The Minor planet bulletin最新文献

Analysis of CCD photometric observations in late 2015 of the Hungaria asteroid 6384 Kervin indicates that it may be a binary asteroid with a primary lightcurve of P ₁ = 3.6194 ± 0.0001 h, A ₁ = 0.06 ± 0.01 mag. The secondary lightcurve parameters are P ₂ = 15.94 ± 0.01 h, A ₂ = 0.03 ± 0.01 mag. No mutual events (occultations or eclipses) were observed. However, other indicators give an estimated diameter ratio on the order of Ds/Dp ~ 0.3, possibly greater.

CCD photometric observations were made of the near-Earth asteroid (348400) 2005 JF21 in 2015 June and August. Initial analysis in June did not find any signs of a satellite. Follow-up analysis in August using both data sets found indications that the asteroid was binary with a primary period of 2.41 h and an orbital period for the satellite of about 14.3 h. In mid-August, analysis of radar observations at Goldstone (Naidu et al., 2015) confirmed that the asteroid is a binary.

Independent CCD photometry observations by the authors of the near-Earth asteroid 2015 HM10 were made in 2015 July. Analysis of both data sets found a synodic rotation period of approximately 0.376 h and amplitude of 1.47 ± 0.05 mag.

Lightcurves for 29 main-belt asteroids were obtained at the Center for Solar System Studies-Palmer Divide Station (CS3-PDS) from 2015 June-September. Hungaria members 1876 Napolitania and (47141) 1999 HB3 are suspected binary asteroids.

Lightcurves for 46 near-Earth asteroids (NEAs) were obtained at the Center for Solar System Studies-Palmer Divide Station (CS3-PDS) from 2015 June-September. Four of the asteroids showed indications of non-principal axis rotation (NPAR), or tumbling, (9400) 1994 TW1, (86666) 2000 FL10, (154807) 2004 PP97, and (206378)2003 RB, but there were insufficient data for full analysis. On the other hand, 2015 JY1 is a confirmed tumbler with a dominate period of 6.442 h and a likely second period of 11.42 h. Evidence of the satellite for the known binary system (385186) 1994 AW1 was found. The estimated size ratio of Ds/Dp ≥ 0.25 is in good agreement with earlier results. A third period was also found but its origin is not confirmed.

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.

The Asteroid Lightcurve Data Exchange Format (ALCDEF) project has been in development for more than five years. To date, almost 2.5 million time-series data points for more than 11400 asteroids have been submitted to the ALCDEF database hosted on the Minor Planet Center web site. These raw time-series observations have helped researchers produce hundreds of shape and spin axis models. The recent introduction of the S-ALCDEF (Simple-ALCDEF) page is hoped to encourage that even more data be submitted and so expedite and facilitate research efforts that depend on these type of data.

Lightcurves for 29 main-belt asteroids were obtained at the Center for Solar System Studies-Palmer Divide Station (CS3-PDS) from 2015 March-June. All but three were members of the Hungaria orbital group or collisional family and observed as part of an ongoing program to obtain data for spin axis and shape modeling. One Hungaria, (79472) 1998 AX4 showed signs of having a satellite. Analysis indicates it is a possible binary.

Lightcurves for 35 near-Earth asteroids (NEAs) were obtained at the Center for Solar System Studies-Palmer Divide Station (CS3-PDS) from 2015 March-June.