Contents  on 23 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 23 April '11

The MPC's NEO Confirmation Page has 5 listings: 1 new, 4 updated

When last checked at 2359 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had one new and four updated listings. Of these, four were "one nighters." So far The Tracking News has counted a total of ten 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 23 April '11

Minor Planet Electronic Circulars

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

MPEC 2011-H25 - "18:20 UT" - 2011 HF

MPEC 2011-H24 - "17:06 UT" - 2007 BP102

<< DOU on 23 Apr. '11 >>  MPEC 2011-H23 - "07:07 UT" - Daily Orbit Update

Observers  on 23 April '11

Sixteen observers appear in today's MPECs.

CodeObserver / observatory
H21Astronomical Research Obs. Westfield in Illinois, 1 in MPEC 2011-H23 -- 2011 GQ59
160Castelmartini Obs. in Italy, 14 in MPEC 2011-H23 -- 2011 EZ78, 2011 AO52, 2007 VG184, 2004 FG1, 38086, 274138, 260141, 250614, 23187, 188174, 163250, 162463, 138883, 137170
807|Robert Holmes via Cerro Tololo Inter-American Obs. in Chile, 1 in MPEC 2011-H25 -- 2011 HF
G58Chabot Obs. in northern California, 1 in MPEC 2011-H23 -- 2011 GD68
113Drebach Obs. in Germany, 2 in MPEC 2011-H23 -- 274138, 260141
J95Great Shefford Obs. in England, 2 in MPECs 2011-H23 & 2011-H25 -- 2011 HF, 2011 GJ3
704LINEAR in New Mexico, 4 in MPEC 2011-H23 -- 2004 FG1, 263976, 163696, 3122
5682David Tholen's team on Mauna Kea in Hawaii, 1 in MPEC 2011-H23 -- 2011 EG17
568\S. Gwyn & J. Qi on Mauna Kea in Hawaii, 1 in MPEC 2011-H24 -- 2007 BP102
A13Naef Obs. in Switzerland, 1 in MPEC 2011-H23 -- 2011 GQ59
A24New Millennium Obs. in Italy, 29 in MPEC 2011-H23 -- 2010 WQ7, 2008 SO, 2007 TB23, 2004 HC, 2004 FG1, 2002 TD60, 2001 QP181, 89958, 89830, 53435, 40267, 274138, 260141, 256412, 252793, 250614, 248083, 23187, 23183, 198856, 162463, 144332, 141525, 141432, 136617, 102873, 4954, 4401, 1866
J69North Obs. in England, 1 in MPEC 2011-H23 -- 260141
D90`Kevin Hills in England via RAS Obs. Moorook in South Australia, 1 in MPEC 2011-H23 -- 2011 GF
H36Sandlot Obs. in Kansas, 1 in MPEC 2011-H25 -- 2011 HF
691Spacewatch 0.9m telescope in Arizona, 1 in MPEC 2011-H25 -- 2011 HF
291Spacewatch 1.8m telescope in Arizona, 6 in MPECs 2011-H23 & 2011-H25 -- 2011 HF, 2011 GS60, 2011 GL62, 2011 FZ2, 2011 ED78, 2010 OF101
C51WISE in Earth polar orbit, 1 in MPEC 2011-H23 -- 2010 FH81
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 23 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 HFJPL Sentry20302014-21102371.1e-06-3.34-3.460JPL: "Analysis based on 12 observations spanning 1.1844 days (2011-Apr-22.16366 to 2011-Apr-23.34807)." Diameter approximately 0.260 km. from mean, weighted H=20.6.

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 April '11

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

2030Noted that JPL Sentry has posted 2011 HF as an impact risk - see above
1900Grabbed MPEC 2011-H25 - 2011 HF - see above
1806Grabbed MPEC 2011-H24 - 2007 BP102 - see above
1627Grabbed MPEC 2011-H23 - Daily Orbit Update - see above