24 Oct. '04 Major News about Minor Objects

Major News for 24 Oct. 2004

Small objects
Discovery & follow-up for 18-24 October 2004

Despite the brightening Moon, this was a good week for observing small asteroids (defined at right), and a great week for mining the archives. Of five asteroid discoveries announced, two were small objects. One was discovered by LINEAR and the other by an amateur online volunteer with Spacewatch's FMO Project. In both cases the only independent confirmation came from amateur astronomers in Europe remotely operating telescopes across the Atlantic over the Internet. And both objects are making close Earth flybys — 2004 UH1 at 0.8 lunar distance (LD) today and 2004 UR at 5.4 LD November 8th.

Another eight small asteroids were tracked, and two more were reported from earlier in the month. Eleven observing facilities participated in the week's work.

Spacewatch came up with prediscovery images for two recently discovered small asteroids, including one with impact solutions. The SZTE Asteroid Program in Hungary located additional positions within existing observation arcs for a small asteroid in 2001 and another in 2002. And Josep Julia Gomez found small asteroids in the SkyMorph archive, including a 2001 prediscovery and additional positions for another two objects from that year.

<< 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 pieces of distant asteroid populations, and they have within their own population tomorrow’s meteors. And their discovery and follow-up represents today’s best 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 the Sormano Observatory SAEL (H>22.0 and Earth MOID<0.015 AU), and NEODyS listings have yet another H calculation.

Small objects – panel 2/2 (table)

Major News for 24 Oct. 2004

Small object observation summary for 18-24 October 2004

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 UH1 K04U01H Aten	8 m/yd	28.21	28.1	28.1 2004-U29	0.001984 AU
2004 UH1 K04U01H Aten	NEW: 2004 UH1 was discovered on 23 Oct. by FMO Project online volunteer Stu Megan reviewing images from the Spacewatch 0.9m telescope. It was quickly confirmed the same morning with the Spacewatch 1.8m telescope and by Robert Hutsebaut in Belgium using a Rent-A-Scope telescope at New Mexico Skies (see image), and was announced in MPEC 2004-U29 of 23 Oct. It passed Earth at 0.8 lunar distances (LD) at about 1740 UT today, 24 Oct. See yesterday's “Intruder alert” and news today below.
2004 TN20 K04T20N Aten	40 m/yd	24.65	24.9	25.1 2004-U04	0.02135 AU	Urgent, visibility ends 1 Nov.
2004 TN20 K04T20N Aten	2004 TN20 was observed on 18 Oct. by LINEAR. It has an MOID of 0.024 AU with Venus.
2004 TV11 K04T11V Amor	43 m/yd	24.49	24.4	24.5 2004-T41	0.103241 AU
2004 TV11 K04T11V Amor	2004 TV11 was observed on 21 Oct. by UKAPP with Faulkes Telescope North. Six positions were reported that added 8.569 days to what had been a 3.714-day observation arc. Before being removed from the SCN Priority List after 22 Oct., 2004 TV11 was noted as going out of view on 25 Oct.
2004 TT12 K04T12T Amor	54 m/yd	23.98	24.0	24.0 2004-T54	0.128388 AU	Necessary, visibility ends 28 Nov.
2004 TT12 K04T12T Amor	2004 TT12 was reported this week as having been found in Oct. 4th images from the Spacewatch 0.9m telescope, 6.002 days before it was discovered with that telescope last week (report). It was also observed on 18 Oct. with the Spacewatch 1.8m telescope. (All observations to date have been with one of these two instruments.)
2004 TW11 K04T11W Apollo	58 m/yd	23.85	24.0	23.9 2004-T42	0.052958 AU	Useful, visibility ends 17 Nov.
2004 TW11 K04T11W Apollo	2004 TW11 was observed on 22 Oct. by Great Shefford Obs., adding 6.135 days to what had been a 6.750-day observing arc. This object has an MOID of 0.035 AU with Mars and passed Earth at 21.7 LD on 21 Oct.
2004 TC18 K04T18C Apollo	59 m/yd	23.80	24.0	24.1 2004-T73	0.028612 AU	Necessary, visibility ends 12 Nov.
2004 TC18 K04T18C Apollo	2004 TC18 was observed on 20 Oct. by LINEAR, adding 3.404 days to what had been a 4.581-day observation arc. It passed Earth at 11.5 LD on 9 Oct.
2001 MS3 K01M03S Apollo	70 m/yd	23.43	23.3	23.3 2001-M30	0.023177 AU
2001 MS3 K01M03S Apollo	2001 MS3 was reported this past week as observed on 15 June 2001 with NEAT's Mt. Palomar telescope. This was found in the SkyMorph archive by Josep Julia Gomez and adds 6.045 days to what had been a 6.969-day observing arc. (2001 MS3 was discovered by NEAT/Palomar on June 21st.)
2001 FP32 K01F32P Apollo	72 m/yd	23.36	23.4	23.4 2001-F33	0.052374 AU
2001 FP32 K01F32P Apollo	This past week four additional positions for 2001 FP32 were reported from NEAT's Haleakala telescope on 21 March 2001, subsequent to three from that telescope that day reported in the discovery MPEC. These were found by Gomez in the archive and, while not expanding the observing arc, do jump the total observations from 12 to 16 for this object, which wasn't reported observed again after its MPEC announcement with a 3.838 days of observation. 2001 FP32 was discovered by NEAT/Haleakala and has an MOID of 0.036 AU with Mars.
2001 PJ29 K01P29J Apollo	84 m/yd	23.02	23.0	22.6 2001-Q06	0.023374 AU
2001 PJ29 K01P29J Apollo	2001 PJ29 was reported this past week as observed on 16 Aug. 2001 by NEAT/Palomar, three positions found in the archive by Gomez within the existing 19.976-day observing arc. (That arc was extended by 5.114 days before discovery by NEAT/Haleakala with a single “faint” position reported from the same telescope in the DOU MPEC of 4 Jan. 2004.)
2002 RA126 K02RC6A Amor	94 m/yd	22.79	22.8	22.5 2002-R61	0.061206 AU
2002 RA126 K02RC6A Amor	2002 RA126 was reported this past week as observed on 11 Sept. 2002 by SZTE Asteroid Program, within the existing 17.073-day observation arc. It has MOIDs of 0.015 AU with Mars and 0.911 AU with Jupiter.
2004 SA20 K04S20A Apollo	102 m/yd	22.61	22.8	22.9 2004-S40	0.032913 AU
2004 SA20 K04S20A Apollo	2004 SA20 was reported this past week as observed on 8 Oct., adding 11.631 days to what had been a 5.318-day observation arc. This work was among further measurements from a 6-9 Oct. observing run by Kyle Smalley with the Whipple Obs. 1.2m telescope under a NASA NEO grant to Tim Spahr (see report). 2004 SA20 has MOIDs of 0.031 AU with Venus and 0.001 AU with Mars.
2004 UR K04U00R Apollo	104 m/yd	22.56	22.9	22.6 2004-U22	0.012398 AU
2004 UR K04U00R Apollo	NEW: 2004 UR was discovered on 20 Oct. by LINEAR, was linked to LINEAR observations from 7 and 9 Oct., and was confirmed on 21 Oct. by Gianluca Masi in Italy and his team using the Southern TIE (SoTIE) remote-controlled telescope in Chile. 2004 UR was announced in MPEC 2004-U22 of 21 Oct., and was further observed on 20 Oct. by Goodricke-Pigott Obs., on 21 Oct. by LINEAR, and on 23 Oct. by Camarillo Obs. This object has an MOID of 0.001 AU with Mars and will pass Earth at 5.4 LD at about 2324 UT on 8 Nov.
2004 TD18 K04T18D Apollo	118 m/yd	22.29	22.3	22.3 2004-T74	0.004679 AU	Necessary, vis. ends 26 Nov. / campaign
2004 TD18 K04T18D Apollo	2004 TD18 was reported this week as observed on 7 Oct. with the Spacewatch 0.9m telescope, 5.887 days before discovery with the telescope last week (report). 2004 TD18 was also observed on 17 Oct. by Farpoint Obs., on 21 and 22 Oct. by Great Shefford Obs. (see image above and at Astrometrica), and on 23 Oct. with the Spacewatch 1.8m telescope. It has an MOID of 0.014 AU with Mars, and had Earth impact solutions until 23 Oct..
2004 RE84 K04R84E Apollo	132 m/yd	22.05	22.2	22.6 2004-R55	0.01995 AU
2004 RE84 K04R84E Apollo	2004 RE84 was reported this past week as observed on 8 Oct. by Smalley with the Whipple Obs. 1.2m telescope, tacking another 5.031 days onto the previous 22.843-day observing arc. This object has an MOID of 0.029 AU with Venus.
2004 TD10 K04T10D Aten	132 m/yd	22.04	22.2	22.2 2004-T30	0.012394 AU	Necessary, visibility ends 7 Nov.
2004 TD10 K04T10D Aten	2004 TD10 was observed on 17 Oct. by Sormano Obs., and on 21 and 23 Oct. from NM Skies. It has MOIDs of 0.002 AU with Mercury and 0.003 AU with Venus, and passed Earth at 18.8 LD on 20 Oct.
2004 SS K04S00S Amor	138 m/yd	21.95	22.0	22.1 2004-S15	0.032764 AU	Useful, visibility ends 10 Dec.
2004 SS K04S00S Amor	2004 SS was observed on 17 Oct. by Farpoint Obs., adding 23.301 days to what had been a 9.745-day observation arc.
2001 YP3 K01Y03P Apollo	141 m/yd	21.91	22.0	22.1 2001-Y34	0.023174 AU
2001 YP3 K01Y03P Apollo	2001 YP3 was reported this past week as observed on 20 Dec. 2001 by the SZTE Asteroid Program, within this object's 108.559-day observing arc.

Small object observation cross index [table top]

Object	Observed by MPC code
2001 FP32	608
2001 MS3	644
2001 PJ29	644
2001 YP3	461
2002 RA126	461
2004 RE84	696
2004 SA20	696
2004 SS	734
2004 TC18	704
2004 TD10	587 & H06
2004 TD18	291, 691, 734 & J95
2004 TN20	704
2004 TT12	291 & 691
2004 TV11	F65
2004 TW11	J95
2004 UH1	291, 691 & H06
2004 UR	670, 683, 704 & I05

Code	Observatory	Objects observed (days)
291	Spacewatch 1.8m telescope	2004 TD18, 2004 TT12 & 2004 UH1
461	SZTE Asteroid Program	2001 YP3 & 2002 RA126
587	Sormano Obs.	2004 TD10
608	NEAT/Haleakala	2001 FP32
644	NEAT/Palomar	2001 MS3 & 2001 PJ29
670	Camarillo Obs.	2004 UR
683	Goodricke-Pigott Obs.	2004 UR
691	Spacewatch 0.9m telescope	2004 TD18, 2004 TT12 & 2004 UH1
696	Whipple Obs.	2004 RE84 & 2004 SA20
704	LINEAR	2004 TC18, 2004 TN20 & 2004 UR(2)
734	Farpoint Obs.	2004 SS & 2004 TD18
F65	Faulkes Telescope North / UKAPP	2004 TV11
H06	New Mexico Skies – Robert Hutsebaut – unidentified	2004 UH1 2004 TD10(2)
I05	Southern TIE / Gianluca Masi & team	2004 UR
J95	Great Shefford Obs.	2004 TD18(2) & 2004 TW11