J/ApJ/793/50 Observed light curve of (3200) Phaethon (Ansdell+, 2014)
Refined rotational period, pole solution, and shape model for (3200) Phaethon.
Ansdell M., Meech K.J., Hainaut O., Buie M.W., Kaluna H., Bauer J.,
Dundon L.
<Astrophys. J., 793, 50 (2014)>
=2014ApJ...793...50A 2014ApJ...793...50A (SIMBAD/NED BibCode)
ADC_Keywords: Minor planets ; Comets ; Photometry, CCD ; Solar system
Keywords: minor planets, asteroids: individual: 3200 Phaethon -
techniques: photometric
Abstract:
(3200) Phaethon exhibits both comet- and asteroid-like properties,
suggesting it could be a rare transitional object such as a dormant
comet or previously volatile-rich asteroid. This justifies detailed
study of (3200) Phaethon's physical properties as a better
understanding of asteroid-comet transition objects can provide insight
into minor body evolution. We therefore acquired time series
photometry of (3200) Phaethon over 15 nights from 1994 to 2013,
primarily using the Tektronix 2048x2048 pixel CCD on the University of
Hawaii 2.2 m telescope. We utilized light curve inversion to (1)
refine (3200) Phaethon's rotational period to P=3.6032±0.0008 hr;
(2) estimate a rotational pole orientation of λ=+85°±13°
and β=-20°±10°; and (3) derive a shape model. We also
used our extensive light curve data set to estimate the slope
parameter of (3200) Phaethon's phase curve as G∼0.06, consistent
with C-type asteroids. We discuss how this highly oblique pole
orientation with a negative ecliptic latitude supports previous
evidence for (3200) Phaethon's origin in the inner main asteroid belt
as well as the potential for deeply buried volatiles fueling impulsive
yet rare cometary outbursts.
Description:
We obtained time series photometry over 15 nights from 1994 to 2013.
All but three nights used the Tektronix 2048x2048 pixel CCD camera
on the University of Hawaii 2.2 m telescope on Mauna Kea. Two nights
used the PRISM 2048x2048 pixel CCD camera on the Perkins 72 inch
telescope at the Lowell Observatory in Flagstaff, Arizona, while one
night used the Optic 2048x4096 CCD camera also on the University of
Hawaii 2.2 m telescope. All observations used the standard
Kron-Cousins R filter with the telescope guiding on (3200) Phaethon
at non-sidereal rates. Raw images were processed with standard IRAF
routines for bias subtraction, flat-fielding, and cosmic ray removal
(Tody, 1986SPIE..627..733T 1986SPIE..627..733T). We constructed reference flat fields by
median combining dithered images of either twilight or the object
field (in both cases, flattening reduced gradients to <1% across the
CCD). We performed photometry using the IRAF phot routine with
circular apertures typically 5'' in radius, although aperture sizes
changed depending on the night and/or exposure as they were chosen to
consistently include 99.5% of the object's light.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
fig1.dat 33 590 Observed light curve of (3200) Phaethon
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See also:
II/190 : IRAS Minor Planet Survey (IMPS) (Tedesco 1992)
Byte-by-byte Description of file: fig1.dat
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Bytes Format Units Label Explanations
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1- 12 F12.4 d JD Julian Date of the observation
14- 20 F7.4 h Obs.h UT hour of the observation
22- 27 F6.3 mag Rmag The R band magnitude
29- 33 F5.3 mag e_Rmag Error in Rmag
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History:
From electronic version of the journal
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 24-Apr-2017