Post by Centaur on Jul 22, 2010 11:17:23 GMT -6
That bright “star” that’ll be rising for Chicagoland from nearly due east this evening (July 22) at 23:00 CDT will actually be the king of the planets: Jupiter. That time will slightly vary elsewhere. It’ll continue to rise about four minutes earlier each following evening. A link to graphics can be found below.
All dates given here are for the US central time zone. Jupiter passed its western quadrature (90° from Sun) on June 23 and will commence apparent retrograde motion tomorrow, July 23.
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’s slightly nearer than the 2011 closest approach will be. Jupiter won’t actually be in opposition to the Sun (by right ascension, celestial longitude and greatest elongation) until the next day, September 21. At that time it’ll be rising around sunset, transiting the local meridian near local midnight, and setting about sunrise.
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 eclipse on October 9, 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 be occurring in late summer and early autumn.
Jupiter will resume apparent direct motion on November 18 and reach eastern quadrature 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 a couple for the dual shadow transits. 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 passed its western quadrature (90° from Sun) on June 23 and will commence apparent retrograde motion tomorrow, July 23.
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’s slightly nearer than the 2011 closest approach will be. Jupiter won’t actually be in opposition to the Sun (by right ascension, celestial longitude and greatest elongation) until the next day, September 21. At that time it’ll be rising around sunset, transiting the local meridian near local midnight, and setting about sunrise.
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 eclipse on October 9, 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 be occurring in late summer and early autumn.
Jupiter will resume apparent direct motion on November 18 and reach eastern quadrature 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 a couple for the dual shadow transits. 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.
