Contents  on 22 April '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 22 April '11

The MPC's NEO Confirmation Page has 5 listings: 2 new, 3 updated

When last checked at 2359 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had two new and three updated listings. All of these were "one nighters." So far The Tracking News has counted a total of nine listings on the NEOCP 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 22 April '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-H22 - "12:35 UT" - 2009 HV44

<< DOU on 22 Apr. '11 >>  MPEC 2011-H21 - "07:06 UT" - Daily Orbit Update

Observers  on 22 April '11

Fourteen observers appear in today's MPECs.

CodeObserver / observatory
H21Astronomical Research Obs. Westfield in Illinois, 15 in MPEC 2011-H21 -- 2011 GX65, 2011 GS60, 2011 GR59, 2011 GQ65, 2011 GO65, 2011 GL62, 2011 GL60, 2011 GL44, 2011 GH62, 2011 GC62, 2011 GC60, 2011 GC55, 2011 GB3, 2011 FB29, 2010 WQ7
160Castelmartini Obs. in Italy, 11 in MPEC 2011-H21 -- 2011 GM62, 2011 GL62, 2011 EM51, 2011 AO52, 2007 VG184, 271480, 256412, 188174, 163250, 138883, 137170
807|Robert Holmes via Cerro Tololo Inter-American Obs. (CTIO) in Chile, 5 in MPECs 2011-H21 & 2011-H22 -- 2011 GO65, 2011 GD62, 2011 GA55, 2011 FB29, 2009 HV44
639Dresden Obs. in Germany, 1 in MPEC 2011-H21 -- 4954
I19El Gato Gris Obs. in Argentina, 1 in MPEC 2011-H21 -- 2011 GC
F654Jim Bedient in Hawaii via Faulkes Telescope North in Hawaii, 3 in MPEC 2011-H21 -- 2011 GD62, 2011 GA62, 2011 GA
J95Great Shefford Obs. in England, 1 in MPEC 2011-H21 -- 2011 GJ3
B67Mirasteilas Obs. in Switzerland, 2 in MPEC 2011-H21 -- 2011 GM62, 2011 EM51
A13Naef Obs. in Switzerland, 3 in MPEC 2011-H21 -- 2008 FT6, 53435, 267729
A24New Millennium Obs. in Italy, 33 in MPEC 2011-H21 -- 2010 WQ7, 2009 FT, 2009 DV42, 2008 FT6, 2004 FG1, 2002 TD60, 2001 QP181, 1999 XR35, 89830, 85953, 53435, 40267, 265196, 256412, 234341, 23183, 228368, 22771, 215167, 21374, 204232, 198856, 163412, 15745, 144332, 141525, 136617, 5646, 4954, 4401, 3554, 3122, 1864
F51Pan-STARRS 1 in Hawaii, 1 in MPEC 2011-H21 -- 2011 GO65
510Siegen Obs. in Germany, 1 in MPEC 2011-H21 -- 2011 GP59
291Spacewatch 1.8m telescope in Arizona, 3 in MPEC 2011-H21 -- 2011 GN44, 2011 GA, 2010 XZ67
I40TRAPPIST in Chile, 1 in MPEC 2011-H21 -- 2011 FP29
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 22 April '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 GN44JPL Sentry15432068-209459.6e-07-2.48-2.580JPL: "Analysis based on 35 observations spanning 18.776 days (2011-Apr-03.44279 to 2011-Apr-22.21906)." Diameter approximately 0.710 km. from mean, weighted H=18.4.
NEODyS15432048-208159.68e-07-2.44-2.550NEODyS: "Based on 35 optical observations (of which 0 are rejected as outliers) from 2011-04-03.444 to 2011-04-22.220."

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 22 April '11

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

1543Noted that JPL Sentry has updated its 2011 GN44 risk assessment - see above
Noted that NEODyS has updated its 2011 GN44 risk assessment - see above
Grabbed MPEC 2011-H21 - Daily Orbit Update - see above
Grabbed MPEC 2011-H22 - 2009 HV44 - see above