J/A+A/532/A36 Galilean satellites mutual events in 2009 (Zhang, 2011)
Calculating the relative coordinates of Galilean satellites by fitting the flux
variation during the mutual occultations.
Zhang X.L., Arlot J.-E., Liu Z.
<Astron. Astrophys. 532, A36 (2011)>
=2011A&A...532A..36Z 2011A&A...532A..36Z
ADC_Keywords: Photometry, CCD ; Positional data ; Solar system
Keywords: techniques: photometric - occultations -
planets and satellites: dynamical evolution and stability -
celestial mechanics
Abstract:
Photometry of mutual events between natural satellites has been
verified to be a most effective and accurate ground-based method for
obtaining accurate astrometric data through fitting the light curves
observed during these events, and it will be valuable to develop the
orbital models of the natural satellites.
Mutual occultations of J2 Europa by J1 Io (Aug 28, 2009), J1 Io by J2
Europa (Nov 9 and Dec 11, 2009) and J1 Io by J3 Ganymede (Nov 28,
2009) were observed at Yunnan Observatory during the PHEMU09
international campaign. We will calculate the astrometric data of
satellites by analyzing and fitting the light curves we got.
The same model proposed by N.V. Emelianov (2003SoSyR..37..314E 2003SoSyR..37..314E) was
used to fit the light curves, with the Lommel-Seeliger scattering law
taking into account.
Dynamical quantities, such as the deviation of the observed relative
satellite motion from the theoretical motion provided by the relevant
ephemeris denoted as Dx and Dy, impact parameter and mid-time
corresponding to the impact parameter, were obtained for each event
respectively. These results have an accuracy of about several mas to
90mas for Dx and Dy and 0.31-2.97s for mid-time. The residuals in
determination of longitude shifts (delta(l1) for J1 Io and delta(l2)
for J2 Europa) explaining the shifts of the mid-times of the events,
were also calculated in the section of discussion which is around 10km
with the best ephemerides.
Description:
File table 2 contains the photometric data of mutual occultations
between Galilean satellites observed at Yunnan Observatory in 2009,
and the number of data is 411. The observational data in this file
belongs to four different mutual occultations, 200908281o2,
200911092o1, 200911283o1 and 200912112o1 respectively, which can be
distinguished from the date. '200908281o2' represents the event of
J1(Io) occulted J2(Europa) occured on 28 Aug, 2009.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 43 411 Points of Galilean satellites' flux observed
during mutual occultations
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See also:
J/A+A/314/312 : Galilean satellites mutual events in 1997 (Arlot 1996)
J/A+A/383/719 : Galilean Satellites mutual events 2002-2003 (Arlot, 2002)
J/A+A/427/371 : Galilean satellites ephemerides (Lainey+, 2004)
J/A+A/437/705 : Observations of PHEMU97 and PHEMU03 at Ukkel (Pauwels+, 2005)
J/A+A/493/1171 : Mutual phenomena of Galilean satellites PHEMU03 (Arlot+, 2009)
J/A+AS/125/399 : Mutual phenomena of the Galilean satellites (Arlot+ 1997)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 10 A10 "YYYY/MM/DD" Obs.Date Date of mutual occultations occured.
12- 23 A12 "h:m:s" Obs.Time Time of the beginning of exposure
25- 27 F3.1 s texp Exposure time of images
29- 35 I7 --- Fluxr Value of reference satellites' flux
during mutual occultations (1)
37- 43 I7 --- Flux Flux of satellites involved in the mutual
occultations
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Note (1): For the mutual occultations of 200908281o2, 200911092o1,
200911283o1 and 200912112o1, the satellite J3(Ganymede), J3, J2
(Europa) and J3 were chosen as the reference satellites respectively.
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Acknowledgements:
Xiliang Zhang, zhangxiliang(at)ynao.ac.cn
(End) Patricia Vannier [CDS] 21-Jun-2011