26 Sept. '04 Major News about Minor Objects

Major News for 26 Sept. 2004

Small objects
Discovery & follow-up for 20-26 September 2004

Even with the brightening Moon, this past week has been a great one for discovering and tracking small asterids (defined at right). Discoveries of ten were announced, which is the best since March except for last week's dozen, ten more were tracked, and observations of four were reported from July. A total of 33 observing facilities participated in the week's work.

Revised 27 Sept.: Seven of the discoveries were from LINEAR in New Mexico. One came from the Siding Spring Survey in New South Wales, one was discovered with the Spacewatch 1.8m telescope in Arizona, and one was caught by FMO Project online volunteer Mariusz Kuczewski of Poland, who was reviewing images from the Spacewatch 0.9m telescope. [This report initially credited LINEAR with eight discoveries, counting one that was actually made with the Spacewatch 1.8m telescope.–Ed.]

Caught only afterward, this week's discoveries 2004 SE26 flew past the Earth at 4.9 lunar distances (LD) on the 19th, 2004 SR21 at 4.2 LD on the 20th, and 2004 ST26 came slightly inside the Earth-Moon system late on the 21st, but 2004 SY4 was picked up before it will pass at 8.4 LD next Wednesday.

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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 26 Sept. 2004

Small object observation summary for 20-26 Sept. 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 OD4 K04O04D Apollo	14 m/yd	26.93	27.0	26.7 2004-O15	0.001025 AU
2004 OD4 K04O04D Apollo	2004 OD4 was reported this past week as observed on 21 July with the Australian Natinal University (ANU) 1m telescope, adding 0.438 day to what had been a 3.911-day observation arc.
2004 SR26 K04S26R Apollo	18 m/yd	26.43	26.6	26.7 2004-S53	0.009774 AU
2004 SR26 K04S26R Apollo	NEW: 2004 SR26 was discovered on 22 Sept. by LINEAR, after having passed Earth at 4.2 LD at 1714 UT on the 20th. It was confirmed on 23 Sept. by LINEAR and Great Shefford Obs., and on 24 Sept. by Three Buttes Obs. and Sabino Canyon Obs., and was announced in MPEC 2004-S53 of 24 Sept. This object was also observed on 24 Sept. by LINEAR.
2004 ST26 K04S26T Apollo	18 m/yd	26.37	26.3	26.3 2004-S55	0.000278 AU
2004 ST26 K04S26T Apollo	NEW: 2004 ST26 was discovered on 23 Sept. by FMO Project online volunteer Mariusz Kuczewski of Poland, who was scanning images from the Spacewatch 0.9m telescope. It was confirmed on 23 Sept. with the Spacewatch 1.8m telescope and by Great Shefford Obs., and on 24 Sept. by Gianluca Masi and Franco Mallia via Southern TIE (SoTIE), the Spacewatch 1.8m telescope, Sabino Canyon Obs., Desert Moon Obs., and Robert Hutsebaut with a Rent-A-Scope telescope. It was announced in MPEC 2004-S55 of 24 Sept., and observations haven't been reported since then. Just before midnight UT on the 21st, 2004 ST26 passed the Earth at 0.956 lunar distance (LD), and just after midnight buzzed the Moon at 0.076 LD. See September 24th cover image and news. This object has an MOID of 0.008 AU with Venus.
2004 SE26 K04S26E Apollo	24 m/yd	25.75	25.8	25.8 2004-S49	0.006637 AU	Urgent, visibility ends 4 Oct.
2004 SE26 K04S26E Apollo	NEW: 2004 SE26 passed Earth at 4.9 LD at 0910 UT on Sept. 19th. It was discovered on 21 Sept. by LINEAR, was confirmed on 22 Sept. by LINEAR, and on 23 Sept. by Grasslands Obs. and Three Buttes Obs., and was announced in MPEC 2004-S49 of 23 Sept. It hasn't been reported observed since.
2004 SW26 K04S26W Aten	25 m/yd	25.67	25.7	25.7 2004-S58	0.041449 AU
2004 SW26 K04S26W Aten	NEW: 2004 SW26 was discovered on 23 Sept. with the Spacewatch 1.8m telescope, was confirmed on 24 Sept. by Great Shefford Obs., Sabino Canyon Obs., the Spacewatch 1.8m telescope, and Hutsebaut, and was announced in MPEC 2004-S58 that same day, which was also the day it flew past Earth at 16.5 LD. 2004 SW26 has an MOID of 0.027 AU with Mercury.
2004 SA1 K04S01A Apollo	31 m/yd	25.18	25.3	25.0 2004-S20	0.021245 AU	Necessary, visibility ends 3 Oct.
2004 SA1 K04S01A Apollo	2004 SA1 was observed on 21 and 22 Sept. by Great Shefford Obs., and on 21 Sept. by Farpoint Obs.
2004 SU26 K04S26U Apollo	39 m/yd	24.69	24.9	24.9 2004-S56	0.018338 AU
2004 SU26 K04S26U Apollo	NEW: 2004 SU26 passed Earth at 13.5 LD on 20 Sept., and was discovered on 23 Sept. by LINEAR. It was confirmed on 23 and 24 Sept. by Great Shefford Obs., and on 24 Sept. by Sabino Canyon Obs., and was announced in MPEC 2004-S56 of 24 Sept.
2004 NF3 K04N03F Amor	44 m/yd	24.42	24.5	24.5 2004-N40	0.057842 AU
2004 NF3 K04N03F Amor	2004 NF3 was reported this past week as observed with the ANU 1m telescope on 21 July, within the existing observation arc. This object has an MOID of 0.046 AU with Mars.
2004 SY4 K04S04Y Apollo	47 m/yd	24.27	24.3	24.3 2004-S26	0.017002 AU	Urgent, visibility ends 12 Oct.
2004 SY4 K04S04Y Apollo	NEW: 2004 SY4 was discovered on 19 Sept. by the Southern Sky Survey (SSS), was confirmed on 20 Sept. by Powell Obs., Jana Pittichova and Jim Bedient with the University of Hawaii 2.2m telescope on Mauna Kea, and by Mt. John, and Hunters Hill observatories, and was announced in MPEC 2004-S26 of 20 Sept. This object was also observed on 20 Sept. by SSS and Mt. John Obs., on 21 Sept. by Reedy Creek Obs., and on 22 Sept. by Desert Moon Obs., but not since. It will pass Earth at 8.4 LD at about 1933 UT on 29 Sept.
2004 SU55 K04S55U Amor	48 m/yd	24.23	24.3	24.3 2004-S60	0.051039 AU
2004 SU55 K04S55U Amor	NEW: 2004 SU55 was discovered on 23 Sept. by LINEAR, was confirmed on 22 Sept. by LINEAR, on 23 Sept. by Great Shefford Obs., on 24 Sept. by LINEAR, and on 25 Sept. by Pla D'Arguines Obs. and Consell Obs., and was announced in MPEC 2004-S60 of 26 Sept. It has an MOID of 0.046 AU with Mars, and will pass Earth at 21.7 LD on Oct. 1st.
2004 ST2 K04S02T Aten	51 m/yd	24.10	24.2	24.1 2004-S23	0.045809 AU	Necessary, visibility ends 8 Oct.
2004 ST2 K04S02T Aten	2004 ST2 was observed on 21 and 23 Sept. by Great Shefford Obs., and on 21 Sept. by Farpoint Obs.
2004 NU7 K04N07U Amor	55 m/yd	23.94	24.4	24.6 2004-O01	0.013776 AU
2004 NU7 K04N07U Amor	2004 NU7 was reported this past week as observed on 21 July with the ANU 1m telescope, adding 2.395 days to what had been a 5.002-day observation arc. It has an MOID of 0.027 AU with Mars.
2004 SR K04S00R Apollo	59 m/yd	23.78	23.8	23.7 2004-S14	0.025356 AU	Useful, visibility ends 29 Oct.
2004 SR K04S00R Apollo	2004 SR was observed on 18 Sept. by Beaconsfield Obs., on 19 Sept. by Mt. John Obs., on 20 Sept. by Petit Jean Mountain Obs. and McCarthy Obs., on 22 Sept. by Begues Obs. (see cover image), and on 23 Sept. by Pla D'Arguines Obs.
2004 RC11 K04R11C Apollo	69 m/yd	23.46	23.6	23.6 2004-R46	0.005008 AU	Necessary, visibility ends 23 Oct.
2004 RC11 K04R11C Apollo	2004 RC11 was observed on 21 Sept. by Farpoint Obs., adding 4.373 days to what had been a 8.679-day observation arc. It has an MOID of 0.023 AU with Mars.
2004 RO111 K04RB1O Aten	80 m/yd	23.13	23.4	23.6 2004-R74	0.023832 AU	Urgent, visibility ends 4 Oct.
2004 RO111 K04RB1O Aten	2004 RO111 was observed on 21 Sept. by Desert Moon Obs., but not since. It has an MOID of 0.035 AU with Venus, and will pass Earth at 28.3 LD on Sept. 29th.
2004 SS26 K04S26S Apollo	81 m/yd	23.10	23.1	23.2 2004-S54	0.033301 AU
2004 SS26 K04S26S Apollo	NEW: 2004 SS26 was discovered on 22 Sept. by LINEAR, was confirmed by LINEAR and Hutsebaut on Sept. 23rd (the day it passed Earth at 15.8 LD), and on 24 Sept. by Great Shefford Obs. and Sabino Canyon Obs., and was announced in MPEC 2004-S54 of 24 Sept. This object was also observed on 24 Sept. by LINEAR. It has an MOID of 0.042 AU with Mars.
2004 HB39 K04H39B Amor	98 m/yd	22.69	22.7	22.5 2004-H74	0.093468 AU
2004 HB39 K04H39B Amor	2004 HB39 was reported this past week as observed with the ANU 1m telescope on 14 and 21 July, within the existing observation arc.
2004 SC56 K04S56C Aten	100 m/yd	22.64	22.9	22.9 2004-S65	0.011185 AU
2004 SC56 K04S56C Aten	NEW: 2004 SC56 was discovered on 25 Sept. by LINEAR, was confirmed on 25 Sept. by Consell Obs., and on 26 Sept. by Farpoint Obs., LINEAR, and Sabino Canyon Obs., and was announced in MPEC 2004-S65 of 26 Sept. It will pass Earth at 13.5 LD on 4 Oct.
2004 RL251 K04RP1L Amor	102 m/yd	22.60	22.7	22.5 2004-R87	0.035564 AU	Useful, visibility ends 15 Nov.
2004 RL251 K04RP1L Amor	2004 RL251 was observed on 18 Sept. by Beaconsfield Obs., Buchloe Obs., and Lumezzane Obs., on 19 Sept. by University Hills Obs., Mt. John Obs., and Roeser Obs., on 20 Sept. by Rezman Obs., Beaconsfield Obs., and McCarthy Obs., on 21 Sept. by Beaconsfield Obs., on 22 Sept. by LINEAR and Great Shefford Obs., and on 23 Sept. by LINEAR and Pla D'Arguines Obs. It has an MOID of 0.009 AU with Mars.
2004 SA20 K04S20A Apollo	105 m/yd	22.54	22.7	22.9 2004-S40	0.032924 AU	Urgent, visibility ends 22 Oct.
2004 SA20 K04S20A Apollo	NEW: 2004 SA20 came to 18.1 LD on 17 Sept. and was discovered on 21 Sept. by LINEAR. It was confirmed on 22 Sept. by Hutsebaut and Grasslands Obs., and was announced in MPEC 2004-S40 of 22 Sept. This object was also observed on 22 Sept. by LINEAR, but hasn't been reported to have been observed since then. It has MOIDs of 0.031 AU with Venus and 0.001 AU with Mars.
2004 QA2 K04Q02A Amor	117 m/yd	22.31	22.3	22.1 2004-Q21	0.030064 AU	Necessary, visibility ends 6 Oct.
2004 QA2 K04Q02A Amor	2004 QA2 was observed on 20 Sept. by Mt. John Obs., adding 14.763 days to what had been a 16.313-day observation arc.
2004 RQ252 K04RP2Q Apollo has VIs	119 m/yd	22.28	22.3	22.3 2004-S05	0.000101 AU	Urgent, visibility ends 12 Oct.
2004 RQ252 K04RP2Q Apollo has VIs	2004 RQ252 was observed on 19 Sept. by Mt. John Obs., on 20 Sept. by Pittichova at Mauna Kea and by Hunters Hill and Mt. John observatories, as well as by Alan Fitzsimmons' team using the remote-controlled educational Faulkes Telescope North on Haleakala, on 21 Sept. by Reedy Creek Obs., and not since then. NEODyS and JPL removed all their impact solutions for 2004 RQ252 on the Sept. 20th, but NEODyS reposted it on Sept. 25th. It has an MOID of 0.045 AU with Venus.
2004 RE84 K04R84E Apollo	134 m/yd	22.01	22.2	22.6 2004-R55	0.019977 AU	Urgent, visibility ends 10 Oct.
2004 RE84 K04R84E Apollo	2004 RE84 was observed on 20 Sept. by Sandlot Obs. and Goodricke-Pigott Obs., on 21 Sept. by Farpoint Obs., on 22 Sept. by Sormano Obs. and Andrushivka Obs., and on 23 Sept. by Pla D'Arguines Obs. and Begues Obs. It has an MOID of 0.029 AU with Venus.
2004 SS K04S00S Amor	140 m/yd	21.92	22.0	22.1 2004-S15	0.032774 AU	Useful, visibility ends 10 Dec.
2004 SS K04S00S Amor	2004 SS was observed on 20 Sept. by Pittichova at Mauna Kea and by Mt. John Obs. and McCarthy observatories, on 21 Sept. by Hutsebaut, on 23 Sept. by LINEAR, and on 24 Sept. by Begues Obs.

Small object observation cross index [table top]

Object	Observed by MPC code
2004 HB39	413
2004 NF3	413
2004 NU7	413
2004 OD4	413
2004 QA2	474
2004 RC11	734
2004 RE84	170, 587, 683, 734, 941, A50 & H36
2004 RL251	130, 163, 215, 474, 704, 932, 941, A41, G72, J92 & J95
2004 RO111	448
2004 RQ252	428, 474, 568, E14 & F65
2004 SA1	734 & J95
2004 SA20	651, 704 & H06
2004 SC56	176, 704, 734 & 854
2004 SE26	651, 704 & G90
2004 SR	170, 474, 932, 941, H41 & J92
2004 SR26	704, 854, G90 & J95
2004 SS	170, 474, 568, 704, 932 & H06
2004 SS26	704, 854, H06 & J95
2004 ST2	734 & J95
2004 ST26	291, 448, 691, 854, H06, I05 & J95
2004 SU26	704, 854 & J95
2004 SU55	176, 704, 941 & J95
2004 SW26	291, 854, H06 & J95
2004 SY4	428, 448, 474, 568, 649, E12 & E14

Code	Observatory	Objects observed (days)
130	Lumezzane Obs.	2004 RL251
163	Roeser Obs.	2004 RL251
170	Begues Obs.	2004 RE84, 2004 SR & 2004 SS
176	Consell Obs.	2004 SC56 & 2004 SU55
215	Buchloe Obs.	2004 RL251
291	Spacewatch 1.8m telescope	2004 ST26(2) & 2004 SW26(2)
413	Australian Natl. Univ. (ANU) 1m telescope	2004 HB39(2), 2004 NF3, 2004 NU7 & 2004 OD4
428	Reedy Creek Obs.	2004 RQ252 & 2004 SY4
448	Desert Moon Obs.	2004 RO111, 2004 ST26 & 2004 SY4
474	Mt. John Obs.	2004 QA2, 2004 RL251, 2004 RQ252(2), 2004 SR, 2004 SS & 2004 SY4(2)
568	Mauna Kea – Jana Pittichova	2004 RQ252, 2004 SS & 2004 SY4
587	Sormano Obs.	2004 RE84
649	Powell Obs.	2004 SY4
651	Grasslands Obs.	2004 SA20 & 2004 SE26
683	Goodricke-Pigott Obs.	2004 RE84
691	Spacewatch 0.9m telescope	2004 ST26
704	LINEAR	2004 RL251(2), 2004 SA20(2), 2004 SC56(2), 2004 SE26(2), 2004 SR26(3), 2004 SS, 2004 SS26(3), 2004 SU26 & 2004 SU55(3)
734	Farpoint Obs.	2004 RC11, 2004 RE84, 2004 SA1, 2004 SC56 & 2004 ST2
854	Sabino Canyon Obs.	2004 SC56, 2004 SR26, 2004 SS26, 2004 ST26, 2004 SU26 & 2004 SW26
932	McCarthy Obs.	2004 RL251, 2004 SR & 2004 SS
941	Pla D'Arguines Obs.	2004 RE84, 2004 RL251, 2004 SR & 2004 SU55
A41	Rezman Obs.	2004 RL251
A50	Andrushivka Obs.	2004 RE84
E12	Southern Sky Survey (SSS)	2004 SY4
E14	Hunters Hill Obs.	2004 RQ252 & 2004 SY4
F65	Faulkes Telescope North – Alan Fitzsimmons' team	2004 RQ252
G72	University Hills Obs.	2004 RL251
G90	Three Buttes Obs.	2004 SE26 & 2004 SR26
H06	New Mexico Skies – Robert Hutsebaut	2004 SA20, 2004 SS, 2004 SS26, 2004 ST26 & 2004 SW26
H36	Sandlot Obs.	2004 RE84
H41	Petit Jean Mountain Obs.	2004 SR
I05	Southern TIE (SoTIE) – G. Masi & F. Mallia	2004 ST26
J92	Beaconsfield Obs.	2004 RL251(3) & 2004 SR
J95	Great Shefford Obs.	2004 RL251, 2004 SA1(2), 2004 SR26, 2004 SS26, 2004 ST2(2), 2004 ST26, 2004 SU26(2), 2004 SU55 & 2004 SW26