LIGHTCURVE PHOTOMETRY OPPORTUNITIES: 2013 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 be the target of radar observations. 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 lists of “targets of opportunity” for the period 2013 July-September. For background on the program details for each of the opportunity lists, refer to previous issues, e.g., Minor Planet Bulletin 36, 188. 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) documentation for an explanation of the U code:

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

Objects with 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.

The first list is an abbreviated list of those asteroids reaching V < 15.0 at brightest during the period and have either no or poorly-constrained lightcurve parameters. An asterisk (*) follows the name if the asteroid is reaching a particularly favorable apparition.

The goal for these asteroids is to find a well-determined rotation rate. The target list 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

In a general note, small objects with periods up to 4 hours or even longer are possible binaries. For longer periods (4–6 hours or so), the odds of a binary may be less, but the bonus is that the size of the secondary, if it exists, is likely larger (see Pravec et al. (2010), Nature 466, 1085–1088), thus eclipses, if they occur, will be deeper and easier to detect.

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.” You will have the best chance of success working objects with low amplitude and periods that allow covering, e.g., a maximum, every night. Objects with large amplitudes and/or long periods are much more difficult for phase angle studies since, for proper analysis, the data have to be reduced to the average magnitude of the asteroid for each night. Without knowing the period and/or the amplitude at the time, that reduction becomes highly uncertain. 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 using average light, which is the method used for values listed by the Minor Planet Center.

The third list is of those asteroids needing only a small number of lightcurves to allow spin axis and/or shape modeling. Those doing work for modeling should contact Josef Ďurech at the email address above and/or visit the Database of Asteroid Models from Inversion Techniques (DAMIT) web site for existing data and models:

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

The fourth list gives a brief ephemeris for planned radar targets. Supporting optical observations to determine the lightcurve period, amplitude, and shape are needed to supplement the radar data. High-precision work, 0.01–0.02 mag, is preferred, especially if the object is a known or potential binary. Those obtaining lightcurves in support of radar observations should contact Dr. Benner directly at the email given above.

Future radar targets

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

Past radar targets

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

Arecibo targets

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

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

Goldstone targets

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

As always, we encourage observations of asteroids even if they have well-established lightcurve parameters and especially if they are lacking good spin axis and/or shape model solutions. Every lightcurve of sufficient quality supports efforts to resolve a number of questions about the evolution of individual asteroids and the general population. For example, pole directions are known for only about 30 NEAs out of a population of 8000. This is hardly sufficient to make even the most general of statements about NEA pole alignments, including whether or not the thermal YORP effect is forcing pole orientations into a limited number of preferred directions (see La Spina et al., 2004, Nature 428, 400–401). Data from many apparitions can help determine if an asteroid’s rotation rate is being affected by YORP, which can also cause the rotation rate of a smaller, irregularly-shaped asteroid to increase or decrease. See Lowry et al. (2007) Science 316, 272–274 and Kaasalainen et al. (2007) Nature 446, 420–422.

The ephemeris listings for the optical-radar listings include lunar elongation and phase. Phase values range from 0.0 (new) to 1.0 (full). If the value is positive, the moon is waxing – between new and full. If the value is negative, the moon is waning – between full and new. The listing also includes the galactic latitude. When this value is near 0°, the asteroid is likely in rich star fields and so may be difficult to work. It is important to emphasize that the ephemerides that we provide are only guides for when you might observe a given asteroid. Obviously, you should use your discretion and experience to make your observing program as effective as possible.

Once you’ve 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.

Funding for Warner and Harris in support of this article is provided by NASA grant NNX10AL35G and by National Science Foundation grant AST-1032896.

Lightcurve Opportunities

		Brightest			LCDB Data
#	Name	Date	Mag	Dec	Period	Amp	U
458	Hercynia	07 01.3	14.4	−12	22.3	0.33–0.35	2
618	Elfriede*	07 02.2	12.3	−18	14.801	0.12–0.20	2
1228	Scabiosa	07 02.3	15.0	−25
6271	Farmer*	07 03.2	14.7	−28	250.	0.13–0.22	2
29742	1999 BQ12*	07 08.8	14.9	−26	4.3	0.7	1+
10731	1988 BL3	07 09.3	15.0	−18	28.02	0.23–0.41	2
1409	Isko	07 11.7	14.7	−12	11.6426	0.20	2
961	Gunnie	07 11.9	14.7	−40
3977	Maxine*	07 11.9	14.6	+0
1159	Granada	07 12.1	14.4	−42	31.	0.28	2
1886	Lowell*	07 12.2	14.7	−35
6307	Maiztegui	07 12.6	14.9	−20	4.68	0.15	2
1686	De Sitter*	07 12.7	14.2	−23
576	Emanuela*	07 12.8	12.2	−25	8.192	0.05–0.06	2−
2543	Machado*	07 13.1	14.1	−47	31.72	0.15	2
589	Croatia	07 13.6	13.5	−7	11.7	0.16	2
4226	Damiaan	07 13.6	14.2	−13	24.	0.05	1
2104	Toronto	07 14.3	14.5	−4	8.9669	0.32	2+
6032	Nobel	07 14.7	14.9	−6
455	Bruchsalia	07 14.9	11.1	−35	11.838	0.10–0.35	2+
1753	Mieke	07 15.2	14.8	−36	8.8	0.2	2
916	America	07 15.6	13.8	−35	38.	0.28	1
741	Botolphia	07 16.5	13.6	−24	23.93	0.12– 0.4	2−
1043	Beate	07 16.7	13.7	−12	44.3	0.47	2+
866	Fatme*	07 18.8	13.6	−26	20.03	0.06–0.21	2
1629	Pecker*	07 19.1	14.2	−15	8.2166	0.08	2
6914	Becquerel	07 19.4	14.8	−24
859	Bouzareah	07 19.6	14.6	−40	23.2	0.13	2−
421	Zahringia	07 19.7	15.0	−9	6.42	0.07–0.12	2
722	Frieda*	07 20.1	13.7	−32		0.04
1145	Robelmonte	07 20.3	13.7	−29	9.01	0.05–0.18	2
1646	Rosseland	07 20.6	14.4	−20	69.2	0.13	2
582	Olympia	07 20.7	14.0	+8	36.	0.05– 0.6	2
9938	Kretlow*	07 20.8	15.0	−25
6386	Keithnoll	07 22.2	14.1	−20	3.1381	0.08	2+
874	Rotraut	07 22.9	14.7	−5	14.586	0.24	2
862	Franzia	07 24.1	13.5	−20	7.52	0.07–0.22	2
481	Emita	07 24.6	12.7	−32	14.35	0.09–0.30	2
1186	Turnera	07 25.2	13.1	−36	12.066	0.25–0.34	2+
1351	Uzbekistania	07 26.7	14.6	−32	73.9	0.20–0.34	2
2829	Bobhope*	07 27.0	13.8	−28	6.0888	0.50–0.55	2
7536	Fahrenheit*	07 27.0	14.6	−19
305	Gordonia	07 28.7	13.9	−13	16.2	0.16–0.17	2
931	Whittemora	07 30.5	13.9	−23	19.2	0.2	2
1952	Hesburgh	08 01.4	14.9	−34	47.7	0.18	2
1799	Koussevitzky	08 02.5	14.8	−10	6.325	0.25	2
3002	Delasalle	08 02.5	14.4	−21
2437	Amnestia	08 02.8	14.6	−12	85.	0.45	2
1042	Amazone	08 02.9	14.4	−46	540.	0.10–0.25	2
569	Misa	08 03.9	13.9	−17	13.52	0.25	2
1073	Gellivara*	08 04.0	14.8	−20	11.32	0.35	2
4333	Sinton*	08 04.3	14.7	−15
2138	Swissair	08 05.9	14.5	−21
17939	1999 HH8*	08 06.5	14.9	−19	5.1	0.18–0.26	2
6495	1992 UB1	08 10.1	14.9	−3	5.697	0.29–0.45	2
52760	1998 ML14*	08 12.4	15.0	−31	14.98	0.12	2
503	Evelyn	08 13.5	13.5	−21	38.7	0.30– 0.5	2
1337	Gerarda	08 13.7	14.8	−5	12.52	0.23	2
1315	Bronislawa	08 14.1	14.3	−4	9.565	0.16–0.24	2
3581	Alvarez*	08 14.1	14.3	+38	33.42	0.06	2
823	Sisigambis	08 16.4	13.9	−8	146.	0.05– 0.7	2
2873	Binzel	08 16.6	14.8	−21
570	Kythera	08 20.2	13.0	−10	8.12	0.15–0.18	2
1358	Gaika*	08 20.2	14.2	−16
1372	Haremari*	08 20.3	14.3	−12	15.25	0.12	2
581	Tauntonia	08 20.6	14.6	−33	16.54	0.07–0.20	2
1683	Castafiore*	08 21.6	13.9	−11	13.931	0.66	2+
1048	Feodosia	08 22.4	13.6	−33	10.46	0.14	2
19082	Vikchernov*	08 22.4	14.9	−12
1290	Albertine	08 22.7	14.9	−8
5847	Wakiya*	08 25.3	14.5	−1	23.95	0.10	1
11574	d’Alviella*	08 25.5	14.7	−17	12.549	0.15	2
3768	Monroe*	08 25.7	14.4	−12
2089	Cetacea	08 26.5	13.9	−30	39.12	0.25–0.40	2
774	Armor	08 29.7	12.3	−1	25.107	0.11–0.34	2
8992	Magnanimity*	08 29.7	14.7	−1
1714	Sy	08 29.8	14.8	−1		0.95
702	Alauda	08 30.0	11.9	+13	8.348	0.07–0.10	2
1486	Marilyn*	08 30.2	14.0	−9	2.2837	0.40	1+
2430	Bruce Helin	08 30.2	14.2	−53	128.	0.6	2
3300	McGlasson	08 30.2	14.1	−30	22.91	0.16	2
1149	Volga	08 31.4	14.3	+8	27.5	0.26	2
4729	Mikhailmil’	09 01.4	14.0	−4	17.74	0.36	2−
7234	1986 QV3*	09 01.5	14.4	−15
527	Euryanthe*	09 03.6	13.1	−17	26.06	0.11	2−
5913	1990 BU*	09 04.2	14.2	+0	52.	0.10	1
6434	Jewitt*	09 04.2	14.7	−19
1184	Gaea*	09 04.6	14.2	−11	2.94	0.09–0.25	2
2865	Laurel	09 04.7	14.4	+1	21.5	0.15	2
3346	Gerla	09 04.7	15.0	−19
3257	Hanzlik	09 04.8	14.6	−15
346	Hermentaria	09 05.1	10.6	−19	28.43	0.07–0.20	2
357	Ninina*	09 05.7	12.9	−16	35.98	0.12	2
1385	Gelria*	09 05.8	13.8	−15		0.36
2244	Tesla	09 05.8	14.9	−17
1728	Goethe Link	09 08.9	14.3	+6	81.	0.39	2
3770	Nizami*	09 09.2	15.0	−5
1347	Patria	09 13.2	14.6	+11	29.5	0.12	2
768	Struveana	09 15.2	14.2	−22	8.76	0.26–0.54	2+
2107	Ilmari	09 15.2	14.7	+7		0.06
5001	EMP*	09 15.2	14.3	−4
1005	Arago*	09 15.5	13.7	−1	8.7819	0.22	2
1124	Stroobantia	09 18.0	14.5	−7	16.39	0.15	1
1118	Hanskya	09 19.1	14.2	+11	15.61	0.18–0.38	2
676	Melitta	09 19.7	13.0	−10	7.87	0.04–0.20	2
1010	Marlene*	09 20.6	14.0	−7	31.06	0.17–0.32	2+
449	Hamburga	09 20.7	13.2	−5	18.263	0.08–0.17	2+
892	Seeligeria	09 21.0	14.0	−2	41.4	0.15	2
596	Scheila	09 23.8	13.4	−17	15.851	0.06–0.09	2+
1622	Chacornac	09 24.0	14.3	+0	12.206	0.24–0.25	2
1461	Jean-Jacques	09 24.7	14.6	−19	16.56	0.09	2
541	Deborah	09 25.0	13.8	+9	13.91	0.04–0.07	2+
8265	1986 RB5	09 25.3	14.9	−8
384	Burdigala	09 26.3	12.8	−5	21.1	0.03	2−
10262	Samoilov*	09 26.5	14.6	−11
1468	Zomba*	09 27.4	13.7	+23	2.77	0.3	2
3255	Tholen*	09 30.4	14.3	+28	3.	0.08	1
994	Otthild*	09 30.5	12.7	+5	5.95	0.09–0.15	2+
1839	Ragazza	09 30.5	15.0	−9
3171	Wangshouguan	09 30.7	14.9	−4

Low Phase Angle Opportunities

#	Name	Date	α	V	Dec	Period	Amp	U
389	Industria	07 02.8	0.17	11.0	−23	8.53	0.18–0.34	3
1496	Turku	07 09.2	0.41	13.4	−23	6.47	−0.51	3−
559	Nanon	07 11.7	0.32	12.5	−21	10.059	0.09–0.26	3
8	Flora	07 20.0	0.56	8.7	−22	12.865	0.03–0.11	3
862	Franzia	07 24.1	0.14	13.5	−20	7.52	−0.13	2
2213	Meeus	07 30.0	0.05	13.9	−19
268	Adorea	07 31.9	0.15	12.6	−19	7.80	0.15–0.20	3
202	Chryseis	08 03.1	0.41	12.0	−16	23.670	0.04–0.23	3
569	Misa	08 03.9	0.13	13.9	−17	13.52	−0.25	2
28	Bellona	08 07.4	0.73	11.4	−14	15.706	0.03–0.31	3
1148	Rarahu	08 12.5	0.69	13.5	−13	6.5447	−0.94	3−
1241	Dysona	08 15.9	0.18	13.2	−13	8.6080	−0.25	3−
52	Europa	08 19.0	0.97	10.9	−16	5.6304	0.08–0.20	3
570	Kythera	08 20.1	0.83	13.1	−10	8.120	0.15–0.18	2
1683	Castafiore	08 21.7	0.36	13.9	−11	13.931	−0.66	2+
1638	Ruanda	08 23.1	0.19	14.0	−11	4.2397	0.06–0.10	3
1874	Kacivelia	08 24.7	0.55	13.6	−10
1486	Marilyn	08 30.3	0.19	14.0	−09	2.2837	−0.40	1+
263	Dresda	08 31.9	0.66	13.6	−07	16.809	0.32–0.55	3
171	Ophelia	09 01.3	0.86	13.2	−11	6.66535	0.14–0.46	3
839	Valborg	09 01.3	0.21	12.9	−08	10.366	−0.19	3
1062	Ljuba	09 02.3	0.14	13.9	−08	33.8	−0.17	3
955	Alstede	09 13.4	0.24	12.9	−04	5.19	−0.27	3
435	Ella	09 13.5	0.93	12.1	−05	4.623	0.30–0.45	3
1005	Arago	09 15.4	0.61	13.8	−01	8.7819	−0.22	2
892	Seeligeria	09 20.9	0.35	14.0	−02	41.40	−0.15	2
124	Alkeste	09 24.2	0.24	11.5	+01	9.921	0.08–0.15	3
139	Juewa	09 24.2	0.11	12.1	+00	20.991	−0.20	3
1035	Amata	09 24.8	0.14	13.4	+00	9.081	−0.44	3
69	Hesperia	09 28.3	0.12	11.1	+02	5.655	0.09–0.24	3
94	Aurora	09 29.5	0.29	11.5	+03	7.22	0.03–0.18	3
1610	Mirnaya	09 29.9	0.35	14.0	+03

Shape/Spin Modeling Opportunities

There are two lists here. The first is for objects for which good occultation profiles are available. These are used to constrain the models obtained from lightcurve inversion, eliminating ambiguous solutions and fixing the size of asteroid. Lightcurves are needed for modeling and/or to establish the rotation phase angle at the time the profile was obtained. The second list is of those objects for which another set of lightcurves from one more apparitions will allow either an initial or a refined solution.

Occultation Profiles Available

		Brightest			LCDB DATA
#	Name	Date	Mag	Dec	Period	Amp	U
580	Selene	07 05.7	14.7	−23	9.47	0.27	3−
559	Nanon	07 11.7	12.5	−21	10.059	0.09–0.26	3
47	Aglaja	07 27.0	11.0	−26	13.178	0.02–0.17	3
81	Terpsichore	08 01.8	12.4	−27	10.943	0.06–0.10	3
93	Minerva	08 07.2	10.8	−27	5.982	0.04–0.20	3
78	Diana	08 07.6	12.4	−20	7.2991	0.02–0.30	3
476	Hedwig	08 12.8	11.7	−05	27.33	0.13	3
238	Hypatia	09 12.3	11.7	+00	8.8745	0.07–0.17	3
324	Bamberga	09 13.3	8.1	+05	29.43	0.07–0.12	3
139	Juewa	09 24.2	12.1	+00	20.991	0.20	3
124	Alkeste	09 24.2	11.4	+01	9.921	0.08–0.15	3
205	Martha	09 29.5	12.8	+09	14.912	0.10–0.50	3−
94	Aurora	09 29.6	11.5	+03	7.22	0.03–0.18	3
3171	Wangshouguan	09 30.7	14.9	−04

Inversion Modeling Candidates

		Brightest			LCDB Data
#	Name	Date	Mag	Dec	Period	Amp	U
686	Gersuind	07 03.9	11.9	−04	6.3127	0.30–0.37	3
252	Clementina	07 07.4	14.1	−08	10.864	0.32–0.44	3
851	Zeissia	07 07.9	14.2	−20	9.34	0.38–0.53	3
1496	Turku	07 09.2	13.4	−23	6.47	0.51	3−
1379	Lomonosowa	07 10.4	14.2	+01	24.488	0.63	3
6307	Maiztegui	07 12.6	14.9	−20	4.68	0.15	2
333	Badenia	07 14.8	13.5	−27	8.192	0.20–0.33	3−
762	Pulcova	07 16.2	13.0	−25	5.839	0.18–0.30	3
2036	Sheragul	07 18.3	13.9	−28	5.41	0.60–1.50	3
4713	Steel	07 19.5	14.5	−35	5.199	0.28–0.44	3
186	Celuta	07 21.9	11.3	−45	19.842	0.4 –0.55	3
1446	Sillanpaa	07 24.6	15.0	−29	9.6602	0.55	3
1503	Kuopio	07 28.4	14.2	−23	9.957	0.77	3
540	Rosamunde	07 29.2	13.5	−09	9.336	0.40–0.66	3−
1388	Aphrodite	08 07.0	14.7	−33	11.9432	0.35–0.65	3
6495	1992 UB1	08 10.1	14.9	−03	5.697	0.29–0.45	2
1900	Katyusha	08 10.2	14.7	−09	9.4999	0.56–0.74	3
503	Evelyn	08 13.5	13.5	−21	38.7	0.30–0.5	2
1835	Gajdariya	08 14.2	15.0	−14	6.3276	0.50	3
1423	Jose	08 16.1	14.3	−18	12.307	0.68–0.85	3
756	Lilliana	08 18.0	14.8	+12	7.834	0.18–0.99	3
1547	Nele	08 18.9	14.6	−04	7.100	0.30–0.45	3−
104	Klymene	08 21.7	12.6	−16	8.984	0.3	3
943	Begonia	08 23.5	14.9	−21	15.66	0.34	3
3300	McGlasson	08 30.2	14.1	−30	22.91	0.16	2
2430	Bruce Helin	08 30.2	14.2	−53	128.	0.6	2
3657	Ermolova	09 01.9	14.5	+02	2.6064	0.18–0.25	3
6406	1992 MJ	09 06.1	14.6	−11	6.819	1.18	3
1467	Mashona	09 07.7	12.7	+05	9.76	0.24	3
1728	Goethe Link	09 08.9	14.3	+06	81.	0.39	2
394	Arduina	09 09.3	12.0	−16	16.5	0.29–0.54	3
565	Marbachia	09 19.5	14.7	+11	4.587	0.20–0.65	3
1314	Paula	09 20.9	14.6	+08	5.9498	0.83	3
408	Fama	09 27.0	13.1	+13	202.10	0.05–0.58	3
994	Otthild	09 30.5	12.7	+05	5.95	0.09–0.14	2+

Radar-Optical Opportunities

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. Some of the targets may be too faint to do accurate photometry with backyard telescopes. However, accurate astrometry using techniques such as “stack and track” is still possible and can be helpful for those asteroids where the position uncertainties are significant. Note that the intervals in the ephemerides are not always the same and that geocentric positions are given. Use these web sites to generate updated and topocentric positions:

MPC: http://www.minorplanetcenter.org/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” in the header 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.

(52760) 1998 ML14 (Jun-Aug, H = 17.6, PHA)

Hicks et al. (1998) determined a rotation period of 14.98 h for this 1 km NEA. Follow-up observations would be a great help. The object is visible for a number of weeks. The phase angle increase dramatically over the span of the ephemeris. In such cases, it is better not to create a single composite lightcurve over that full period but multiple lightcurves based on subsets of data obtained about 1–2 weeks apart. This allows following the evolution of the lightcurve’s amplitude and shape and provides even better modeling information.

DATE	RA	Dec	ED	SD	V	α	SE	ME	MP	GB
06/25	18 25.4	−31 10	0.40	1.41	16.7	5.8	172	23	−0.96	−9
07/02	18 15.4	−31 53	0.34	1.35	16.4	8.2	169	118	−0.32	−7
07/09	18 02.0	−32 34	0.28	1.29	16.1	14.6	161	152	+0.01	−5
07/16	17 44.9	−33 08	0.24	1.23	15.9	23.0	152	65	+0.49	−2
07/23	17 23.8	−33 30	0.20	1.17	15.7	33.0	141	44	−1.00	+1
07/30	16 56.9	−33 31	0.16	1.12	15.4	44.8	129	142	−0.47	+6
08/06	16 19.7	−32 50	0.12	1.07	15.2	59.4	115	123	−0.01	+12
08/13	15 21.0	−30 13	0.09	1.03	15.1	79.7	95	26	+0.34	+22

(153349) 2001 PJ19 (Jul-Aug, H = 18.0)

There is no previously determined period in the lightcurve database (LCDB; Warner et al., 2009) for this 600-meter NEA. While the asteroid doesn’t reach very low phase angles, the range is still substantial and so it may be worth obtaining blocks of data at several times and generating multiple lightcurves.

DATE	RA	Dec	ED	SD	V	α	SE	ME	MP	GB
07/20	00 23.1	+51 11	0.08	1.02	16.0	87.9	88	117	+0.89	−11
07/25	22 07.5	+35 58	0.10	1.07	15.7	56.6	119	42	−0.93	−16
07/30	21 18.6	+24 49	0.14	1.12	16.0	39.4	135	73	−0.47	−17
08/04	20 55.7	+18 03	0.19	1.18	16.5	30.0	145	130	−0.08	−17
08/09	20 42.9	+13 35	0.24	1.23	16.9	24.8	149	146	+0.04	−17
08/14	20 35.3	+10 23	0.30	1.28	17.4	22.4	151	89	+0.45	−18
08/19	20 30.8	+07 56	0.35	1.33	17.8	21.7	151	25	+0.94	−18
08/24	20 28.3	+05 59	0.41	1.38	18.2	22.1	149	60	−0.89	−18

2010 AF30 (Jul, H = 21.6)

The estimated size of this NEA (assuming taxonomic type S) is only 150 meters. In which case, there is a chance that it may have a rotation period of less than 2 hours and might even be tumbling. There are no entries in the LCDB.

DATE	RA	Dec	ED	SD	V	α	SE	ME	MP	GB
07/15	05 19.0	−41 38	0.05	1.00	18.9	106.7	71	98	+0.38	−34
07/16	04 49.9	−46 16	0.05	1.01	18.5	99.4	78	106	+0.49	−40
07/17	04 16.0	−50 21	0.05	1.01	18.2	92.2	85	110	+0.60	−45
07/18	03 37.7	−53 36	0.05	1.02	18.0	85.2	92	109	+0.70	−50
07/19	02 56.6	−55 52	0.05	1.02	17.8	78.5	99	103	+0.80	−54
07/20	02 15.1	−57 08	0.05	1.03	17.7	72.3	105	95	+0.89	−57
07/21	01 35.6	−57 29	0.05	1.04	17.7	66.6	111	84	+0.95	−59
07/22	01 00.1	−57 09	0.06	1.04	17.7	61.4	116	73	+0.99	−60

1627 Ivar (Jul-Nov, H = 13.2)

This may be one of the easier NEAs that you’ll ever observe. It is bright (be careful about overexposing) and well-placed for more than 3 months. Here’s a great opportunity to get multiple lightcurves over a range of phase angles. The period is well-known: 4.798 h. The amplitude has ranged from 0.25 to 1.4 mag.

DATE	RA	Dec	ED	SD	V	α	SE	ME	MP	GB
07/01	23 37.2	+07 29	0.32	1.13	12.5	62.4	101	22	−0.42	−51
07/21	00 58.9	+05 30	0.33	1.13	12.5	61.1	103	102	+0.95	−57
08/10	01 55.0	+01 09	0.34	1.18	12.5	54.2	110	143	+0.10	−58
08/30	02 21.6	−04 33	0.36	1.25	12.5	42.6	123	54	−0.35	−59
09/19	02 19.1	−10 17	0.40	1.34	12.5	28.3	141	46	+1.00	−63
10/09	01 56.6	−13 43	0.47	1.44	12.8	16.8	155	132	+0.19	−70
10/29	01 34.0	−13 23	0.60	1.55	13.5	17.8	152	126	−0.31	−73
11/18	01 25.0	−10 19	0.79	1.66	14.4	24.1	137	46	−1.00	−71

(7753) 1988 XB (Jul, H = 18.6)

There are no entries for this NEA in the LCDB. The estimated size ranges from 0.5 to 1.1 km, depending on the assumed albedo. The SMASS II survey found a taxonomic type of B, making it dark (low albedo) object, which leads to the larger size.

DATE	RA	Dec	ED	SD	V	α	SE	ME	MP	GB
07/01	13 03.3	−15 38	0.13	1.05	16.8	71.7	101	174	−0.42	+47
07/02	12 53.5	−15 10	0.13	1.04	16.8	75.0	98	165	−0.32	+48
07/03	12 43.5	−14 39	0.13	1.03	16.9	78.4	95	151	−0.23	+48
07/04	12 33.2	−14 06	0.12	1.03	17.0	81.9	91	137	−0.16	+49
07/05	12 22.7	−13 30	0.12	1.02	17.1	85.4	88	122	−0.09	+49
07/06	12 12.1	−12 52	0.12	1.01	17.2	89.0	84	108	−0.05	+49
07/07	12 01.3	−12 12	0.12	1.00	17.3	92.7	81	94	−0.02	+49
07/08	11 50.4	−11 29	0.12	1.00	17.4	96.4	77	79	+0.00	+49

(232691) 2004 AR1 (Jul-Aug, H = 19.8)

This NEA has an estimated size of about 300 meters. As such, its rotation period is probably 2 hours or more. This one is definitely for Southern Hemisphere observers.

DATE	RA	Dec	ED	SD	V	α	SE	ME	MP	GB
07/20	20 23.2	−51 15	0.24	1.23	18.3	25.1	149	49	+0.89	−35
07/25	20 10.7	−53 20	0.21	1.19	18.0	28.1	146	54	−0.93	−33
07/30	19 51.7	−55 35	0.18	1.16	17.7	32.6	142	108	−0.47	−30
08/04	19 21.8	−57 55	0.14	1.12	17.4	39.1	136	140	−0.08	−27
08/09	18 33.0	−60 02	0.12	1.09	17.1	48.1	127	107	+0.04	−21
08/14	17 11.0	−60 30	0.09	1.05	16.8	61.2	114	51	+0.45	−12
08/19	15 10.3	−54 32	0.07	1.02	16.8	81.8	94	66	+0.94	+3
08/24	13 14.2	−34 37	0.05	0.99	17.9	114.1	63	150	−0.89	+28

89 Julia (Jul-Nov, H = 6.6)

The rotation period for this inner main-belt asteroid is 11.38 hours. This makes it difficult for a single station to get complete coverage of the lightcurve without an prolonged campaign. A collaboration involving observers well-separated in longitude would be ideal. The estimated diameter is 151 km.

DATE	RA	Dec	ED	SD	V	α	SE	ME	MP	GB
07/01	23 50.5	+06 44	1.71	2.11	10.6	28.4	99	19	−0.42	−53
07/21	00 03.2	+11 56	1.49	2.10	10.3	26.6	112	91	+0.95	−49
08/10	00 05.3	+16 45	1.31	2.09	9.9	22.5	128	162	+0.10	−45
08/30	23 54.7	+20 31	1.18	2.09	9.4	16.4	144	79	−0.35	−40
09/19	23 34.4	+22 22	1.13	2.09	9.2	11.3	156	23	+1.00	−37
10/09	23 14.5	+22 01	1.16	2.09	9.3	13.6	150	109	+0.19	−36
10/29	23 06.0	+20 32	1.28	2.10	9.7	19.6	135	147	−0.31	−36
11/18	23 11.8	+19 15	1.46	2.12	10.2	24.2	119	66	−1.00	−38

324 Bamberga (Jul-Nov, H = 6.82)

This middle main-belt asteroid has an estimated diameter of 230 km. It’s a type CP (Tholen, 1989), meaning is has a lower albedo on the order of 0.06. The rotation period of 29.4 h makes this another object where a collaboration among observers will have the best chance of securing a complete lightcurve.

DATE	RA	Dec	ED	SD	V	α	SE	ME	MP	GB
07/01	23 19.9	−06 57	1.37	1.98	10.3	28.7	111	31	−0.42	−60
07/21	23 33.7	−03 05	1.14	1.92	9.8	25.5	125	79	+0.95	−60
08/10	23 36.1	+00 34	0.96	1.87	9.2	19.2	143	178	+0.10	−57
08/30	23 25.2	+03 42	0.85	1.83	8.5	9.9	162	91	−0.35	−53
09/19	23 06.1	+05 55	0.81	1.80	8.2	6.8	168	7	+1.00	−48
10/09	22 51.5	+07 15	0.86	1.79	8.7	16.9	149	99	+0.19	−45
10/29	22 51.4	+08 22	0.97	1.78	9.3	25.2	130	159	−0.31	−44
11/18	23 06.4	+09 53	1.13	1.79	9.7	30.0	115	69	−1.00	−45

(277475) 2005 WK4 (Aug-Sep, H = 20.2, PHA)

2005 WK4 is an NEA with an estimated size of 280 meters. There are no entries in the LCDB for it. While brightest around mid-August, rapid sky motion at that time may make good photometry a bit difficult. If you have the resources and are in the Southern Hemisphere, observations soon after closest approach might be more productive.

DATE	RA	Dec	ED	SD	V	α	SE	ME	MP	GB
08/05	04 33.7	+49 22	0.03	1.00	17.0	116.5	62	48	−0.04	+1
08/10	01 40.2	+07 53	0.02	1.02	14.1	67.5	111	146	+0.10	−53
08/15	23 59.3	−27 53	0.03	1.04	14.3	34.4	144	107	+0.56	−78
08/20	23 11.2	−38 54	0.06	1.06	15.3	29.5	149	40	+0.98	−66
08/25	22 45.0	−42 55	0.08	1.08	16.1	30.4	147	64	−0.81	−60
08/30	22 29.2	−44 33	0.11	1.10	16.8	32.3	145	115	−0.35	−57
09/04	22 19.1	−45 04	0.13	1.11	17.3	34.2	142	143	−0.02	−55
09/09	22 12.8	−44 58	0.16	1.13	17.8	36.1	139	105	+0.13	−54

(137126) 1999 CF9 (Aug-Sep, H = 17.9, PHA)

The estimated diameter for this NEA is 800 meters. The rotation period is not known, or at least is not included in the LCDB. The end of August and early September may offer the best compromise between brightness, sky motion, and changing phase angle.

DATE	RA	Dec	ED	SD	V	α	SE	ME	MP	GB
08/20	14 35.9	+04 27	0.07	0.99	16.1	106.8	69	95	+0.98	+56
08/25	17 32.8	−10 08	0.07	1.04	14.4	65.7	111	118	−0.81	+12
08/30	19 40.4	−17 04	0.10	1.08	14.6	39.2	137	150	−0.35	−18
09/04	20 40.1	−18 31	0.15	1.13	15.3	29.7	146	162	−0.02	−32
09/09	21 11.2	−18 42	0.20	1.18	16.0	26.7	148	106	+0.13	−39
09/14	21 30.3	−18 32	0.26	1.23	16.6	26.0	148	41	+0.65	−43
09/19	21 43.6	−18 13	0.32	1.28	17.1	26.2	146	29	+1.00	−46
09/24	21 53.8	−17 50	0.38	1.33	17.6	26.9	143	91	−0.79	−48

2007 CN26 (Aug-Oct, H = 21.0, PHA)

As with many other asteroids presented this quarter, there is no reported rotation period in the LCDB. 2007 CN26 is an NEA with an estimated diameter of 200 meters. This puts it on the edge of being a candidate for having a rotation rate of less than 2 hours. Until you know one way or the other, keep exposures to a minimum but long enough so that scintillation noise doesn’t dominate (~10 sec for backyard telescopes).

DATE	RA	Dec	ED	SD	V	α	SE	ME	MP	GB
08/30	05 16.7	+27 29	0.03	1.00	17.0	101.9	76	9	−0.35	−6
09/04	03 57.5	+05 45	0.04	1.02	16.5	75.2	103	85	−0.02	−34
09/09	03 16.8	−06 46	0.05	1.03	16.7	58.7	119	151	+0.13	−50
09/14	02 51.9	−13 37	0.07	1.05	17.0	48.3	129	116	+0.65	−59
09/19	02 34.3	−17 37	0.09	1.07	17.3	41.1	136	51	+1.00	−64
09/24	02 20.6	−20 03	0.11	1.09	17.6	35.6	141	42	−0.79	−68
09/29	02 09.1	−21 30	0.13	1.11	17.9	31.6	145	91	−0.33	−71
10/04	01 59.2	−22 14	0.15	1.13	18.2	28.7	147	140	−0.01	−74

(329437) 2002 OA22 (Aug-Oct, H = 19.3, PHA)

Behrend et al. (2012) report a period of 10.5 h for 2002 OA22, a 400 meter NEA. The period is based mostly on a single night of observations that appeared to include a maximum and minimum (0.41 mag amplitude). However, a second night showed a nearly flat lightcurve. For a period of 10.5 h, the tumbling damping time is about 1.4 Gyr, so it’s not entirely out of the question that the asteroid is tumbling. Make no assumptions and go where the data lead.

DATE	RA	Dec	ED	SD	V	α	SE	ME	MP	GB
08/20	01 06.9	+20 43	0.20	1.14	18.0	48.6	123	71	+0.98	−42
08/27	01 17.7	+20 03	0.17	1.12	17.5	45.7	127	25	−0.63	−42
09/03	01 28.8	+18 21	0.14	1.11	17.0	42.2	133	105	−0.06	−44
09/10	01 41.2	+14 52	0.11	1.09	16.2	38.0	138	166	+0.22	−46
09/17	01 57.2	+07 53	0.08	1.07	15.4	33.7	144	69	+0.92	−52
09/24	02 23.6	−07 11	0.05	1.05	14.5	34.1	144	31	−0.79	−60
10/01	03 27.8	−39 41	0.04	1.02	14.3	57.5	121	96	−0.16	−55
10/08	07 33.0	−68 56	0.04	0.99	16.0	96.4	81	83	+0.11	−22

(152664) 1998 FW4 (Sep, H = 19.5, PHA)

Here’s another NEA with no reported rotation period. The estimated diameter is 340 meters.

DATE	RA	Dec	ED	SD	V	α	SE	ME	MP	GB
09/01	00 22.2	−01 31	0.29	1.28	18.6	20.4	154	103	−0.18	−63
09/05	00 29.6	−00 28	0.24	1.23	18.0	19.8	156	149	+0.00	−63
09/09	00 39.8	+01 04	0.19	1.19	17.5	19.8	157	160	+0.13	−62
09/13	00 55.6	+03 31	0.14	1.14	16.8	21.1	156	110	+0.54	−59
09/17	01 24.6	+08 02	0.10	1.09	16.1	26.0	152	61	+0.92	−54
09/21	02 34.2	+17 51	0.06	1.05	15.4	41.5	136	24	−0.97	−39
09/25	05 56.7	+32 26	0.05	1.01	16.0	84.8	93	24	−0.70	+4
09/29	09 18.1	+25 56	0.07	0.96	18.9	124.3	53	23	−0.33	+43