[BAA-ebulletin 00896] Jupiter’s upcoming opposition, notable satellite phenomena, and an occultation

[BAA electronic bulletins service]

 Jupiterwill be at opposition on March 8, and thus above the horizon all night long. Onestriking phenomenon for a day or so around opposition is that the galileanmoons can transit directly in front of their shadows on Jupiter’s disk.  This year, on the night of March 7/8, therewill be a very rare opportunity to see both Europa and Io doing this at thesame time!  Europa and its shadow moveonto the disk at 23:09-12 UT; Io and its shadow, at 00:28-29 UT, while Europais in the centre of the disk; Europa and shadow leave at 01:57-58, and Io andshadow at 02:43.  This will be very wellplaced for observers all over Europe including the UK.  Asecond dual phenomenon occurs on March 9 at 18:54-58 UT:  Ganymede ends a transit just as Io and itsshadow begin a transit.  Ganymede’sshadow remains on the disk till 19:10; Europa is hidden behind the planet.  This event will be visible from America, butwill be very low in the sky for European observers.  You cansee hi-res images of moons transiting in front of their shadows (one at a time),at the last 4 oppositions, on our web site at:            http://www.britastro.org/jupiter/2014_15report04.htm            http://www.britastro.org/jupiter/2013_14report05.htm            http://www.britastro.org/jupiter/2012_13report08.htm            http://www.britastro.org/jupiter/2011report02.htm Jupiter’smoons have coupled orbits, so dual transits of Europa and Io will continue tooccur at intervals of 3.5 days right up to mid-April, as well as dual transitsof Ganymede and Io on March 16, 23/24, and 31. Times are given in the BAA Handbook, and simulated views can be producedin WinJUPOS.  Onemore notable and rare event occurs on April 12: Jupiter will occult a 7th-magnitudestar.  Ingress is at approx. 14:45 UT,visible from the Far East and Australia. Egress is at ~17:45 UT, visible from western Asia and south-easternEurope.  Although the star will be ratherfaint relative to the planet, observers with large telescopes may be able totake videos of the event, which can involve irregular fading and multipleflashes as the star passes behind the planet’s atmosphere.  Details can be found in:            A. A. Christou & E. Kardasis,‘Stellar occultation by Jupiter and Ganymede’,            http://www.hellas-astro.gr/articles/astromanos-2015-12-13-1615Forresults from the last stellar occultation, on 2009 Aug.3/4, see the Journal ofthe BAA (2016 Feb), vol.126, p.37. 

John Rogers,BAA Jupiter Section Director
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