Jupiter rising, zoomed with Moons

Event Date: October 24th

Time: 9:00 PM

Brief

   I have shown Jupiter transiting several times since it emerged from the Sun post-conjunction about 5 months ago.  This time, I will show it rising, along with the celestial guidelines and its orbit.  Although currently slightly south of the ecliptic, Jupiter's declination is far enough north that we see it almost as long each night as a first-day-of-Summer Sun (in the daytime), transiting the late-night sky, and still above the horizon by the time daylight washes it out in the west-northwest.  

   The first image is a zoom-out showing the lines, along with the unlabeled Pleiades and Hyades Star Clusters not far from the planet.  The second image is a zoom-in showing the Galilean Moons visible as well.  The magnification of that image is about 200x.  

click on images to enlarge: courtesy of Starry Night Pro Plus, version 6.4.3, by Simulation Curriculum Corp.

Detailed

   When looking at image two, notice the different positions of the Moons since I last showed Jupiter about a week ago at transit.  They change from day to day, with different orbit sizes, although seeing Jupiter over the course of several hours near the time of opposition lets us see smaller-orbit ones move gradually: Io, in particular.

  Since conjunction, Jupiter has risen about an hour earlier every 15 days, mainly as a result of our revolution yet also its own.  That is, when Jupiter has moved at its fastest in prograde, as the case for days surrounding conjunction, is moved at its fastest west to east against the sky and therefore, the rises times are closer to the 3 minute mark instead of 4.  Now in retrograde, with opposition in early December, it is currently rising at intervals a little bigger than the sidereal 3 minute, 56 seconds.  For example, 4 minutes, 14 seconds tomorrow, and 4:15 the next day.  By the time of opposition, the interval increases to well over four minutes earlier.  I will remind viewers of that on opposition day.

   When magnifying Jupiter when low, a stable atmosphere and very light winds are a must, to see its features somewhat clearly.  Since atmospheric pollution is an issue while rising it is better to wait until it is high enough to see out of most of the pollution.  Remember to try to keep it in your telescope at and shortly after Sunrise, as it is bright enough (-2.7, near its peak for the year).