Sunday13 June 20045:08pm MDT2004-06-13 UTC 2308 back top next  

The Asteroid/Comet Connection's
daily news journal about
asteroids, comets, and meteors


Today's issue status: done
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Cover: Small object 2004 LC caught by Robert Hutsebaut working from Belgium with a rented 0.25m telescope at New Mexico Skies just after this object's discovery confirmation process was closed out on June 9th. He notes that this image consists of 18 ten-second exposures stacked "for 22.33"/min. towards 126.5°." The fast apparent motion of this little asteroid as it wings past Earth is such that stars appear in this image as "strings of beads." Read about the discovery and pursuit of this object below.

Small objects – panel 1/2 Major News for 13 June 2004 back top next  

Small objects
Discovery & follow-up for 7-13 June

Most of the nine small objects (defined at right) observed this past week were discovered in the last seven days. LINEAR in New Mexico found four, and the Siding Spring Survey (SSS) in Australia and LONEOS in Arizona discovered one each. One of three others that were tracked, 2004 KH17, hadn't fit into the "small asteroid" definition from discovery May 29th until the MPC published a new orbit calculation yesterday using observations reported from early Friday. A total of 23 amateur and professional observing facilities participated in this work. Archival sleuthing resulted in new data published this last week also for a small object, 1998 HG49, that hasn't been seen since May 2002.

A/CC reported June 6th that no small object close flybys were predicted for the month, but it turned out that 2004 LC was at 8.5 lunar distances (LD) that day, and 2004 LB1 and 2004 LV flew past Earth at, respectively, 14.4 and 12.3 LD on Friday. Tomorrow 2004 LO2 flies past at 8.5 LD, and 2004 LB2 at 16.3 LD.

<< previous report | skip table | Small objects table >>

What's so big about “small objects”? If an asteroid's orbit brings it to within 0.05 astronomical units (AU) of Earth's orbit, it is categorized as "potentially hazardous" unless it has an absolute magnitude H greater than 22.0, which corresponds to a diameter on the order of 135 meters/yards. Larger H means less bright, thus smaller size. And 0.05 AU is about 19.5 times the distance between Earth and Moon (0.00256 AU). To be discovered and tracked, such objects usually must come close (a few are Earth's nearest neighbors, coming closer than the Moon). They are exposed samplings of distant asteroid populations, they have within their own population tomorrow's meteors, and their discovery and follow-up represents a good sampling of the best of today's amateur and professional asteroid observing work. Diameter & Earth MOID: In the following observation summary table, the stated diameters are rough best estimates from a standard but very inexact H-to-size formula using H (absolute magnitude, or brightness) from the JPL NEO Orbital Elements page, source also for Earth MOID (minimum orbital intersection distance). Current Minor Planet Center H is also given, along with the original H from each object's discovery MPEC. Other sources: Planetary MOIDs are from Lowell Observatory. Priorities and visibilities are from the European Spaceguard Central Node (SCN). And flyby distances and times are from the JPL Close Approach Table. See also Sormano Observatory's SAEL list of asteroids with H>22.0 and Earth MOID<0.015 AU.
Small objects – panel 2/2 (table) Major News for 13 June 2004 back top next  

Small object observation summary for 7-13 June

H = absolute magnitude (brightness), from which size is roughly estimated   —   m/yd = meters/yards   —   [cross index]
All objects had observations reported last week. Those on a light-blue background had observations from only before the week.


Object
Estimated
diameter
JPL
H
MPC
H
Discovery
H in MPEC
Earth
MOID
European Spaceguard Central Node
priority/visibility/campaign
2004 LO2
Aten
41 m/yd24.5824.624.8 2004-L470.01325 AUUrgent, visibility ends 19 June
NEW: 2004 LO2 was discovered on 11 June by LINEAR, was confirmed 11 June by Great Shefford Obs. and 12 June by Tenagra II Obs., and was announced in MPEC 2004-L22 of 12 June. This object was also observed on 11 June by Obs. Astronomico de Mallorca (OAM) and on 12 June by Mt. John Obs. and Great Shefford Obs. It will fly past Earth at 8.5 lunar distances (LD) on 14 June.
2004 LC
Apollo
50 m/yd24.1524.424.4 2004-L150.01305 AUNecessary, visibility ends 8 July
NEW: 2004 LC was discovered on 8 June by LINEAR, was confirmed on 8 June by KLENOT, OAM, Starkenburg Obs., Modra Obs., and Ondrejov Obs., and on 9 June by Three Buttes Obs., Tenagra II Obs., and Sabino Canyon Obs., and was announced in MPEC 2004-L15 of 9 June. This object was also observed on 9 June by LINEAR, Tenagra II Obs., and Robert Hutsebaut via New Mexico Skies (see the "cover" above), on 10 June by Tenagra II Obs., LINEAR, and Begues Obs., on 11 June by Tenagra II Obs., and on 12 June by Tenagra II Obs. and Desert Moon Obs. It flew past Earth at 8.5 LD on 6 June.
2004 LV
Apollo
59 m/yd23.7924.224.2 2004-L270.02526 AU
NEW: 2004 LV was discovered on 9 June by LINEAR, was confirmed on 10 June by LINEAR and OAM, and was announced in MPEC 2004-L27 of 10 June. This object was also observed on 11 and 12 June by Great Shefford Obs. Before it was removed from the SCN Priority List on the June 13th, it was predicted to have visibility end on the 14th (tomorrow). It has MOIDs of 0.024 AU with Venus and 0.007 AU with Mars, and flew past Earth on June 11th at 0.0316 AU (12.3 LD).
2004 KN10
Amor
63 m/yd23.6623.723.5 2004-K450.10075 AUUseful, visibility ends 15 July
2004 KN10 was observed on 7 June with the Australian Natl. Univ. (ANU) Obs. 1m telescope and by Linz Obs. and KLENOT, and on 9 and 11 June by Tenagra II Obs.
2004 JN1
Apollo
70 m/yd23.4323.723.6 2004-J480.02336 AUUseful, visibility ends 13 July
2004 JN1 was observed on 7 June with the ANU 1m telescope and on 11 June by Tenagra II Obs.
2004 LB1
Apollo
78 m/yd23.1823.223.1 2004-L300.03332 AUNecessary, visibility ends 9 July
NEW: 2004 LB1 was discovered on 10 June by LINEAR, was confirmed on 11 June by Great Shefford Obs., Tenagra II Obs., and Reedy Creek Obs., and was announced in MPEC 2004-L30 of 11 June. This object was also observed on 11 June by Reedy Creek Obs., on 12 June by Great Shefford Obs., Tenagra II Obs., and Mt. John Obs., and on 13 June by Great Shefford Obs. It flew past Earth at 14.4 LD on June 11th.
2004 LK
Amor
92 m/yd22.8322.822.7 2004-L220.06881 AUNecessary, visibility ends 10 Oct.
NEW: 2004 LK was discovered and pursued for just over four hours on 9 June by the Southern Sky Survey (SSS), was confirmed on 10 June by Three Buttes Obs., and was announced in MPEC 2004-L22 of 10 June. This object was also observed on 10-12 June by Tenagra II Obs. and on 12 June by Mt. John Obs.
2004 LB2
Apollo
123 m/yd22.2022.222.4 2004-L340.00960 AUUrgent, visibility ends 18 June
NEW: 2004 LB2 was discovered on 11 June by LONEOS, was confirmed on 11 June by SSS, and on 12 June by OAM, Great Shefford Obs., Hutsebaut/NM Skies, Three Buttes Obs., Grasslands Obs., and Tenagra II Obs., and was announced in MPEC 2004-L34 of 12 June. This object was also observed on 12 June by Mt. John Obs. It will fly past Earth at 16.3 LD on June 14th.
1998 HG49
Amor
139 m/yd21.9422.122.0 1998-J070.07587 AU
1998 HG49 was reported this past week as observed on 9 and 18 May 2002 by NEAT/Palomar, and on 16 May 2002 by NEAT/Haleakala. 1998 HG49 was discovered 27 April 1998 with the Spacewatch 0.9m telescope and went out of view on 3 May 1998 with 14 observations spanning only 6.106 days. It was recovered on May 10th four years later with the Spacewatch 1.8m telescope, and was observed until the 14th with that telescope and by LINEAR and KLENOT, adding 25 positions over 4.028 days. Brigitta Sipocz tells A/CC that it was Krisztian Sarneczky at the Szeged University (SZTE) Asteroid program in Hungary who found 1998 HG49 in NEAT archive images, thus adding nine more positions and more than doubling the length of the 2002 segment of the observation arc (to 8.972 days).
2004 KH17
Aten
139 m/yd21.9322.121.8 2004-K760.00394 AUNecessary, visibility ends 23 June
2004 KH17 was observed on 6-12 June by Tenagra II Obs., on 6 June by Wykrota Obs., on 6 and 7 June by Herrenberg and Great Shefford observatories, on 7 June by KLENOT and Jurassien-Vicques Obs., and on 11 June by Desert Moon Obs. After discovery May 9th by LINEAR and 11.847 days with 122 observations from many observatories (for example, see the June 2nd "cover" with confirmation imagery), the next observations on June 11th (by Tenagra II and Desert Moon observatories) were followed by a new calculation of absolute magnitude (H=22.1) from the Minor Planet Center, which on June 12th for the first time classified 2004 KH17 as a small object. It came with 25.0 LD of Earth on June 6th.

  Small object observation cross index   [table top]
ObjectObserved by MPC code
1998 HG49608 & 644
2004 JN1413 & 926
2004 KH17185, 240, 246, 448, 859, 926 & J95
2004 KN10246, 413, 540 & 926
2004 LB1428, 474, 704, 926 & J95
2004 LB2474, 620, 651, 699, 926, E12, G90, H06 & J95
2004 LC118, 170, 246, 448, 557, 611, 620, 704, 854, 926, G90 & H06
2004 LK474, 926, E12 & G90
2004 LO2474, 620, 704, 926 & J95
2004 LV620, 704 & J95
CodeObservatoryObjects observed (days)
118Modra Obs.2004 LC
170Begues Obs.2004 LC
185Jurassien-Vicques Obs.2004 KH17
240Herrenberg Obs.2004 KH17(2)
246KLENOT2004 KH17, 2004 KN10 & 2004 LC
413Australian Natl. Univ. (ANU) Obs. 1m telescope2004 JN1 & 2004 KN10
428Reedy Creek Obs.2004 LB1(2)
448Desert Moon Obs.2004 KH17 & 2004 LC
474Mt. John Obs.2004 LB1, 2004 LB2, 2004 LK & 2004 LO2
540Linz Obs.2004 KN10
557Ondrejov Obs.2004 LC
608NEAT/Haleakala1998 HG49
611Starkenburg Obs.2004 LC
620Obs. Astron. de Mallorca2004 LB2, 2004 LC, 2004 LO2 & 2004 LV
644NEAT/Palomar1998 HG49(2)
651Grasslands Obs.2004 LB2
699LONEOS2004 LB2
704LINEAR2004 LB1, 2004 LC(3), 2004 LO2 & 2004 LV(2)
854Sabino Canyon Obs.2004 LC
859Wykrota Obs.2004 KH17
926Tenagra II Obs.2004 JN1, 2004 KH17(7), 2004 KN10(2), 2004 LB1(2), 2004 LB2, 2004 LC(5), 2004 LK(3) & 2004 LO2
E12Southern Sky Survey (SSS)2004 LB2 & 2004 LK
G90Three Buttes Obs.2004 LB2, 2004 LC & 2004 LK
H06Robert Hutsebaut/New Mexico Skies2004 LB2 & 2004 LC
J95Great Shefford Obs.2004 KH17(2), 2004 LB1(3), 2004 LB2, 2004 LO2(2) & 2004 LV(2)
News briefs – panel 1/1 Major News for 13 June 2004 back top next  
News briefs

Big PHO:  MPEC 2004-L49 today announces that Reiner Stoss has located 2004 LJ1 in archive images from 3 February 1995 from the 1.2m U.K. Schmidt Telescope (DSS) at Siding Spring in Australia and 12 January 2002 from the 1.2-m Oschin Schmidt (NEAT) at Mt. Palomar in California.

2004 LJ1's absolute magnitude is now put at H=15.2 by the Minor Planet Center, but at H=14.92 by JPL, which bumps its rough size estimate up by another half kilometer. The discovery of this big PHO was announced Friday, and it was shown in the "cover" image yesterday.

Meteor news:  News of yesterday's morning couch-bashing meteor fall in Auckland, New Zealand is being widely reported. Looking among many links for something new finds a picture at ITV today showing some of the debris-covered leather couch, and another at BBC today shows the hole in the roof. And the New Zealand Herald, with an article dated tomorrow, shows a rather different photographic view of the meteorite, showing more texture. The article reports that a search of the neighborhood for more pieces has been fruitless so far, and tells about the ensuing experience for the home owners: "We called the insurance company and within a few hours the house was crawling with scientists." See more info and links yesterday.

Risk monitoring - panel 1/1 Major News for 13 June 2004 back top next  
Risk monitoring 13 June

JPL today posted 2004 LV3, which was announced today in MPEC 2004-L51 as discovered yesterday morning by LINEAR in New Mexico. It was confirmed this morning by Andrushivka Observatory in the Ukraine, and by Three Buttes and Tenagra II observatories in Arizona. JPL puts the diameter estimate at 660 meters/yards, and has the first impact solution at Christmas four years from now. This risk assessment is highly preliminary, of course, being based on an observation arc only 26 hours long, and remember that impact solutions are not predictions but rather possibilities that haven't yet been eliminated. For more about that, see "Understanding Risk Pages" by Jon Giorgini of JPL.

Summary Risk Table - sources checked at 2305 UTC, 13 Jun

Object

Assessment

Years

VI
PS
cum
PS
max
T
S
Arc 
days
 2004 LV3JPL 6/132008-210397-2.84-3.1201.084
VI = count of "virtual impactors" (impact solutions)
See A/CC's Consolidated Risk Tables for more and maybe
  newer details, and check the monitors' links for latest info.
Note that only objects recently in view are shown here.
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