Graphical evidence for the solar coronal structure during the Maunder minimum: Comparative study of the total eclipse drawings in 1706 and 1715

We discuss the significant implications of three eye-witness drawings of the total solar eclipse on 1706 May 12 in comparison with two on 1715 May 3, for our understanding of space climate change. These events took place just after what has been termed the "deep Maunder Minimum"but fall within the "extended Maunder Minimum"being in an interval when the sunspot numbers start to recover. Maria Clara Eimmert's image in 1706 is particularly important because she was both a highly accomplished astronomical observer and an excellent artist: It was thought lost and was only re-discovered in 2012. Being the earliest coronal drawings of observational value yet identified, these drawings corroborate verbal accounts a corona without significant streamers, seen at totality of this and another eclipse event in 1652 during the Maunder Minimum. The graphical evidence implies that the coronal solar magnetic field was not lost but significantly weakened and the lack of coronal structure means there was little discernable open flux (either polar or at lower latitudes) even during the recovery phase of the Maunder Minimum. These observations provide evidence for a different state of oscillation of the solar dynamo, and hence behaviour of the Sun, in comparison with that during normal solar cycle minima (when a streamer belt between two polar coronal holes is visible) or near normal sunspot maxima (when coronal structure is caused by coronal holes at all latitudes) even to observers without a telescope

Commission 8: Astrometry

This triennial report from Commission 8 covers astrometry-related matters for objects ranging from Solar system bodies out to Milky Way stars and QSOs at cosmological distances. This enormous range of distances is needed to establish, maintain, and improve the metric of the visible Universe–a very challenging effort since everything is moving. The progress of astrometry in the last three years (2002-2005) is reflected here. To locate the references, the reader is advised to check the NASA ADS Astronomy Abstract Service and the expanded report posted at URL http://www.pha.jhu.edu/iau_comm8/comm8.htm

Unobservable mutual events of the Galilean satellites

Mutual eclipses and occultations of the Galilean satellites of Jupiter which will occur in 2002–2003 were predicted independently by J.-E. Arlot and by K. Aksnes, and information on the visibility of the events from any site on the Earth is provided on the IMCCE web site based on Arlot's predictions. However, many unobservable events, such as the eclipsed satellites are in the shadow of Jupiter, are included in Arlot's predictions and there is no way of eliminating of such unobservable events from his predictions. This paper lists all such events