Contents  on 24 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 24 April '11

The MPC's NEO Confirmation Page has 46 listings: 4 new, 42 updated

When last checked at 2359 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had four new and 42 updated listings. Of these, 37 were "one nighters." So far The Tracking News has counted a total of 58 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 24 April '11

Minor Planet Electronic Circulars

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

MPEC 2011-H29 - "16:30 UT" - 2011 HJ

MPEC 2011-H28 - "13:49 UT" - 2011 HH

MPEC 2011-H27 - "13:35 UT" - 2011 HG

<< DOU on 24 Apr. '11 >>  MPEC 2011-H26 - "07:06 UT" - Daily Orbit Update

Observers  on 24 April '11

Sixteen observers appear in today's MPECs.

CodeObserver / observatory
B03Alter Satzberg Obs. in Austria, 1 in MPEC 2011-H28 -- 2011 HH
J16An Carraig Obs. in Northern Ireland, 1 in MPEC 2011-H26 -- 137170
160Castelmartini Obs. in Italy, 7 in MPEC 2011-H26 -- 2004 FG1, 2002 TD60, 274138, 260141, 250614, 23187, 141525
703Catalina Sky Survey (CSS) in Arizona, 2 in MPECs 2011-H26 & 2011-H28 -- 2011 HH, 251722
807|Robert Holmes via Cerro Tololo Inter-American Obs. in Chile, 1 in MPEC 2011-H28 -- 2011 HH
595Farra d'Isonzo Obs. in Italy, 1 in MPEC 2011-H28 -- 2011 HH
J95Great Shefford Obs. in England, 2 in MPECs 2011-H26 & 2011-H28 -- 2011 HH, 2011 GM62
704LINEAR in New Mexico, 5 in MPEC 2011-H26 -- 2004 FG1, 271480, 260141, 251732, 141525
B67Mirasteilas Obs. in Switzerland, 1 in MPEC 2011-H26 -- 267729
118Modra Obs. in Slovakia, 1 in MPEC 2011-H28 -- 2011 HH
900Moriyama Obs. in Japan, 1 in MPEC 2011-H29 -- 2011 HJ
G96Mt. Lemmon Survey (MLS) in Arizona, 2 in MPECs 2011-H26 & 2011-H29 -- 2011 HJ, 256004
A24New Millennium Obs. in Italy, 29 in MPEC 2011-H26 -- 2011 GF, 2011 FS29, 2011 EM51, 2009 FT, 2004 FU4, 2004 FG1, 2002 TD60, 89830, 85953, 53435, 40267, 267136, 265196, 263976, 252793, 250614, 234341, 163696, 163412, 162463, 144332, 141531, 141525, 136874, 136617, 102873, 8176, 5626, 1866
854Sabino Canyon Obs. in Arizona, 1 in MPEC 2011-H28 -- 2011 HH
H36Sandlot Obs. in Kansas, 1 in MPEC 2011-H28 -- 2011 HH
291Spacewatch 1.8m telescope in Arizona, 4 in MPECs 2011-H26 & 2011-H27 -- 2011 HG, 2011 HF, 2011 GL44, 2010 KY127
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 24 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 Sentry16122030-21101528.9e-07-3.87-4.320JPL: "Analysis based on 15 observations spanning 2.0428 days (2011-Apr-22.16366 to 2011-Apr-24.20649)." Diameter approximately 0.265 km. from mean, weighted H=20.5.
NEODyS16122030-2088144.28e-07-4.06-4.350NEODyS: "Based on 15 optical observations (of which 0 are rejected as outliers) from 2011-04-22.164 to 2011-04-24.207."

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 24 April '11

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

1709Grabbed MPEC 2011-H29 - 2011 HJ - see above
1612Noted that JPL Sentry has updated its 2011 HF risk assessment - see above
Noted that NEODyS has posted 2011 HF as an impact risk - see above
Grabbed MPEC 2011-H26 - Daily Orbit Update - see above
Grabbed MPEC 2011-H27 - 2011 HG - see above
Grabbed MPEC 2011-H28 - 2011 HH - see above