Abstract
Lightcurves for 46 near-Earth asteroids (NEAs) obtained at the Center for Solar System Studies-Palmer Divide Station (CS3-PDS) from 2016 July-September were analyzed for rotation period and signs of satellites or tumbling.
CCD photometric observations of 46 near-Earth asteroids (NEAs) were made at the Center for Solar System Studies-Palmer Divide Station (CS3-PDS) from 2016 July-September. Table I lists the telescope/CCD camera combinations used for the observations. All the cameras use CCD chips from the KAF blue-enhanced family and so have essentially the same response. The pixel scales for the combinations range from 1.24–1.60 arcsec/pixel.
Table I.
List of CS3-PDS telescope/CCD camera combinations.
| Desig | Telescope | Camera |
|---|---|---|
| Squirt | 0.30-m f/6.3 Schmidt-Cass | ML-1001E |
| Borealis | 0.35-m f/9.1 Schmidt-Cass | FLI-1001E |
| Eclipticalis | 0.35-m f/9.1 Schmidt-Cass | STL-1001E |
| Australius | 0.35-m f/9.1 Schmidt-Cass | STL-1001E |
| Zephyr | 0.50-m f/8.1 R-C | FLI-1001E |
All lightcurve observations were unfiltered since a clear filter can result in a 0.1–0.3 magnitude loss. The exposure duration varied depending on the asteroid’s brightness and sky motion. Guiding on a field star sometimes resulted in a trailed image for the asteroid. If necessary, an elliptical aperture with the long axis parallel to the asteroid’s path was used.
Measurements were made using MPO Canopus. The Comp Star Selector utility in MPO Canopus found up to five comparison stars of near solar-color for differential photometry. Catalog magnitudes were usually taken from the CMC-15 (http://svo2.cab.inta-csic.es/vocats/cmc15/) or APASS (Henden et al., 2009) catalogs. The MPOSC3 catalog was used as a last resort. This catalog is based on the 2MASS catalog (http://www.ipac.caltech.edu/2mass) with magnitudes converted from J-K to BVRI (Warner, 2007). The nightly zero points for the catalogs are generally consistent to about ± 0.05 mag or better, but on occasion reach 0.1 mag and more. There is a systematic offset among the catalogs so, whenever possible, the same catalog is used throughout the observations for a given asteroid. Period analysis is also done with MPO Canopus, which implements the FALC algorithm developed by Harris (Harris et al., 1989).
In the plots below, the “Reduced Magnitude” is Johnson V as indicated in the Y-axis title. These are values that have been converted from sky magnitudes to unity distance by applying –5*log (rΔ) to the measured sky magnitudes with r and Δ being, respectively, the Sun-asteroid and Earth-asteroid distances in AU. The magnitudes were normalized to the given phase angle, e.g., alpha(6.5°), using G = 0.15, unless otherwise stated. The X-axis is the rotational phase, ranging from –0.05 to +1.05.
For the sake of brevity, only some of the previously reported results may be referenced in the discussions on a specific asteroid. For a more complete listing, the reader is directed to the asteroid lightcurve database (LCDB; Warner et al., 2009). The on-line version at http://www.minorplanet.info/lightcurvedatabase.html allows direct queries that can be filtered a number of ways and the results saved to a text file. A set of text files of the main LCDB tables, including the references with bibcodes, is also available for download. When possible, readers are strongly encouraged to check against the original references listed in the LCDB.
If the plot includes an amplitude, e.g., “Amp: 0.65”, this is the amplitude of the Fourier model curve and not necessarily the adopted amplitude for the lightcurve. The value is provided as a matter of convenience.
433 Eros.
This well-known and extensively studied NEA was observed twice at PDS in 2016, first in July and then in late August. During the approximately six-week interval between data sets, the lightcurve shape and amplitude evolved significantly as the asteroid went from phase angle 28° to 10°. The lower amplitude at a lower phase angle is a well-established trait of most asteroid lightcurves (Zappala et al., 1990).
1863 Antinous.
Binzel (1987) first reported a period of 4.02 h. Harris et al. (1999) observed the asteroid at about the same time in 1982 and found a period of 4.386 h. Observations by Pravec et al. (1999w) led to a more reliable solution of 7.4568 h. The NEA was observed at CS3-PDS in early 2016 (Warner, 2016a; 7.453 h). The latest PDS observations made in 2016 August led to a period of 7.471 h, which is consistent with the Pravec et al. and earlier PDS results.
2100 Ra-Shalom.
The period for Ra-Shalom was first established at 19.79 h by Ostro et al. (1984). The period found from the 2016 PDS data is slightly longer, 19.89 h, but still consistent with earlier results.
3352 McAuliffe.
This is a suspected binary asteroid (Warner, 2012). No signs of the purported satellite were seen at the 2016 apparition.
5143 Heracles.
This is a known binary (Taylor et al., 2012) based on radar observations. The estimated effective diameter ratio is about 0.16 and the orbital period in the range of 14–17 hours. The small size ratio is on the edge of being detectable with photometry observations alone, so it is not too surprising that the satellite had not been discovered before the radar observations.
(5587) 1990 SB.
Koff et al. (2002) did an extensive study of 1990 SB that included observations from before and after opposition. This allowed showing the evolution of the lightcurve shape and synodic period over several months. The period found from the 2016 PDS data is consistent with the average period from Koff et al. and other previous results.
(5836) 1993 MF.
The period of 4.953 h found from the PDS data is consistent with earlier results such as Mottola et al. (1995; 4.959 h) and Pravec et al. (1997w; 4.9543 h). The NEA was observed in 2016 June (Warner, 2016c; 4.948 h) when the amplitude was 0.82 mag. The 0.88 mag found in September is the largest found in the LCDB for 1993 MF.
(7341) 1991 VK.
Pravec et al. (1998) found a period of 4.2096 h. The period of 4.211 h derived from the 2016 PDS data is consistent with that earlier result.
It’s of some note that the AKARI survey (Usui et al., 2011) reported a very high albedo, pV = 0.625, which is somewhat unusual within the NEA population. Even if using a different absolute magnitude, H =16.95 (Pravec et al., 2012), and the correcting algorithm of Harris and Harris (1997), the albedo is still 0.49 ± 0.10. This is more consistent with type E (possibly type M) asteroids (Warner et al., 2009) rather than the more typical S-complex or, to a lesser extent, C-complex types seen among the NEA population.
The asteroid has a very favorable apparition in 2017 February, at which time it will be a strong radar target. Supporting photometric observations are encouraged. The close encounter may also allow spectroscopic observations of the asteroid that will help determine its true taxonomic class.
(7888) 1993 UC.
The PDS observations in 2016 led to a period of 2.337 h, which is consistent with the 2.340 h found by Pravec et al. (1996). Unfortunately, there appears to be no results between these two, making it difficult – if not impossible – to determine if the rotation period is being affected by YORP.
(10636) 1998 QK56.
The results from PDS appear the first to be reported for this NEA. The asteroid has a favorable apparition in 2017 March, when it will reach V ~ 15.2 mag. Follow-up observations at PDS are planned. Other observations are encouraged.
(162117) 1998 SD15.
There were no previously reported periods in the LCDB for 1998 SD15. The 2016 apparition was the last good chance for photometric observations until 2025 September, when the asteroid will reach V ~ 17.0. Before then, it is mostly below 20th magnitude.
(16834) 1997 WU22.
The usual lightcurve shape for 1997 WU22 may have been due in good part to the high phase angle, when shadowing effects can come into play. The period agrees with Pravec et al. (2000w; 9.345h) and Stephens (2013w; 9.374 h).
(40263) 1999 FQ5.
There were no other periods in the LCDB for 1999 FO5. The next favorable apparition is not until 2036.
(52750) 1998 KK17.
Higgins (2005) reported a period of 3.124 h for this NEA while the author (Warner, 2015) reported 2.28 h. Neither of these fit the single period analysis of the data.
A plot of the raw data from late August to early September showed indications of a long period with, possibly, a short-period component as well. On this presumption, a dual-period search was done using MPO Canopus where a solution for a long period was found and then subtracted from the data to determine if there was a short period. The short period was subtracted to confirm the long period. The process continued until both periods stabilized. The results are shown in the four plots, two being period spectra and the others the individual components of the combined lightcurve.
Note that the short period is very close to the one found by Higgins. It’s possible that by using arbitrary zero-point adjustments, the long period was unintentionally removed, which serves as a cautionary tale to “let the data fall where they may” until there is good reason to do otherwise.
1998 KK17 may be another example of a so-called very wide binary asteroid. See Warner (2016b) for a discussion of this suspected subclass of binary asteroids.
(68346) 2001 KZ66.
Based on radar observations, Benner et al. (2006) estimated a rotation period of about 2.7 hours. Subsequent photometric observations by the author in 2016 May (Warner, 2016c) found a more likely period of 4.987 h. The more recent PDS data, obtained in 2016 July, support the longer period, though it may need further refinement at the next favorable apparition (2022, V ~ 18.4).
(87684) 2000 SY2.
Higgins (2005) found a period of 8.80 hours. The 2016 PDS data do not support that result, but favor one of 2.8712 h.
(106538) 2000 WK63.
This appears to be the first reported period for 2000 WK63. The next good chance to obtain follow-up data comes in 2020 March.
Based on times to dampen from tumbling (non-principal axis rotation) to single axis rotation (Pravec et al., 2014, and references therein), there is a reasonable chance that this asteroid should be tumbling. There were no obvious signs of tumbling, e.g., the slope of the data on a given night not following the slope of the Fourier curve. A better judgement of tumbling would require following the asteroid through at least another quarter rotation to see if the lightcurve repeated itself within the data noise level.
(154244) 2002 KL6.
Koehn et al. (2014) followed this NEA for several months in 2009. The approximate average of the several synodic periods was 4.608 h, which is essentially identical to the period found with the 2016 PDS data.
(162117) 1998 SD15 , (163348) 2002 NN4.
These are the first reported results in the LCDB for these two NEAs.
(250458) 2004 BO41.
There were no previously reported periods for 2004 BO41 in the LCDB. There were several solutions, each commensurate with an Earth day. However, the best solution, based on the slopes of the lightcurve, is for a period of 16.19 h.
(257838) 2000 JQ66.
Using observations from 2000, Pravec et al. (2000w) found a period of 11.1 hours. The PDS data from 2016 led to a consistent and slightly more refined result of 11.094 h.
(347813) 2002 NP1, (357024) 1999 YR14.
There were no previous entries in the LCDB for 2002 NP1 and 1999 YR14.
Spectroscopic observations by Thomas et al. (2014) determined that 2002 NP1 is a type Q asteroid on the Bus-DeMeo taxonomic system (DeMeo et al., 2009, and references therein). The Q asteroids, 1862 Apollo being one of the well-known members, are uncommon among the inner main-belt. They are an “outlier” class in the Bus-DeMeo system, being an intermediate type between the Vestoids (V) and much more common S-complex.
(370307) 2002 RH52.
The period found from the 2016 PDS data agrees well with the one of 4.222 h found by Pravec et al. (2003w).
(385343) 2002 LV.
Pravec et al. (2002w) and Hicks et al. (2009w) both reported a period of about 6.20 h. The results from the PDS observation agree with that period.
(452389) 2002 NW16.
There were no previous results in the LCDB to help guide finding the period for 2002 NW16. The period appears commensurate with an Earth day. Based on a half-period solution and the reasonable slopes of the Fourier curve, a period of 46.7 h is adopted for this paper. The amplitude of 0.67 mag could be off significantly from the true value.
(464797) 2004 FZ1.
This appears to be another example of a very wide binary asteroid. The lightcurve for these objects consists of a long-period component with an amplitude A > 0.3 mag and a short-period component with a smaller amplitude, usually A < 0.15 mag. The primary body is presumed to the one with the long period. See Warner (2016b) for more about these asteroids.
(467336) 2002 LT38.
This appears to be the first published period for 2002 LT38. Even when assuming a longer damping time from tumbling to single axis rotation (Pravec et al., 2014, and references therein), the 21.8 hour period found here makes this a likely tumbler candidate. There may be some indications of tumbling in the lightcurve, for example, the “break” in the Fourier curve around 0.45 rotation phase.
(468448) 2003 LS3.
This NEA was observed twice at PDS in 2016. The first time was in July, when a period of 5.325 h and amplitude of 0.32 mag were found. The phase angle was about 23°. About six weeks later, the synodic period was statistically the same, but the amplitude had dropped to 0.23 mag, which was expected due to the lower phase angle of about 8°.
(469513) 2003 QR79, (469634) 2004 SZ19, (470510) 2008 CJ116.
These look to be the first reported periods for the three NEAs. The low amplitude and significant noise in the lightcurve for 2003 QR79 make the solution less than secure, but it is still a reasonable estimate. The gap in the lightcurve for 2004 SZ19 is partly due to the adopted period being commensurate with an Earth day. Every 48 hours, approximately the same part of the lightcurve was covered. The gap was outside the observing window between the asteroid rising and setting or start of twilight.
The period for 2008 CJ116 makes it a good candidate for being a tumbler. However, there were no obvious signs in the data set. See Pravec et al. (2005) for a detailed discussion of tumbling asteroids.
(471241) 2011 BX18.
The high phase angle at which the observations of 2011 BX18 were made introduced the likelihood of strong shadowing effects that would produce an atypical lightcurve. Combined with possible solutions commensurate with an Earth day, a definitive solution could not be found. The period spectrum favored 4.828 hours. However, as seen in the alternate lightcurve, the data fit almost as well to a period of 4.023 h. The two periods represent a difference of almost exactly one rotation over 24 hours.
1999 SO5.
While the period spectrum allows for several possible solutions, the dominant one is the most physically plausible (see Harris et al., 2014). The alternate solutions represent either the half-period or integral multiples of the half-period greater than the adopted period of 1.380 hours.
2005 TF.
This is the first reported period for 2005 TF.
2009 ES.
The very high noise in the data makes any solution suspect. However, there did appear to be two components to the lightcurve, making it another potential very wide binary candidate (see Warner, 2016b). For the long period, the period spectrum settled between 25 and 30 hours, with 28.1 h adopted here. It’s hardly conclusive. Subtracting the resulting Fourier model curve produces a relatively convincing solution of 2.988 h, despite the noise being nearly greater than the amplitude.
Unfortunately, the 2016 apparition was the last time the asteroid will be brighter than V ~ 21 through 2050.
2013 TV5.
The maximums of the lightcurve for 2013 TV are not 0.5 rotation phase apart, but the minimums nearly are. Such asymmetry is not impossible, especially at higher phase angles. However, it does make the solution at least somewhat suspect.
On the other hand, the period spectrum shows only a few obvious possibilities and the longer periods produce physically improbable lightcurves with multiple maximum/minimum pairs.
2014 KD91.
There were no previously reported periods in the LCDB for 2014 KD91. Given the extensive coverage of the lightcurve and time span of the observations, the period is considered secure despite the low amplitude and somewhat noisy data set.
2016 NA1.
The period of 8.67 hours adopted here is considered a “best guess” given the low amplitude and noisy data set. The period spectrum offered little help, showing a number of nearly likely solutions.
2016 PN1.
This asteroid faded from view too soon, and so it was not possible to get a more complete data set. The period of 76 hours is a best fit to the data, but it is likely wrong.
2016 RB1.
The estimated diameter of only 7 meters made 2016 RB1 an excellent candidate for being a super-fast rotator (P < 1 hour). For this reason, exposures were kept to 10 seconds in order to avoid rotational smearing (see Pravec et al., 2000). This would work only if the rotation period was greater than about 50 seconds.
The raw lightcurve showed what appeared to be just noise but, given the possibility for a very short period, a search was made from 0.001 to 2.5 hours in 0.001 h steps. This lead to the approximate period of 0.027 h, which was further refined to 0.02674 h.
2016 NH15.
The adopted period of 52.6 h makes this a good tumbling candidate. The data set was too limited and noisy to see any obvious signs of tumbling.
2016 NG33.
A period of 2.321 hours is adopted for this paper. However, as the period spectrum shows, a number of other solutions are possible. The amplitude of 0.25 mag lends support to the adopted period (see Harris et al., 2014).
2016 RP33.
There were no previous entries in the LCDB for this NEA.
2016 LX48.
Initial analysis of the data set led to a solution of about 3.8 hours, which produced a bimodal lightcurve. At large phase angles, this is not always a good assumption. Soon after the PDS observations, Amadeo Aznar in Spain also made observations of the asteroid. His analysis showed that a period of about 5.5 hours was more likely (Aznar, private communications).
Another search was made with the PDS data set, which led to the adopted period of 5.669 h for this paper, despite the unusual shape of the lightcurve and the fact that the PDS data fit almost as well to the 3.8 hour period.
2016 CL264.
There were no previous entries in the LCDB for this NEA. The sparse coverage of the lightcurve makes the period less than certain. However, as with some earlier cases, a search on half-periods and the slopes of the Fourier curve make the adopted period a good “best estimate.”
Table III.
Observing circumstances. Pts is the number of data points used in the analysis. The phase angle (α) is given at the start and end of each date range, unless it reached a minimum, which is then the second of three values. If a single value is given, the phase angle did not change significantly and the average value is given. LPAB and BPAB are, respectively the average phase angle bisector longitude and latitude, unless two values are given (first/last date in range). Grp is the orbital group of the asteroid. See Warner et al. (LCDB; 2009; Icarus 202, 134–146.).
| Number | Name | 2016 mm/dd | Pts | Phase | LPAB | BPAB | Period | P.E. | Amp | A.E. | Grp |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 433 | Eros | 07/04–07/06 | 223 | 28.8,28.2 | 326 | 2 | 5.271 | 0.001 | 0.47 | 0.01 | NEA |
| 433 | Eros | 08/29–08/31 | 1272 | 9.2,10.4 | 329 | 9 | 5.270 | 0.001 | 0.33 | 0.01 | NEA |
|
| |||||||||||
| 1863 | Antinous | 08/06–08/10 | 159 | 42.6,40.2 | 7 | 0 | 7.471 | 0.005 | 0.33 | 0.02 | NEA |
| 2100 | Ra-Shalom | 08/10–08/20 | 287 | 57.2,54.5 | 12 | 4 | 19.89 | 0.05 | 0.55 | 0.03 | NEA |
| 3352 | McAuliffe | 09/25–09/27 | 156 | 23.2,22.5 | 34 | −7 | 2.212 | 0.002 | 0.12 | 0.02 | NEA |
| 5143 | Heracles | 09/12–09/17 | 133 | 31.4,31.8 | 52 | 11 | 2.704 | 0.002 | 0.15 | 0.03 | NEA |
| 5587 | 1990 SB | 08/05–08/10 | 129 | 38.4,37.2 | 23 | 2 | 5.0520 | 0.0005 | 0.70 | 0.02 | NEA |
| 5836 | 1993 MF | 09/09–09/11 | 212 | 45.9,44.7 | 31 | 11 | 4.953 | 0.005 | 0.88 | 0.02 | NEA |
| 7341 | 1991 VK | 09/05–09/08 | 142 | 20.8,19.5 | 8 | 8 | 4.211 | 0.003 | 0.21 | 0.03 | NEA |
| 7888 | 1993 UC | 09/09–09/15 | 109 | 42.4,44.4 | 52 | −25 | 2.337 | 0.002 | 0.16 | 0.02 | NEA |
| 10636 | 1998 QK56 | 09/12–09/15 | 163 | 2.7,0.2 | 353 | 0 | 9.84 | 0.01 | 0.32 | 0.03 | NEA |
| 16834 | 1997 WU22 | 08/06–08/10 | 365 | 79.9,74.2 | 275 | 38 | 9.343 | 0.005 | 0.60 | 0.02 | NEA |
| 40263 | 1999 FQ5 | 08/29–09/11 | 211 | 48.6,46.3 | 25 | −8 | 28.00 | 0.05 | 0.27 | 0.03 | NEA |
| 52750 | 1998 KK17 | 08/26–09/08 | 259 | 47.6,54.0 | 29 | −14 | 26.43 | 0.05 | 0.24 | 0.01 | NEA |
| 68346 | 2001 KZ66 | 07/17–07/19 | 123 | 67.3,69.3 | 269 | 46 | 4.996 | 0.003 | 0.35 | 0.02 | NEA |
| 87684 | 2000 SY2 | 08/22–09/04 | 216 | 59.5,51.8 | 32 | −13 | 2.8712 | 0.0004 | 0.09 | 0.01 | NEA |
| 106538 | 2000 WK63 | 08/21–09/01 | 224 | 64.8,52.4 | 278 | 11 | 51.2 | 0.2 | 0.60 | 0.04 | NEA |
| 154244 | 2002 KL6 | 09/09–09/11 | 210 | 40.9,38.7 | 14 | 7 | 4.609 | 0.005 | 0.92 | 0.02 | NEA |
| 162117 | 1998 SD15 | 09/12–09/15 | 402 | 71.2,62.5 | 345 | 40 | 7.33 | 0.01 | 0.26 | 0.03 | NEA |
| 163348 | 2002 NN4 | 08/04–08/09 | 196 | 20.2,19.9,20.6 | 316 | 14 | 14.50 | 0.03 | 0.74 | 0.05 | NEA |
| 250458 | 2004 BO41 | 09/15–09/28 | 1398 | 85.2,61.6 | 330 | 39 | 16.19 | 0.01 | 0.85 | 0.05 | NEA |
| 257838 | 2000 JQ66 | 07/03–07/08 | 254 | 38.0,12.4,36.8 | 281 | 15 | 11.094 | 0.005 | 0.63 | 0.03 | NEA |
| 347813 | 2002 NP1 | 08/02–08/05 | 177 | 29.1,27.4 | 337 | 6 | 5.915 | 0.005 | 0.86 | 0.03 | NEA |
| 357024 | 1999 YR14 | 08/30–09/01 | 1085 | 57.7,63.9 | 7 | −16 | 4.2477 | 0.0005 | 1.19 | 0.03 | NEA |
| 370307 | 2002 RH52 | 09/23–09/27 | 171 | 36.0,36.3 | 37 | 9 | 4.218 | 0.003 | 0.78 | 0.03 | NEA |
| 385343 | 2002 LV | 07/03–07/05 | 138 | 36.4,37.3 | 254 | 36 | 6.20 | 0.01 | 0.51 | 0.03 | NEA |
| 452389 | 2002 NW16 | 07/07–07/16 | 196 | 67.5,65.8 | 334 | 0 | 46.7 | 0.2 | 0.65 | 0.05 | NEA |
| 464797 | 2004 FZ1 | 08/11–08/17 | 1754 | 51.1,31.6 | 338 | 26 | 45.4 | 0.2 | 0.39 | 0.03 | NEA |
| 467336 | 2002 LT38 | 06/27–07/06 | 391 | 66.2,87.2 | 238 | 14 | 21.80 | 0.05 | 1.16 | 0.05 | NEA |
|
| |||||||||||
| 468448 | 2003 LS3 | 07/05–07/08 | 146 | 23.7,23.2 | 299 | 16 | 5.325 | 0.005 | 0.32 | 0.02 | NEA |
| 468448 | 2003 LS3 | 08/23–08/25 | 148 | 8.5,8.3 | 327 | 4 | 5.329 | 0.005 | 0.02 | 0.02 | NEA |
|
| |||||||||||
| 469513 | 2003 QR79 | 09/02–09/04 | 95 | 11.4,15.3 | 335 | 7 | 4.11 | 0.01 | 0.18 | 0.03 | NEA |
| 469634 | 2004 SZ19 | 08/25–08/28 | 234 | 31.3,28.0 | 353 | 13 | 16.39 | 0.03 | 0.34 | 0.04 | NEA |
| 470510 | 2008 CJ116 | 12/31–12/31 | 445 | 31.3,0.0,28.0 | 0 | 0 | 32.26 | 0.01 | 1.00 | 0.03 | NEA |
| 471241 | 2011 BX18 | 08/05–08/09 | 337 | 73.0,61.3 | 356 | 14 | 4.828 | 0.005 | 0.27 | 0.02 | NEA |
| 1999 SO5 | 09/28–09/30 | 194 | 29.1,26.4 | 24 | 5 | 1.380 | 0.001 | 0.73 | 0.03 | NEA | |
| 2005 TF | 09/28–10/02 | 163 | 15.8,13.9 | 18 | −3 | 2.57 | 0.005 | 0.29 | 0.03 | NEA | |
| 2009 ES | 09/10–09/14 | 960 | 37.2,44.3 | 332 | 16 | 28.0 | 0.5 | 0.33 | 0.04 | NEA | |
| 2013 TV5 | 09/27–09/28 | 287 | 41.6,43.4 | 340 | 12 | 0.8367 | 0.0002 | 0.42 | 0.03 | NEA | |
| 2014 KD91 | 09/13–09/26 | 250 | 31.3,25.8 | 19 | 19 | 2.829 | 0.001 | 0.15 | 0.02 | NEA | |
| 2016 NA1 | 08/02–08/04 | 268 | 13.5,15.6 | 317 | 7 | 8.67 | 0.05 | 0.14 | 0.04 | NEA | |
| 2016 PN1 | 09/03–09/09 | 342 | 38.4,35.1 | 10 | 6 | 76 | 1 | 0.16 | 0.03 | NEA | |
| 2016 RB1 | 09/07–09/07 | 422 | 0.0,0.0 | 0 | 0 | 0.02674 | 0.00001 | 0.18 | 0.03 | NEA | |
| 2016 NH15 | 07/25–07/31 | 230 | 13.6,14.3 | 309 | 9 | 52.6 | 0.5 | 0.29 | 0.04 | NEA | |
| 2016 NG33 | 08/05–08/06 | 205 | 36.9,35.3 | 335 | −3 | 2.321 | 0.003 | 0.25 | 0.04 | NEA | |
| 2016 RP33 | 09/18–09/24 | 411 | 4.6,6.6 | 357 | 1 | 4.682 | 0.002 | 0.15 | 0.03 | NEA | |
| 2016 LX48 | 09/09–09/11 | 614 | 85.5,79.1 | 312 | 27 | 5.669 | 0.002 | 0.45 | 0.03 | NEA | |
| 2016 CL264 | 08/07–08/10 | 601 | 102.5,75.9 | 93 | −9 | 19.9 | 0.1 | 0.57 | 0.05 | NEA | |
Acknowledgements
Thanks to Amado Aznar for his comments and suggestions regarding 2016 LX48.
Funding for PDS observations, analysis, and publication was provided by NASA grant NNX13AP56G. Work on the asteroid lightcurve database (LCDB) was also funded in part by National Science Foundation grant AST-1507535.
This research was made possible in part based on data from CMC15 Data Access Service at CAB (INTA-CSIC) (http://svo2.cab.inta-csic.es/vocats/cmc15/) and the AAVSO Photometric All-Sky Survey (APASS), funded by the Robert Martin Ayers Sciences Fund.
This publication makes use of data products from the Two Micron All Sky Survey, which is a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center/California Institute of Technology, funded by the National Aeronautics and Space Administration and the National Science Foundation. (http://www.ipac.caltech.edu/2mass/)
References
- Benner LAM, Nolan MC, Ostro SJ, Giorgini JD, Pray DP, Harris AW, Magri C, Margot J-L. (2006). “Near-Earth Asteroid 2005 CR37: Radar images and photometry of a candidate contact binary.” Icarus 182, 474–481. [Google Scholar]
- Binzel RP. (1987). “A photoelectric survey of 130 asteroids.” Icarus 72, 135–208. [Google Scholar]
- DeMeo FE, Binzel RP, Slivan SM, Bus SJ. (2009). “An Extension of the Bus Asteroid Taxonomy into the Near-Infrared.” Icarus 202, 160–180. [Google Scholar]
- Harris AW, Young JW, Bowell E, Martin LJ, Millis RL, Poutanen M, Scaltriti F, Zappala V, Schober HJ, Debehogne H, Zeigler KW. (1989). “Photoelectric Observations of Asteroids 3, 24, 60, 261, and 863.” Icarus 77, 171–186. [Google Scholar]
- Harris AW, Harris AW. (1997). “On the Revision of Radiometric Albedos and Diameters of Asteroids.” Icarus 126, 450–454. [Google Scholar]
- Harris AW, Young JW, Bowell E, Tholen DJ. (1999). “Asteroid Lightcurve Observations from 1981 to 1983.” Icarus 142, 173–201. [Google Scholar]
- Harris AW, Pravec P, Galad A, Skiff BA, Warner BD, Vilagi J, Gajdos S, Carbognani A, Hornoch K, Kusnirak P, Cooney WR, Gross J, Terrell D, Higgins D, Bowell E, Koehn BW. (2014). “On the maximum amplitude of harmonics on an asteroid lightcurve.” Icarus 235, 55–59. [Google Scholar]
- Henden AA, Terrell D, Levine SE, Templeton M, Smith TC, Welch DL. (2009). http://www.aavso.org/apass
- Hicks M, Rhoades H, Somers J, Grote M. (2009w). Astronomer’s Telegram 2134. http://www.astronomerstelegram.org [Google Scholar]
- Higgins DJ. (2005). “Lightcurve and period determination for 479 Caprera, 2351 O’Higgins (36378) 2000 OL19, (52750) 1998 KK17, (87684) 2000 SY2.” Minor Planet Bul 32, 36–38. [Google Scholar]
- Koehn BW, Bowell ELG, Skiff BA, Sanborn JJ, McLelland KP, Pravec P, Warner BD. (2014). “Lowell Observatory Near-Earth Asteroid Photometric Survey (NEAPS) - 2009 January through 2009 June.” Minor Planet Bul 41, 286–300. [Google Scholar]
- Koff RA, Pravec P, Sarounova L, Kusnirak P, Brincat S, Goretti V, Sposetti S, Stephens R, Warner B. (2002). Collaborative Lightcurve Photometry of Asteroid (5587) 1990 SB.” Minor Planet Bul 29, 51–53. [Google Scholar]
- Mottola S, De Angelis G, Di Martino M, Erikson A, Hahn G, Meukum G. (1995). “The near-earth objects follow-up program: First results.” Icarus 117, 62–70 [Google Scholar]
- Ostro SJ, Harris AW, Campbell DB, Shapiro II, Young J. (1984). “Radar and photoelectric observations of asteroid 2100 Ra-Shalom.” Icarus 60, 391–403. [Google Scholar]
- Pravec P, Sarounova L, Wolf M. (1996). “Lightcurves of 7 Near-Earth Asteroids.” Icarus 124, 471–482. [Google Scholar]
- Pravec P, Wolf M, Sarounova L. (1998). “Lightcurves of 26 Near-Earth Asteroids.” Icarus 136, 124–153. [Google Scholar]
- Pravec P, Wolf M, Sarounova L. (1997w, 1999w, 2000w, 2002w, 2003w). http://www.asu.cas.cz/~ppravec/neo.htm
- Pravec P, Harris AW, Scheirich P, Kušnirák P, Šarounová L, Hergenrother CW, Mottola S, Hicks MD, Masi G, Krugly Yu.N., Shevchenko VG, Nolan MC, Howell ES, Kaasalainen M, Galád A, Brown P, Degraff DR, Lambert JV, Cooney WR, Foglia S. (2005). “Tumbling asteroids.” Icarus 173, 108–131. [Google Scholar]
- Pravec P, Harris AW, Kusnirak P, Galad A, Hornoch K. (2012). “Absolute magnitudes of asteroids and a revision of asteroid albedo estimates from WISE thermal observations.” Icarus 221, 365–387. [Google Scholar]
- Pravec P, Scheirich P, Durech J, Pollock J, Kusnirak P, Hornoch K, Galad A, Vokrouhlicky D, Harris AW, Jehin E, Manfroid J, Opitom C, Gillon M, Colas F, Oey J, Vrastil J, Reichart D, Ivarsen K, Haislip J, LaCluyze A. (2014). “The tumbling state of (99942) Apophis.” Icarus 233, 48–60. [Google Scholar]
- Pravec P, Hergenrother C, Whiteley R, Sarounova L, Kusnirak P. (2000). “Fast Rotating Asteroids 1999 TY2, 1999 SF10, and 1998 WB2.” Icarus 147, 477–486. [Google Scholar]
- Stephens RD. (2013w). http://www.planetarysciences.org/PHP/CS3_Lightcurves.php [Google Scholar]
- Taylor P, Nolan MC, Howell ES. (2012) CBET 3176. [Google Scholar]
- Thomas CA, Emery JP, Trilling DE, Delbo M, Hora JL, Mueller M. (2014). Physical characterization of Warm Spitzer-observed near-Earth objects.” Icarus 228, 217–246. [Google Scholar]
- Usui F, Kuroda D, Müller TG, Hasegawa S, Ishiguro M, Ootsubo T, Ishihara D, Kataza H, Takita S, Oyabu S, Ueno M, Matsuhara H, Onaka T. (2011). “Asteroid Catalog Using Akari: AKARI/IRC Mid-Infrared Asteroid Survey.” Pub. Ast. Soc. of Japan 63, 1117–1138. [Google Scholar]
- Warner BD. (2007). “Initial Results of a Dedicated H-G Program.” Minor Planet Bull 34, 113–119. [Google Scholar]
- Warner BD, Harris AW, Pravec P. (2009). “The Asteroid Lightcurve Database.” Icarus 202, 134–146. Last update: 2016 Feb. http://www.minorplanet.info/lightcurvedatabase.html [Google Scholar]
- Warner BD. (2012). “Asteroid Lightcurve Analysis at the Palmer Divide Observatory: 2011 December - 2012 March.” Minor Planet Bul 39, 158–167. [PMC free article] [PubMed] [Google Scholar]
- Warner BD. (2015). Near-Earth Asteroid Lightcurve Analysis at CS3-Palmer Divide Station: 2015 March-June.” Minor Planet Bul 42, 256–266. [PMC free article] [PubMed] [Google Scholar]
- Warner BD. (2016a). “Near-Earth Asteroid Lightcurve Analysis at CS3-Palmer Divide Station: 2016 January-April.” Minor Planet Bul 43, 240–250. [PMC free article] [PubMed] [Google Scholar]
- Warner BD. (2016b). Three Additional Candidates for the Group of Very Wide Binary Asteroids.” Minor Planet Bul 43, 306–309. [PMC free article] [PubMed] [Google Scholar]
- Warner BD. (2016c). “Near-Earth Asteroid Lightcurve Analysis at CS3- Palmer Divide Station: 2016 April-July.” Minor Planet Bul 43, 311–319. [PMC free article] [PubMed] [Google Scholar]
- Zappala V, Cellini A, Barucci AM, Fulchignoni M, Lupishko DE. (1990). “An analysis of the amplitude-phase relationship among asteroids.” Astron. Astrophys 231, 548–560. [Google Scholar]