J/A+A/553/A36 Catalogue of Observations of Phoebe (Desmars+, 2013)
Phoebe's orbit from ground-based and space-based observations.
Desmars J., Li S.N., Tajeddine R., Peng Q.Y., Tang Z.H.
<Astron. Astrophys. 553, A36 (2013)>
=2013A&A...553A..36D 2013A&A...553A..36D
ADC_Keywords: Planets ; Positional data
Keywords: ephemerides - astrometry - planets and satellites: individual: Phoebe
Abstract:
The ephemeris of Phoebe, the ninth satellite of Saturn, is not very
accurate. Previous dynamical models were usually too simplified, the
astrometry is heterogeneous and, the Saturn's ephemeris itself is an
additionnal source of error.
The aim is to improve Phoebe's ephemeris by using a large set of
observations, correcting some systematic errors and updating the
dynamical model.
Description:
The table provides the statistics of astrometric residuals of Phoebe's
ephemeris PH12.
Number of accepted observations, total number of observations, mean
and root mean square (rms) of the residuals in right ascension (R.A.)
and declination (Dec.) and time-span are indicated for each
bibliographic reference. Symbol * indicates that the observations have
been corrected for bias.
The catalogue provides the ground-based observations of Phoebe used to
determine the orbit of the satellite.
3367 observations are available from 1898 to 2012. The format of the
catalogue is similar to the Catalogue of Observations of the Saturnian
Satellites -COSS08- (Desmars et al., 2009, Cat. J/A+A/493/1183). In
the specific case of Phoebe, all observations are in absolute
coordinate (typ=0 and csrf=*) and there is only one observed satellite
(csob=9) in this catalogue. First coordinate is right ascension and
second coordinate is declination of the satellite.
Information about the catalogue used for the reduction, the correction
of the bias and the estimated variance of the observation used in the
fitting process, has been added.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table5.dat 187 119 Statistics of astrometric residuals
cop2012.dat 168 3367 Catalogue of ground-based observations of Phoebe
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See also:
J/other/KFNT/15.483 : Positions of Thebe and Amalthea (Ledovskaya+ 1999)
J/A+A/391/767 : CCD observations of Phoebe in 1998-1999 (Fienga+, 2002)
J/A+A/454/379 : 2003-2004 Phoebe CCD astrometry (Qiao+, 2006)
J/A+A/493/1183 : Saturn major satellites observations (1874-2007)
(Desmars+, 2009)
Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Code [13/500] Bibliographic code
5- 47 A43 --- Ref Reference
52- 55 I4 --- na Number of accepted observations
58- 61 I4 --- nt Total number of observations
64- 71 F8.4 arcsec mu1 ?=999.9999 Mean of the residuals in
right ascension (1)
73- 80 F8.4 arcsec mu2 ?=999.9999 Mean of the residuals in
declination (1)
83- 90 F8.4 arcsec rms1 ?=999.9999 Root mean square of the
residuals in R.A. (1)
92- 99 F8.4 arcsec rms2 ?=999.9999 Root mean square of the
residuals in Dec. (1)
101-109 A9 yr Time Time-span (year1-year2)
110 A1 --- Flag [*] Symbol of correction of bias (2)
112-130 A19 --- BibCode BibCode, mainly from ADS
132-187 A56 --- Comm Complete reference if no BibCode
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Note (1): 999.9999 if na=0
Note (2): Symbol * indicates that the observations have been corrected for bias.
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Byte-by-byte Description of file: cop2012.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Opp [280/390] Opposition number (1)
5- 22 A18 --- Date UTC date of observation (YYYY/MM/DD.ddddddd)
23- 29 F7.3 s dt TT-UTC (seconds)
31- 33 A3 --- Obs Observatory code (2)
35- 37 I3 --- Code [13/500] Reference code, in table5.dat
39 I1 --- Type [0] Observation type (3)
42 I1 --- S [9] Observed satellite (4)
43 A1 --- Sr [*] Reference satellite (4)
45 I1 --- f_Obs1 [1] Presence flag for first coordinate (5)
46 I1 --- f_Obs2 [1] Presence flag for second coordinate (5)
50- 60 F11.7 deg Obs1 First coordinate of pair
64- 74 F11.7 deg Obs2 Second coordinate of pair
76 I1 --- Sys [0/7] Reference system (6)
78 I1 --- Fr [0/1] Reference frame (7)
80- 86 F7.3 arcsec (O-C)1 [-5/5]?=888.888 (O-C) residual for first
coordinate (α) (8)
88- 94 F7.3 arcsec (O-C)2 [-5/5]?=888.888 (O-C) residual for second
coordinate (δ) (8)
96 I1 --- rf [0/1] Refraction correction (9)
98 I1 --- ab [0/3] Aberration correction (9)
100 I1 --- ph [2] Phase effects correction (9)
102 A1 --- Cat Catalogue used for reduction (10)
104-110 F7.3 arcsec xb Bias in right ascension
112-118 F7.3 arcsec yb Bias in declination
120-126 F7.3 arcsec w1 Estimated variance of first coordinate (11)
128-134 F7.3 arcsec w2 Estimated variance of second coordinate (11)
136-168 A33 --- info Information (12)
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Note (1): Opp#1 in 1610, Opp#257 in 1874, Opp#390 in 2012
Note (2): From Minor Planet Center (code IAU)
http://cfa-www.harvard.edu/iau/lists/ObsCodes.html
Note (3): Observation type as follows:
0 = α, δ (degrees)
Note (4): Reference satellite as follows:
* = absolute coordinates
9 = Phoebe
Note (5): Presence flag as follows:
0 = missing coordinate
1 = present coordinate
Note (6): Reference system as follows:
0 = ICRF
1 = mean equator and equinox of J2000
2 = mean equator and equinox of B1950
3 = true equator and equinox of date of the observation
4 = mean equator and equinox of date of the observation
5 = mean equator and equinox at 1 January of the year of observation
6 = mean equator and equinox at 1 January of the a specific year
7 = mean equator and equinox of specific epoch
Note (7): Reference frame as follows:
0 = topocentric
1 = geocentric
2 = heliocentric (used for mutual events)
Note (8): 888.888 if residual great than 5.0 arcsec
Note (9): Correction code as follows:
0 = corrected
1 = presumedly corrected
2 = not presumedly corrected
3 = not corrected
Note (10): Catalogue used for reduction in Minor Planet Center format
as follows:
a = USNO-A1.0, Cat. I/243
b = USNO-SA1.0
c = USNO-A2.0, Cat. I/252
d = USNO-SA2.0
e = UCAC1, Cat. I/268
f = Tycho-1, Cat. I/239
g = Tycho-2, Cat. I/259
h = GSC 1.0
i = GSC 1.1, Cat. I/220
j = GSC 1.2, Cat. I/254
k = GSC 2.2, Cat. I/271
l = ACT, Cat. I/246
m = GSC ACT, Cat. I/255
n = TRC, Tycho Reference Catalogue, Cat. I/250
o = USNO B1.0, Cat. I/284
p = PPM, Cat. I/146 and I/193
q = UCAC2-beta
r = UCAC2, Cat. I/289
s = USNO B2.0
t = UCAC3-beta
u = UCAC3, Cat. I/315
v = NOMAD, Cat. I/297
w = CMC, Carlsberg Meridian Catalogs, Cat. I/256
x = Hip 2 , Cat. I/311
z = GSC (generic)
Note (11): Estimated variance used in the fitting process (see paper)
Note (12): This column contains:
* Year of the 1st January in the case of reference system Sys=6
* Epoch in the case of reference system Sys=7
* Geocentric position of WISE (Obs=C51), in km
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Acknowledgements:
Josselin Desmars, desmars(at)imcce.fr
(End) J. Desmars [SHAO/IMCCE], Patricia Vannier [CDS] 05-Mar-2013