LIGHTCURVE PHOTOMETRY OPPORTUNITIES: 2019 JANUARY-MARCH

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 January-March.

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 italics is a near-Earth asteroid (NEA).

		Brightest				LCDB Data
Number	Name	Date		Mag	Dec	Period	Amp	U
6941	Dalgarno	01	02.4	15.5	+5
7520	1990 BV	01	03.9	15.0	+24
7865	Francoisgros	01	05.3	15.5	+24
7261	Yokootakeo	01	07.0	15.5	+0
2745	San Martin	01	07.9	15.3	−3		0.04
11151	Oodaigahara	01	08.2	15.1	+16
2670	Chuvashia	01	08.4	14.8	+22		0.14
22106	Tomokoarai	01	10.0	15.3	−16
2595	Gudiachvili	01	10.4	15.5	+12	4.72	0.5	1
5131	1990 BG	01	16.1	15.0	+29	37.2	0.34	2−
18348	1990 BM1	01	17.1	14.6	+17
1212	Francette	01	17.6	14.1	+15	22.433	0.13	2
69971	Tanzi	01	19.0	15.0	+21
4970	Druyan	01	19.3	15.5	+19		0.30
449	Hamburga	01	20.2	11.6	+23	18.263	0.08-0.17	2+
3658	Feldman	01	20.7	15.3	+23
4056	Timwarner	01	22.8	15.3	+12
4156	Okadanoboru	01	23.4	15.0	+22	12.015	0.47	2
1435	Garlena	01	25.7	15.0	+12
394130	2006 HY51	01	25.7	13.8	−20
100006	1987 DA7	01	27.0	15.1	+19
4163	Saaremaa	01	27.9	15.1	+18
10111	Fresnel	01	28.8	15.5	+14
27027	1998 QA98	01	29.1	15.4	+19
5924	Teruo	01	31.3	15.5	+20
1269	Rollandia	02	01.9	13.6	+17	19.98	0.02-0.13	2
6258	Rodin	02	02.0	15.3	+17	6.1	0.03	1
3549	Hapke	02	07.6	15.1	+8	7.071	0.24-0.31	2
4148	McCartney	02	08.5	14.6	+16
16058	1999 JP75	02	10.6	15.4	+6
1802	Zhang Heng	02	10.9	15.1	+14	3.162	0.27-0.37	2+
69270	1989 BB	02	13.1	15.1	+13		0.71
4215	Kamo	02	19.4	15.2	+2	12.6	0.11-0.21	2
5297	Schinkel	02	24.0	15.2	+11
488	Kreusa	02	27.1	11.6	+25	32.666	0.08-0.2	2+
2602	Moore	02	27.3	14.9	+8		0.30
2727	Paton	02	28.5	15.0	+4
1614	Goldschmidt	03	02.4	14.3	+7	8.873	0.14-0.14	2−
6918	Manaslu	03	05.4	15.4	+5	8.97	0.21	2
16578	Essjayess	03	07.0	15.5	+5
2761	Eddington	03	07.2	15.4	+9
6843	Heremon	03	10.1	15.2	+14		0.5
37652	1994 JS1	03	11.9	14.9	+5
12265	1990 FG	03	14.8	15.4	+6	56.6	0.65	2
2640	Hallstrom	03	17.5	15.1	+3	22.9	0.15	1
4533	Orth	03	20.1	14.5	+1	>24.	0.1-0.68	2
4171	Carrasco	03	24.9	15.4	−2	33.53	0.17-0.22	2

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
277	Elvira	01	05.2	0.48	13.6	+21	29.69	0.34-0.59	3
638	Moira	01	05.3	0.16	13.9	+23	9.875	0.10-0.31	3
1107	Lictoria	01	06.6	0.37	13.1	+22	8.562	0.16-0.30	3
607	Jenny	01	06.9	0.09	13.8	+22	8.521	0.16-0.26	3
370	Modestia	01	07.8	0.40	13.3	+23	22.530	0.24-1.39	3
24	Themis	01	14.0	0.40	10.7	+23	8.374	0.09-0.14	3
738	Alagasta	01	25.6	0.25	14.0	+18	18.86	0.11-0.20	2
89	Julia	01	31.0	0.16	10.2	+18	11.387	0.10-0.25	3
159	Aemilia	01	31.3	0.22	11.7	+17	24.476	0.16-0.24	3
1269	Rollandia	02	01.8	0.09	13.6	+17	19.98	0.02-0.13	2
65	Cybele	02	04.8	0.47	11.6	+15	6.081	0.02-0.12	3
558	Carmen	02	08.3	0.39	12.7	+14	11.387	0.2 –0.31	3
335	Roberta	02	15.0	0.14	12.5	+13	12.054	0.05-0.78	3
334	Chicago	02	15.1	0.42	13.1	+14	7.361	0.20-0.67	3
208	Lacrimosa	02	19.4	0.52	12.7	+13	14.085	0.15-0.33	3
435	Ella	02	20.4	0.79	13.9	+13	4.623	0.30-0.38	3
108	Hecuba	02	25.5	0.48	12.3	+11	14.256	0.09-0.12	3
64	Angelina	03	02.8	0.50	10.4	+06	8.752	0.04-0.42	3
167	Urda	03	09.1	0.08	13.0	+05	13.07	0.24-0.39	3
50	Virginia	03	16.6	0.14	13.8	+02	14.315	0.07-0.20	3
175	Andromache	03	17.1	0.47	13.7	+03	8.324	0.28-0.30	3
337	Devosa	03	17.1	0.09	11.1	+01	4.653	0.08-0.75	3
59	Elpis	03	18.6	0.56	11.9	+03	13.671	0.07-0.42	3
126	Velleda	03	22.5	0.65	12.7	+01	5.367	0.07-0.22	3
302	Clarissa	03	24.1	0.20	13.9	−01	14.381	0.6	3
291	Alice	03	25.4	0.67	13.3	+00	4.313	0.15-0.55	3
1453	Fennia	03	28.0	0.23	13.7	−02	4.412	0.10-0.20	3
670	Ottegebe	03	29.5	0.76	14.0	−01	10.045	0.34-0.35	3
737	Arequipa	03	30.6	0.55	12.6	−02	7.026	0.10-0.27	3
161	Athor	03	31.3	0.90	12.2	−02	7.280	0.08-0.27	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
651	Antikleia	01	01.8	14.2	+37	20.299	0.13-0.41	3
1562	Gondolatsch	01	05.0	14.4	+19	8.78	0.30- 0.4	3−
1123	Shapleya	01	06.1	13.6	+28	52.92	0.25-0.38	3−
1107	Lictoria	01	06.6	13.1	+22	8.562	0.16-0.30	3
663	Gerlinde	01	07.5	13.5	+1	10.251	0.19-0.35	3
850	Altona	01	11.6	14.2	+18	11.191	0.09-0.17	3
3873	Roddy	01	12.8	14.5	−16	2.478	0.05-0.11	3
9068	1993 OD	01	12.8	14.4	+31	3.407	0.19-0.20	3
418	Alemannia	01	13.6	13.2	+14	4.671	0.14-0.33	3
1309	Hyperborea	01	15.6	14.2	+5	13.88	0.34-0.54	3
1717	Arlon*	01	17.9	13.9	+29	5.148	0.07-0.12	3
420	Bertholda	01	20.1	13.0	+12	11.04	0.24-0.29	3
5806	Archieroy	01	20.8	14.4	+21	12.163	0.34-0.47	3
300	Geraldina	01	23.2	14.2	+21	6.842	0.04-0.32	3
2167	Erin	01	23.8	14.5	+11	5.719	0.3-0.53	3
658	Asteria	01	24.9	14.2	+21	21.034	0.22-0.28	3
224	Oceana	01	25.1	12.3	+26	9.401	0.09-0.14	3
895	Helio	01	26.4	12.7	−10	9.347	0.10-0.23	3
219	Thusnelda	01	27.2	13.2	+3	59.74	0.19-0.24	3
1028	Lydina	01	31.2	13.9	+30	11.68	0.22- 0.7	3
2460	Mitlincoln	02	04.0	14.4	+12	3.01	0.03-0.20	3
909	Ulla	02	07.8	14.1	+12	8.73	0.08-0.24	3
558	Carmen	02	08.3	12.7	+14	11.387	0.2-0.31	3
972	Cohnia	02	12.1	14.3	+6	18.472	0.19-0.21	3
781	Kartvelia	02	16.1	14.4	+17	19.04	0.16-0.28	3−
790	Pretoria	02	21.4	13.7	−14	10.37	0.05-0.18	3
388	Charybdis	02	24.0	13.0	+13	9.516	0.14-0.25	3
454	Mathesis	02	25.0	12.3	+18	8.378	0.20-0.37	3
712	Boliviana	02	25.0	12.1	−10	11.743	0.10-0.12	3
359	Georgia	02	26.3	13.2	+13	5.537	0.16-0.54	3
653	Berenike	02	28.5	13.3	+15	12.489	0.03-0.11	3
779	Nina	03	05.8	12.7	−11	11.186	0.06-0.32	3
1304	Arosa	03	05.9	13.7	+32	7.748	0.13-0.38	3
1590	Tsiolkovskaja	03	09.1	14.3	−1	6.731	0.10- 0.4	3
1084	Tamariwa	03	11.2	14.5	+2	6.196	0.25-0.42	3
100	Hekate	03	17.2	12.5	+8	27.066	0.11-0.23	3
175	Andromache	03	17.2	13.7	+3	8.324	0.28-0.30	3
59	Elpis	03	18.5	11.9	+3	13.671	0.07-0.42	3
696	Leonora	03	20.7	14.7	−15	26.896	0.04-0.31	3
151	Abundantia	03	21.3	12.3	+6	9.864	0.15-0.20	3
111	Ate	03	21.5	11.1	−7	22.072	0.08-0.18	3
851	Zeissia	03	21.8	13.5	+2	9.34	0.38-0.53	3
1146	Biarmia	03	22.3	14.1	−13	5.47	0.20-0.32	3
126	Velleda	03	22.5	12.7	+1	5.367	0.07-0.22	3
1113	Katja	03	22.8	13.8	−12	18.465	0.08-0.17	3
868	Lova	03	23.3	14.4	+6	41.118	0.10-0.40	3
1817	Katanga	03	26.9	14.0	+43	8.481	0.22-0.42	3
1453	Fennia	03	28.0	13.7	−2	4.412	0.10-0.20	3
197	Arete	03	28.8	13.6	+9	6.608	0.10-0.16	3
535	Montague	03	30.3	12.6	+6	10.248	0.18-0.25	3
737	Arequipa	03	30.7	12.6	−2	7.026	0.10-0.27	3
191	Kolga	03	30.8	13.5	+4	17.604	0.21- 0.5	3

Radar-Optical Opportunities

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

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. If “Bin” is followed by “?” it 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

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

The “A” is for Arecibo and “G” is for Goldstone. Note that this calculator assumes full power at Arecibo.

The estimated SNR uses the current MPCORB absolute magnitude (H), a period of 4 hours (2 hours if D ≤ 170 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. This would produce a marginal signal, not enough for imaging, but might allow improving orbital parameters.

(141053) 2001 XT1 (Jan, H = 18.7)

There’s no reported period in the LCDB for this 500-meter NEA. This ephemeris covers the first few days of 2019. If you can, observe it during the last week of 2018 December as well.

DATE	RA		Dec		ED	SD	V	α	SE	ME	MP	GB
01/01	07	08.9	+28	36	0.34	1.32	17.5	5.9	172	116	−0.23	+16
01/02	07	05.1	+28	30	0.35	1.33	17.5	5.0	173	130	−0.15	+15
01/03	07	01.5	+28	24	0.36	1.34	17.5	4.3	174	143	−0.09	+15
01/04	06	58.1	+28	18	0.37	1.35	17.6	4.0	174	15 6	−0.04	+14
01/05	06	54.8	+28	12	0.38	1.36	17.6	4.1	174	168	−0.01	+13
01/06	06	51.7	+28	05	0.39	1.37	17.7	4.5	174	173	+0.00	+12
01/07	06	48.8	+27	59	0.40	1.38	17.8	5.2	173	163	+0.01	+12
01/08	06	46.0	+27	52	0.41	1.39	17.9	6.0	172	151	+0.03	+11
01/09	06	43.4	+27	46	0.42	1.39	18.0	6.8	170	139	+0.08	+11
01/10	06	40.9	+27	39	0.43	1.40	18.1	7.7	169	127	+0.14	+10

(418849) 2008 WM64 (Dec-Jan, H = 20.6)

Both Rowe (2018) and Warner (2018) found a period of 2.4 h based on observations in mid- to late-December of 2017. This makes it a potential binary candidate, so careful observations are in order. Note the ephemeris starts in late December 2018. Make it a New Year’s Resolution.

DATE	RA		Dec		ED	SD	V	α	SE	ME	MP	GB
12/25	03	25.3	+15	24	0.05	1.02	15.5	38.4	140	72	−0.93	−33
12/26	03	07.1	+25	42	0.05	1.02	15.7	41.1	137	87	−0.85	−28
12/27	02	49.9	+33	57	0.06	1.02	16.1	44.8	133	102	−0.76	−23
12/28	02	33.9	+40	21	0.06	1.02	16.4	48.4	129	114	−0.65	−18
12/29	02	19.2	+45	17	0.07	1.03	16.8	51.5	125	124	−0.54	−15
12/30	02	05.8	+49	05	0.08	1.03	17.1	54.2	122	131	−0.43	−12
12/31	01	53.5	+52	04	0.09	1.03	17.4	56.4	119	134	−0.33	−10
01/01	01	42.4	+54	27	0.10	1.03	17.7	58.2	117	134	−0.23	−8
01/02	01	32.3	+56	21	0.11	1.03	17.9	59.6	115	132	−0.15	−6
01/03	01	23.2	+57	55	0.12	1.03	18.2	60.8	113	128	−0.09	−5

2004 XP14 (Jan, H = 19.3, PHA)

The radar observers are hoping for hi-res imaging of this 300 meter NEA. Some astrometry and photometry before, during, and after their runs on Jan 2-5 will be a great help. The bad news is that the period is possibly more than 100 hours. Given that and the short observing window for photometry, a collaboration of several observers at widely separated longitudes is in order.

DATE	RA		Dec		ED	SD	V	α	SE	ME	MP	GB
01/01	04	10.3	+48	00	0.08	1.05	15.4	36.5	141	139	−0.23	−3
01/02	04	01.7	+41	19	0.08	1.04	15.3	36.5	141	153	−0.15	−9
01/03	03	54.4	+34	04	0.07	1.04	15.3	37.7	140	162	−0.09	−15
01/04	03	48.1	+26	29	0.07	1.04	15.3	40.0	137	158	−0.04	−22
01/05	03	42.6	+18	50	0.07	1.04	15.4	43.4	134	145	−0.01	−28
01/06	03	37.9	+11	25	0.08	1.03	15.5	47.4	129	130	+0.00	−34
01/07	03	33.8	+04	27	0.08	1.03	15.7	51.6	125	115	+0.01	−40
01/08	03	30.2	−01	53	0.08	1.03	16.0	55.7	120	100	+0.03	−44
01/09	03	27.0	−07	34	0.09	1.02	16.2	59.6	116	86	+0.08	−48
01/10	03	24.2	−12	34	0.09	1.02	16.4	63.1	112	74	+0.14	−51

433 Eros (Jan-Mar, H = 11.2)

Yes, there’s still reason to observe this NEA even after it was studied in depth by the NEAR-Shoemaker space craft. The main purpose is to extend the time span of observations and so get a good handle on how much the YORP (Yarkovsky–O'Keefe–Radzievskii–Paddack) thermal effect is decreasing or increasing Eros’ period.

DATE	RA		Dec		ED	SD	V	α	SE	ME	MP	GB
01/01	04	13.0	+50	59	0.22	1.16	9.1	33.3	140	136	−0.23	+0
01/11	04	25.0	+43	06	0.21	1.15	9.1	36.0	137	89	+0.21	−4
01/21	04	44.3	+34	15	0.21	1.14	9.2	39.6	133	45	+1.00	−8
01/31	05	08.2	+25	29	0.22	1.13	9.3	43.4	128	174	−0.20	−9
02/10	05	34.7	+17	37	0.24	1.14	9.6	46.7	123	67	+0.22	−8
02/20	06	02.6	+11	07	0.27	1.14	9.9	49.1	119	67	−1.00	−6
03/02	06	31.0	+05	59	0.30	1.15	10.2	50.6	116	159	−0.18	−2
03/12	06	59.7	+02	01	0.34	1.17	10.5	51.2	113	55	+0.26	+3
03/22	07	28.5	−01	02	0.38	1.19	10.8	51.2	111	83	−0.99	+8
04/01	07	57.2	−03	25	0.43	1.21	11.1	50.9	110	147	−0.17	+13

2016 AZ8 (Jan, H = 21.0, PHA)

This is another target for hi-res imaging. It’s also an NHATS target, i.e., a potential target for human missions. The rotation period is not known for the 190 meter NEA.

DATE	RA		Dec		ED	SD	V	α	SE	ME	MP	GB
01/08	17	42.6	+48	09	0.03	0.98	17.2	104.8	74	79	+0.03	+31
01/09	17	03.9	+55	48	0.03	0.98	16.8	95.0	83	92	+0.08	+37
01/10	16	14.1	+61	49	0.03	0.99	16.6	86.1	92	103	+0.14	+42
01/11	15	14.2	+65	47	0.04	0.99	16.5	78.1	100	110	+0.21	+45
01/12	14	10.4	+67	41	0.04	1.00	16.4	71.3	107	114	+0.29	+48
01/13	13	11.8	+67	56	0.04	1.00	16.4	65.5	112	113	+0.38	+49
01/14	12	23.6	+67	08	0.05	1.01	16.5	60.5	117	109	+0.47	+50
01/15	11	46.3	+65	49	0.05	1.01	16.6	56.2	121	102	+0.58	+50
01/16	11	18.0	+64	17	0.05	1.02	16.7	52.6	125	93	+0.68	+50
01/17	10	56.3	+62	44	0.06	1.02	16.7	49.4	128	83	+0.77	+50

(90403) 2003 YE45 (Jan-Mar, H = 17.6)

This is one of two targets this quarter where the date of brightest magnitude is several months removed from the date of closest approach. For 2003 YE45, closest approach is June 29 (0.135 AU). The rotation period for the 900-meter NEA is not known.

DATE	RA		Dec		ED	SD	V	α	SE	ME	MP	GB
01/01	07	56.6	+22	24	0.41	1.38	17.1	12.0	163	105	−0.23	+24
01/11	07	25.3	+16	47	0.36	1.34	16.4	3.8	175	126	+0.21	+15
01/21	06	49.8	+09	53	0.33	1.30	16.7	16.4	158	20	+1.00	+4
01/31	06	17.4	+02	52	0.34	1.26	17.1	30.6	139	156	−0.20	−6
02/10	05	53.3	−03	07	0.35	1.22	17.4	42.9	123	71	+0.22	−14
02/20	05	38.6	−07	47	0.38	1.17	17.8	52.7	110	76	−1.00	−20
03/02	05	31.8	−11	26	0.40	1.13	18.1	60.4	99	136	−0.18	−23
03/12	05	30.7	−14	28	0.42	1.08	18.3	66.7	90	43	+0.26	−24
03/22	05	33.4	−17	13	0.44	1.04	18.4	72.3	83	110	−0.99	−25
04/01	05	38.0	−19	54	0.44	1.00	18.5	77.6	77	110	−0.17	−25

(454177) 2013 GJ35 (Jan-Mar, H = 15.8)

This is one of the larger asteroids in the list: 2.1 km. The rotation period is not known. The first 2-3 weeks of January favor northern observers. Southern observers get the rest of the observing window.

DATE	RA		Dec		ED	SD	V	α	SE	ME	MP	GB
01/01	09	30.5	+32	18	0.27	1.21	14.7	29.9	142	87	−0.23	+46
01/11	08	43.5	+04	40	0.20	1.17	13.7	21.1	155	144	+0.21	+27
01/21	07	40.5	−30	17	0.21	1.13	14.4	42.4	129	51	+1.00	−4
01/31	06	37.6	−49	31	0.30	1.11	15.5	58.4	107	108	−0.20	−22
02/10	05	49.1	−57	19	0.40	1.10	16.3	63.9	95	81	+0.22	−31
02/20	05	17.2	−60	45	0.50	1.09	16.8	64.6	88	96	−1.00	−35
03/02	04	58.3	−62	32	0.60	1.11	17.1	63.2	84	91	−0.18	−37
03/12	04	49.3	−63	43	0.68	1.13	17.4	60.9	83	79	+0.26	−38
03/22	04	48.2	−64	45	0.74	1.16	17.6	58.3	82	102	−0.99	−37
04/01	04	54.5	−65	51	0.79	1.20	17.7	55.7	84	82	−0.17	−36

(18736) 1998 NU (Jan-Mar, H = 15.8)

This NEA also has a diameter of about 2.1 km. There is no rotation period given in the LCDB. Its size virtually assures that the period will be > ≈2.2 hours. The large range of phase angles make this a good subject for finding the H-G parameters.

DATE	RA		Dec		ED	SD	V	α	SE	ME	MP	GB
01/01	07	47.2	+23	15	0.44	1.41	15.4	10.2	165	108	−0.23	+22
01/11	07	45.5	+22	21	0.38	1.36	14.7	3.0	176	130	+0.21	+21
01/21	07	42.3	+21	08	0.33	1.31	14.4	5.0	173	4	+1.00	+20
01/31	07	40.0	+19	34	0.30	1.28	14.5	13.2	163	144	−0.20	+19
02/10	07	41.4	+17	39	0.28	1.25	14.6	20.9	153	97	+0.22	+19
02/20	07	48.9	+15	28	0.27	1.22	14.6	27.5	145	40	−1.00	+20
03/02	08	03.5	+13	05	0.27	1.21	14.8	32.6	139	168	−0.18	+22
03/12	08	24.9	+10	34	0.28	1.21	14.9	36.0	134	74	+0.26	+26
03/22	08	51.8	+07	57	0.29	1.21	15.1	37.9	132	62	−0.99	+30
04/01	09	22.2	+05	19	0.32	1.23	15.3	38.7	130	168	−0.17	+36

(180186) 2003 QZ30 (Jan-Mar, H = 17.4)

The rotation period for the 1-km 2003 QZ30 is not known. The lightcurve shape could be affected by shadowing effects at the large phase angles during the apparition. Expect the unexpected.

DATE	RA		Dec		ED	SD	V	α	SE	ME	MP	GB
01/01	00	12.4	−36	39	0.25	0.93	17.6	95.1	71	120	−0.23	−77
01/08	01	23.1	−36	40	0.21	0.96	17.1	88.9	79	63	+0.03	−78
01/15	02	47.3	−33	15	0.20	1.01	16.6	78.1	91	42	+0.58	−64
01/22	04	10.1	−25	45	0.20	1.05	16.3	64.4	105	84	−0.99	−46
01/29	05	17.2	−16	22	0.22	1.11	16.2	51.5	119	139	−0.38	−28
02/05	06	06.6	−07	53	0.26	1.16	16.4	41.9	128	126	+0.00	−14
02/12	06	42.9	−01	18	0.31	1.22	16.8	35.9	134	61	+0.41	−2
02/19	07	10.5	+03	30	0.37	1.28	17.2	32.7	135	38	+0.99	+6
02/26	07	32.5	+06	56	0.45	1.34	17.6	31.4	135	128	−0.55	+12
03/05	07	51.0	+09	24	0.53	1.41	18.1	31.0	133	149	−0.02	+17

(419880) 2011 AH37 (Jan-Feb, H = 19.5)

There’s no rotation period given in the LCDB for 2011 AH37, which has an estimated diameter of 370 meters. This makes it unlikely to have a super-fast period. However, rules are made to be broken.

DATE	RA		Dec		ED	SD	V	α	SE	ME	MP	GB
01/20	00	35.8	+23	11	0.11	0.97	18.0	95.0	79	86	+0.98	−40
01/23	01	24.8	+36	09	0.10	0.99	17.4	82.8	91	110	−0.95	−26
01/26	02	32.1	+47	25	0.11	1.02	17.1	70.2	104	128	−0.70	−12
01/29	03	53.3	+54	17	0.12	1.04	17.1	59.3	115	139	−0.38	+0
02/01	05	11.9	+56	35	0.14	1.07	17.2	50.9	123	143	−0.13	+10
02/04	06	13.9	+56	03	0.16	1.09	17.4	44.9	129	135	−0.01	+17
02/07	06	58.1	+54	21	0.19	1.12	17.7	40.5	132	117	+0.04	+23
02/10	07	29.3	+52	19	0.21	1.15	17.9	37.4	135	92	+0.22	+27
02/13	07	51.8	+50	20	0.24	1.18	18.2	35.1	137	63	+0.51	+30

(137805) 1999 YK5 (Jan-Feb, H = 16.6)

This is one of the few asteroids with a reported rotation period (Warner, 2016; 3.390 h) and (Aznar et al. 2018, 3.468 h). These differ by more than several times the formal errors. Maybe new observations will lead to a more secure result.

DATE	RA		Dec		ED	SD	V	α	SE	ME	MP	GB
01/01	11	44.2	+46	34	0.47	1.27	17.2	44.0	117	70	−0.23	+66
01/08	11	47.1	+50	44	0.42	1.25	16.8	42.6	121	132	+0.03	+63
01/15	11	44.3	+56	06	0.36	1.23	16.5	41.6	124	110	+0.58	+59
01/22	11	30.0	+62	52	0.32	1.20	16.1	41.8	126	51	−0.99	+52
01/29	10	46.1	+70	51	0.28	1.16	15.8	44.4	124	97	−0.38	+43
02/05	08	26.8	+77	31	0.25	1.12	15.7	50.5	118	120	+0.00	+32
02/12	04	48.1	+74	04	0.23	1.08	15.7	60.4	108	66	+0.41	+18
02/19	03	15.5	+62	17	0.22	1.03	15.9	73.4	94	77	+0.99	+4
02/26	02	39.7	+48	52	0.22	0.97	16.4	88.0	79	143	−0.55	−10
03/05	02	19.8	+36	02	0.24	0.91	17.1	103.4	63	81	−0.02	−23

2013 CW32 (Jan-Feb, H = 16.6)

Despite its diminutive size of 120 meters, this NEA will pass close enough to Earth to provide large SNR values at Arecibo and Goldstone. The rotation period is not known but there’s a good chance that it is shorter than 2 hours. With that in mind, keep exposures as short as possible for the initial observations and until there is a better idea of the period. The rapid sky motion will make short exposures necessary regardless.

DATE	RA		Dec		ED	SD	V	α	SE	ME	MP	GB
01/25	10	46.9	−68	42	0.06	0.98	18.8	88.0	89	75	−0.80	−9
01/27	09	43.5	−55	16	0.04	1.00	17.7	72.8	105	69	−0.59	−2
01/29	09	00.9	−31	45	0.04	1.01	16.5	48.4	130	88	−0.38	+10
01/31	08	32.0	−02	43	0.04	1.02	15.8	20.1	159	125	−0.20	+21
02/02	08	11.9	+19	26	0.05	1.03	16.0	11.2	168	161	−0.07	+26
02/04	07	57.5	+32	39	0.06	1.04	17.0	21.4	157	165	−0.01	+27
02/06	07	47.0	+40	30	0.08	1.05	17.7	29.1	149	140	+0.01	+27
02/08	07	39.1	+45	27	0.10	1.06	18.4	34.3	143	116	+0.09	+27

(455176) 1999 VF22 (Feb, H = 20.6)

The estimated size is 225 meters, large enough that super-fast rotation is not likely but, again, not impossible.

DATE	RA		Dec		ED	SD	V	α	SE	ME	MP	GB
02/12	12	41.0	+15	24	0.14	1.09	18.1	38.5	136	140	+0.41	+78
02/13	12	50.9	+16	01	0.13	1.08	17.9	40.3	135	130	+0.51	+79
02/14	13	03.3	+16	46	0.11	1.07	17.7	42.7	133	119	+0.62	+79
02/15	13	19.1	+17	40	0.10	1.05	17.4	45.9	130	109	+0.72	+79
02/16	13	39.9	+18	43	0.09	1.04	17.2	50.2	126	99	+0.82	+76
02/17	14	08.1	+19	53	0.07	1.03	17.1	56.2	120	92	+0.90	+71
02/18	14	46.7	+21	01	0.06	1.01	16.9	64.6	112	86	+0.96	+63
02/19	15	39.5	+21	41	0.06	1.00	17.0	76.2	101	85	+0.99	+52
02/20	16	46.9	+21	01	0.05	0.99	17.3	91.2	86	88	−1.00	+36
02/21	18	01.0	+18	21	0.05	0.97	18.1	108.1	69	94	−0.97	+19

(381677) 2009 BJ81 (Jan-Mar, H = 20.6)

The rotation period is unknown. Mainzer et al. (2016) give a diameter of 470 meters and an albedo of 0.346.

DATE	RA		Dec		ED	SD	V	α	SE	ME	MP	GB
01/15	09	45.0	+18	31	0.38	1.33	17.8	20.6	152	110	+0.58	+46
01/25	09	58.6	+21	31	0.30	1.27	17.1	16.6	158	33	−0.80	+50
02/04	10	15.5	+26	15	0.23	1.21	16.4	14.9	162	155	−0.01	+55
02/14	10	40.8	+33	16	0.18	1.15	15.9	19.8	157	83	+0.62	+61
02/24	11	27.1	+42	45	0.14	1.11	15.6	31.3	144	64	−0.75	+67
03/06	13	02.0	+52	29	0.11	1.07	15.5	47.5	128	131	+0.00	+65
03/16	15	35.8	+53	51	0.10	1.03	15.8	65.0	110	92	+0.67	+50
03/26	17	37.2	+43	37	0.11	1.01	16.3	77.8	96	64	−0.71	+31

(162361) 2000 AF6 (Feb-Mar, H = 20.1)

The estimated diameter is 280 meters, making this an unlikely super-fast rotation candidate.

DATE	RA		Dec		ED	SD	V	α	SE	ME	MP	GB
02/20	11	58.8	+12	16	0.20	1.17	18.0	22.0	154	20	−1.00	+71
02/23	11	50.6	+14	39	0.18	1.16	17.7	18.5	158	29	−0.84	+71
02/26	11	39.9	+17	28	0.16	1.15	17.3	15.5	162	73	−0.55	+71
03/01	11	26.2	+20	46	0.15	1.14	17.1	14.1	164	113	−0.26	+70
03/04	11	08.7	+24	31	0.14	1.12	16.9	15.8	162	151	−0.06	+67
03/07	10	46.5	+28	40	0.13	1.11	16.9	21.0	156	157	+0.00	+62
03/10	10	18.8	+33	00	0.12	1.10	16.9	28.6	148	118	+0.10	+57
03/13	09	45.1	+37	13	0.11	1.08	17.1	37.6	138	74	+0.35	+50
03/16	09	05.4	+40	53	0.11	1.07	17.2	47.6	128	32	+0.67	+42
03/19	08	21.2	+43	35	0.11	1.05	17.5	57.9	117	37	+0.94	+34

(86667) 2000 FO10 (Mar-Apr, H = 17.6)

Polishook and Brosch (2008) reported a period of 26 hours, but it was very uncertain (U = 1 in the LCDB). They also gave an amplitude of > 0.5 mag. The diameter is about 900 meters.

DATE	RA		Dec		ED	SD	V	α	SE	ME	MP	GB
03/02	04	33.3	−56	28	0.19	0.98	17.1	87.2	82	94	−0.18	−41
03/07	05	58.9	−46	58	0.20	1.03	16.7	74.5	95	89	+0.00	−28
03/12	06	52.0	−35	57	0.21	1.07	16.7	63.9	105	70	+0.26	−15
03/17	07	26.1	−26	05	0.24	1.11	16.8	56.5	112	48	+0.78	−5
03/22	07	50.0	−18	07	0.28	1.14	17.0	51.9	115	78	−0.99	+4
03/27	08	08.2	−11	55	0.32	1.18	17.3	49.3	117	129	−0.61	+11
04/01	08	23.0	−07	10	0.37	1.21	17.6	48.0	116	149	−0.17	+17
04/06	08	35.7	−03	29	0.42	1.23	17.9	47.4	115	106	+0.01	+21

(163081) 2002 AG29 (Feb-Mar, H = 18.4)

The estimated diameter is 620 meters. Skiff (2011) found a secure period of 19.70 h and 0.25 mag lightcurve amplitude. This one’s exclusively for southern observers.

DATE	RA		Dec		ED	SD	V	α	SE	ME	MP	GB
02/01	10	41.2	−42	44	0.30	1.15	18.0	50.9	115	89	−0.13	+14
02/08	10	43.8	−47	45	0.27	1.13	17.8	52.8	115	124	+0.09	+10
02/15	10	45.3	−53	05	0.24	1.10	17.5	55.5	113	100	+0.72	+5
02/22	10	46.0	−58	57	0.21	1.08	17.3	59.1	110	64	−0.92	+0
03/01	10	45.8	−65	43	0.18	1.06	17.1	64.1	106	81	−0.26	−6
03/08	10	45.1	−74	00	0.15	1.03	16.9	70.8	101	101	+0.02	−13
03/15	10	44.2	−84	50	0.13	1.01	16.8	80.0	93	110	+0.56	−23
03/22	22	44.0	−80	11	0.11	0.99	16.9	92.5	81	97	−0.99	−35
03/29	22	45.1	−60	06	0.10	0.96	17.4	108.2	66	53	−0.42	−51
04/05	22	47.6	−37	30	0.10	0.94	18.4	122.7	52	46	+0.00	−62

(88254) 2001 FM129 (Mar-Apr, H = 17.6)

Mainzer et al. (2014) reported a diameter of 800 meters and albedo of 0.252. Thomas et al. (2014) found 2001 FM129 to be a type Q asteroid, which is relatively uncommon among the inner main-belt asteroids.

DATE	RA		Dec		ED	SD	V	α	SE	ME	MP	GB
03/10	02	42.9	+01	05	0.10	0.93	17.6	124.1	51	15	+0.10	−51
03/13	04	16.4	+04	28	0.09	0.97	16.0	103.1	72	13	+0.35	−31
03/16	05	54.6	+07	13	0.09	1.00	15.3	81.0	94	22	+0.67	−9
03/19	07	10.2	+08	28	0.11	1.04	15.2	64.6	109	44	+0.94	+8
03/22	08	00.5	+08	47	0.14	1.07	15.5	54.4	119	75	−0.99	+19
03/25	08	33.8	+08	44	0.17	1.10	15.8	48.3	124	108	−0.80	+27
03/28	08	56.9	+08	35	0.21	1.14	16.2	44.6	127	141	−0.52	+32
03/31	09	13.9	+08	24	0.24	1.17	16.5	42.3	128	169	−0.24	+35
04/03	09	27.1	+08	12	0.28	1.20	16.8	40.9	129	153	−0.05	+38
04/06	09	37.7	+08	00	0.32	1.22	17.2	39.9	128	120	+0.01	+40

(5189) 1990 UQ (Mar-Apr, H = 17.8)

This is second object in the list where dates of brightest and closest are separated by several months. Closest approach for 1990 UQ is July 19 (0.207 AU). It will be only a few degrees from the Sun at that time.

Warner (2018) found a period of 6.676 h and 1.02 mag lightcurve amplitude. Here’s another good opportunity to get an H-G phase curve. Being so faint, it may require very large scopes or careful transformation from clear/no filter to the V standard band.

DATE	RA		Dec		ED	SD	V	α	SE	ME	MP	GB
03/15	12	02.1	+06	37	0.58	1.57	18.0	4.7	173	87	+0.56	+66
03/18	11	57.0	+07	32	0.56	1.55	17.9	4.3	173	42	+0.87	+67
03/21	11	51.4	+08	30	0.54	1.53	17.8	5.6	171	5	−1.00	+67
03/24	11	45.4	+09	30	0.52	1.51	17.8	8.1	168	50	−0.88	+66
03/27	11	39.1	+10	31	0.50	1.49	17.9	11.0	163	91	−0.61	+66
03/30	11	32.5	+11	32	0.49	1.47	17.9	14.2	159	130	−0.33	+66
04/02	11	25.7	+12	33	0.48	1.45	17.9	17.5	154	167	−0.10	+65
04/05	11	18.9	+13	32	0.47	1.42	18.0	20.9	150	154	+0.00	+64
04/08	11	12.1	+14	28	0.46	1.40	18.0	24.3	145	115	+0.07	+64
04/11	11	05.5	+15	21	0.45	1.38	18.0	27.7	140	74	+0.31	+63

Table I.

Summary of radar-optical opportunities in 2018 July-October. Data from the asteroid lightcurve database (Warner et al., 2009; Icarus 202, 134-146). *The SNRs for 2003 SD220 will be enormous: A: 1.76E+6, G: 96800.

Asteroid	Period	Amp	App	Last	R	SNR
(141053) 2001 XT1	-	-	-	-	A	14
NEA					G	-
(418884) 2008 WM64	-	-	-	-	A	1590
NEA					G	90
2004 XP14	>100	-	1	2007	A	1850
NEA					G	210
433 Eros	5.27	0.08	13+	2016	A	900
NEA		1.40			G	100
2016 AZ8	-	-	-	-	A	1850
NEA					G	210
(90403) 2003 YE45	-	-	-	-	A	*52
NEA						June
(454177) 2013 GJ35	-	-	-	-	A	43
NEA
(18736) 1998 NU	-	-	-	-	A	11
NEA
(180186) 2003 QZ30	-	-	-	-	A	14
NEA
(419880) 2011 AH37	-	-	-	-	A	40
NEA
(137805) 1999 YK5	3.930	0.09	2	2016	A	55
NEA		0.38
2013 CW32	-	-	-	-	A	510
NEA					G	55
(455176) 1999 VF22	-	-	-	-	A	370
NEA					G	41
(381677) 2009 BJ81	-	-	-	-	A	10
NEA
(162361) 2000 AF6	-	-	-	-	A	20
NEA
(86667) 2000 FO10	26	0.7	1	2004	A	32
NEA		1.0
(163081) 2002 AG29	19.70	0.25	1	2011	A	299
NEA					G	26
(88254) 2001 FM129	-	-	-	-	A	300
NEA					G	33
(5189) 1990 UQ	6.676	1.02	1	2017	A	*11
NEA						July