Contents  on 26 April '11

Resources:

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 26 April '11

The MPC's NEO Confirmation Page has 41 listings: 10 new, 31 updated

When last checked at 2359 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had ten new and 31 updated listings. Of these, 39 were "one nighters." So far The Tracking News has counted a total of 82 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 26 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-H38 - "11:03 UT" - 2009 AH16


<< DOU on 26 Apr. '11 >>  MPEC 2011-H37 - "07:07 UT" - Daily Orbit Update


MPEC 2011-H36 - "00:34 UT" - 2011 HH1

Observers  on 26 April '11

A total of 21 observers appear in today's MPECs.

CodeObserver / observatory
H21Astronomical Research Obs. Westfield in Illinois, 1 in MPEC 2011-H37 -- 2011 AN16
G51Byrne Obs., 1 in MPEC 2011-H37 -- 2011 HQ
160Castelmartini Obs. in Italy, 1 in MPEC 2011-H37 -- 267494
703Catalina Sky Survey (CSS) in Arizona, 13 in MPEC 2011-H37 -- 2011 GQ59, 2011 GL62, 2011 EZ78, 2008 FT6, 2005 SA71, 2001 QP181, 53435, 267729, 263976, 163696, 159857, 141531, 1866
807|Robert Holmes via Cerro Tololo Inter-American Obs. (CTIO) in Chile, 8 in MPECs 2011-H37 & 2011-H38 -- 2011 HF, 2011 GZ54, 2011 GV65, 2011 GM44, 2011 GL62, 2011 ET4, 2011 EF17, 2009 AH16
A77Chante-Perdrix Obs. in France, 1 in MPEC 2011-H37 -- 2011 GL60
J95Great Shefford Obs. in England, 1 in MPEC 2011-H36 -- 2011 HH1
A17Guidestar Obs. in Germany, 3 in MPEC 2011-H37 -- 2011 GQ65, 2011 GL62, 2011 FB29
704LINEAR in New Mexico, 3 in MPEC 2011-H37 -- 2011 HQ, 2011 GC60, 24445
844Los Molinos Obs. in Uruguay, 1 in MPEC 2011-H37 -- 172722
B67Mirasteilas Obs. in Switzerland, 2 in MPEC 2011-H37 -- 2011 AO52, 2010 XJ
G96Mt. Lemmon Survey (MLS) in Arizona, 4 in MPECs 2011-H36 & 2011-H37 -- 2011 HH1, 2011 GG60, 2011 EZ78, 2009 DV42
644NEAT's Mt. Palomar telescope in southern California, 1 in MPEC 2011-H37 -- 2007 TL23
A24New Millennium Obs. in Italy, 28 in MPEC 2011-H37 -- 2011 DS9, 2011 CH71, 2011 AO52, 2011 AN16, 2010 WQ7, 2010 TV149, 2008 SO, 2007 TB23, 2007 PP6, 1999 XR35, 89830, 85953, 260141, 256412, 248083, 23187, 23183, 228368, 22771, 21374, 204232, 198856, 163250, 8507, 4954, 3554, 3122, 1864
F51Pan-STARRS 1 (PS1) in Hawaii, 15 in MPECs 2011-H36 & 2011-H37 -- 2011 HH1, 2011 GC55, 2005 SA71, 2004 RH340, 2004 FU4, 2004 EV9, 2000 JE5, 267729, 263976, 250614, 141874, 136617, 6037, 5626, 3122
204Schiaparelli Obs. in Italy, 15 in MPEC 2011-H37 -- 2011 GP44, 2011 GK44, 2011 GC62, 2011 GC60, 2011 FR6, 2011 FG41, 2010 UF7, 2010 RO82, 2007 EX, 2006 FV35, 2004 HC, 2004 EV9, 2002 OM4, 1999 LP28, 271480
E12Siding Spring Survey (SSS) in New South Wales, 3 in MPEC 2011-H37 -- 86878, 108519, 1916
691Spacewatch 0.9m telescope in Arizona, 6 in MPEC 2011-H37 -- 2010 VN65, 2007 PP6, 2005 WD1, 24445, 7753, 1866
291Spacewatch 1.8m telescope in Arizona, 4 in MPEC 2011-H37 -- 2011 HG, 2011 EF15, 2011 CG22, 2011 BJ24
I28Starhoo Obs. in Massachusetts, 1 in MPEC 2011-H37 -- 53435
C51WISE in Earth polar orbit, 3 in MPEC 2011-H37 -- 2006 DS14, 2003 CR1, 184990
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 26 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.
0000NNN000

Object

Risk
Monitor
When
Noted
UTC
0000T0000
Year
Range

VI
#
000NN00
Prob
Cum
T0000
PS
Cum
T0000
PS
Max

T
S


Notes for Today's Latest Risk Assessments
2011 HTNEODyS16032014-2089352.59e-07-4.47-4.630NEODyS: "Based on 17 optical observations (of which 0 are rejected as outliers) from 2011-04-25.314 to 2011-04-25.889."
JPL Sentry01592014-21101756.6e-07-4.18-4.430JPL: "Analysis based on 17 observations spanning .57502 days (2011-Apr-25.3136 to 2011-Apr-25.88862)." Diameter approximately 0.171 km. from mean, weighted H=21.5.
2011 HSNEODyS16032072-207721.21e-08-6.12-6.120NEODyS: "Based on 21 optical observations (of which 0 are rejected as outliers) from 2011-04-25.266 to 2011-04-25.921."
JPL Sentry01002072-209421.7e-08-6.09-6.130JPL: "Analysis based on 21 observations spanning .65573 days (2011-Apr-25.26497 to 2011-Apr-25.9207)." Diameter approximately 0.180 km. from mean, weighted H=21.3.
2011 HFJPL Sentry16032030-2110914.2e-07-4.26-4.620JPL: "Analysis based on 22 observations spanning 3.1232 days (2011-Apr-22.16366 to 2011-Apr-25.28689)." Diameter approximately 0.258 km. from mean, weighted H=20.6.
NEODyS16032030-209091.0e-06-3.73-4.190NEODyS: "Based on 22 optical observations (of which 0 are rejected as outliers) from 2011-04-22.164 to 2011-04-25.288."

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 26 April '11

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

1603Noted that JPL Sentry has updated its 2011 HF risk assessment - see above
Noted that NEODyS has updated its 2011 HF risk assessment - see above
Noted that NEODyS has posted 2011 HS as an impact risk - see above
Noted that NEODyS has posted 2011 HT as an impact risk - see above
Grabbed MPEC 2011-H37 - Daily Orbit Update - see above
Grabbed MPEC 2011-H38 - 2009 AH16 - see above
0159Noted that JPL Sentry has posted 2011 HT as an impact risk - see above
0100Noted that JPL Sentry has posted 2011 HS as an impact risk - see above
Grabbed MPEC 2011-H36 - 2011 HH1 - see above