Contents  on 27 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 27 April '11

The MPC's NEO Confirmation Page has 47 listings: 7 new, 40 updated

When last checked at 2359 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had seven new and 40 updated listings. Of these, 27 were "one nighters." So far The Tracking News has counted a total of 91 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 27 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.


<< DOU on 27 Apr. '11 >>  MPEC 2011-H40 - "07:07 UT" - Daily Orbit Update


MPEC 2011-H39 - "04:22 UT" - 2007 RX19

Observers  on 27 April '11

Seventeen observers appear in today's MPECs.

CodeObserver / observatory
H21Astronomical Research Obs. Westfield in Illinois, 1 in MPEC 2011-H40 -- 2011 GH3
703Catalina Sky Survey (CSS) in Arizona, 4 in MPEC 2011-H40 -- 2011 HQ, 2011 HH1, 2011 AO52, 163250
807|Robert Holmes via Cerro Tololo Inter-American Obs. (CTIO) in Chile, 11 in MPECs 2011-H39 & 2011-H40 -- 2011 HP, 2011 HJ, 2011 HH, 2011 GZ54, 2011 GP65, 2011 GF, 2011 GA55, 2011 FY2, 2011 FB29, 2010 RA147, 2007 RX19
F65%Tim Lister in southern California via Faulkes Telescope North in Hawaii, 1 in MPEC 2011-H40 -- 2011 HH1
J95Great Shefford Obs. in England, 2 in MPEC 2011-H40 -- 2011 HS, 2011 HJ
H15ISON-NM Obs. in New Mexico, 2 in MPEC 2011-H40 -- 256670, 152941
168Kourovskaya Obs. in Russia, 3 in MPEC 2011-H40 -- 85953, 274138, 137170
704LINEAR in New Mexico, 10 in MPEC 2011-H40 -- 2011 HQ, 2011 GC60, 2004 HC, 2004 FU4, 2001 QP181, 267729, 138359, 5626, 4954, 4401
G96Mt. Lemmon Survey (MLS) in Arizona, 5 in MPEC 2011-H40 -- 2011 HP, 2011 GX65, 2009 CA2, 2004 EV9, 190161
A13Naef Obs. in Switzerland, 1 in MPEC 2011-H40 -- 141432
A24New Millennium Obs. in Italy, 19 in MPEC 2011-H40 -- 2008 FT6, 2004 FU4, 2004 FJ29, 2004 FG1, 2002 TD60, 2001 QP181, 89958, 53435, 40267, 274138, 267729, 267136, 252793, 144332, 141525, 136874, 136617, 102873, 4401
F51Pan-STARRS 1 in Hawaii, 1 in MPEC 2011-H40 -- 162463
204Schiaparelli Obs. in Italy, 1 in MPEC 2011-H40 -- 2011 HT
691Spacewatch 0.9m telescope in Arizona, 3 in MPEC 2011-H40 -- 2010 VN65, 1998 HK49, 24445
291Spacewatch 1.8m telescope in Arizona, 2 in MPEC 2011-H40 -- 2011 HF, 2011 GN44
A48Verona Obs. in Italy, 2 in MPEC 2011-H40 -- 2001 QP181, 274138
G56Walnut Creek Obs. in northern California, 1 in MPEC 2011-H40 -- 274138
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 27 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 HTJPL Sentry16182014-2089983.8e-07-4.22-4.350JPL: "Analysis based on 19 observations spanning .62665 days (2011-Apr-25.3136 to 2011-Apr-25.94025)." Diameter approximately 0.170 km. from mean, weighted H=21.5.
NEODyS16182014-2089279.74e-07-4.21-4.440NEODyS: "Based on 19 optical observations (of which 0 are rejected as outliers) from 2011-04-25.314 to 2011-04-25.941."
2011 HSJPL Sentry1618209812.7e-10-7.99-7.990JPL: "Analysis based on 24 observations spanning .79389 days (2011-Apr-25.26497 to 2011-Apr-26.05886)." Diameter approximately 0.190 km. from mean, weighted H=21.3.
NEODyS16182082-208211.2e-09-7.19-7.190NEODyS: "Based on 24 optical observations (of which 0 are rejected as outliers) from 2011-04-25.266 to 2011-04-26.060."
2011 HFNEODyS1618R E M O V E D-
JPL Sentry1618R E M O V E DJPL: Risk listing removed at 1140 UTC.
2011 GN44JPL Sentry1618206811.8e-07-3.13-3.130JPL: "Analysis based on 38 observations spanning 23.737 days (2011-Apr-03.44279 to 2011-Apr-27.17939)." Diameter approximately 0.700 km. from mean, weighted H=18.4.
NEODyS16182068-206821.2e-07-3.28-3.280NEODyS: "Based on 38 optical observations (of which 0 are rejected as outliers) from 2011-04-03.444 to 2011-04-27.180."

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 27 April '11

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

1618Noted 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 removed 2011 HF as an impact risk - see above
Noted that NEODyS has removed 2011 HF as an impact risk - see above
Noted that JPL Sentry has updated its 2011 HS risk assessment - see above
Noted that NEODyS has updated its 2011 HS risk assessment - see above
Noted that JPL Sentry has updated its 2011 HT risk assessment - see above
Noted that NEODyS has updated its 2011 HT risk assessment - see above
Grabbed MPEC 2011-H40 - Daily Orbit Update - see above
0429Grabbed MPEC 2011-H39 - 2007 RX19 - see above