Neptune transit: eastern quadrature

Event Date: November 23rd

Time: 6:09.(40) AM

Brief

   Neptune has just past eastern quadrature by a couple of days: 90º elongated from the Sun, which happens about halfway between opposition and conjunction for outer planets.  Of course, inner planets do not have quadrature west or east, yet instead of have 2 conjunctions: inferior, as we saw with the Venus transit as an extreme example in June, and superior, when the planets go behind the Sun for awhile.

More about quadrature is in the detailed section, while for the moment, I will show Neptune transiting.  With quadrature two days ago, Neptune's separation from the set-Sun is 88.2º.

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

Detailed

   For eastern quadrature, it simply means that the Sun has progressed approximately one-quarter of the way through the sky along the ecliptic, relative to the planet that it had opposition with.  Since the orbits of each planet are not quite even with the ecliptic, it is because of that, that the Sun may not have to go exactly one quarter of the way during the calendar year.  Also, because of a planet's prograde and retrograde motions, seen at different lengths and rates for each planet depending on its distance from Earth and the Sun, that can also play a part as well.

   Sometimes, depending where the Sun and a planet are in the sky, the Sun may be set when the planet transits, as seen with this example, or not set.  Since the Sun spends very little time above the horizon at this time of year compared to the weeks surrounding the June solstice (summer for us), it means that the separation with Neptune must come from the Sun starting there, if we think in terms of angles.

Seen also in the image, near the waxing Moon, is Uranus, although too washed out perhaps to easily see this evening with a small telescope.  Once the Moon is out of the way, Uranus' green-blue color becomes easier to see in even some small telescopes.