Skywatch Line for Monday and Tuesday, November 13th and 14th, 2017

This is the Skywatch Line for Monday and Tuesday, November 13th and 14th.

The Sun sets at 4:34 PM; night falls at 6:11. Dawn begins at 5:07 AM and ends with the Sun rising at 6:46.

Saturn is the easiest planet to see in the twilight sky. It lies moderately low in the southwestern constellation of Ophiuchus; it shines with zero magnitude about 13 degrees above the horizon and sets at 6:38 PM. Saturn is slowly descending into the Sun’s glare; now is the time for last looks.

Mercury is beginning an appearance 15 degrees below Saturn. Also in Ophiuchus, it peeks above the southwestern skyline, shines with minus 0.3 magnitude and appears about 81 percent illuminated. Mercury sets at 5:24 PM.

While Saturn sets, Neptune, still in Aquarius, shines at 8th magnitude near the bright star Hydor. Uranus, also still residing in Pisces, has moved slightly. It now is about 3 degrees above the brighter star Mu Piscium. Mu Piscium shines with 4th magnitude about 3 degrees below Uranus. Mu Piscium is also an interesting double star. The two stars lie about 3 arc-minutes apart, within the ability of most moderately sized telescopes. Neptune is best observed at 7:15 PM and sets at 12:51 AM. Uranus is best seen at 9:57 PM and sets at 4:38 AM.

Mars rises about 3:29 AM in Virgo. The Red Planet shines at 1st magnitude, appears about 4 arc-seconds in size and about 96 percent lit. The bright, 3rd magnitude, star Porrima glows about 3 degrees above Mars.

Tuesday’s Moon rises also in Virgo and blazes at minus 6th magnitude. The 26-day-old Moon is about 15 percent crescent and rose at 2:37 AM. Wednesday’s Moon also lies in Virgo, appears thinner and about half the size of Monday’s Moon and rises at 3:40 AM.

Civil Dawn presents a dramatic scene for early rising astronomers. Venus rises in Virgo about 16 degrees below Mars at 5:32 AM. Venus dazzles at minus-4th magnitude and appears about 97 percent lit. Jupiter, also in Virgo, rises at the same time and blazes at minus 1st magnitude. The two easily fit in a binocular or telescope field. They are separated by 1 degree on Tuesday, and 2 degrees on Wednesday. Follow them and note that Jupiter rises while Venus sinks as the month goes on.

Followers of the Skywatch Line know that the Milky Way, which tonight stretches from horizon to horizon, represents the rim of our galaxy. They also know that the faint glow in Andromeda is that of a giant galaxy, similar to ours. However, these “island universes” are not isolated from each other. Their gravitational fields clump galaxies into groups. The Local Group is made of our Milky Way, Andromeda, M 33 in Triangulum, and about a dozen other galaxies. This group is traveling together through space. Some galaxies also interact with each other. A prime example is M 51, off the Big Dipper’s Handle. Telescopes show one galaxy seemingly stealing material from another. Some astronomers think that giant galaxies like our own grow by absorbing smaller ones. Colliding galaxies are common telescopic sights. It is thought that two spiral galaxies will merge to form an elliptical galaxy. In fact, in about three billion years, Andromeda and the Milky Way will probably collide and merge. The result will be a giant galaxy marked by very active star formation

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