793, 144332, 102873
F51Pan-STARRS 1 (PS1) in Hawaii, 5 in MPEC 2011-J01 -- 2011 HS4, 2007 PP6, 159923, 154993, 141432
204Schiaparelli Obs. in Italy, 1 in MPEC 2011-J02 -- 2011 HY52
691Spacewatch 0.9m telescope in Arizona, 1 in MPEC 2011-J01 -- 1999 HD1
291Spacewatch 1.8m telescope in Arizona, 5 in MPEC 2011-J01 -- 2011 HJ7, 2011 HG, 2011 GN44, 2011 GA, 2011 BX18
G56Walnut Creek Obs. in northern California, 1 in MPEC 2011-J01 -- 2011 GL62
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 1 May '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 HP24NEODyS16052020-208952.92e-07-6.33-6.350NEODyS: "Based on 11 optical observations (of which 0 are rejected as outliers) from 2011-04-28.437 to 2011-04-29.325."
2011 HJ7JPL Sentry1605209411.1e-09-7.71-7.710JPL: "Analysis based on 15 observations spanning 4.9711 days (2011-Apr-26.21907 to 2011-May-01.19019)." Diameter approximately 0.120 km. from mean, weighted H=22.2.
2011 HS4JPL Sentry1605R E M O V E DJPL: Risk listing removed at 1155 UTC.
2011 GN44JPL Sentry1605206811.2e-07-3.30-3.300JPL: "Analysis based on 50 observations spanning 27.799 days (2011-Apr-03.44279 to 2011-May-01.24205)." Diameter approximately 0.700 km. from mean, weighted H=18.4.
NEODyS16052068-206816.3e-08-3.56-3.560NEODyS: "Based on 50 optical observations (of which 0 are rejected as outliers) from 2011-04-03.444 to 2011-05-01.243."
2009 VZ39JPL Sentry04062011-21108007.1e-06-6.04-6.800JPL: "Analysis based on 8 observations spanning .04342 days (2009-Nov-10.27204 to 2009-Nov-10.31546)." Diameter approximately 0.009 km. from mean, weighted H=27.9.

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 1 May '11

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

2359Grabbed MPEC 2011-J02 - 2011 HY52 - see above
1605Noted that JPL Sentry has updated its 2011 GN44 risk assessment - see above
Noted that NEODyS has updated its 2011 GN44 risk assessment - see above
Noted that JPL Sentry has updated its 2011 HJ7 risk assessment - see above
Noted that NEODyS has posted 2011 HP24 as an impact risk - see above
Noted that JPL Sentry has removed 2011 HS4 as an impact risk - see above
Grabbed MPEC 2011-J01 - Daily Orbit Update - see above
0406Noted that JPL Sentry has updated its 2009 VZ39 risk assessment - see above