3 research outputs found
Time-series photometry of Earth flyby asteroid 2012 DA14
Context. The object 2012 DA14 is a near-Earth asteroid with a size of several
tens of meters. It had approached closely the Earth on 15 February, 2013 UT,
providing an opportunity for precise measurements of this tiny asteroid. Aims.
The solar phase angle of 2012 DA14 had varied widely around its closest
approach but was almost constant during the following night. We performed
time-series photometric observations on those two nights to determine the
rotational properties and phase effect. Methods. The observations were carried
out using the 0.55-m telescope at Saitama University, Japan. The R-band images
were obtained continuously over a 2 hr period at the closest approach and for
about 5 hr on the next night. Results. The lightcurve data from the second
night indicates a rotational period of 11.0 +1.8/-0.6 hr and a peak-to-peak
amplitude of 1.59 +/- 0.02 mag. The brightness variation before and after the
closest approach was separated into two components that are derived from the
rotation and phase effect. We found that the phase curve slope of this asteroid
is significantly shallower than those of other L-type asteroids. Conclusions.
We suggest that 2012 DA14 is coated with a coarse surface that lacks fine
regolith particles and/or a high albedo surface.Comment: 4 pages, 4 figures, accepted for publication in Astronomy and
Astrophysic