Article: September Umpqua Star Gazer

Umpqua Star Gazer September 2017 By Paul Morgan Evening Planets Jupiter slowly sinks into the evening twilight. The Gas Giant is now very low in the southwestern sky as twilight begins. That bright “star” low in the west southwest is Jupiter. Each night, Jupiter will slip a bit lower into the brighter twilight and drift a bit more toward the west. Look on September 21st to see Jupiter paired with an ultra-thin crescent moon. Telescope observers will find it difficult to watch cloud features on Jupiter but may enjoy the nightly movement of the four bright Galilean Moons. Saturn drops a bit of altitude this month but remains well placed for telescope observers. Saturn surpasses maximum altitude as twilight ends. Look toward the south southwest horizon to spot a modestly bright “star”. That’s Saturn. Point even a small telescope at that ”star” and you will see the magnificent rings wrapping around Saturn. Neptune reaches maximum brightness and apparent size on September 4th and slowly fades after mid-month. Use a star chart to find this 8th magnitude Ice Giant in Aquarius. Neptune is now up all night and is well placed for observing after 9 p.m. PDT tonight. Look to the southeast to find the “Mercedes Benz” asterism in Aquarius. About 10 degrees below is the 4th magnitude Lambda Aquarii. Use your binoculars to look about a “moon width” to the left and 3 stars down to spot dim Neptune. Uranus follows Neptune into the sky by about an hour. Look about 9:30 p.m. PDT tonight toward the east to find 4th magnitude Omicron Piscium in order to find 6th magnitude Uranus. It may help to find 2nd magnitude Hamal in Aries and then sweep your binoculars about 15 degree west to find Omicron. Uranus is about 1 degree straight above Omicron. Dawn Planets Dawn skies will exhibit 3 bright planets dancing about the brightest star of Leo, Regulus. Look before sunrise to spot brilliant Venus, bright Mercury and modest Mars in the east. Look at 5:45 a.m. PDT just above the eastern horizon to spot a trio of bright “stars”. Mars sits about 1 degree above Regulus and Mercury is about 2 degrees to the right. This gathering occurs in bright twilight and will be challenging to see. High above and to the right of this trio shines dazzling Venus. On the morning of September 6th, Mars will appear to have dropped and Mercury climbed a bit to form a diagonal line about 2 ½ degrees long with Regulus between Mars and Mercury. About 90 minutes before sunrise , look to the east to see Mars now 2 degrees to the lower left of Regulus and Mercury only 1 degree to the right. Meanwhile, Venus has retreated to within 12 degrees of Mercury- Regulus. On the morning of September 10th, Mercury and Regulus are less than a “moon-width” apart. Mercury and Mars appear to move steadily away from Regulus by September 13th. Each morning, Mercury slips toward pokey Mars as Venus continues to drop toward Regulus. On September 16th, Mars and Mercury are less than 11 arc minutes apart forming a bright “double star”. This conjunction rapidly breaks apart as Mercury races downward toward the rising sun. Look on September 18th, for a 12 degree row of 3 planets, Regulus and a very thin old crescent moon. Venus and Regulus appear to have a close encounter, about a “moon width” apart on the mornings of September 19th and 20th. Mercury exits the gathering a few mornings later. Mars soars higher and Venus descends each morning, headed for a close conjunction in early October. Autumn Equinox The sun will sit on the Celestial Equator at 1:02 p.m. PDT on September 22nd to mark the beginning of the Northern Hemisphere’s fall season. Careful observers will note that the sun rises and sets due east and west on the 22nd. Many people think that on this day the length of daylight equals the length of darkness (night) but that actually occurs on the next day or September 23rd here in Douglas County. Umpqua Astronomers September Meeting Come on September August 12th at 7 p.m. at U.C.C. Wayne Crooch Hall Room 18 to share our experiences of the August 21st Solar Eclipses. Everyone is welcome to come and ask questions. Newcomers to astronomy are invited to a special pre-meeting at 6:30 p.m. to ask questions and learn about beginning astronomy. Anyone interested in learning about astronomy is welcome. For more information call 541-673-1081 or visit http://www.umpquaastronomers.org .