Contents  on 21 April '09

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 21 April '09

The MPC's NEO Confirmation Page has 4 listings: 1 new, 3 updated

When last checked at 2358 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had one new and three updated listings. Of these, three were "one nighters." So far The Tracking News has counted a total of fourteen listings on the NEOCP at some point 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 21 April '09

Minor Planet Electronic Circulars

As of last check at 2358 UTC, there have been eleven MPECs posted today from the International Astronomical Union's Minor Planet Center in Cambridge, Massachusetts.


MPEC 2009-H35 - "22:10 UT" - 2009 HL21


MPEC 2009-H34 - "18:00 UT" - 2009 HJ21


MPEC 2009-H33 - "17:57 UT" - 2009 HH21


MPEC 2009-H32 - "17:54 UT" - 2009 HG21


MPEC 2009-H31 - "17:51 UT" - 2009 HF21


MPEC 2009-H30 - "17:49 UT" - 2009 HE21


MPEC 2009-H29 - "17:45 UT" - 2009 HD21


MPEC 2009-H28 - "17:42 UT" - 2009 HC21


MPEC 2009-H27 - "17:39 UT" - 2009 HB21


MPEC 2009-H26 - "17:37 UT" - 2009 HA21


<< DOU on 21 Apr. '09 >>  MPEC 2009-H25 - "06:08 UT" - Daily Orbit Update

Observers  on 21 April '09

A total of 25 observing facilities appear in today's MPECs.

CodeObserver / observatory
B03Alter Satzberg Obs. in Austria, 1 in MPEC 2009-H35 -- 2009 HL21
621Bergisch Gladbach Obs. in Germany, 1 in MPEC 2009-H35 -- 2009 HL21
703Catalina Sky Survey (CSS) in Arizona, 9 in MPECs 2009-H25, 2009-H29 & 2009-H31 -- 2009 HF21, 2009 HD21, 2009 HD, 2009 FH44, 2009 DF1, 2009 BL2, 2008 SQ7, 2005 YS165, 212546
850Cordell-Lorenz Obs. in Tennessee, 1 in MPEC 2009-H27 -- 2009 HB21
448Desert Moon Obs. in New Mexico, 5 in MPECs 2009-H25 & 2009-H29 -- 2009 HD21, 2009 FU4, 2009 DC43, 162882, 155334
113Drebach Obs. in Germany, 6 in MPECs 2009-H25 & 2009-H35 -- 2009 HL21, 2009 HE, 2009 HD, 2009 FY29, 2005 YS165, 2002 EL6
808El Leoncito Obs. in Argentina, 11 in MPEC 2009-H25 -- 2009 FA, 2009 DL1, 2008 WN2, 2005 SG19, 85867, 175706, 155334, 136617, 5604, 3199, 1036
114Engelhardt Obs. Zelenchukskaya Station in Karachay-Cherkessia, 1 in MPEC 2009-H35 -- 2009 HL21
651Grasslands Obs. in Arizona, 5 in MPECs 2009-H27, 2009-H28, 2009-H29, 2009-H31 & 2009-H32 -- 2009 HG21, 2009 HF21, 2009 HD21, 2009 HC21, 2009 HB21
J95Great Shefford Obs. in England, 4 in MPECs 2009-H28, 2009-H29, 2009-H31 & 2009-H35 -- 2009 HL21, 2009 HF21, 2009 HD21, 2009 HC21
A17Guidestar Obs. in Germany, 1 in MPEC 2009-H35 -- 2009 HL21
704LINEAR in New Mexico, 9 in MPECs 2009-H25 & 2009-H27 -- 2009 HD, 2009 HB21, 2009 FY29, 2008 SW150, 2005 SA71, 2004 JN13, 35107, 141432, 5332
H01Magdalena Ridge Obs. (MRO) in New Mexico, 4 in MPECs 2009-H25, 2009-H26, 2009-H28 & 2009-H31 -- 2009 HF21, 2009 HC21, 2009 HA21, 2004 JR
B67Mirasteilas Obs. in Switzerland, 1 in MPEC 2009-H25 -- 40329
474Mt. John Obs. in New Zealand, 3 in MPECs 2009-H31, 2009-H33 & 2009-H34 -- 2009 HJ21, 2009 HH21, 2009 HF21
G96Mt. Lemmon Survey (MLS) in Arizona, 13 in MPECs 2009-H25, 2009-H26, 2009-H27, 2009-H28, 2009-H29, 2009-H30, 2009-H32, 2009-H33 & 2009-H34 -- 2009 HJ21, 2009 HH21, 2009 HG21, 2009 HE21, 2009 HD21, 2009 HC21, 2009 HB21, 2009 HA21, 2009 BL2, 2004 JR, 2003 UN12, 2003 SL5, 68031
D29Purple Mtn. Obs. XuYi Station in China, 1 in MPEC 2009-H25 -- 39557
J41Raheny Obs. in Ireland, 1 in MPEC 2009-H29 -- 2009 HD21
B36Redshed Obs. in Austria, 1 in MPEC 2009-H35 -- 2009 HL21
B76Schonfeld Obs. in Germany, 1 in MPEC 2009-H25 -- 2007 BT2
E12Siding Spring Survey in New South Wales, 1 in MPEC 2009-H25 -- 1036
691Spacewatch 0.9m telescope in Arizona, 1 in MPEC 2009-H25 -- 139622
291Spacewatch 1.8m telescope in Arizona, 4 in MPEC 2009-H25 -- 2009 HC, 2009 CC3, 2009 CB3, 2001 SF262
611Starkenburg Obs. in Germany, 1 in MPEC 2009-H35 -- 2009 HL21
6735Jim Young via Table Mtn. Obs. in southern California, 3 in MPECs 2009-H25 & 2009-H27 -- 2009 HF, 2009 HC, 2009 HB21
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 21 April '09

Summary Risk Table for Risk Assessments Updated Today   (last checks: NEODyS and JPL at 2358 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. Beginning Jan. 22nd, both are also posting impact solutions beyond 100 years for a few 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
2009 HD21JPL Sentry21122012-21083904.9e-07-2.59-3.200JPL: "Analysis based on 22 observations spanning 1.0082 days (2009-Apr-20.32627 to 2009-Apr-21.33448)." Diameter approximately 0.771 km. from mean, weighted H=18.2.
2009 HA21JPL Sentry2009207211.4e-10-7.10-7.100JPL: "Analysis based on 16 observations spanning .95553 days (2009-Apr-20.24948 to 2009-Apr-21.20501)." Diameter approximately 0.330 km. from mean, weighted H=20.1.
2009 HU2NEODyS13252026-2070527.16e-08-3.66-4.180NEODyS: "Based on 28 optical observations (of which 0 are rejected as outliers) from 2009/04/19.132 to 2009/04/20.292."
2009 HEJPL Sentry13252062-206722.5e-10-7.13-7.370JPL: "Analysis based on 26 observations spanning 3.5939 days (2009-Apr-17.30454 to 2009-Apr-20.89845)." Diameter approximately 0.250 km. from mean, weighted H=20.6.
2009 HCJPL Sentry13252097-210848.5e-07-6.48-6.900JPL: "Analysis based on 47 observations spanning 3.1892 days (2009-Apr-17.23164 to 2009-Apr-20.42088)." Diameter approximately 0.036 km. from mean, weighted H=24.9.

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 21 April '09

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

2223Grabbed MPEC 2009-H35 - 2009 HL21 - see above
2112Noted that JPL Sentry has posted 2009 HD21 as an impact risk - see above
2009Noted that JPL Sentry has posted 2009 HA21 as an impact risk - see above
1900Grabbed MPEC 2009-H34 - 2009 HJ21 - see above
1801Grabbed MPEC 2009-H26 - 2009 HA21 - see above
Grabbed MPEC 2009-H27 - 2009 HB21 - see above
Grabbed MPEC 2009-H28 - 2009 HC21 - see above
Grabbed MPEC 2009-H29 - 2009 HD21 - see above
Grabbed MPEC 2009-H30 - 2009 HE21 - see above
Grabbed MPEC 2009-H31 - 2009 HF21 - see above
Grabbed MPEC 2009-H32 - 2009 HG21 - see above
Grabbed MPEC 2009-H33 - 2009 HH21 - see above
1325Noted that JPL Sentry has updated its 2009 HC risk assessment - see above
Noted that JPL Sentry has reposted 2009 HE as an impact risk - see above
Noted that NEODyS has posted 2009 HU2 as an impact risk - see above
Grabbed MPEC 2009-H25 - Daily Orbit Update - see above