LIGHTCURVE PHOTOMETRY OPPORTUNITIES: 2014 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 several lists of asteroids that are prime targets for photometry during the period 2014 July-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) 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 page on the Minor Planet Center web site:

http://www.minorplanetcenter.net/light_cuxrve

We believe this to be the largest publicly available database of raw lightcurve data that contains 1.5 million observations for more than 2300 objects.

Lightcurve Opportunities

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

		Brightest			LCDB Data
#	Name	Date	Mag	Dec	Period	Amp	U
926	Imhilde	07 02.1	14.3	−44	26.8	0.27	2
978	Aidamina	07 03.1	14.0	+6	10.099	0.10–0.13	2
426	Hippo	07 04.9	12.6	−37	34.3	0.15–0.22	2
924	Toni	07 12.0	13.2	−13	21.1	0.1–0.14	1
838	Seraphina	07 12.1	13.8	−10	15.67	0.07–0.30	2
1343	Nicole*	07 13.3	13.7	−32	70.	0.29	1
1269	Rollandia	07 14.9	14.5	−20	15.4	0.02–0.13	2
982	Franklina*	07 15.1	12.6	−25	>16.	0.05	2−
1415	Malautra	07 15.2	14.4	−25	>12.	0.03	1
1249	Rutherfordia	07 16.2	14.4	−17	18.2	0.69–0.81	2+
4826	Wilhelms*	07 17.5	14.3	−40	54.	1.18	2
2569	Madeline	07 17.6	14.4	−33		0.	1
331	Etheridgea	07 17.7	13.6	−30	13.092	0.05–0.12	2
917	Lyka	07 18.8	13.4	−29	7.92	0.14	2
5235	Jean-Loup*	07 19.2	14.3	−15		0.09
6669	Obi*	07 19.8	14.1	−34
3107	Weaver*	07 20.0	14.1	−19
936	Kunigunde*	07 20.8	13.5	−24	8.8	0.25	2
3860	Plovdiv*	07 21.3	14.3	−18	6.114	0.37	2+
1128	Astrid*	07 25.0	14.1	−21	10.228	0.29	2+
605	Juvisia	07 25.1	13.9	−42	15.93	0.24–0.26	2
375	Ursula	07 27.0	11.4	−33	16.83	0.04–0.17	2
1341	Edmee	07 31.8	14.0	−26	23.745	0.22–0.60	2+
6364	Casarini*	08 01.5	14.5	−33
705	Erminia	08 04.2	13.1	−47	53.96	0.05–0.17	2
15673	Chetaev*	08 04.2	14.4	−19
11650	1997 CN*	08 04.3	14.4	−14
739	Mandeville	08 07.3	12.4	−15	11.931	0.14	2
2554	Skiff	08 08.0	14.2	−13
1001	Gaussia	08 09.1	14.1	−5	9.17	0.04–0.16	2−
1236	Thais	08 13.4	14.0	−42	> 72.	0.08	1
609	Fulvia*	08 21.0	14.2	−10	> 12.	0.05	1+
10076	1989 PK*	08 21.1	14.4	−12
2869	Nepryadva*	08 22.2	14.4	−23		0.04–0.1
795	Fini	08 23.7	14.1	−31	9.292	0.02–0.06	1+
1114	Lorraine	08 24.1	14.2	−1	33.	0.16	1
275	Sapientia	08 25.6	13.2	−13	14.766	0.05–0.06	2
548	Kressida	08 28.9	13.7	−15	11.940	0.44	2
1366	Piccolo*	08 30.4	13.7	−20	16.57	0.24–0.33	2
2699	Kalinin	09 04.8	14.5	−34	2.927	0.22–0.24	2+
329	Svea	09 08.5	12.8	+0	22.77	0.09–0.26	2+
395	Delia	09 09.5	13.9	+0	19.71	0.25	2
309	Fraternitas*	09 13.1	13.4	−5	13.2	0.10–0.12	2
857	Glasenappia	09 13.5	13.3	−13	8.23	0.27–0.75	2
439	Ohio	09 15.3	14.4	+10	19.2	0.24	2
1424	Sundmania	09 18.2	14.0	−11	93.73	0.42	2+
2525	O’Steen*	09 18.8	14.2	−6	3.55	0.19–0.22	2
314	Rosalia*	09 19.0	13.1	−3	20.43	0.21–0.40	2
248	Lameia	09 19.9	13.3	+5	12.	0.10	2
842	Kerstin*	09 19.9	14.4	−5
1097	Vicia	09 21.5	13.6	−3	26.5	0.08	1
1271	Isergina	09 22.2	14.1	−8
393	Lampetia*	09 22.5	10.7	+15	38.7	0.12–0.14	2−
791	Ani	09 24.3	12.9	−18	16.72	0.17–0.38	2
1110	Jaroslawa*	09 24.4	12.6	+12	94.432	0.44–0.80	2+
379	Huenna*	09 24.5	11.9	+0	14.14	0.07–0.09	2
2484	Parenago*	09 24.5	13.7	+1
269	Justitia	09 25.6	12.7	−3	16.545	0.14–0.25	2
784	Pickeringia	09 26.1	13.6	−2	13.17	0.20–0.40	2
952	Caia*	09 30.4	11.8	−1	7.51	0.03–0.13	2

An asterisk (*) follows the name if the asteroid is reaching a particularly favorable apparition.

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.”

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 have to 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 tricky. Refer to Harris, et al. (“Phase Relations of High Albedo Asteroids.” Icarus 81, p365 ff) 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.

#	Name	Date	α	V	Dec	Period	Amp	U
552	Sigelinde	07 02.7	0.98	13.3	−20	17.156	0.16	3
514	Armida	07 05.8	0.50	13.1	−21	21.851	0.16–0.42	3
240	Vanadis	07 07.5	0.23	12.8	−22	10.64	0.30–0.34	3
334	Chicago	07 16.8	0.47	12.8	−20	7.361	0.15–0.67	3
49	Pales	07 20.1	0.31	11.8	−20	10.42	0.18–0.20	3
30	Urania	07 20.9	0.27	10.1	−21	13.686	0.11–0.45	3
212	Medea	07 21.8	0.50	12.7	−22	10.283	0.04–0.16	3
27	Euterpe	07 22.2	0.41	10.4	−21	10.4082	0.13–0.21	3
586	Thekla	07 23.5	0.71	13.6	−18	13.670	0.22–0.30	3
861	Aida	07 24.6	0.52	13.2	−21	10.95	0.32	3
888	Parysatis	07 27.5	0.16	13.2	−19	5.9314	0.22–0.26	3
817	Annika	07 31.0	0.25	13.7	−19	10.56	0.16–0.27	3
147	Protogeneia	08 03.4	0.85	12.8	−15	7.8528	0.25–0.28	3
16	Psyche	08 07.1	0.51	9.3	−15	4.196	0.03–0.42	3
739	Mandeville	08 07.4	0.41	12.4	−15	11.931	0.14	2
112	Iphigenia	08 11.1	0.24	11.8	−16	31.466	0.30	3
243	Ida	08 17.0	0.01	13.6	−14	4.634	0.40–0.86	3
96	Aegle	08 18.2	0.42	12.3	−12	13.82	0.05–0.29	3
606	Brangane	08 18.4	0.88	12.3	−11	12.2950	0.20	3−
63	Ausonia	08 24.8	0.56	9.7	−12	9.298	0.15–0.95	3
275	Sapientia	08 25.6	0.69	13.2	−13	14.766	0.05–0.06	2
489	Comacina	09 03.3	0.66	12.8	−06	9.02	0.12–0.39	3
723	Hammonia	09 06.1	0.05	13.7	−07	5.436	0.18	3
760	Massinga	09 06.8	0.96	13.3	−03	10.72	0.12–0.14	3
33	Polyhymnia	09 09.4	0.80	9.8	−07	18.608	0.13–0.20	3
309	Fraternitas	09 13.2	0.31	13.4	−05	13.2	0.10–0.12	2
260	Huberta	09 16.0	0.41	13.0	−04	8.29	0.21–0.27	3
4910	Kawasato	09 18.6	0.65	13.7	−01
314	Rosalia	09 19.0	0.79	13.1	−03	20.43	0.21–0.40	2
373	Melusina	09 23.7	0.60	12.5	−01	12.97	0.20–0.25	3
379	Huenna	09 24.5	0.23	11.9	+00	14.14	0.07–0.09	2
2484	Parenago	09 24.6	0.66	13.7	+01
635	Vundtia	09 26.0	0.04	12.8	+01	11.790	0.15–0.27	3

Shape/Spin Modeling Opportunities

Those doing work for modeling should contact Josef Ďurech at the email address above 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

if looking to add lightcurves for objects already in the DAMIT database.

Below is a partial list of objects reaching brightest this quarter with well-determined periods and are not in the DAMIT database. However, since they have a high U rating, this means there is at least one dense lightcurve of high quality. A second one, along with sparse data, could easily lead to the asteroid being added to DAMIT, thus increasing the total number of asteroids with spin axis and shape models.

Note that you can compare and combine the results of searches using the ephemeris generator and LCDB query (limited to with or without a pole solution) at the sites listed above to create your own customized list of objects.

		Brightest			LCDB Data
#	Name	Date	Mag	Dec	Period	Amp	U
901	Brunsia*	07 02.2	12.5	−21	3.1363	0.11–0.28	3
552	Sigelinde*	07 02.6	13.2	−20	17.156	0.16	3
1157	Arabia*	07 06.4	13.8	−35	15.225	0.37	3
881	Athene*	07 07.6	13.8	−19	13.895	0.39–0.53	3–
2474	Ruby*	07 09.6	14.0	−11	7.42	0.11–0.16	3
1842	Hynek*	07 12.7	13.8	−14	3.941	0.10–0.17	3
939	Isberga*	07 13.8	13.6	−25	2.9173	0.22–0.25	3
634	Ute*	07 20.1	13.1	−15	11.7554	0.14–0.17	3
1666	van Gent*	07 23.8	13.8	−17	4.166	0.30	3
861	Aida*	07 24.6	13.2	−21	10.95	0.32	3
172	Baucis*	07 28.4	11.1	−28	27.417	0.23–0.35	3
805	Hormuthia*	08 02.7	13.4	−3	9.51	0.05	3–
794	Irenaea*	08 09.3	13.6	−12	9.14	0.40	3–
2650	Elinor*	08 09.9	13.5	−23	2.762	0.12–0.18	3
112	Iphigenia*	08 11.1	11.8	−16	31.466	0.30	3
4150	Starr*	08 20.3	13.9	−15	4.5179	0.08–0.20	3
672	Astarte*	08 23.6	14.0	−16	22.572	0.10–0.16	3
883	Matterania*	08 28.7	13.7	−2	5.64	0.36–0.42	3
285	Regina*	09 01.8	14.0	+6	9.542	0.13–0.16	3
4909	Couteau*	09 02.3	14.0	−12
2292	Seili*	09 03.9	13.8	−2	5.121	0.25–0.42	3
723	Hammonia*	09 06.1	13.7	−7	5.436	0.18	3
33	Polyhymnia*	09 09.4	9.8	−7	18.608	0.13–0.21	3
10217	Richardcook*	09 11.8	13.9	−9	23.33	0.45	3−
1641	Tana*	09 14.1	14.0	+1	7.95	0.32–0.33	3−
4910	Kawasato*	09 18.5	13.6	−1
373	Melusina*	09 23.6	12.5	−1	12.97	0.20–0.25	3
635	Vundtia*	09 26.0	12.8	+1	11.79	0.15–0.27	3
84	Klio*	09 26.5	10.8	+14	23.562	0.04–0.21	3

Radar-Optical Opportunities

There are several lists to help plan observations in support of radar.

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

However, 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 using the RSS feeds from the Minor Planet Center

http://www.minorplanetcenter.net/iau/rss/mpc_feeds.html

In particular, monitor the NEA feed 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 if you get data (through Dr. Benner’s email listed above). They may not always be observing the target but, in some cases, 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” 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.

2010 LE15 (Jul-Aug, H = 19.5, PHA)

There are known lightcurve parameters for this NEA. Its estimated diameter is about 400 meters. While possible, it’s not too likely that it is a superfast rotator with a period of < 2 hours.

DATE	RA	Dec	ED	SD	V	α	SE	ME	MP	GB
07/15	23 09.3	+22 01	0.16	1.09	17.8	60.1	112	35	−0.90	−35
07/20	23 23.0	+20 43	0.13	1.08	17.4	59.0	115	44	−0.40	−38
07/25	23 40.8	+18 22	0.11	1.07	16.9	57.9	117	99	−0.04	−41
07/30	00 06.4	+14 01	0.08	1.06	16.2	57.4	119	152	+0.08	−47
08/04	00 47.8	+05 26	0.06	1.04	15.6	58.8	118	152	+0.50	−57
08/09	02 03.4	−11 37	0.04	1.03	15.1	67.7	110	95	+0.95	−67
08/14	04 16.3	−33 48	0.04	1.01	15.7	88.2	89	67	−0.85	−46
08/19	06 36.7	−42 37	0.05	1.00	17.1	105.7	71	66	−0.35	−21

2001 RZ11 (Jul-Sep, H = 16.4, PHA)

The estimated size for this NEA is 1.6 km. It will be moving rapidly north around the middle of August. Fortunately it will be very bright and so short exposures to avoid excessive trailing will be possible even for small telescopes. There are no known lightcurve parameters.

DATE	RA	Dec	ED	SD	V	α	SE	ME	MP	GB
07/10	04 54.9	−53 20	0.61	1.11	17.9	65.3	82	108	+0.91	−39
07/20	04 42.7	−54 16	0.47	1.09	17.4	68.8	86	73	−0.40	−40
07/30	04 12.2	−56 30	0.32	1.08	16.5	70.0	93	98	+0.08	−44
08/09	02 13.8	−59.54	0.16	1.08	14.8	60.5	111	81	+0.95	−54
08/19	20 43.8	−10 59	0.09	1.10	12.3	15.4	163	123	−0.35	−30
08/29	19 07.0	+28 24	0.22	1.13	15.3	51.9	118	97	+0.11	+9
09/08	18 43.7	+36 07	0.38	1.17	16.7	55.8	106	64	+0.98	+17
09/18	18 38.1	+38 50	0.54	1.22	17.5	54.4	100	123	−0.32	+19

(163132) 2002 CU11 (Aug-Sep, H = 18.3, PHA)

Thomas et al. (2014, Icarus 228, 217–246) report 2002 CU11 as a type C/X asteroid. Assuming an albedo for type C, p_V = 0.057, this gives an estimated diameter of 1.2 km. There were no lightcurve parameters found.

DATE	RA	Dec	ED	SD	V	α	SE	ME	MP	GB
08/15	07 26.0	+79 45	0.23	0.95	18.6	99.9	67	82	−0.76	+28
08/20	06 27.7	+76 44	0.16	0.97	17.9	101.8	70	58	−0.26	+25
08/25	05 23.0	+66 24	0.08	0.99	16.6	102.1	73	72	+0.00	+16
08/30	04 18.8	+04 51	0.03	1.01	14.0	85.4	93	139	+0.17	−31
09/04	03 20.9	−62 18	0.08	1.03	15.3	68.8	107	93	+0.67	−47
09/09	02 31.5	−73 41	0.15	1.06	16.7	66.4	106	77	+1.00	−42
09/14	01 50.9	−77 12	0.22	1.08	17.5	64.5	104	95	−0.71	−39
09/19	01 18.3	−78 33	0.30	1.11	18.1	62.6	102	107	−0.23	−38

(276049) 2002 CE26 (Aug-Oct, H = 18.4, Binary)

Shepard et al. (2004, IAUC 8397) using radar observations first reported this NEA as being a binary. Using photometry observations, Pravec et al. (2006, Icarus 181, 63–93) reported a rotation period for the primary of 3.2930 h. The orbital period of the satellite was found to be 15.6 hours. The phase angle bisector longitude will be similar during this apparition as it was during the time of the Pravec et al. observations. This makes it likely that mutual events (occultations or eclipses involving the satellite) will be seen. Given that possibility, high-precision observations, on the order of 0.01–0.02 mag, and – preferably – well-calibrated to at least an internal system will be required.

DATE	RA	Dec	ED	SD	V	α	SE	ME	MP	GB
08/05	21 48.6	+47 16	0.56	1.35	17.9	43.1	115	105	+0.60	−5
08/15	21 44.0	+44 33	0.41	1.28	17.1	42.7	121	59	−0.76	−7
08/25	21 35.3	+36 08	0.27	1.21	15.9	38.5	132	135	+0.00	−12
09/04	21 20.9	+08 00	0.15	1.14	14.0	23.8	153	55	+0.67	−28
09/14	20 52.2	−55 10	0.14	1.08	14.7	53.6	120	110	−0.71	−39
09/24	18 39.6	−83 59	0.25	1.04	16.5	75.1	91	90	+0.00	−27
10/04	11 19.3	−83 22	0.39	1.01	17.5	78.2	80	82	+0.74	−21
10/14	10 20.7	−78 43	0.51	0.99	18.0	76.2	74	103	−0.67	−18