216 Kleopatra with its two moons. 
Credit: Keck II, Marchis, et al.

UC Berkeley has a news item about the double satellites of 216 Kleopatra which have been named for historical twins Alexhelios and Cleoselene. Read more here and see Franck Marchis's blog post from last year about studying other multiple asteroid systems. Image credit: Keck II, Marchis, et al.


Contents  on 24 February '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 24 February '11

The MPC's NEO Confirmation Page has 1 listing: 1 updated

When last checked at 2359 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had one updated listing. This was a "one nighter." So far The Tracking News has counted a total of four 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 February '11

Minor Planet Electronic Circulars

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


MPEC 2011-D36 - "18:24 UT" - Observations and Orbits of Comets


MPEC 2011-D35 - "16:26 UT" - 2011 DW


MPEC 2011-D34 - "12:54 UT" - 2011 DV


MPEC 2011-D33 - "12:38 UT" - 2011 DU


<< DOU on 24 Feb. '11 >>  MPEC 2011-D32 - "07:06 UT" - Daily Orbit Update


MPEC 2011-D31 - "00:07 UT" - 2011 DS


MPEC 2011-D30 - "00:03 UT" - 2011 DR

Observers  on 24 February '11

A total of 51 observers appear in today's MPECs.

CodeObserver / observatory
349Ageo Obs. in Japan, 9 in MPEC 2011-D36 -- P/2011 A1, P/2010 WK, C/2010 G2, C/2009 U5, C/2007 D1, C/2005 L3, 247P, 29P, 10P
J24Altamira Obs. in the Canary Islands, 2 in MPEC 2011-D36 -- C/2010 B1, 10P
B03Alter Satzberg Obs. in Austria, 1 in MPEC 2011-D32 -- 2011 CG71
H21Astronomical Research Obs. Westfield in Illinois, 2 in MPEC 2011-D32 -- 2011 CR4, 2008 EE
B75Betelgeuse Station in Italy, 7 in MPEC 2011-D36 -- P/2010 WK, C/2010 S1, C/2009 K5, 247P, 240P, 123P, 29P
B96Brixiis Obs. in Belgium, 1 in MPEC 2011-D36 -- C/2010 S1
235CAST Obs. in Italy, 2 in MPEC 2011-D36 -- P/2011 A1, 103P
703Catalina Sky Survey (CSS) in Arizona, 11 in MPECs 2011-D30, 2011-D31, 2011-D32 & 2011-D36 -- 2011 DS, 2011 DR, 2011 BO59, 2005 EY169, 2001 DQ8, 22771, 215167, 145656, 143381, 231P, 31P
A77Chante-Perdrix Obs. in France, 7 in MPECs 2011-D32 & 2011-D36 -- C/2010 X1, C/2008 S3, 215167, 73P, 31P, 29P, 10P
B60Deep Sky Obs. in Germany, 1 in MPEC 2011-D32 -- 18882
113Drebach Obs. in Germany, 5 in MPECs 2011-D30, 2011-D31 & 2011-D32 -- 2011 DS, 2011 DR, 2011 CG71, 2011 CG2, 2011 BO59
595Farra d'Isonzo Obs. in Italy, 1 in MPEC 2011-D31 -- 2011 DS
E10Faulkes Telescope South in New South Wales, 1 in MPEC 2011-D33 -- 2011 DU
372Geisei Obs. in Japan, 2 in MPEC 2011-D36 -- P/2010 V1, P/2010 T2
E94Gisborne Obs. in New Zealand, 4 in MPEC 2011-D36 -- C/2010 FB87, C/2010 B1, C/2009 F4, 29P
E16Grove Creek Obs. in New South Wales, 1 in MPEC 2011-D36 -- C/2010 FB87
355Hadano Obs. in Japan, 2 in MPEC 2011-D36 -- C/2011 C1, C/2010 X1
H15ISON-NM Obs. in New Mexico, 8 in MPEC 2011-D36 -- P/2011 A2, C/2010 X1, P/2010 WK, C/2010 S1, 249P, 240P, 123P, 29P
J28Jaen Obs. in Spain, 1 in MPEC 2011-D32 -- 36284
585Kiev Comet Station in the Ukraine, 3 in MPECs 2011-D32 & 2011-D36 -- P/2010 WK, 3554, 29P
D95Kurihara Obs. in Japan, 7 in MPEC 2011-D36 -- C/2010 B1, C/2009 Y1, C/2005 L3, 240P, 123P, 103P, 29P
704LINEAR in New Mexico, 10 in MPECs 2011-D32 & 2011-D36 -- 2011 CY46, P/2010 WK, C/2010 G2, 2007 EJ, C/2005 L3, 2002 SZ, 162463, 138175, 3122, 123P
J38La Vara Obs. in Spain, 1 in MPEC 2011-D36 -- 240P
B33Libbiano Obs. in Italy, 1 in MPEC 2011-D36 -- 103P
C10Maisoncelles Obs. in France, 3 in MPEC 2011-D36 -- C/2010 X1, 73P, 29P
118Modra Obs. in Slovakia, 2 in MPECs 2011-D34 & 2011-D36 -- 2011 DV, P/2011 C2
900Moriyama Obs. in Japan, 9 in MPEC 2011-D36 -- C/2011 A3, C/2010 X1, P/2010 WK, C/2010 S1, C/2010 B1, C/2005 L3, 247P, 103P, 29P
E07Murrumbateman Obs. in New South Wales, 7 in MPEC 2011-D36 -- C/2010 X1, C/2010 FB87, C/2010 B1, 103P, 43P, 31P, 29P
A13Naef Obs. in Switzerland, 2 in MPECs 2011-D32 & 2011-D36 -- 2004 CK39, 247P
J47Nazaret Obs. in Spain, 4 in MPEC 2011-D36 -- C/2010 X1, 123P, 103P, 29P
583Odessa-Mayaki Obs. in the Ukraine, 1 in MPEC 2011-D36 -- 29P
5611Janos Kelemen via Piszkesteto Sta. in Hungary, 8 in MPEC 2011-D36 -- C/2011 A3, P/2011 A1, C/2010 X1, P/2010 WK, C/2010 S1, C/2010 G3, C/2010 G2, C/2009 K5
H06|H. Sato in Japan via RAS Obs. Mayhill in New Mexico, 2 in MPEC 2011-D36 -- C/2011 C3, C/2011 C1
D90`Kevin Hills in England via RAS Obs. Moorook in South Australia, 5 in MPECs 2011-D32 & 2011-D36 -- 2011 AO52, 2010 XK52, C/2010 X1, 43P, 29P
E03`program code "`" (30) via RAS Obs. Victoria in Victoria, 1 in MPEC 2011-D36 -- C/2010 FB87
473Remanzacco Obs. in Italy, 1 in MPEC 2011-D36 -- 10P
939Rodeno Obs. in Spain, 3 in MPEC 2011-D36 -- C/2010 G2, 240P, 103P
204Schiaparelli Obs. in Italy, 9 in MPEC 2011-D36 -- P/2010 D2, 246P, 231P, 162P, 126P, 117P, 73P, 71P, 31P
E12Siding Spring Survey in New South Wales, 1 in MPEC 2011-D35 -- 2011 DW
510Siegen Obs. in Germany, 2 in MPEC 2011-D36 -- 123P, 103P
G68Sierra Stars Obs. in northern California, 1 in MPEC 2011-D36 -- 103P
691Spacewatch 0.9m telescope in Arizona, 5 in MPECs 2011-D32, 2011-D33 & 2011-D34 -- 2011 DV, 2011 DU, 2004 EM20, 22771, 5646
291Spacewatch 1.8m telescope in Arizona, 17 in MPECs 2011-D32, 2011-D33 & 2011-D34 -- 2011 DV, 2011 DU, 2011 CY3, 2011 CX46, 2011 CU4, 2011 CT4, 2011 CR1, 2011 CP4, 2011 CO14, 2011 CN2, 2011 CG22, 2011 BY18, 2011 BV15, 2011 BO40, 2011 BG40, 2011 BD40, 2011 BA12
I40TRAPPIST in Chile, 1 in MPEC 2011-D36 -- 9P
H10Tzec Maun Obs. Mayhill in New Mexico, 17 in MPECs 2011-D32 & 2011-D36 -- 2011 CH71, C/2010 X1, C/2010 B1, C/2009 K5, C/2008 S3, C/2005 L3, 215167, 247P, 241P, 231P, 203P, 123P, 103P, 71P, 31P, 29P, 10P
D96Tzec Maun Obs. Moorook in South Australia, 3 in MPEC 2011-D36 -- C/2010 FB87, C/2010 B1, 103P
H47Vicksburg Obs. in Mississippi, 1 in MPEC 2011-D36 -- C/2010 B1
198Wildberg Obs. in Germany, 1 in MPEC 2011-D36 -- P/2011 A1
I15Wishing Star Obs. in Rhode Island, 3 in MPEC 2011-D32 -- 2002 SZ, 2001 DQ8, 1864
D79YSVP Obs., 1 in MPEC 2011-D36 -- C/2010 B1
J08Zonalunar Obs. in Spain, 1 in MPEC 2011-D36 -- 123P
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 24 February '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 DVJPL Sentry17172016-21103036.1e-06-3.29-3.970JPL: "Analysis based on 8 observations spanning 1.6597 days (2011-Feb-22.51614 to 2011-Feb-24.1758)." Diameter approximately 0.219 km. from mean, weighted H=20.9.
2011 DSNEODyS17172031-2090212.1e-06-6.63-7.030NEODyS: "Based on 15 optical observations (of which 0 are rejected as outliers) from 2011-02-23.400 to 2011-02-23.921."
JPL Sentry02202031-2110283.2e-06-6.51-7.050JPL: "Analysis based on 15 observations spanning .52088 days (2011-Feb-23.39905 to 2011-Feb-23.91993)." Diameter approximately 0.013 km. from mean, weighted H=27.0.
2011 CF66JPL Sentry23002012-20785878.2e-06-5.99-6.810JPL: "Analysis based on 11 observations spanning .17761 days (2011-Feb-13.33976 to 2011-Feb-13.51737)." Diameter approximately 0.010 km. from mean, weighted H=27.8.
2011 BA60NEODyS17172038-208045.78e-10-7.29-7.330NEODyS: "Based on 7 optical observations (of which 0 are rejected as outliers) from 2011-01-29.261 to 2011-01-31.237."
JPL Sentry03012081-2107391.3e-08-6.69-8.160JPL: "Analysis based on 7 observations spanning 1.9754 days (2011-Jan-29.26046 to 2011-Jan-31.235902)." Diameter approximately 0.123 km. from mean, weighted H=22.1.
2011 BM45JPL Sentry23002078-209064.3e-05-2.53-2.551JPL: "Analysis based on 39 observations spanning 13.872 days (2011-Jan-30.4027 to 2011-Feb-13.275)." Diameter approximately 0.160 km. from mean, weighted H=21.7.
2011 AG5JPL Sentry23002036-205772.7e-04-2.05-2.101JPL: "Analysis based on 119 observations spanning 42.789 days (2011-Jan-08.2673 to 2011-Feb-20.056036)." Diameter approximately 0.140 km. from mean, weighted H=21.9.

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 February '11

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

2300Noted that JPL Sentry has updated its 2011 AG5 risk assessment - see above
Noted that JPL Sentry has updated its 2011 BM45 risk assessment - see above
Noted that JPL Sentry has posted 2011 CF66 as an impact risk - see above
1923Grabbed MPEC 2011-D36 - Observations and Orbits of Comets - see above
1717Noted that NEODyS has posted 2011 BA60 as an impact risk - see above
Noted that NEODyS has posted 2011 DS as an impact risk - see above
Noted that JPL Sentry has posted 2011 DV as an impact risk - see above
Grabbed MPEC 2011-D32 - Daily Orbit Update - see above
Grabbed MPEC 2011-D33 - 2011 DU - see above
Grabbed MPEC 2011-D34 - 2011 DV - see above
Grabbed MPEC 2011-D35 - 2011 DW - see above
0301Noted that JPL Sentry has posted 2011 BA60 as an impact risk - see above
0220Noted that JPL Sentry has posted 2011 DS as an impact risk - see above
0106Grabbed MPEC 2011-D31 - 2011 DS - see above
0006Grabbed MPEC 2011-D30 - 2011 DR - see above