The Minor planet bulletin最新文献

Lightcurves for 38 near-Earth asteroids (NEAs) obtained at the Center for Solar System Studies (CS3) from 2019 March-July were analyzed for rotation period, peak-to-peak amplitude, and signs of satellites or tumbling.

CCD photometric observations of 19 main-belt asteroids were obtained at the Center for Solar System Studies (CS3) from 2019 April to June.

CCD photometric observations of three Hilda asteroids were made at the Center for Solar System Studies (CS3) from 2019 January-March. For 1038 Tuckia, the period solution was ambiguous at either P = 18.020 h, amplitude 0.22 mag or P = 14.401 h, amplitude 0.20 mag. For 2246 Bowell, the analysis found P = 4.997 and amplitude 0.46 mag. For 4317 Garibaldi, we found a dual-period solution with P₁ = 17.843 or 8.92 h and P₂ = 11.426 h. The shorter value for P₁ is similar to previously reported results but this is the first time a true dual-period solution, i.e., not an ambiguous single period solution, has been reported.

CCD photometric observations of the near-Earth asteroid (152931) 2000 EA107 were made in 2019 March and April at the Center for Solar System Studies (CS3). Analysis of the data found that the asteroid is likely a binary. The primary period is P ₁ = 4.1367 ± 0.0002 h with a lightcurve amplitude of A ₁ = 0.29 ± 0.02 mag. The secondary period is P ₂ = 16.079 ± 0.006 h with a lightcurve amplitude of A ₂ = 0.16 ± 0.01 mag. No mutual events (occultations and/or eclipses) were seen to confirm the presence of a satellite.

CCD photometric observations of 10 main-belt asteroids were obtained from the Center for Solar System Studies from 2019 January to March. In light of recent period analysis, images of 2120 Tyumenia obtained in 2004 were re-examined. The resulting analysis found a period of 17.515 h, which is consistent with the recent results.

Lightcurves for four L₅ Jovian Trojan asteroids were obtained at the Center for Solar System Studies (CS3) from 2019 January to March. The suspected binary Trojan, 2207 Antenor was observed again and a single attenuation event was detected.

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.

CCD photometric observations at the Center for Solar System Studies (CS3) were made of the near-Earth asteroid (12538) 1998 OH in 2018 November. The goal was to find a secure period and so resolve ambiguous solutions from previous years. Final analysis of the 2018 data found that it is anything but ordinary. One possibility is that it is a low-amplitude, fast-rotating tumbler. The other, more exotic, possibility is that it may be an asteroid pair in the making, i.e., the two fast-rotating components have not yet broken their mutual bond. Future observations may show that one of these, or yet another solution, correctly describes the asteroid.

Lightcurve analysis of the near-Earth asteroids (442742) 2012 WP3, (523604) 2004 QB17, and 2018 RL indicate that they are potential members of a relatively rare class of "very wide binary asteroids." These objects feature a primary rotational period of tens to hundreds of hours and a secondary rotational period less than 24 hours, usually less than 10 hours. These three bring to 30 the number of suspected members of the class.

Lightcurves for four Hilda asteroids were obtained at the Center for Solar System Studies (CS3) from 2018 September-November: 3514 Hooke, 3557 Sokolsky, 4495 Dassanowksy, and 10331 Peterbluhm. 4495 Dassanowksy appears to be a binary asteroid with a primary period of either 2.6314 hr or 5.263 hr and an orbital period of 18.516 hr. The secondary-to-primary ratio of the effective diameters is 0.26 ± 0.02.