Post by Centaur on Sept 10, 2010 10:54:22 GMT -6
That brilliant beacon in the evening eastern sky, giant Jupiter, has been growing brighter and rising about four minutes earlier each night. It will reach opposition to the Sun (by right ascension, celestial longitude and greatest elongation) on September 21. At that time it’ll be rising around sunset, transiting the local meridian near local midnight, and setting about sunrise. It currently exhibits apparent retrograde motion on star charts.
All dates given here are for the US central time zone. Jupiter will be at perihelion next March and will be only 3.9539 AU from Earth on September 20 at an angular diameter of 49.8 arcseconds and magnitude -2.9. That’ll be the closest, widest and brightest for its current 11.86-year orbital period, but only slightly better than at the 2011 opposition.
Jupiter’s opposition declination has been improving for northern hemisphere observers since the low of 2008. This year it is wavering around the celestial equator before a six-year stay north of it. So its transit altitudes for observers north of the tropics will be better than in recent years but not as good as in the years to come.
The tilt of Jupiter’s equatorial plane at opposition will be +2.4° which is greater than last year. The orbital planes of the four Galilean satellites lay close to that plane, so the mutual events (transits, occultations, eclipses) not involving Jupiter that we observed last year will not occur this year. In fact following Callisto’s partial occultation on February 20/21, a nearly three-year period will commence in which Callisto will not be involved in events with Jupiter.
Of course the events involving Jupiter and the inner three Galilean satellites will still happen during every one of their orbital periods. Interestingly a couple of series of dual shadow transits will commence in October and January. Eight such events are expected between October 1 and January 17.
Jupiter will resume apparent direct motion on November 18 and reach eastern quadrature (90° from Sun) on December 16 at which time it will be setting around local midnight. Conjunction behind the Sun will be achieved on 2011 APR 06.
I’ve created several graphics related to Jupiter and its current apparition. That includes long-term graphs for brightness and declination. They can be seen by going to www.curtrenz.com/astronomical then clicking to the page for Superior Planets.
Photos and descriptions of Jupiter and its satellites during this apparition would be welcome additions to this thread.
All dates given here are for the US central time zone. Jupiter will be at perihelion next March and will be only 3.9539 AU from Earth on September 20 at an angular diameter of 49.8 arcseconds and magnitude -2.9. That’ll be the closest, widest and brightest for its current 11.86-year orbital period, but only slightly better than at the 2011 opposition.
Jupiter’s opposition declination has been improving for northern hemisphere observers since the low of 2008. This year it is wavering around the celestial equator before a six-year stay north of it. So its transit altitudes for observers north of the tropics will be better than in recent years but not as good as in the years to come.
The tilt of Jupiter’s equatorial plane at opposition will be +2.4° which is greater than last year. The orbital planes of the four Galilean satellites lay close to that plane, so the mutual events (transits, occultations, eclipses) not involving Jupiter that we observed last year will not occur this year. In fact following Callisto’s partial occultation on February 20/21, a nearly three-year period will commence in which Callisto will not be involved in events with Jupiter.
Of course the events involving Jupiter and the inner three Galilean satellites will still happen during every one of their orbital periods. Interestingly a couple of series of dual shadow transits will commence in October and January. Eight such events are expected between October 1 and January 17.
Jupiter will resume apparent direct motion on November 18 and reach eastern quadrature (90° from Sun) on December 16 at which time it will be setting around local midnight. Conjunction behind the Sun will be achieved on 2011 APR 06.
I’ve created several graphics related to Jupiter and its current apparition. That includes long-term graphs for brightness and declination. They can be seen by going to www.curtrenz.com/astronomical then clicking to the page for Superior Planets.
Photos and descriptions of Jupiter and its satellites during this apparition would be welcome additions to this thread.
