J/AJ/154/241 Photometry of a Kuiper Belt object: 2002 CC249 (Thirouin+, 2017)
A possible dynamically Cold Classical contact binary: (126719) 2002 CC249.
Thirouin A., Sheppard S.S.
<Astron. J., 154, 241-241 (2017)>
=2017AJ....154..241T 2017AJ....154..241T (SIMBAD/NED BibCode)
ADC_Keywords: Solar system ; Minor planets ; Photometry, VRI ; Photometry, SDSS
Keywords: Kuiper belt objects: individual ((126719) 2002 CC249) -
techniques: photometric
Abstract:
Images of the Kuiper Belt object (126719) 2002 CC249 obtained in
2016 and 2017 using the 6.5 m Magellan-Baade Telescope and the 4.3 m
Discovery Channel Telescope are presented. A light curve with a
periodicity of 11.87±0.01 hr and a peak-to-peak amplitude of
0.79±0.04 mag is reported. This high amplitude double-peaked light
curve can be due to a single elongated body, but it is best explained
by a contact binary system from its U-/V-shaped light curve. We
present a simple full-width-at-half-maximum test that can be used to
determine if an object is likely a contact binary or an elongated
object based on its light curve. Considering that 2002 CC249 is in
hydrostatic equilibrium, a system with a mass ratio qmin=0.6, and
a density ρmin=1 g/cm3, or less plausible a system with
qmax=1, and ρmax=5 g/cm3 can interpret the light curve.
Assuming a single Jacobi ellipsoid in hydrostatic equilibrium and an
equatorial view, we estimate ρ≥0.34 g/cm3, and a/b=2.07.
Finally, we report a new color study showing that 2002 CC249
displays an ultra red surface characteristic of a dynamically Cold
Classical trans-Neptunian object.
Description:
We present in situ observations carried out with the Discovery Channel
Telescope (DCT) and the 6.5 m Magellan Telescope (Baade unit) in 2016
and in 2017. The DCT is located in Arizona (Happy Jack, United States
of America). Our observations were obtained with the Large Monolithic
Imager (LMI). This instrument is a 6144x6160 pixels CCD for a total field
of view of 12.5'x12.5', and a pixel scale of 0.12"/pixel (Levine et al.
2012SPIE.8444E..19L 2012SPIE.8444E..19L). The light-curve study was performed at DCT using
the VR-filter or r'-filter.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 51 10 Summary of Our Observations
table2.dat 36 191 Photometry Used in This Paper
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See also:
J/A+A/380/347 : BVRI photometry of 27 Kuiper Belt Objects (Delsanti+, 2001)
J/ApJ/749/10 : SDSS observations of Kuiper belt objects (Ofek, 2012)
J/AJ/152/80 : Astrometry of Pluto and trans-Neptunian objects (Holman+, 2016)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 11 A11 "date" Date UT date of observation
13- 17 A5 --- N Number of image(s) obtained each night
19- 24 F6.3 AU rh [38.034/38.059] Heliocentric distance rh (1)
26- 31 F6.3 AU Delta [37.037/37.334] Geocentric distance Δ (1)
33- 35 F3.1 deg alpha [0/1.1] Phase angle of the observations α
(1)
37- 42 A6 --- Filter [VR g'r'i'] Filter(s) used
44- 51 A8 --- Tel Telescope name (DCT, Magellan)
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Note (1): Heliocentric, geocentric distances, and phase angle are from the minor
planet center ephemeris Generator.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 11 A11 "date" Date UT date of observation
13- 25 F13.5 d JD Julian Date (1)
27- 31 F5.2 mag relmag [-0.39/0.44] Relative magnitude (in V R or r'
band, see Table 1)
33- 36 F4.2 mag e_relmag [0.02/0.19] Uncertainty in relmag
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Note (1): Julian date is without light-time correction.
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History:
From electronic version of the journal
(End) Tiphaine Pouvreau [CDS] 17-Aug-2018