Contents  on 5 September '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 5 September '11

The MPC's NEO Confirmation Page has 13 listings

When last checked at 2359 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had thirteen objects listed. Of these, seven were "one nighters." So far The Tracking News has counted a total of 23 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 5 September '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-R22 - "16:46 UT" - Comet C/2011 Q4 (SWAN)

MPEC 2011-R21 - "16:37 UT" - 2011 MD11

MPEC 2011-R20 - "16:13 UT" - Comet C/2011 R1 (McNaught)

<< DOU on 5 Sept. '11 >>  MPEC 2011-R19 - "06:04 UT" - Daily Orbit Update

Observers  on 5 September '11

Nineteen observers appear in today's MPECs.

CodeObserver / observatory
J16An Carraig Obs. in Northern Ireland, 1 in MPEC 2011-R19 -- 37336
I74Baxter Garden Obs., 1 in MPEC 2011-R19 -- 2011 QF23
807|Robert Holmes via Cerro Tololo Inter-American Obs. in Chile, 1 in MPEC 2011-R21 -- 2011 MD11
B50Corner Obs. in Germany, 1 in MPEC 2011-R19 -- 1917
I39Cruz del Sur Obs. in Argentina, 1 in MPEC 2011-R20 -- C/2011 R1
595Farra d'Isonzo Obs. in Italy, 1 in MPEC 2011-R20 -- C/2011 R1
E94Gisborne Obs. in New Zealand, 1 in MPEC 2011-R22 -- C/2011 Q4
J95Great Shefford Obs. in England, 1 in MPEC 2011-R20 -- C/2011 R1
E16Grove Creek Obs. in New South Wales, 2 in MPECs 2011-R21 & 2011-R22 -- C/2011 Q4, 2011 MD11
046Klet Obs. in the Czech Republic, 1 in MPEC 2011-R19 -- 2011 OV4
474Mt. John Obs. in New Zealand, 9 in MPECs 2011-R19, 2011-R20 & 2011-R21 -- C/2011 R1, 2011 QS49, 2011 QE48, 2011 QD50, 2011 QD48, 2011 QC46, 2011 MD11, 2009 OO9, 2000 RM12
A24New Millennium Obs. in Italy, 10 in MPEC 2011-R19 -- 2011 NZ, 2011 KN9, 2008 TR10, 2000 CP101, 280136, 20086, 159399, 4596, 3988, 1917
F51Pan-STARRS 1 in Hawaii, 1 in MPEC 2011-R19 -- 2005 VC
D90`Kevin Hills in England via RAS Obs. Moorook in South Australia, 2 in MPECs 2011-R20 & 2011-R21 -- C/2011 R1, 2011 MD11
I20Rio Cuarto Obs. in Argentina, 4 in MPECs 2011-R19, 2011-R20, 2011-R21 & 2011-R22 -- C/2011 R1, C/2011 Q4, 2011 PT1, 2011 MD11
E12Siding Spring Survey (SSS) in New South Wales, 3 in MPECs 2011-R20, 2011-R21 & 2011-R22 -- C/2011 R1, C/2011 Q4, 2011 MD11
291Spacewatch 1.8m telescope in Arizona, 1 in MPEC 2011-R19 -- 2011 OR15
A98Taurus-1 Obs. in Belarus, 1 in MPEC 2011-R19 -- 2011 OV4
B18Terskol Obs. in Russia, 1 in MPEC 2011-R20 -- C/2011 R1
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 5 September '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 risk pages.





Notes for Today's Latest Risk Assessments
2011 QD48JPL Sentry16472043-2111263.4e-08-3.91-4.200JPL: "Analysis based on 41 observations spanning 4.8807 days (2011-Aug-30.5432 to 2011-Sep-04.4239)." Diameter approximately 0.854 km. from mean, weighted H=18.0.
NEODyS16472041-204531.43e-10-6.13-6.510NEODyS: "Based on 41 optical observations (of which 0 are rejected as outliers) from 2011-08-30.544 to 2011-09-04.425."

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 5 September '11

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

1840Grabbed MPEC 2011-R22 - Comet C/2011 Q4 (SWAN) - see above
1647Noted that JPL Sentry has updated its 2011 QD48 risk assessment - see above
Noted that NEODyS has updated its 2011 QD48 risk assessment - see above
Grabbed MPEC 2011-R19 - Daily Orbit Update - see above
Grabbed MPEC 2011-R20 - Comet C/2011 R1 (McNaught) - see above
Grabbed MPEC 2011-R21 - 2011 MD11 - see above