Contents  on 17 September '13

Asteroid/Comet Connection (A/CC) 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.

Traffic Report  on 17 September '13

Five objects reported inside ten LD

There are five objects reported to be within ten lunar distances (LD) of Earth today. Closest of these, tiny risk-listed intruder 2013 RZ53, possibly an artificial object, is slowly passing through the Earth-Moon system and, inside Earth's Hill sphere, 2013 RM73 comes its closest to Earth this time around, reaching 2.28 LD at 0036 UT.

Further away, newly announced 2013 RF74 is inbound from 6.84 to 5.77 LD while risk-listed 2013 RS43 is outbound from 5.29 to 6.44 LD and 2013 RT73 from 8.34 to 8.77 LD.

This report was generated at 1548 UTC with the discovery announced late yesterday of 2013 RF74 and follow-up in today's DOU MPEC for 2013 RM73 and 2013 RZ53.



Notes: Ten times the distance to the Moon (ten LD) has no astronomical significance but is a useful reporting boundary. Earth's Hill sphere (of gravitational influence) is estimated to extend out to around 3.89 LD. Object distances are interpreted by A/CC from JPL Horizons data. See also current sky chart and object details (alt-details), ephemerides, and today's timeline.

NEOCP Activity  on 17 September '13

The MPC's NEO Confirmation Page has 17 listings

When last checked at 2359 UTC today, the Minor Planet Center's Near Earth Object discovery Confirmation Page (NEOCP) had seventeen objects listed. Of these, five were "one nighters." So far The Tracking News has counted a total of 24 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 17 September '13

Minor Planet Electronic Circulars

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


MPEC 2013-S20 - "23:38 UT" - 2013 RX80


MPEC 2013-S19 - "17:35 UT" - 2013 RJ74


<< DOU on 17 Sept. '13 >>  MPEC 2013-S18 - "06:05 UT" - Daily Orbit Update

Observers  on 17 September '13

A total of 20 observers appear in today's MPECs.

CodeObserver / observatory
H21Astronomical Research Obs. Westfield in Illinois, 1 in MPEC 2013-S19 -- 2013 RJ74
300Bisei Spaceguard Center in Japan, 3 in MPECs 2013-S18 & 2013-S20 -- 2013 RX80, 2013 RG74, 1998 SO
U82CS3 Palmer Divide Station in southern California, 1 in MPEC 2013-S18 -- 368664
703Catalina Sky Survey (CSS) in Arizona, 11 in MPEC 2013-S18 -- 2011 SD173, 2009 SK1, 88710, 354182, 351545, 350988, 329437, 276786, 219071, 6063, 4450
K37Cereseto Obs., 1 in MPEC 2013-S18 -- 2010 TN54
J01Cielo Profundo Obs. in Spain, 1 in MPEC 2013-S20 -- 2013 RX80
850Cordell-Lorenz Obs. in Tennessee, 1 in MPEC 2013-S18 -- 2013 RM73
J95Great Shefford Obs. in England, 1 in MPEC 2013-S18 -- 2013 RZ53
355Hadano Obs. in Japan, 1 in MPEC 2013-S20 -- 2013 RX80
V37LCOGT Fort Davis in Texas, 1 in MPEC 2013-S20 -- 2013 RX80
J75La Sagra Obs. in Spain, 1 in MPEC 2013-S20 -- 2013 RX80
G96Mt. Lemmon Survey (MLS) in Arizona, 2 in MPECs 2013-S18 & 2013-S19 -- 2013 RJ74, 1998 SO
A24New Millennium Obs. in Italy, 1 in MPEC 2013-S20 -- 2013 RX80
I41Palomar Transient Factory (PTF) in southern California, 3 in MPEC 2013-S18 -- 2011 BN24, 65733, 326946
H45Petit Jean Mtn. South Obs. (PJMSO) in Arkansas, 4 in MPEC 2013-S18 -- 2013 QJ10, 2012 TS, 2010 TN54, 329437
Y00SONEAR Obs. in Brazil, 12 in MPEC 2013-S18 -- 2013 HG20, 2012 ER14, 2009 SK1, 65733, 368664, 355256, 269690, 168378, 162566, 159699, 4450, 3691
291Spacewatch 1.8m telescope in Arizona, 1 in MPEC 2013-S19 -- 2013 RJ74
673!Jana Pittichova via Table Mtn. Obs. in southern California, 1 in MPEC 2013-S20 -- 2013 RX80
G56Walnut Creek Obs. in northern California, 1 in MPEC 2013-S18 -- 2013 QJ10
718Wiggins Obs. in Utah, 1 in MPEC 2013-S18 -- 2013 QJ10
For a list of all participating observatories that have Web addresses, see A/CC's Observatory Links page.

Impact Risk Monitoring  on 17 September '13

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 CLOMON2 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
2013 RJ74JPL Sentry23282014-2111341.8e-07-2.22-2.230JPL: "Analysis based on 24 observations spanning 3.0146 days (2013-Sep-14.30424 to 2013-Sep-17.31883)." Diameter approximately 0.468 km. from mean, weighted H=19.3.
2013 RH74JPL Sentry0017209313.1e-10-7.34-7.340JPL: "Analysis based on 20 observations spanning .84640 days (2013-Sep-15.35861 to 2013-Sep-16.20501)." Diameter approximately 0.300 km. from mean, weighted H=20.3.
2013 RG74NEODyS15252032-203635.71e-09-6.79-6.880NEODyS: "Based on 31 optical observations (of which 0 are rejected as outliers) from 2013-09-15.308 to 2013-09-16.196."
JPL Sentry1525R E M O V E DJPL #2 for the day: Risk listing removed at 1301 UTC.
2013 RE74NEODyS15252014-206437.23e-10-6.22-6.350NEODyS: "Based on 8 optical observations (of which 0 are rejected as outliers) from 2013-09-14.502 to 2013-09-15.314."
JPL Sentry04122033-2089113.8e-09-6.61-7.270JPL: "Analysis based on 8 observations spanning .81198 days (2013-Sep-14.50128 to 2013-Sep-15.313262)." Diameter approximately 0.150 km. from mean, weighted H=21.8.
2013 RZ53JPL Sentry15252058-2104114.2e-06-8.79-9.090JPL: "Analysis based on 31 observations spanning 2.7164 days (2013-Sep-13.37086 to 2013-Sep-16.087304)." Diameter approximately 0.002 km. from mean, weighted H=31.2.
NEODyS15252108-210812.71e-10-13.05-13.050NEODyS: "Based on 34 optical observations (of which 5 are rejected as outliers) from 2013-09-13.372 to 2013-09-16.088."

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 17 September '13

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

2359Grabbed MPEC 2013-S20 - 2013 RX80 - see above
2328Noted that JPL Sentry has posted 2013 RJ74 as an impact risk - see above
1822Grabbed MPEC 2013-S19 - 2013 RJ74 - see above
1548Generated Traffic Report
1525Noted that NEODyS has posted 2013 RE74 as an impact risk - see above
Noted that JPL Sentry has removed 2013 RG74 as an impact risk - see above
Noted that NEODyS has posted 2013 RG74 as an impact risk - see above
Noted that JPL Sentry has updated its 2013 RZ53 risk assessment - see above
Noted that NEODyS has updated its 2013 RZ53 risk assessment - see above
Grabbed MPEC 2013-S18 - Daily Orbit Update - see above
0412Noted that JPL Sentry has posted 2013 RE74 as an impact risk - see above
Noted that JPL Sentry has posted 2013 RG74 as an impact risk - see above
0017Noted that JPL Sentry has posted 2013 RH74 as an impact risk - see above