1. 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

2. 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.

3. Geometry of events  Every 6 years the orbits of galilean moons align with Earth and Sun  Numerous mutual eclipses and occultations

4. Eclipses and occultations http://www.bdl.fr/Phemu03/ntph01_eng.html

5. 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

6. 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

7. 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

8. 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

9. Observed events DATETYPEOBS. STARTOBS. ENDSAMPLESEXPTIMEFILTEROBS. 30/12/02 2 ECL 1 20:30:08 20:59:02 144 (154) 5.0 V I/II 30/12/02 4 OCC 3 21:06:32 21:36:21 180 1.0+5.0 V III+IV/I 06/01/03 2 ECL 1 23:24:08 23:49:04 400 0.5 C I/II 14/01/03 2 ECL 1 02:19:47 02:53:34 523 (537) 0.5 C I/II 16/01/03 4 OCC 2 23:46:32*O1:05:27 502 (604) 1.0 V IV+II/III 19/02/03 4 OCC 1 20:19:29 20:41:30 282 1.0 V IV+I/III 19/02/03 4 ECL 1 22:00:25 22:27:47 448 1.0 V I/III 15/03/03 3 ECL 4 21:47:40 22:32:30 579 (599) 1.0+2.0 R IV/III 17/03/03 1 ECL 3 18:09:20 18:40:14 560 1.0 V III/I 20/03/03 1 OCC 2 23:46:04 00:00:00 201 1.0 V I+II/III 25/03/03 1 ECL 3 19:58:18 20:20:41 250 (420) 0.5 V III+II/I 25/03/03 2 OCC 3 20:37:18 20:56:16353 0.5 V III+II/I 25/03/03 2 ECL 3 23:58:35*00:20:21 305 (326) 1.0 V III/II 11/04/03 3 ECL 2 20:53:23 21:11:15 261 1.0 V 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.

10. Beginning of an eclipse

11. 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

12. Europe ecl. Io Jan 6, 2003

13. Callisto occ. Europe Jan 17, 2003

14. Ganymede ecl. Callisto Mar 15, 2003

15. Io ecl. Ganymede Mar 17, 2003

16. Europe ecl. Ganymede Mar 25, 2003

18. Mid event timings DATEEVENT PREDICTED TT OBSERVED TT* ERROR s* O-C s 30.12.20022ECL120:45:5820:45:561.6-2 30.12.20024OCC321:20:3121:20:225.1-9 6.1.20032ECL123:33:5123:33:570.5+6 14.1.20032ECL12:47:012:47:310.6+30 17.1.20034OCC20:44:550:44:400.5-15 19.2.20034OCC120:32:2020:32:060.3-14 19.2.20034ECL122:16:4622:16:260.5-20 15.3.20033ECL422:15:5322:15:430.4-10 17.3.20031ECL318:23:4018:23:290.7-11 20.3.20031OCC223:53:3823:53:211.4-17 25.3.20031ECL320:09:3220:09:141.1-18 25.3.20032OCC320:49:14 1.00 26.3.20032ECL30:10:300:10:260.9-4 11.4.20033ECL221:03:0321:03:080.9+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.)www.peranso.com

19. Challenges  Weather !  only about 15 percentage of the events were observable  Brightness of moons  short exposure -> scintillation -> scatter  Timing  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

20. Acknowledgements  Jenny and Antti Wihuri Foundation  supporting the Nyrölä observatory  AAVSO and Curry Foundation  providing the ST8XE CCD camera

21. Questions? Arto Oksanen tel: +358-40-5659438 arto.oksanen@jklsirius.fi http://www.ursa.fi/sirius http://nyrola.jklsirius.fi/phemu03/