2009 HC82 observed May 4th by Peter Birtwhistle 
(c)Copyright 2009 Great Shefford Obs.

All remaining impact solutions were removed today for highly unusual object 2009 HC82. Discovered April 29th by the Catalina Sky Survey, it was posted as a risk on May 4th following observations reported that morning from Peter Birtwhistle in England (including the frames stacked into this image, note the faint dot at center). 2009 HC82 is large for an NEO, and possibly larger yet if it is an inactive comet nucleus, as suggested by its retrograde orbit. Image ©copyright 2009 Great Shefford Observatory. See more info.

Contents  on 6 May '09


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 6 May '09

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

When last checked at 2344 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 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 6 May '09

Minor Planet Electronic Circulars

As of last check at 2344 UTC, there have been four MPECs posted today from the International Astronomical Union's Minor Planet Center in Cambridge, Massachusetts.

MPEC 2009-J31 - "18:30 UT" - 2009 JM1

MPEC 2009-J30 - "18:26 UT" - 2009 JL1

MPEC 2009-J29 - "18:19 UT" - 2009 JK1

<< DOU on 6 May '09 >>  MPEC 2009-J28 - "06:08 UT" - Daily Orbit Update

Observers  on 6 May '09

Thirteen observing facilities appear in today's MPECs.

CodeObserver / observatory
A50Andrushivka Obs. in the Ukraine, 1 in MPEC 2009-J28 -- 3103
H55Astronomical Research Obs. (ARO) in Illinois, 6 in MPEC 2009-J28 -- 2009 JR, 2009 HG60, 2009 HD21, 2009 CR2, 2009 BL2, 2007 BT2
J51Atlante Obs. in the Canary Islands, 5 in MPEC 2009-J28 -- 2009 HV44, 207945, 159399, 138883, 5620
160Castelmartini Obs. in Italy, 6 in MPEC 2009-J28 -- 2009 HV44, 2009 HM82, 85989, 159399, 143651, 138883
H26Doc Greiner Research Obs. in Wisconsin, 1 in MPEC 2009-J28 -- 2008 WL60
E10Faulkes Telescope South in New South Wales, 2 in MPECs 2009-J30 & 2009-J31 -- 2009 JM1, 2009 JL1
J28Jaen Obs. in Spain, 1 in MPEC 2009-J28 -- 90367
G96Mt. Lemmon Survey (MLS) in Arizona, 2 in MPECs 2009-J29 & 2009-J30 -- 2009 JL1, 2009 JK1
D29Purple Mtn. Obs. XuYi Station (XuYi Sta.) in China, 2 in MPEC 2009-J28 -- 138911, 5620
E12Siding Spring Survey (SSS) in New South Wales, 3 in MPECs 2009-J28 & 2009-J31 -- 2009 JM1, 2009 JG1, 2006 UR216
691Spacewatch 0.9m telescope in Arizona, 10 in MPECs 2009-J28, 2009-J29, 2009-J30 & 2009-J31 -- 2009 JM1, 2009 JL1, 2009 JK1, 2009 HY67, 2009 HD82, 2005 SA71, 2000 TG2, 99799, 136874, 5879
291Spacewatch 1.8m telescope in Arizona, 7 in MPECs 2009-J28, 2009-J29, 2009-J30 & 2009-J31 -- 2009 JM1, 2009 JL1, 2009 JK1, 2009 HV58, 2009 HM73, 2009 HF88, 2009 HC82
I13Washington D.C. Obs. in Washington, D.C., 1 in MPEC 2009-J28 -- 143651
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 6 May '09

Summary Risk Table for Risk Assessments Updated Today   (last checks: NEODyS and JPL at 2344 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.





Notes for Today's Latest Risk Assessments
2009 JF1NEODyS1349202213.14e-04-3.60-3.600NEODyS: "Based on 25 optical observations (of which 0 are rejected as outliers) from 2009/05/04.421 to 2009/05/05.660."
2009 HC82JPL Sentry1349R E M O V E DJPL: Risk listing removed at 0854 UTC.
NEODyS1349R E M O V E D-
2009 HV58JPL Sentry13492011-209353.7e-08-4.45-5.010JPL: "Analysis based on 34 observations spanning 10.061 days (2009-Apr-25.39439 to 2009-May-05.45527)." Diameter approximately 0.440 km. from mean, weighted H=19.4.
NEODyS13492011-209062.95e-08-4.50-4.940NEODyS: "Based on 34 optical observations (of which 0 are rejected as outliers) from 2009/04/25.395 to 2009/05/05.456."

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 6 May '09

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

1900Grabbed MPEC 2009-J29 - 2009 JK1 - see above
Grabbed MPEC 2009-J30 - 2009 JL1 - see above
Grabbed MPEC 2009-J31 - 2009 JM1 - see above
1349Noted that JPL Sentry has removed 2009 HC82 as an impact risk - see above
Noted that NEODyS has removed 2009 HC82 as an impact risk - see above
Noted that JPL Sentry has updated its 2009 HV58 risk assessment - see above
Noted that NEODyS has updated its 2009 HV58 risk assessment - see above
Noted that NEODyS has posted 2009 JF1 as an impact risk - see above
Grabbed MPEC 2009-J28 - Daily Orbit Update - see above