LIGHTCURVE PHOTOMETRY OPPORTUNITIES: 2019 JULY-SEPTEMBER

Abstract

We present lists of asteroid photometry opportunities for objects reaching a favorable apparition and have no or poorly-defined lightcurve parameters. Additional data on these objects will help with shape and spin axis modeling via lightcurve inversion. We also include lists of objects that will or might be radar targets. Lightcurves for these objects can help constrain pole solutions and/or remove rotation period ambiguities that might not come from using radar data alone.

We present several lists of asteroids that are prime targets for photometry during the period 2019 July through September.

In the first three sets of tables, “Dec” is the declination and “U” is the quality code of the lightcurve. See the asteroid lightcurve data base (LCDB; Warner et al., 2009) documentation for an explanation of the U code:

http://www.minorplanet.info/lightcurvedatabase.html

The ephemeris generator on the CALL web site allows you to create custom lists for objects reaching V ≤ 18.0 during any month in the current year, e.g., limiting the results by magnitude and declination.

http://www.minorplanet.info/PHP/call_OppLCDBQuery.php

We refer you to past articles, e.g., Minor Planet Bulletin 36, 188, for more detailed discussions about the individual lists and points of advice regarding observations for objects in each list.

Once you’ve obtained and analyzed your data, it’s important to publish your results. Papers appearing in the Minor Planet Bulletin are indexed in the Astrophysical Data System (ADS) and so can be referenced by others in subsequent papers. It’s also important to make the data available at least on a personal website or upon request. We urge you to consider submitting your raw data to the ALCDEF database. This can be accessed for uploading and downloading data at

http://www.alcdef.org

Containing almost 3.2 million observations for more than 13380 objects, we believe this to be the largest publicly available database of raw asteroid time-series lightcurve data.

Now that many backyard astronomers and small colleges have access to larger telescopes, we have expanded the photometry opportunities and spin axis lists to include asteroids reaching V = 15.5 and brighter (sometimes 15.0 when the list has more than 100 objects.

Lightcurve/Photometry Opportunities

Objects with U = 3− or 3 are excluded from this list since they will likely appear in the list for shape and spin axis modeling. Those asteroids rated U = 1 should be given higher priority over those rated U = 2 or 2+, but not necessarily over those with no period. On the other hand, do not overlook asteroids with U = 2/2+ on the assumption that the period is sufficiently established. Regardless, do not let the existing period influence your analysis since even high quality ratings have been proven wrong at times. Note that the lightcurve amplitude in the tables could be more or less than what’s given. Use the listing only as a guide.

An entry in bold italics is a near-Earth asteroid (NEA).

		Brightest				LCDB Data
Number	Name	Date		Mag	Dec	Period	Amp	U
4717	Kaneko	07	01.2	15.0	−31
3882	Johncox	07	01.9	15.1	−14
3439	Lebofsky	07	03.5	15.1	−31	5.969	0.20	2
1055	Tynka	07	04.0	13.4	−15	11.893	0.06-0.33	2
18571	1997 WQ21	07	04.7	15.1	−20
10359	1993 TU36	07	04.9	15.4	−26	2.411	0.18	2
21910	1999 VT23	07	05.1	15.1	−13	9.4	0.35	2
6419	Susono	07	07.6	14.9	−19
9849	1990 RF2	07	08.3	15.5	−20	2.608	0.12	2
18765	1999 JN17	07	10.5	15.0	−13
3761	Romanskaya	07	12.8	14.4	+6	15.32	0.34	2
3638	Davis	07	13.9	15.1	−22	8.9	0.40	2
2587	Gardner	07	14.8	15.0	−23	11.631	0.48	2
21526	Mirano	07	15.4	14.9	−1
12069	1998 FC59	07	15.8	15.3	−9
11927	Mount Kent	07	15.9	15.4	−21
23120	Paulallen	07	16.4	14.8	−21
2938	Hopi	07	18.3	14.9	−30
900	Rosalinde	07	18.7	14.2	−1	16.648	0.28-0.52	2+
12228	1985 TZ3	07	20.7	15.3	−23
3578	Carestia	07	20.8	13.7	−12	9.93	0.13	2
4420	Alandreev	07	20.8	13.6	−22
24525	2001 CS4	07	21.0	15.4	−19		0.49
9900	Llull	07	21.4	14.6	−18	183.319	0.88	2
791	Ani	07	21.5	12.6	−15	16.72	0.17-0.38	2
8263	1986 QT	07	21.7	15.4	−20
13403	Sarahmousa	07	22.6	15.3	−32
6649	Yokotatakao	07	22.7	14.5	−27
6658	Akiraabe	07	22.9	15.3	−21		0.61
2158	Tietjen	07	24.0	14.6	−18
997	Priska	07	25.0	15.0	−4	16.22	0.61	2
455432	2003 RP8	07	25.5	14.1	−24
6934	1994 YN2	07	27.0	15.4	−28
13803	1998 WU10	07	27.9	15.4	−15
7241	Kuroda	07	31.0	15.3	−22	59.6	0.61	2
5250	Jas	08	01.2	15.2	−16
24730	1991 VM5	08	02.1	15.3	−30
23297	2001 AX3	08	02.2	15.0	−7
32897	Curtharris	08	02.3	14.7	−14		0.36
9065	1993 FN1	08	02.9	15.1	−13	3.064	0.19-0.19	2
1354	Botha	08	03.1	14.3	−27	4.	0.21	1+
2096	Vaino	08	05.5	14.9	−17	3.32	0.06-0.10	2
4342	Freud	08	07.4	15.2	−17
7217	Dacke	08	07.6	14.8	−20
19158	1990 SN7	08	08.4	15.4	−26
6260	Kelsey	08	08.8	14.4	−20	5.11	0.17	2
2519	Annagerman	08	08.9	14.8	−19	12.982	0.14	2
5900	Jensen	08	09.1	15.3	−12
7820	1990 TU8	08	10.2	15.4	−20
4139	Ul'yanin	08	12.0	15.3	−15
8096	Emilezola	08	12.4	15.0	−16
835	Olivia	08	12.8	15.4	−14
4864	1988 RA5	08	12.8	15.2	−20
26851	Sarapul	08	13.3	14.9	−12
8271	Imai	08	15.4	14.7	−15
3150	Tosa	08	15.5	15.4	−30
7248	Alvsjo	08	15.6	15.3	−18
15596	2000 GZ95	08	16.7	15.5	−14	2.923	0.25-0.35	2
12518	1998 HM52	08	17.6	15.0	−25
1066	Lobelia	08	17.9	13.8	−17
10990	Okunev	08	17.9	15.3	−6
2918	Salazar	08	19.0	15.3	−14
99915	1997 TR6	08	19.6	15.2	−14
6567	Shigemasa	08	19.7	15.1	−4
3502	Huangpu	08	20.4	15.1	−15
4643	Cisneros	08	21.6	15.0	−14	5.25	0.32-0.33	2
9053	Hamamelis	08	21.7	15.5	−23	10.386	0.29-0.33	2
3302	Schliemann	08	23.7	14.8	−11
153842	2001 XT30	08	23.8	15.1	−22
306381	1993 RR2	08	23.8	14.4	−8
13050	1990 SY	08	24.0	15.2	−11
8142	Zolotov	08	25.4	15.2	−17
9061	1992 WC3	08	25.4	15.3	−22
5309	MacPherson	08	25.7	15.2	−4
5437	1990 DU3	08	25.7	15.2	−8
7752	Otauchunokai	08	25.9	15.1	−5
1136	Mercedes	08	27.0	13.1	+3	24.64	0.10-0.15	2
3568	ASCII	08	27.0	15.3	−40
52930	1998 SK127	08	27.3	15.2	−11
82676	2001 PV23	08	27.5	15.4	−20
19707	Tokunai	08	28.4	15.1	−19
1686	De Sitter	08	29.2	14.4	−10
6100	Kunitomoikkansa	08	29.3	15.3	−6	30.267	0.27	2-
1897	Hind	08	29.6	15.1	−17	2.633	0.09	2
7078	Unojonsson	08	30.6	15.1	−10
80593	2000 AG144	09	01.0	14.7	+13
2858	Carlosporter	09	01.2	14.9	−15	3.35	0.15-0.47	2
7365	Sejong	09	01.2	14.1	−8
11790	Goode	09	01.2	15.4	−12
4434	Nikulin	09	01.3	15.2	−7
4961	Timherder	09	01.3	15.3	−3
15815	1994 PY18	09	02.2	14.9	−4
7463	Oukawamine	09	03.6	14.7	−10
7534	1995 UA7	09	04.1	14.8	−17
24277	Schoch	09	04.1	15.4	−6
4268	Grebenikov	09	04.2	15.3	−10
3860	Plovdiv	09	04.8	14.6	+3	6.114	0.34-0.37	2+
2628	Kopal	09	05.2	15.5	−6
4264	Karljosephine	09	05.9	14.6	−4	30.96	0.09-0.45	2
1043	Beate	09	06.8	13.5	−7	44.3	0.47	2+
3056	INAG	09	07.0	14.7	−11
2629	Rudra	09	07.4	15.0	−5	123.171	0.58	2
2389	Dibaj	09	08.0	14.3	−3
2555	Thomas	09	08.3	15.1	−5
5857	Neglinka	09	08.9	15.5	−5
848	Inna	09	09.0	14.4	−5
4445	Jimstratton	09	09.5	15.1	−1	3.74	0.13	2
14441	1992 SJ	09	09.5	15.2	−10
5421	Ulanova	09	10.7	15.1	+1	9.814	0.60	2+
5890	Carlsberg	09	10.8	14.9	−21
2580	Smilevskia	09	11.2	13.7	−7
5391	Emmons	09	12.0	14.1	−3	3.028	0.16	2
8842	1990 KF	09	12.5	15.2	−13
7052	1988 VQ2	09	14.0	15.3	−34
4604	Stekarstrom	09	14.1	15.1	−4
3427	Szentmartoni	09	15.6	15.5	+0		0.75
467317	2000 QW7	09	15.9	14.0	−37	71.3	1.0	2
1073	Gellivara	09	16.2	15.0	−5	11.32	0.35	2
1366	Piccolo	09	16.4	13.8	−10	16.57	0.24-0.33	2
10090	Sikorsky	09	16.7	15.4	−1
707	Steina	09	17.5	13.8	+5	414.	1.00-1.00	2+
4300	Marg Edmondson	09	18.6	15.2	+2	9.328	0.12	2
13065	1991 PG11	09	18.9	15.0	−1
3340	Yinhai	09	19.1	14.7	−9
3811	Karma	09	19.6	14.5	+3	13.23	0.20-0.33	2+
7759	1990 QD2	09	19.9	15.3	−4
1725	CrAO	09	20.3	14.7	−5	21.45	0.08-0.28	2
5804	Bambinidipraga	09	20.8	15.4	+9	11.379	0.39	2
12374	Rakhat	09	20.8	15.4	−14	18.17	0.31	2
7527	Marples	09	23.2	15.2	+6
4021	Dancey	09	24.2	14.9	−5
354030	2001 RB18	09	25.5	14.6	+20
10418	1998 WZ23	09	26.2	15.3	−2
2466	Golson	09	26.3	14.3	−2
29032	2059 T-1	09	26.7	14.8	+2
1174	Marmara	09	27.0	14.8	+2	12.	0.2	2
10261	Nikdollezhal'	09	27.5	14.9	+13	16.747	0.06-0.09	2
7868	Barker	09	27.8	15.1	−3
11026	1986 RE1	09	28.4	15.1	+4
3346	Gerla	09	28.5	14.8	+3
4087	Part	09	28.6	15.1	−1	16.47	0.59	2
2226	Cunitza	09	29.4	14.9	+0
5640	Yoshino	09	30.4	15.1	+1
10720	Danzl	09	30.4	15.3	+2
29763	1999 CH20	09	30.7	15.4	+0
25632	2000 AO55	09	30.9	15.5	−7

Low Phase Angle Opportunities

The Low Phase Angle list includes asteroids that reach very low phase angles. The “α” column is the minimum solar phase angle for the asteroid. Getting accurate, calibrated measurements (usually V band) at or very near the day of opposition can provide important information for those studying the “opposition effect.” Use the on-line query form for the LCDB to get more details about a specific asteroid.

http://www.minorplanet.info/PHP/call_OppLCDBQuery.php

You will have the best chance of success working objects with low amplitude and periods that allow covering at least half a cycle every night. Objects with large amplitudes and/or long periods are much more difficult for phase angle studies since, for proper analysis, the data must be reduced to the average magnitude of the asteroid for each night. This reduction requires that you determine the period and the amplitude of the lightcurve; for long period objects that can be difficult. Refer to Harris et al. (1989; Icarus 81, 365-374) for the details of the analysis procedure.

As an aside, some use the maximum light to find the phase slope parameter (G). However, this can produce a significantly different value for both H and G versus when using average light, which is the method used for values listed by the Minor Planet Center.

The International Astronomical Union (IAU) has adopted a new system, H-G₁₂, introduced by Muinonen et al. (2010; Icarus 209, 542-555). It will be some years before H-G₁₂ becomes the standard. Furthermore, it still needs refinement. That can be done mostly by having data for more asteroids, but only if at very low and moderate phase angles. We strongly encourage obtaining data every degree between 0° to 7°, the non-linear part of the curve that is due to the opposition effect. At angles α > 7°, well-calibrated data every 2° or so out to about 25-30°, if possible, should be sufficient. Coverage beyond about 50° is not generally helpful since the H-G system is best defined with data from 0-30°.

Num	Name	Date		α	V	Dec	Period	Amp	U
323	Brucia	07	01.1	0.51	12.5	−24	9.463	0.19-0.36	3
424	Gratia	07	04.9	0.24	13.5	−24	19.47	0.32	3−
2524	Budovicium	07	10.1	0.09	14.3	−22	10.0819	0.17	3
371	Bohemia	07	10.9	0.40	11.8	−21	10.7391	0.12-0.18	3
351	Yrsa	07	11.0	0.69	13.2	−24	13.29	0.40-0.42	3
158	Koronis	07	12.1	0.12	13.1	−22	14.218	0.28-0.43	3
367	Amicitia	07	12.2	0.95	13.5	−24	5.0554	0.25-0.90	3
1171	Rusthawelia	07	13.5	0.27	14.5	−21	10.98	0.26-0.31	3
379	Huenna	07	15.1	0.83	12.5	−19	14.141	0.07-0.12	3
657	Gunlod	07	18.1	0.29	14.3	−22	15.6652	0.19-0.20	3
149	Medusa	07	20.4	0.55	13.0	−20	26.023	0.33-0.56	3
4420	Alandreev	07	20.8	0.77	13.5	−22
440	Theodora	07	23.2	0.20	14.3	−20	4.828	0.43-0.72	3
570	Kythera	07	23.4	0.77	13.4	−18	8.120	0.12-0.20	2
1162	Larissa	07	23.8	0.71	14.5	−23	6.516	0.12-0.20	3
1127	Mimi	07	29.3	0.48	14.1	−18	12.749	0.72-0.95	3
142	Polana	07	29.4	0.45	12.8	−18	9.764	0.11-0.21	3
1271	Isergina	07	29.7	0.13	14.4	−19	7.5993	0.25-0.36	3−
383	Janina	07	30.1	0.67	14.3	−21	6.4	0.06-0.17	3
206	Hersilia	08	01.8	0.59	12.3	−16	11.122	0.13-0.20	3
180	Garumna	08	02.9	0.08	14.5	−18	23.866	0.27-0.6	3
1727	Mette	08	06.6	0.35	14.1	−17	2.9811	0.19-0.38	3
16	Psyche	08	07.2	0.51	9.3	−15	4.196	0.03-0.34	3
181	Eucharis	08	09.6	0.89	12.8	−13	52.23	0.04-0.15	3
1641	Tana	08	18.0	0.68	13.9	−15	7.95	0.32-0.33	3−
723	Hammonia	08	20.2	0.74	13.9	−11	5.436	0.08-0.18	3
1467	Mashona	08	20.4	0.17	12.4	−12	9.76	0.24-0.31	3
203	Pompeja	08	22.9	0.61	12.2	−13	24.052	0.10	3
1686	De Sitter	08	29.2	0.21	14.5	−10
333	Badenia	08	30.6	0.63	12.9	−11	9.862	0.20-0.33	3
243	Ida	09	01.0	0.15	13.6	−08	4.634	0.45-0.86	3
7365	Sejong	09	01.2	0.48	14.2	−08
317	Roxane	09	02.6	0.30	11.9	−08	8.169	0.61-0.75	3
1128	Astrid	09	03.1	0.60	14.3	−09	10.228	0.13-0.35	2+
135	Hertha	09	06.2	0.15	9.6	−07	8.403	0.12-0.30	3
190	Ismene	09	06.5	0.44	13.1	−05	6.52	0.10-0.16	3
1043	Beate	09	06.8	0.36	13.5	−07	44.3	0.47	2+
268	Adorea	09	08.6	0.70	13.1	−08	7.80	0.15-0.20	3
848	Inna	09	09.0	0.44	14.4	−05
232	Russia	09	09.3	0.80	14.0	−07	21.905	0.14-0.31	3
624	Hektor	09	11.0	0.37	14.1	−03	6.924	0.10-1.10	3
5391	Emmons	09	12.1	0.73	14.2	−03	3.028	0.16	2
150	Nuwa	09	15.8	0.76	11.5	−01	8.1347	0.08-0.31	3
1494	Savo	09	16.8	0.99	13.7	−01	5.3501	0.38-0.63	3
748	Simeisa	09	17.1	0.81	14.3	+00	11.919	0.22-0.36	2
2006	Polonskaya	09	22.2	0.26	14.3	−01	3.1183	0.08-0.16	3
711	Marmulla	09	22.9	0.26	13.2	+00	2.721	0.03-0.18	3
247	Eukrate	09	23.1	0.23	10.4	−01	12.093	0.10-0.18	3
422	Berolina	09	24.5	0.96	11.6	−01	25.978	0.06-0.16	3
104	Klymene	09	25.6	0.94	12.2	−02	8.984	0.2 −0.3	3
1645	Waterfield	09	28.8	0.59	14.5	+03	4.861	0.18-0.20	3
611	Valeria	09	30.0	0.40	12.9	+04	6.977	0.08-0.16	3

Shape/Spin Modeling Opportunities

Those doing work for modeling should contact Josef Ďurech at the email address above. If looking to add lightcurves for objects with existing models, visit the Database of Asteroid Models from Inversion Techniques (DAMIT) web site

http://astro.troja.mff.cuni.cz/projects/asteroids3D

An additional dense lightcurve, along with sparse data, could lead to the asteroid being added to or improving one in DAMIT, thus increasing the total number of asteroids with spin axis and shape models.

Included in the list below are objects that:

1. Are rated U = 3− or 3 in the LCDB

2. Do not have reported pole in the LCDB Summary table

3. Have at least three entries in the Details table of the LCDB where the lightcurve is rated U ≥ 2.

The caveat for condition #3 is that no check was made to see if the lightcurves are from the same apparition or if the phase angle bisector longitudes differ significantly from the upcoming apparition. The last check is often not possible because the LCDB does not list the approximate date of observations for all details records. Including that information is an on-going project.

Favorable apparitions are in bold text. NEAs are in italics.

		Brightest				LCDB Data
Num	Name	Date		Mag	Dec	Period	Amp	U
323	Brucia	07	01.2	12.5	−24	9.463	0.19-0.36	3
713	Luscinia	07	02.0	13.6	−10	9.9143	0.09-0.40	3
428	Monachia	07	04.5	14.9	−34	3.6338	0.18-0.34	3
4375	Kiyomori	07	07.6	15.5	−17	6.4709	0.15-0.16	3
266	Aline	07	09.7	12.8	−6	13.018	0.05-0.10	3
3682	Welther	07	10.3	14.7	−10	3.5973	0.21-0.37	3
1694	Kaiser	07	12.1	14.2	−43	13.02	0.14-0.32	3
1171	Rusthawelia	07	13.5	14.5	−21	10.98	0.26-0.31	3
869	Mellena	07	14.0	14.1	−12	6.5155	0.20-0.27	3
1675	Simonida	07	14.8	15.0	−33	5.2885	0.16-0.65	3
947	Monterosa	07	16.1	13.3	−31	5.164	0.15-0.23	3−
3879	Machar	07	16.4	14.9	−31	4.131	0.19-0.23	3
657	Gunlod	07	18.0	14.3	−22	15.6652	0.19-0.20	3
214088	2004 JN13	07	21.4	13.9	−59	6.342	0.17-0.40	3
754	Malabar	07	23.8	14.0	+10	11.74	0.19-0.38	3
1777	Gehrels	07	26.2	14.9	−22	2.8355	0.21-0.27	3
1520	Imatra	07	26.6	14.6	−2	18.635	0.27-0.35	3−
618	Elfriede	07	28.3	12.3	−25	14.791	0.11-0.17	3
373	Melusina	07	29.4	13.2	−39	12.97	0.20-0.25	3
206	Hersilia	08	01.8	12.3	−16	11.122	0.13-0.20	3
1115	Sabauda	08	03.8	14.9	−35	6.718	0.16-0.27	3
1727	Mette	08	06.6	14.0	−17	2.9811	0.19-0.38	3
298	Baptistina	08	06.9	14.2	−25	16.23	0.10-0.25	3
654	Zelinda	08	07.5	12.4	+9	31.735	0.08- 0.3	3
635	Vundtia	08	07.8	13.5	−5	11.79	0.15-0.27	3
255	Oppavia	08	08.3	14.5	−28	19.499	0.14-0.16	3
252	Clementina	08	11.8	14.0	−3	10.864	0.32-0.44	3
2131	Mayall	08	12.9	14.1	+17	2.5678	0.05-0.09	3
235	Carolina	08	14.9	12.7	−27	17.61	0.25-0.38	3
1342	Brabantia	08	15.0	14.7	−8	4.1754	0.17-0.21	3
971	Alsatia	08	17.3	14.2	−31	9.614	0.17-0.29	3
289	Nenetta	08	19.4	12.5	−7	6.902	0.18-0.19	3
970	Primula	08	19.4	14.6	−11	2.777	0.16-0.30	3
3028	Zhangguoxi	08	20.8	15.0	−3	4.826	0.12-0.25	3
975	Perseverantia	08	22.0	14.3	−16	7.267	0.17-0.23	3
911	Agamemnon	08	24.1	14.8	−15	6.592	0.04-0.29	3
1509	Esclangona	08	25.5	15.0	+25	3.2528	0.11-0.35	3
348	May	08	28.7	13.8	−22	7.3812	0.14-0.16	3
504	Cora	08	28.8	12.6	−27	7.588	0.15- 0.4	3−
333	Badenia	08	30.7	12.9	−11	9.862	0.20-0.33	3
66146	1998 TU3	08	31.8	11.9	−85	2.375	0.07-0.15	3
305	Gordonia	08	31.9	13.5	−4	12.893	0.10-0.23	3
472	Roma	09	01.9	12.2	−21	9.8007	0.27-0.46	3
3870	Mayre	09	02.1	15.0	+6	3.9915	0.44-0.45	3
759	Vinifera	09	04.3	13.1	+10	14.229	0.36-0.40	3
380	Fiducia	09	04.9	12.4	−16	13.69	0.04-0.32	3
143	Adria	09	05.2	12.9	−4	22.005	0.07-0.10	3
232	Russia	09	09.2	14.0	−7	21.905	0.14-0.31	3
4224	Susa	09	11.3	14.5	+5	6.178	0.21-0.27	3−
2486	Metsahovi	09	17.5	15.0	−4	4.4518	0.04-0.13	3
3948	Bohr	09	17.9	14.7	−1	24.884	0.2-0.90	3
240	Vanadis	09	19.9	11.6	−5	10.64	0.08-0.34	3
3332	Raksha	09	20.5	14.8	−16	4.8065	0.25-0.36	3
275	Sapientia	09	22.1	13.3	−5	14.931	0.05-0.12	3−
2006	Polonskaya	09	22.2	14.2	−1	3.1183	0.08-0.16	3
592	Bathseba	09	22.6	13.2	−3	7.7465	0.22-0.32	3
888	Parysatis	09	29.1	12.7	−18	5.9314	0.22-0.26	3
483	Seppina	09	29.2	12.9	−3	12.727	0.14-0.29	3
611	Valeria	09	30.1	12.9	+4	6.977	0.08-0.16	3

Radar-Optical Opportunities

Past radar targets:

http://echo.jpl.nasa.gov/~lance/radar.nea.periods.html

Arecibo targets:

http://www.naic.edu/~pradar

http://www.naic.edu/~pradar/ephemfuture.txt

Goldstone targets:

http://echo.jpl.nasa.gov/asteroids/goldstone_asteroid_schedule.html

These are based on known targets at the time the list was prepared. It is very common for newly discovered objects to move up the list and become radar targets on short notice. We recommend that you keep up with the latest discoveries the Minor Planet Center observing tools

In particular, monitor NEAs and be flexible with your observing program. In some cases, you may have only 1-3 days when the asteroid is within reach of your equipment. Be sure to keep in touch with the radar team (through Dr. Benner’s email or their Facebook or Twitter accounts) if you get data. The team may not always be observing the target but your initial results may change their plans. In all cases, your efforts are greatly appreciated.

Use the ephemerides below as a guide to your best chances for observing, but remember that photometry may be possible before and/or after the ephemerides given below. Note that geocentric positions are given. Use these web sites to generate updated and topocentric positions:

MPC: http://www.minorplanetcenter.net/iau/MPEph/MPEph.html

JPL: http://ssd.jpl.nasa.gov/?horizons

In the ephemerides below, ED and SD are, respectively, the Earth and Sun distances (AU), V is the estimated Johnson V magnitude, and α is the phase angle. SE and ME are the great circles distances (in degrees) of the Sun and Moon from the asteroid. MP is the lunar phase and GB is the galactic latitude. “PHA” indicates that the object is a “potentially hazardous asteroid”, meaning that at some (long distant) time, its orbit might take it very close to Earth.

About YORP Acceleration

Many, if not all, of the targets in this section are near-Earth asteroids. These objects are particularly sensitive to YORP acceleration. YORP (Yarkovsky–O'Keefe–Radzievskii–Paddack) is the asymmetric thermal re-radiation of sunlight that can cause an asteroid’s rotation period to increase or decrease. High precision lightcurves at multiple apparitions can be used to model the asteroid’s sidereal rotation period and see if it’s changing.

It usually takes four apparitions to have sufficient data to determine if the asteroid rotation rate is changing under the influence of YORP. This is why observing asteroids that already have well-known periods is still a valuable use of telescope time. It is even more so when considering the BYORP (binary-YORP) effect among binary asteroids that has stabilized the spin so that acceleration of the primary body is not the same as if it would be if there were no satellite.

To help focus efforts in YORP detection, Table I gives a quick summary of this quarter’s radar-optical targets. The family or group for the asteroid is given under the number name. Also under the name will be additional flags such as “PHA” for Potentially Hazardous Asteroid, NPAR for a tumbler, and/or “BIN” to indicate the asteroid is a binary (or multiple) system. “BIN?” means that the asteroid is a suspected but not confirmed binary. The period is in hours and, in the case of binary, for the primary. The Amp column gives the known range of lightcurve amplitudes. The App columns gives the number of different apparitions at which a lightcurve period was reported while the Last column gives the year for the last reported period. The R SNR column indicates the estimated radar SNR using the tool at

Table I.

Summary of radar-optical opportunities for the current quarter. Period and amplitude data are from the asteroid lightcurve database (Warner et al., 2009; Icarus 202, 134-146). SNR values are estimates that are affected by power output of the radar along with rotation period, size, and distance. They are given for relative comparisons among the objects in the list.

Asteroid	Period	Amp	App	Last	R	SNR
(418900) 2009 BE2	-	-	-	-	A	35
NEA					G	-
(494999) 2010 JU39	-	-	-	-	A	110
NEA PHA					G	35
(441987) 2010 NY65	5.541	0.16	3	2018	A	2340
NEA		0.24			G	780
(11500) Tomaiyowit NEA	73	0.5	1	1998	A	10
(90403) 2003 YE45	500	0.81	1	2019	A	180
NEA					G	60
(293054) 2006 WP127 NEA	5.311	0.35	1	2015	A	40
(455432) 2003 RP8 NEA	-	-	-	-	A	13
(66146) 1998 TU3	2.375	0.07	6	2017	A	25
NEA		0.15			G	25
(237805) 2002 CF26	3.776	0.99	1	2017	A	60
NEA					G	20
(141593) 2002 HK12	12.690	1.5	1	2002	A	470
NEA					G	160
(1620) Geographos	5.222	0.95	4	2019	G	25
NEA		2.03
(504800) 2010 CO1	-	-	-	-	A	15
NEA					G	25
(467317) 2000 QW7	71.3	1.0	1	2000	A	2950
NEA					G	990
(2100) Ra-Shalom	19.797	0.30	4	2016	A	35
NEA		0.55			G	12
(354030) 2001 RB18	-	-	-	-	A	40
NEA					G	15
(297418) 2000 SP43	-	-	-	-	G	47
NEA
1996 TC1	-	-	-	-	A	2870
NEA					G	960

http://www.naic.edu/~eriverav/scripts/index.php

The “A” is for Arecibo; “G” is for Goldstone. The calculator SNRs for Arecibo are based on a reduced power of 600 kW.

The SNRs were calculated using the current MPCORB absolute magnitude (H), a period of 4 hours (2 hours if D ≤ 200 m) if it’s not known, and the approximate minimum Earth distance during the current quarter.

If the SNR value is in bold text, the object was found on the radar planning pages listed above. Otherwise, the planning tool at

http://www.minorplanet.info/PHP/call_OppLCDBQuery.php

was used to find known NEAs that were V < 18.0 during the quarter. An object is usually placed on the list only if the estimated Arecibo SNR > 10 when using the SNR calculator mentioned above.

(418900) 2009 BE2 (H = 19.2)

The estimated size is 430 m for the asteroid with no reported rotation period. Because of its size, the period is likely P > 2.2 h.

DATE	RA		Dec		ED	SD	V	α	SE	ME	MP	GB
06/20	14	04.0	+31	07	0.12	1.05	17.1	70.9	103	101	−0.93	+74
06/23	14	12.7	+18	47	0.11	1.06	16.8	65.1	109	127	−0.72	+70
06/26	14	21.6	+04	41	0.10	1.07	16.5	58.8	116	156	−0.44	+59
06/29	14	30.9	−09	40	0.11	1.08	16.4	53.6	122	170	−0.17	+46
07/02	14	40.5	−22	35	0.11	1.09	16.5	50.2	125	135	−0.01	+34
07/05	14	50.7	−33	09	0.13	1.10	16.8	48.6	126	98	+0.07	+23
07/08	15	01.4	−41	22	0.15	1.11	17.0	48.0	126	64	+0.34	+15
07/11	15	12.6	−47	39	0.17	1.12	17.3	47.8	125	39	+0.67	+9
07/14	15	24.4	−52	26	0.19	1.13	17.6	47.8	124	38	+0.92	+4
07/17	15	36.8	−56	06	0.21	1.15	17.9	47.8	123	57	−1.00	+0

(494999) 2010 JU39 (H = 19.6)

There is no reported period for this 360-m NEA. Note that most of the positions are actually in the previous quarter (June) since the asteroid makes a very brief appearance at acceptable phase angles and solar elongations. The radar team will need photometry and astrometry.

DATE	RA		Dec		ED	SD	V	α	SE	ME	MP	GB
06/20	18	11.5	+24	24	0.12	1.10	17.0	43.2	132	53	−0.93	+19
06/21	17	58.0	+24	27	0.11	1.10	16.8	43.5	132	62	−0.87	+22
06/22	17	41.6	+24	24	0.10	1.09	16.5	44.0	132	72	−0.80	+26
06/23	17	21.7	+24	10	0.09	1.08	16.3	45.0	131	85	−0.72	+30
06/24	16	57.4	+23	38	0.08	1.07	16.1	46.7	130	99	−0.63	+35
06/25	16	27.9	+22	39	0.08	1.06	16.0	49.4	127	114	−0.54	+41
06/26	15	52.5	+20	57	0.07	1.06	15.9	53.4	123	130	−0.44	+48
06/27	15	11.5	+18	21	0.06	1.05	15.8	59.2	118	147	−0.35	+57
06/28	14	26.8	+14	45	0.06	1.04	15.9	66.4	110	157	−0.25	+65
06/29	13	41.3	+10	23	0.06	1.03	16.2	74.7	102	148	−0.17	+70
06/30	12	58.4	+05	46	0.06	1.02	16.5	83.1	93	130	−0.10	+69

(441987) 2010 NY65 (H = 21.5)

This 150-meter NEA is going to “light up” both Arecibo and Goldstone, assuming – as always – that they are operational and at full power. This is a potentially hazardous asteroid (PHA) and also a good candidate for measuring the Yarkovsky effect on the asteroid. This is a thermal force that leads to the size of the orbit decreasing (retrograde rotation) or increasing (prograde rotation).

DATE	RA		Dec		ED	SD	V	α	SE	ME	MP	GB
06/27	15	21.1	+45	19	0.03	1.02	16.3	78.4	100	125	−0.35	+55
06/28	15	55.9	+37	17	0.03	1.03	16.4	68.4	110	129	−0.25	+50
06/29	16	15.9	+31	21	0.04	1.03	16.6	61.4	117	133	−0.17	+46
06/30	16	28.7	+26	59	0.04	1.04	16.8	56.5	121	136	−0.10	+42
07/01	16	37.6	+23	42	0.05	1.05	17.0	52.9	125	136	−0.04	+39
07/02	16	44.2	+21	09	0.06	1.05	17.2	50.2	127	134	−0.01	+37
07/03	16	49.2	+19	07	0.06	1.06	17.4	48.2	129	128	+0.00	+35
07/04	16	53.2	+17	28	0.07	1.06	17.6	46.6	131	120	+0.02	+34
07/05	16	56.4	+16	05	0.08	1.07	17.8	45.3	132	110	+0.07	+33
07/06	16	59.2	+14	55	0.08	1.08	18.0	44.3	132	99	+0.14	+31

(11500) Tomaiyowit (H = 12.6)

This asteroid will barley be within reach of the Arecibo radar, but it is still worth photometric efforts. Note that the period is almost three Earth days. This calls for a coordinated campaign involving observers at well-separated longitudes.

DATE	RA		Dec		ED	SD	V	α	SE	ME	MP	GB
06/30	13	17.7	+25	09	0.20	1.04	17.7	79.1	90	122	−0.10	+84
07/03	13	46.7	+23	06	0.21	1.05	17.7	74.4	94	92	+0.00	+77
07/06	14	12.0	+20	58	0.23	1.07	17.7	70.1	98	59	+0.14	+71
07/09	14	33.9	+18	52	0.24	1.09	17.8	66.5	101	32	+0.45	+65
07/12	14	52.9	+16	51	0.26	1.11	17.9	63.4	103	32	+0.77	+60
07/15	15	09.6	+14	57	0.28	1.12	18.0	60.8	105	56	+0.96	+56
07/18	15	24.3	+13	11	0.30	1.14	18.1	58.5	107	85	−0.99	+52
07/21	15	37.5	+11	32	0.32	1.16	18.2	56.6	108	113	−0.85	+48
07/24	15	49.3	+10	00	0.34	1.17	18.3	55.0	109	140	−0.60	+45
07/27	16	00.1	+08	34	0.36	1.19	18.4	53.7	110	156	−0.31	+42

(90403) 2003 YE45 (H = 17.6)

By the smallest of margins, this asteroid was actually brighter back in January. However, NEAs can have more than one opposition and close approach in a given year. On this second time around, it offers a prolonged period where it is within reach of many backyard telescopes, if they are well north of the equator.

The period is believed to be on the order of 500 hours (almost three Earth weeks). That’s hardly the record, but it this does call for another prolonged, coordinated observing campaign involving several, well-separated observers. It will also require careful calibration of the data so that all observing runs have essentially the same zero point.

The long period also makes this a very likely candidate for tumbling and so makes the needed for tightly-calibrated data even more essential.

DATE	RA		Dec		ED	SD	V	α	SE	ME	MP	GB
07/15	00	29.8	+36	39	0.17	1.03	16.6	81.3	89	108	+0.96	−26
07/22	23	48.2	+44	10	0.19	1.06	16.7	72.2	97	51	−0.78	−17
07/29	23	08.1	+48	47	0.22	1.09	16.8	64.9	104	78	−0.13	−11
08/05	22	30.8	+51	06	0.25	1.12	17.0	59.0	109	121	+0.21	−6
08/12	21	58.1	+51	41	0.28	1.15	17.1	54.2	113	85	+0.89	−3
08/19	21	31.6	+50	59	0.31	1.18	17.3	50.3	116	65	−0.89	+0
08/26	21	11.5	+49	24	0.35	1.21	17.5	47.2	118	98	−0.26	+1
09/02	20	57.7	+47	11	0.38	1.25	17.7	44.6	120	110	+0.10	+1
09/09	20	49.5	+44	36	0.42	1.27	17.9	42.6	121	70	+0.78	+0
09/16	20	46.0	+41	51	0.46	1.30	18.1	41.2	121	69	−0.97	−1

(293054) 2006 WP127 (H = 18.3)

Mid-July provides the best observing opportunities, if considering only the galactic latitude. The estimated diameter is 650 meters. The period is known to be about 5.3 hours, but that needs confirmation and/or refinement.

DATE	RA		Dec		ED	SD	V	α	SE	ME	MP	GB
07/10	13	44.6	+80	49	0.11	0.98	17.3	105.1	69	85	+0.57	+36
07/13	17	53.7	+65	34	0.10	1.02	16.3	83.6	91	85	+0.85	+30
07/16	18	38.6	+45	42	0.11	1.06	15.9	63.0	111	68	+0.99	+21
07/19	18	55.2	+30	03	0.13	1.10	15.9	47.3	127	61	−0.96	+12
07/22	19	03.9	+19	05	0.16	1.14	16.1	36.7	138	75	−0.78	+6
07/25	19	09.3	+11	27	0.19	1.18	16.4	29.8	145	102	−0.51	+1
07/28	19	13.1	+06	00	0.23	1.22	16.7	25.5	149	134	−0.21	−2
07/31	19	16.1	+01	57	0.26	1.25	17.0	23.0	151	156	−0.02	−5
08/03	19	18.7	−01	08	0.30	1.29	17.3	21.6	152	129	+0.05	−7
08/06	19	21.0	−03	35	0.35	1.33	17.6	21.1	152	89	+0.31	−8
08/09	19	23.1	−05	32	0.39	1.37	18.0	21.1	151	50	+0.64	−10
08/12	19	25.2	−07	09	0.43	1.40	18.3	21.4	150	18	+0.89	−11
08/15	19	27.3	−08	29	0.48	1.44	18.5	21.9	148	29	+1.00	−12
08/18	19	29.5	−09	37	0.52	1.47	18.8	22.5	146	61	−0.94	−13

(455432) 2003 RP8 (H = 18.2)

There’s no rotation period in the asteroid lightcurve database (LCDB) for this 680-meter NEA. The size virtually assures that the rotation period is going to be P > 2 hours. Southern Hemisphere observers are decidedly favored this time around.

DATE	RA		Dec		ED	SD	V	α	SE	ME	MP	GB
07/01	22	41.5	−70	29	0.29	1.19	17.6	46.8	121	110	−0.04	−43
07/06	22	13.5	−68	07	0.24	1.17	17.2	44.6	126	127	+0.14	−43
07/11	21	37.8	−63	50	0.20	1.16	16.6	40.4	132	89	+0.67	−42
07/16	20	57.8	−55	59	0.16	1.14	15.8	32.7	143	40	+0.99	−40
07/21	20	18.4	−41	47	0.12	1.13	14.9	19.3	158	48	−0.85	−33
07/26	19	43.8	−19	22	0.11	1.12	14.1	7.5	172	109	−0.41	−20
07/31	19	15.9	+05	42	0.11	1.11	14.9	28.6	148	152	−0.02	−3
08/05	18	54.6	+24	25	0.14	1.11	15.9	45.8	129	94	+0.21	+10
08/10	18	39.1	+35	56	0.17	1.10	16.6	55.7	116	61	+0.74	+18
08/15	18	28.2	+42	58	0.21	1.10	17.2	61.0	108	73	+1.00	+22

(66146) 1998 TU3 (H = 14.5)

If looking at Table I, it may seem strange that the estimated SNR is the same for Arecibo and Goldstone. The reason is that the asteroid is significantly farther away during the time it can be observed by Arecibo, which has a more restricted declination range of about −1° to +38°.

Closest approach is actually in late August, but the viewing geometry doesn’t allow visual observations until a few days later. Note that the ephemeris goes into the fourth quarter (October) and that the interval is four days.

DATE	RA		Dec		ED	SD	V	α	SE	ME	MP	GB
09/01	20	27.8	−85	21	0.09	1.03	11.9	72.7	102	97	+0.04	−29
09/05	20	29.2	−71	38	0.11	1.05	12.0	62.8	112	69	+0.38	−33
09/09	20	30.7	−62	13	0.13	1.07	12.3	57.2	116	41	+0.78	−35
09/13	20	32.6	−55	34	0.16	1.09	12.6	54.3	118	50	+0.99	−36
09/17	20	34.9	−50	39	0.18	1.11	13.0	52.9	119	85	−0.93	−37
09/21	20	37.6	−46	52	0.21	1.12	13.3	52.5	118	127	−0.62	−37
09/25	20	40.6	−43	49	0.24	1.13	13.6	52.5	117	156	−0.20	−38
09/29	20	44.1	−41	16	0.27	1.14	13.9	52.8	115	114	+0.00	−38
10/03	20	47.9	−39	06	0.30	1.15	14.1	53.3	113	60	+0.23	−39
10/07	20	52.0	−37	12	0.33	1.16	14.4	53.9	111	19	+0.63	−39

(237805) 2002 CF26 (H = 17.4)

The ephemeris interval is 7 days for this 980-meter NEA and so it covers just more than two months. The period is P ~ 3.77 h. The phase angle is always relatively large, which could make for some interesting lightcurve shapes due to shadowing; a bimodal lightcurve cannot always be guaranteed under such circumstances.

The phase angle bisector longitude swings from 335° to 0° and then up to 35° during the ephemeris interval. The latitude changes by more than 90° over the same time.

DATE	RA		Dec		ED	SD	V	α	SE	ME	MP	GB
08/01	02	03.3	−45	47	0.42	1.22	17.8	51.5	110	110	+0.00	−67
08/08	02	02.4	−42	59	0.34	1.19	17.4	51.4	113	122	+0.53	−69
08/15	01	55.7	−38	37	0.27	1.16	16.7	50.0	118	63	+1.00	−72
08/22	01	40.1	−30	45	0.20	1.14	15.9	45.6	127	43	−0.66	−79
08/29	01	08.7	−14	14	0.13	1.12	14.7	35.2	140	123	−0.03	−76
09/05	00	08.0	+19	21	0.10	1.10	13.9	29.4	148	128	+0.38	−42
09/12	22	23.8	+51	41	0.13	1.08	15.0	51.6	123	68	+0.96	−5
09/19	20	24.1	+62	58	0.18	1.07	16.2	65.0	105	83	−0.80	+14
09/26	19	01.7	+64	48	0.25	1.06	17.0	69.9	96	93	−0.11	+23
10/03	18	15.7	+64	27	0.32	1.06	17.5	71.1	91	86	+0.23	+28

(141593) 2002 HK12 (H = 18.1)

The rotation period for 2002 HK12 is P ~ 12.7 hours. A single station can eventually cover the entire lightcurve but two observers at well-separated longitudes could make much quicker work of completing the lightcurve. The estimated diameter is 710 meters. The combination of a closest approach of 0.062 AU, the diameter, and period should make this a bright radar target.

DATE	RA		Dec		ED	SD	V	α	SE	ME	MP	GB
09/05	04	17.1	+35	45	0.11	1.02	16.2	80.6	93	159	+0.38	−11
09/12	03	41.0	+33	31	0.14	1.06	16.2	65.3	107	96	+0.96	−17
09/19	03	15.3	+31	27	0.17	1.10	16.3	52.6	120	18	−0.80	−22
09/26	02	54.3	+29	26	0.20	1.14	16.5	41.2	131	93	−0.11	−26
10/03	02	36.0	+27	23	0.23	1.19	16.6	30.9	142	154	+0.23	−30
10/10	02	20.0	+25	19	0.26	1.24	16.7	21.5	153	68	+0.87	−33
10/17	02	06.6	+23	18	0.30	1.29	16.8	13.4	163	25	−0.91	−36
10/24	01	55.8	+21	26	0.35	1.34	17.0	7.4	170	117	−0.23	−39
10/31	01	47.9	+19	48	0.41	1.39	17.4	6.7	171	136	+0.11	−41
11/07	01	42.7	+18	26	0.47	1.45	17.9	10.4	165	49	+0.74	−43

(1620) Geographos (H = 15.6)

Based on diameter, rotation period, and minimum distance, this NEA would normally be a good target for Arecibo. However, it will move too far away before it gets into the behemoth radar’s field of view. The period is well known (P ~ 5.22204 h), but data from each new apparition helps refine the amount that YORP is increasing the asteroid’s rotation rate (decreasing the period), which has been given as (1.5±0.2)^10⁻³ rad yr⁻² (Durech et al., 2008; AA 489, L25-L28).

DATE	RA		Dec		ED	SD	V	α	SE	ME	MP	GB
09/10	18	29.0	−20	46	0.16	1.07	14.0	62.0	110	25	+0.85	−5
09/13	18	57.1	−16	34	0.17	1.09	14.1	57.7	114	54	+0.99	−9
09/16	19	20.2	−12	53	0.19	1.10	14.2	54.3	117	84	−0.97	−12
09/19	19	39.4	−09	45	0.21	1.12	14.4	51.7	119	114	−0.80	−15
09/22	19	55.5	−07	06	0.23	1.14	14.6	49.7	120	146	−0.51	−17
09/25	20	09.4	−04	52	0.25	1.15	14.7	48.2	121	162	−0.20	−20
09/28	20	21.5	−02	59	0.28	1.17	14.9	47.1	121	129	−0.01	−21
10/01	20	32.3	−01	23	0.30	1.19	15.1	46.2	121	90	+0.08	−23
10/04	20	42.1	−00	01	0.33	1.20	15.3	45.5	121	54	+0.33	−24
10/07	20	51.1	+01	10	0.35	1.22	15.5	44.9	121	26	+0.63	−26

(504800) 2010 CO1 (H = 21.8)

The estimated diameter of this NEA is 130 meters. That makes it a good candidate for being a super-fast rotator (P < 2 h). If for no other reason that this, use the minimum exposure time that allows a useful SNR, at least until a good estimate of the rotation period has been made. Keep in mind that exposures must be less than 0.187P to avoid “rotational smearing” (Pravec et al., 2000; Icarus 147, 477-486).

DATE	RA		Dec		ED	SD	V	α	SE	ME	MP	GB
09/10	10	39.5	−81	41	0.05	1.01	18.5	90.1	87	76	+0.85	−20
09/12	18	40.3	−78	18	0.04	1.01	17.6	79.3	99	66	+0.96	−26
09/14	19	50.0	−54	29	0.04	1.02	16.9	64.9	113	63	−1.00	−30
09/16	20	06.7	−29	19	0.04	1.03	16.8	53.6	125	74	−0.97	−28
09/18	20	14.3	−10	46	0.05	1.04	17.1	49.6	128	94	−0.87	−23
09/20	20	18.9	+01	05	0.06	1.04	17.6	49.5	128	114	−0.71	−19
09/22	20	22.0	+08	39	0.07	1.05	18.1	50.4	126	131	−0.51	−16
09/24	20	24.6	+13	45	0.09	1.06	18.6	51.3	125	143	−0.30	−14
09/26	20	26.7	+17	20	0.10	1.06	19.0	52.2	123	141	−0.11	−12
09/28	20	28.7	+19	59	0.12	1.07	19.3	52.8	122	125	−0.01	−11

(467317) 2000 QW7 (H = 19.8)

Here’s another NEA with a known period that is long and, to make things more difficult, is nearly commensurate with an Earth day. This calls for another well-coordinated observing campaign.

On the plus side, the estimated size of 330 meters and minimum distance of about 0.036 AU mean that the SNR for Arecibo could be near 3000 and 1000 for Goldstone.

DATE	RA		Dec		ED	SD	V	α	SE	ME	MP	GB
07/01	18	28.2	−07	46	0.31	1.32	18.6	11.9	164	155	−0.04	+2
07/16	18	15.1	−06	29	0.23	1.23	18.1	20.6	155	19	+0.99	+5
07/31	18	03.5	−06	36	0.17	1.15	17.7	34.1	140	153	−0.02	+8
08/15	18	03.7	−09	05	0.12	1.09	17.1	47.2	128	48	+1.00	+6
08/30	18	37.8	−16	49	0.07	1.05	16.1	54.0	123	128	+0.00	−5
09/14	22	15.7	−36	34	0.04	1.04	14.1	35.4	143	32	−1.00	−56
09/29	02	46.6	−19	56	0.06	1.05	15.5	39.9	138	144	+0.00	−63
10/14	03	29.5	−10	05	0.12	1.09	16.7	34.4	142	33	−1.00	−49
10/29	03	33.1	−05	04	0.18	1.16	17.5	23.3	153	160	+0.01	−46
11/13	03	27.5	−01	05	0.26	1.23	18.1	15.4	161	17	−1.00	−44

(2100) Ra-Shalom (H = 16.1)

Because of orbital geometries, Ra-Shalom (1.8 km) has reported rotation periods (not counting sidereal periods from modeling) from only four apparitions between 1978 and 2016. The period is about 19.8 h, which makes it a difficult target but it’s going to be available for almost three months starting in August. That should be enough time to get a good data set.

The large range of phase angles will likely lead to large changes in lightcurve amplitude and shape. In such circumstances, it’s better to do analysis on subsets of data where the synodic period and amplitude are nearly the same. Doing this can be highly instructive for showing the effect of the phase angle on lightcurve amplitude and shape.

DATE	RA		Dec		ED	SD	V	α	SE	ME	MP	GB
08/01	01	26.1	+27	39	0.41	1.15	16.7	61.5	98	96	+0.00	−35
08/11	01	28.0	+25	38	0.36	1.17	16.3	55.8	107	121	+0.82	−37
08/21	01	23.5	+22	00	0.30	1.19	15.7	48.1	119	17	−0.75	−40
08/31	01	09.2	+15	33	0.25	1.19	14.9	36.9	135	142	+0.01	−47
09/10	00	41.3	+04	32	0.20	1.19	14.0	20.5	155	70	+0.85	−58
09/20	23	58.1	−11	16	0.18	1.18	13.3	8.7	170	66	−0.71	−70
09/30	23	06.0	−26	57	0.19	1.16	14.1	29.5	145	132	+0.03	−67
10/10	22	18.4	−37	21	0.22	1.13	14.9	48.1	122	24	+0.87	−56
10/20	21	44.0	−42	55	0.26	1.09	15.6	61.4	105	136	−0.66	−49
10/30	21	21.9	−45	56	0.31	1.05	16.1	71.5	92	71	+0.05	−45

(354030) 2001 RB18 (H = 18.5)

There’s no reported period in the LCDB for this 600 meter NEA. The ephemeris stretches into the fourth quarter (October) with a 10-day interval, or nearly three months. It’s unusual to have such a prolonged observing opportunity for an NEA. Take advantage if you can.

DATE	RA		Dec		ED	SD	V	α	SE	ME	MP	GB
07/25	21	28.5	+00	07	0.38	1.37	18.1	19.6	153	69	−0.51	−34
08/04	21	37.0	+02	45	0.31	1.30	17.4	17.5	157	148	+0.12	−34
08/14	21	47.6	+05	38	0.24	1.25	16.8	16.6	159	33	+0.98	−35
08/24	22	03.9	+08	52	0.19	1.19	16.2	17.1	160	90	−0.46	−36
09/03	22	31.5	+12	35	0.15	1.15	15.6	18.1	159	129	+0.18	−38
09/13	23	20.4	+16	41	0.12	1.12	15.0	18.7	159	31	+0.99	−41
09/23	00	39.8	+19	56	0.10	1.09	14.6	20.7	157	84	−0.40	−43
10/03	02	16.1	+19	33	0.09	1.08	14.8	27.1	150	150	+0.23	−39
10/13	03	32.4	+16	00	0.11	1.09	15.2	32.4	144	45	+0.99	−32
10/23	04	16.7	+12	22	0.13	1.11	15.7	32.3	144	75	−0.34	−26

(297418) 2000 SP43 (H = 18.5)

Another 600-meter NEA, 2000 SP43 has no reported rotation period. It’s in the Sun’s glare until the end of September, so the ephemeris carries into mid-October as an incentive to observe early and observe often (weather and moon allowing). Here again, the phase angles are large: look out for unusual lightcurve shapes.

DATE	RA		Dec		ED	SD	V	α	SE	ME	MP	GB
09/25	18	00.2	−08	37	0.08	1.00	16.1	86.7	89	138	−0.20	+7
09/27	18	38.9	−06	40	0.09	1.02	16.1	78.5	96	119	−0.05	+0
09/29	19	08.8	−05	02	0.10	1.03	16.1	72.3	102	97	+0.00	−6
10/01	19	32.1	−03	42	0.12	1.04	16.3	67.7	106	75	+0.08	−11
10/03	19	50.4	−02	37	0.13	1.05	16.5	64.3	109	53	+0.23	−14
10/05	20	05.3	−01	45	0.15	1.06	16.7	61.8	111	34	+0.43	−17
10/07	20	17.5	−01	01	0.16	1.07	16.8	59.9	112	21	+0.63	−20
10/09	20	27.8	−00	25	0.18	1.08	17.0	58.4	113	25	+0.80	−22
10/11	20	36.7	+00	05	0.19	1.09	17.2	57.3	113	40	+0.93	−23
10/13	20	44.4	+00	32	0.21	1.10	17.4	56.5	113	60	+0.99	−25

1996 TC1 (H = 23.9)

1996 TC1 is a PHA and virtual impactor with a diameter of only 50 meters. That makes it very likely that its period is P < 2 h and, maybe less so, that it is tumbling. The observing window for backyard telescopes is only 4-6 days.

According to the Minor Planet Center ephemeris, the sky motion (arcsec/min) at 0 h UT will be: Sep 25, 81; Sep 26, 194; Sep 27, 54; Sep 28, 19; Sep 29, 9. To paraphrase a famous movie line, “You’re going to need a bigger telescope.”

DATE	RA		Dec		ED	SD	V	α	SE	ME	MP	GB
09/25	08	40.2	−24	54	0.02	0.99	20.0	124.1	55	45	−0.20	+10
09/26	04	08.9	−18	40	0.01	1.01	16.1	61.4	118	91	−0.11	−44
09/27	01	13.0	+00	31	0.02	1.02	16.1	14.9	165	141	−0.05	−62
09/28	00	25.1	+06	23	0.03	1.03	16.9	5.0	175	163	−0.01	−56
09/29	00	05.1	+08	43	0.04	1.05	17.8	7.2	172	167	+0.00	−52
09/30	23	54.3	+09	57	0.06	1.06	18.5	9.8	170	154	+0.03	−50
10/01	23	47.6	+10	41	0.07	1.07	19.0	11.6	168	140	+0.08	−49
10/02	23	43.0	+11	11	0.09	1.08	19.5	13.0	166	125	+0.15	−48
10/03	23	39.8	+11	32	0.10	1.10	19.9	14.1	164	112	+0.23	−48
10/04	23	37.4	+11	47	0.11	1.11	20.2	15.1	163	98	+0.33	−47