Astrometric results of observations of mutual occultations and eclipses of the Saturnian satellites in 2009

Abstract

Context. The photometry of mutual occultations and eclipses of natural planetary satellites can be used to infer very accurate astrometric data. This can be achieved by processing the light curves of the satellites observed during international campaigns of photometric observations of these mutual events.Aims. This work focuses on processing the complete database of photometric observations of the mutual occultations and eclipses of the Saturnian satellites made during the international campaign in 2009. The final goal is to derive new accurate astrometric data. Methods. We develop an accurate photometric model of mutual event observations of sufficiently high accuracy. Our original method is applied to derive astrometric data from photometric observations of the mutual occultations and eclipses of the Saturnian satellites. Results. We process the 26 light curves obtained during the international campaign of photometric observations of the Saturnian satellites in 2009. Compared with the theory TASS 1.7 by Vienne and Duriez, we find that the root mean square of the "O-C" residuals for the 23 highest quality observations are equal to 48.5 and 21.7 mas in right ascension and declination, respectively, we obtain 16.4 and 20.7 mas with the new theory by Lainey and collaborators and 17.3 and 21.6 mas with JPL SAT351 ephemerides. Topocentric or heliocentric angular differences for satellites pairs are obtained for 16 time instants during the time period

Astrometry of mutual approximations between natural satellites. Application to the Galilean moons

“…The particular nature of orbital geometry in mutual phenomena offers valuable constrains in the orbital solutions of the satellites (Lainey et al 2004). However, these phenomena can be observed only every 6 years for Jupiter, every 15 years for Saturn and every 42 years for Uranus (Arlot et al 2012(Arlot et al , 2013(Arlot et al , 2014.…”

Analysis of mutual events of Galilean satellites observed from VBO during 2014–2015

“…Subsequent International campaigns and analysis of the observations during the 1979, 1985, 1991, 1997, 2003 and 2009 apparitions have provided an extensive data set of inter satellite astrometric positions (Aksnes et al 1984;GSO 1991;Vasundhara 1991;Arlot et al 1992;Mallama 1992;Vasundhara 1994;Arlot et al 1997;Kaas et al 1999;Vasundhara 2002;Vasundhara et al 2003;Arlot et al 2006Arlot et al , 2009Emelyanov 2009;Dias-Oliveira 2013;Arlot et al 2014). Following the success of the jovian mutual events, the technique has been extended to mutual events of ⋆ E-mail:rvas@iiap.res.in(RV),selva@iiap.res.in(GS), anbu@iiap.res.in (PA) saturnian system in 1995 and 2009 (Thuillot et al 2001;Mallama et al 2009;Arlot et al 2012;Zhang, Liu & Tang 2013), and uranian system in 2007(Asafin et al 2009Christou et al 2009;Arlot et al 2013). We report here astrometric results of 23 mutual events of the jovian satellites observed from the Vainu Bappu Observatory(VBO) during 2014-15.…”

APPROX – mutual approximations between the Galilean moons: the 2016–2018 observational campaign

“…The drawback is that they can only be observed during the equinox of the host planet, when the Earth and the Sun pass through the orbital plane of the satellites. In the case of Jupiter it happens every 6 years, for Saturn every 15 and for Uranus every 42 (Arlot et al 2012(Arlot et al , 2013(Arlot et al , 2014. For the Galileans satellites, mutual phenomena may deliver relative positions with a precision better than 5 mas (Dias-Oliveira et al 2013;Emelyanov 2009).…”