J/A+A/598/A63 2015 TB145 light curve (Mueller+, 2017)
Large Halloween asteroid at lunar distance.
Mueller T.G., Marciniak A., Butkiewicz-Bak M., Duffard R., Oszkiewicz D.,
Kaeufl H.U., Szakats R., Santana-Ros T., Kiss C., Santana-Sanz P.
<Astron. Astrophys. 598, A63 (2017)>
=2017A&A...598A..63M 2017A&A...598A..63M (SIMBAD/NED BibCode)
ADC_Keywords: Minor planets ; Photometry
Keywords: minor planets, asteroids: individual: 2015 TB145 -
radiation mechanisms: thermal - techniques: photometric -
infrared: planetary systems
Abstract:
The near-Earth asteroid (NEA) 2015 TB145 had a very close encounter
with Earth at 1.3 lunar distances on October 31, 2015. We obtained
3-band mid-infrared observations of this asteroid with the ESO
VLT-VISIR instrument covering about 4 hours in total. We also
monitored the visual lightcurve during the close-encounter phase. The
NEA has a (most likely) rotation period of 2.939±0.005-hours and the
visual lightcurve shows a peak-to-peak amplitude of about
0.12±0.02mag. A second rotation period of 4.779±0.012h, with an
amplitude of the Fourier fit of 0.10±0.02mag, also seems compatible
with the available lightcurve measurements. We estimate a V-R colour
of 0.56±0.05mag from different entries in the MPC database. A
reliable determination of the object's absolute magnitude was not
possible. Applying different phase relations to the available
R-/V-band observations produced HR=18.6mag (standard H-G
calculations) or HR=19.2mag and HV=19.8mag (via the H-G12
procedure for sparse and low-quality data), with large uncertainties
of about 1mag. We performed a detailed thermophysical model analysis
by using spherical and partially also ellipsoidal shape models. The
thermal properties are best explained by an equator-on (±∼30°)
viewing geometry during our measurements with a thermal inertia in the
range 250-700J/m2/s0.5/K (retrograde rotation) or above
500J/m2/s0.5/K (prograde rotation). We find that the NEA has a
minimum size of about 625m, a maximum size of just below 700m, and a
slightly elongated shape with a/b∼1.1.
Description:
In this paper we used photometric data gained by the 1.23-m telescope
at Calar Alto Observatory (CAHA) in Almeria (Spain), the 1.5-m
telescope at Sierra Nevada Observatory (OSN) in Granada (Spain) and
the 0.80-m telescope at La Hita Observatory, near Toledo, also in
Spain. Additionally we worked with data presented by Warner et al.
(2016).
objects:
------------------------------------------------------
Name H i e a
(mag) (deg) (AU)
------------------------------------------------------
2015 TB145 19.97 19.697116 0.86036548 2.10240435
------------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table.dat 22 1503 Photometric data of 2015 TB145 used for this work
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 14 F14.6 d JD Julian date
16- 22 F7.4 mag mag Magnitude
--------------------------------------------------------------------------------
Acknowledgements:
Thomas Mueller, tmueller(at)mpe.mpg.de,
MPI fuer Extraterrestrische Physik
(End) Thomas Mueller [MPI], Patricia Vannier [CDS] 24-Oct-2016