Results of Observations of 14 Mutual
Events of Galilean Moons of Jupiter
Arto Oksanen (Nyrölä observatory, Finland)
Apostolos Christou (Armagh Observatory, Northern Ireland)
AstroCon 2004
AL • AAVSO • ALPO • ASP
PHEMU03 campaign



In 2002-2003, the Earth and the Sun go through the
common orbital plane of the galilean satellites of
Jupiter. This occurs only every 6 years and allows the
observation of mutual eclipses and occultations between
the satellites.
These observations were made during the last opportunities since
1973 until the former campaign of 1997 and they have led to
interesting results well in astrometry (dynamics of the system) as in
planetology (physics of the surfaces of the satellites) thanks to the
large number of data obtained on a long interval of time.
Observations are easy to perform even
with a small telescope
(Galilean satellites have a magnitude
about 5) and, in order to make them
possible to the observers, we propose
the information provided here.
Geometry of events
 Every
6 years the orbits of galilean moons
align with Earth and Sun
 Numerous mutual eclipses and
occultations
Eclipses and occultations
http://www.bdl.fr/Phemu03/ntph01_eng.html
Observable events
 105
phenomena were observable at
Nyrola Observatory
 Sun
elevation < -10.0 deg.
 Jupiter elevation > 10.0 deg.
 distance to the planet > 1.0 planetary radii
 magnitude drop > 0.010
Table of observable events
-----------------------------------------------------------------------------------------------------Magn. Durat. Distance
Distance Planet
Sun
Date of maximum(TT)
to
Right As. Declination
to
Event
Drop
planet
of planet (P)
Earth
Az
H
Az
H
-----------------------------------------------------------------------------------------------------Year m D h m s
s
(RP)
h m s
d ' "
AU
d
d
d
d
2002 10 20 22 51 39 2 OCC 1 P 0.261
302
5.0
9 10 48
+16 48 13
5.49 -107 10 -165 -37
2002 10 28 1 12 3 2 OCC 1 P 0.410
342
5.2
9 14 13
+16 34 25
5.39
-69 29 -124 -30
2002 11 4 3 32 10 2 OCC 1 P 0.410
363
5.4
9 17 7
+16 22 44
5.28
-23 42 -89 -17
2002 11 12 23 9 30 4 OCC 2 P 0.158
371
6.4
9 19 58
+16 11 34
5.14
-85 21 -157 -44
2002 11 17 0 44 35 1 OCC 2 P 0.011
83
1.5
9 20 59
+16 7 47
5.08
-58 33 -128 -38
2002 11 21 21 21 28 2 OCC 1 P 0.146
353
5.7
9 21 56
+16 4 29
5.00 -101 12 165 -47
2002 11 24 2 53 0 1 OCC 2 P 0.091
156
1.2
9 22 17
+16 3 25
4.97
-12 43 -96 -26
2002 11 28 21 36 22 2 ECL 1 P 0.275
245
5.1
9 22 48
+16 2 8
4.90
-92 17 169 -49
2002 11 28 23 41 24 2 OCC 1 P 0.080
326
5.8
9 22 48
+16 2 7
4.89
-63 31 -147 -46
2002 12 1 4 59 46 1 OCC 2 P 0.191
189
1.0
9 22 56
+16 2 0
4.86
38 39 -68 -13
2002 12 5 20 18 35 3 OCC 4 P 0.431
909
13.8
9 23 1
+16 2 43
4.80 -103 11 142 -46
2002 12 5 23 58 56 2 ECL 1 P 0.453
328
5.4
9 23 1
+16 2 46
4.79
-51 36 -142 -46
2002 12 6 2 1 57 2 OCC 1 P 0.036
284
5.8
9 23 1
+16 2 48
4.79
-13 43 -108 -34
2002 12 7 22 18 35 1 OCC 4 P 0.343
791
5.9
9 22 58
+16 3 29
4.77
-74 26 -177 -50
2002 12 13 2 24 1 2 ECL 1 A 0.624
400
5.5
9 22 35
+16 6 30
4.70
3 44 -103 -33
2002 12 13 4 23 46 2 OCC 1 P 0.011
221
5.9
9 22 35
+16 6 34
4.70
41 38 -76 -19
2002 12 16 2 11 35 4 OCC 1 T 0.361
395
3.8
9 22 12
+16 8 59
4.66
3 44 -106 -35
2002 12 20 4 52 31 2 ECL 1 A 0.711
471
5.7
9 21 30
+16 13 14
4.61
57 34 -71 -16
2002 12 20 21 40 10 2 OCC 1 P 0.245 9118
3.3
9 21 22
+16 14 3
4.60
-71 28 167 -51
2002 12 20 22 57 15 2 OCC 1 P 0.245 9118
3.3
9 21 21
+16 14 7
4.60
-51 36 -165 -50
2002 12 23 0 49 41 2 OCC 3 A 0.480 3779
8.3
9 20 54
+16 16 43
4.57
-14 43 -129 -43
2002 12 24 3 12 6 2 OCC 4 P 0.120
287
1.4
9 20 38
+16 18 11
4.56
33 41 -93 -28
2002 12 24 3 57 13 1 OCC 4 P 0.332
331
1.7
9 20 37
+16 18 14
4.56
47 37 -83 -23
2002 12 25 1 51 2 3 OCC 4 P 0.147
531
10.4
9 20 24
+16 19 30
4.55
9 44 -112 -37
2002 12 26 3 13 55 3 OCC 1 P 0.052 1070
2.5
9 20 7
+16 21 2
4.54
36 40 -93 -28
2002 12 27 20 16 21 2 OCC 1 A 0.149 1932
1.5
9 19 38
+16 23 38
4.52
-84 22 138 -46
2002 12 28 3 4 27 2 OCC 1 P 0.083
909
5.6
9 19 33
+16 24 4
4.52
36 40 -95 -29
2002 12 30 20 45 58 2 ECL 1 P 0.584
590
5.9
9 18 43
+16 28 34
4.49
-74 27 147 -48
2002 12 30 21 20 31 4 OCC 3 P 0.205
804
13.9
9 18 42
+16 28 36
4.49
-66 30 158 -49
International Pro-am collaboration

A. Oksanen (Nyrölä
Observatory, Finland)
 observations

A. Christou (Armagh
Observatory, Northern
Ireland)
 image
calibration
 photometry

IMCCE (Paris Obs,
France)
 campaign
coordination
 final analysis
Observations by Arto
 V-filtered
CCD-images with
short exposures
 16-inch Meade LX200 +
SBIG ST8XE
 Accurate timing (local ntp
server)
 Short duration events (few
minutes)
 Easy to find targets
Observed events
DATE
TYPE
OBS. START OBS. END SAMPLES EXPTIME
FILTER OBS.
30/12/02
30/12/02
06/01/03
14/01/03
16/01/03
19/02/03
19/02/03
15/03/03
17/03/03
20/03/03
25/03/03
25/03/03
25/03/03
11/04/03
2
4
2
2
4
4
4
3
1
1
1
2
2
3
20:30:08
21:06:32
23:24:08
02:19:47
23:46:32*
20:19:29
22:00:25
21:47:40
18:09:20
23:46:04
19:58:18
20:37:18
23:58:35*
20:53:23
V
V
C
C
V
V
V
R
V
V
V
V
V
V
ECL 1
OCC 3
ECL 1
ECL 1
OCC 2
OCC 1
ECL 1
ECL 4
ECL 3
OCC 2
ECL 3
OCC 3
ECL 3
ECL 2
20:59:02
21:36:21
23:49:04
02:53:34
O1:05:27
20:41:30
22:27:47
22:32:30
18:40:14
00:00:00
20:20:41
20:56:16
00:20:21
21:11:15
144 (154)
180
400
523 (537)
502 (604)
282
448
579 (599)
560
201
250 (420)
353
305 (326)
261
5.0
1.0+5.0
0.5
0.5
1.0
1.0
1.0
1.0+2.0
1.0
1.0
0.5
0.5
1.0
1.0
I/II
III+IV/I
I/II
I/II
IV+II/III
IV+I/III
I/III
IV/III
III/I
I+II/III
III+II/I
III+II/I
III/II
II/III
* in these cases the dataset was truncated by removing data points before midnight in order to
facilitate plotting. The actual data files contain the full dataset.
Beginning of an eclipse
Photometry by dr. Christou
 Aperature
photometry with IDL
 Relative flux of
 eclipsed
moon vs. eclipsing moon
 occulting moon + occulted moon vs. third
moon
 Moons
move during events
 Photometry data given to IMCCE
Europe ecl. Io Jan 6, 2003
Callisto occ. Europe Jan 17, 2003
Ganymede ecl. Callisto Mar 15, 2003
Io ecl. Ganymede Mar 17, 2003
Europe ecl. Ganymede Mar 25, 2003
Mid event timings
DATE
30.12.2002
30.12.2002
6.1.2003
14.1.2003
17.1.2003
19.2.2003
19.2.2003
15.3.2003
17.3.2003
20.3.2003
25.3.2003
25.3.2003
26.3.2003
11.4.2003
EVENT
2
4
2
2
4
4
4
3
1
1
1
2
2
3
ECL
OCC
ECL
ECL
OCC
OCC
ECL
ECL
ECL
OCC
ECL
OCC
ECL
ECL
1
3
1
1
2
1
1
4
3
2
3
3
3
2
PREDICTED OBSERVED ERROR O-C
TT
TT*
s*
s
20:45:58
20:45:56
1.6
-2
21:20:31
21:20:22
5.1
-9
23:33:51
23:33:57
0.5
+6
2:47:01
2:47:31
0.6
+30
0:44:55
0:44:40
0.5
-15
20:32:20
20:32:06
0.3
-14
22:16:46
22:16:26
0.5
-20
22:15:53
22:15:43
0.4
-10
18:23:40
18:23:29
0.7
-11
23:53:38
23:53:21
1.4
-17
20:09:32
20:09:14
1.1
-18
20:49:14
20:49:14
1.0
0
0:10:30
0:10:26
0.9
-4
21:03:03
21:03:08
0.9
+5
*Measured with Peranso (www.peranso.com) using the Kwee-van Woerden method (Kwee, K., van
Woerden, H., 1956, Bulletin of the Astronomical Institutes of the Netherlands BAN, Vol XII, 464.)
Challenges

Weather !
 only
about 15 percentage of the events were
observable

Brightness of moons
 short

Timing
exposure -> scintillation -> scatter
 Only full seconds in FITS headers
 Shutter delay, about 0.5 s
 0.1 s accuracy of ntp server
 Windows, about 0.1 s accuracy

Minimum finding with Peranso
 Assumes
symmetrical light curves
!
Acknowledgements
 Jenny
and Antti Wihuri Foundation
 supporting
 AAVSO
the Nyrölä observatory
and Curry Foundation
 providing
the ST8XE CCD camera
Questions?
http://nyrola.jklsirius.fi/phemu03/
Arto Oksanen
tel: +358-40-5659438
arto.oksanen@jklsirius.fi
http://www.ursa.fi/sirius