J/AJ/155/184 Irregular planetary satellites colors & shapes (Graykowski+, 2018)
Colors and shapes of the irregular planetary satellites.
Graykowski A., Jewitt D.
<Astron. J., 155, 184-184 (2018)>
=2018AJ....155..184G 2018AJ....155..184G (SIMBAD/NED BibCode)
ADC_Keywords: Solar system ; Planets ; Photometry, UBVRI
Keywords: Kuiper belt: general - planets and satellites: general
Abstract:
It is widely recognized that the irregular satellites of the giant planets
were captured from initially heliocentric orbits. However, the mechanism
of capture and the source region from which they were captured both
remain unknown. We present an optical color survey of 43 irregular
satellites of the outer planets conducted using the LRIS camera on the
10 m telescope at the Keck Observatory in Hawaii. The measured colors
are compared to other planetary bodies in search for similarities and
differences that may reflect upon the origin of the satellites. We find
that ultrared matter (with color index B-R≥1.6), while abundant in
the Kuiper Belt and Centaur populations, is depleted from the irregular
satellites. We also use repeated determinations of the absolute magnitudes
to make a statistical estimate of the average shape of the irregular
satellites. The data provide no evidence that the satellites and the
main-belt asteroids are differently shaped, consistent with collisions
as the major agent shaping both.
Description:
The data were collected over nine nights between 2008 March and 2015
December at the W. M. Keck Observatory on Mauna Kea, Hawaii using the
LRIS instrument on the 10 meter Keck I telescope (Oke et al.
1995PASP..107..375O 1995PASP..107..375O, Table 2). The data used were all taken under
photometric conditions with the telescope tracked at non-sidereal
rates to follow the motion of each satellite. Most satellites were
observed on multiple nights in order to check for repeatability of the
measurements. We used the B, V, and R filters, for which the central
wavelengths, λc, and full-widths at half maxima, FWHM, are
B (4370 Å, 878 Å), V (5473 Å, 948 Å) and R (6417 Å,
1185 Å). The images were flat-fielded using composites of images
recorded from an illuminated patch inside the Keck dome and
photometrically calibrated using observations of stars with Sun-like
colors from Landolt (1992, Cat. II/183).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 109 66 Geometry and photometry
table3.dat 67 43 Adopted absolute magnitudes and colors
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See also:
II/183 : UBVRI Photometric Standards (Landolt 1992)
J/A+AS/138/247 : Uranian satellites 1995-1998 (Veiga+, 1999)
J/A+A/453/349 : CCD positions for eight Jovian irregular satellites
(Veiga, 2006)
J/other/SoSyR/45.523 : CCD observations of saturnian satellites
(Grosheva+, 2011)
J/A+A/572/A43 : Saturnian satellites Cassini ISS astrometry
(Cooper+, 2014)
J/A+A/575/A73 : Astrometry of the Saturnian satellites 2004-12
(Tajeddine+, 2015)
J/A+A/582/A8 : Astrometry of the main satellites of Uranus
(Camargo+, 2015)
J/AJ/149/27 : Cassini ISS astrometry of Saturnian satellites
(Cooper+, 2015)
J/MNRAS/462/1351 : Outer satellites occultation predictions
(Gomes-Junior+, 2016)
J/AJ/153/147 : The orbits of Jupiter's irregular satellites
(Brozovic+, 2017)
J/A+A/610/A2 : Saturnian satellites Cassini ISS astrometry
(Cooper+, 2018)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- Planet Planet name (Jupiter, Neptune, Saturn, Uranus)
9- 26 A18 --- Sat Satellite name
28- 38 A11 "date" Date UT date of the integration start
40- 44 A5 "h:m" Time1 First time of range of integration
46- 50 A5 "h:m" Time2 Last time of range of integration
52- 56 F5.2 AU rH [4.89/30.06] Heliocentric distance
58- 62 F5.2 AU Delta [3.89/29.31] Geocentric distance Δ
64- 68 F5.2 deg alpha [0.08/11.5] Phase angle α
70- 74 F5.2 mag Rmag [15.88/25.34] Apparent magnitude in the R filter
76- 79 F4.2 mag e_Rmag [0.01/0.31] 1σ uncertainty in Rmag
81- 84 F4.2 mag B-V [0.58/1.03]? B-V color index
86- 89 F4.2 mag e_B-V [0.01/0.18]? 1σ uncertainty in B-V
91- 94 F4.2 mag V-R [0.24/0.84]? V-R color index
96- 99 F4.2 mag e_V-R [0.01/0.42]? 1σ uncertainty in V-R
101-104 F4.2 mag B-R [0.83/1.63]? B-R color index
106-109 F4.2 mag e_B-R [0.01/0.18]? 1σ uncertainty in B-R
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- Planet Planet name (Jupiter, Neptune, Saturn, Uranus)
9- 26 A18 --- Sat Satellite name
28- 32 F5.2 mag RMag [4.26/15.93] Absolute magnitude in the R filter
34- 37 F4.2 mag e_RMag [0.01/0.15] Uncertainty in RMag
39- 42 F4.2 mag B-V [0.57/0.97]? Absolute B-V color index
44- 47 F4.2 mag e_B-V [0.01/0.11]? 1σ uncertainty in B-V
49- 52 F4.2 mag V-R [0.23/0.66]? Absolute V-R color index
54- 57 F4.2 mag e_V-R [0.01/0.13]? 1σ uncertainty in V-R
59- 62 F4.2 mag B-R [0.91/1.63]? Absolute B-R color index
64- 67 F4.2 mag e_B-R [0.01/0.15]? 1σ uncertainty in B-R
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History:
From electronic version of the journal
(End) Tiphaine Pouvreau [CDS] 22-Nov-2018