Umpqua Star Gazer: October

October 1, 2018


Venus concludes its evening sky tour after the first week of October. Each night, Venus drops a bit closer to the setting sun. Tonight, Venus sets only 38 minutes after the sun. Look low to the west to spot a very bright “star.” That’s Venus. In less than a week, Venus will set just a few minutes after the sun in bright twilight. By Halloween, Venus the evening “star” will become the morning “star.” Telescope observers of Venus will be severely challenged. Our sister world is extremely low after sunset, you will have only a few minutes to see Venus before it drops into the tree tops. Strategies to observe Venus until Oct. 20 will be discussed at the Umpqua Astronomer’s October meeting.

Mercury will make a poor evening appearance in late October. Look for the swift planet about three degrees below Jupiter on Oct. 27 to 29 as the sky darkens slightly. Strategies to observe Mercury until November will be discussed at the Umpqua Astronomer’s October meeting.

Jupiter continues to fade almost imperceptibly from 33 arc-seconds to 31 arc-seconds by month’s close. Jupiter is also starting to lose altitude as the sky darkens. Telescope observers will want to seek out Jupiter in the twilight sky for steadier viewing. Tonight, Jupiter will set only 1 1/2 hours after the sun. Look as the sky darkens toward the west southwest to spot a bright “star.” That’s Jupiter. By month’s close, Jupiter will follow the setting sun by less than an hour.

Saturn hovers near the “top of the teapot” in Sagittarius. Saturn remains a steady 16 arc-seconds in apparent size and dims just a smidge during October. Tonight, look low toward the south, just after 7 p.m. to spot a modestly bright star. That’s Saturn. Telescope observers will need to turn their telescopes toward Saturn as soon as the sky darkens for best views. Each week, Saturn will seem to drift more toward the southwest and drop a bit lower by nightfall. By month’s close, Saturn will be very low in the southwest as twilight ends.

Mars accelerates its fade in apparent brightness and size. Look toward the south tonight after twilight fades. Mars is that bright reddish “star” about 20 degrees above the horizon. This month earth speed away from Mars by about eight million miles. Mars will appear to fade from -1.29 to –0.6 magnitude and shrink from 16 arc-seconds to 12 arc-seconds. Mars is still the brightest “star” in the south southeast and it is best placed for telescope observers by 8 p.m. tonight. The global dust storm that has shrouded Mars from late June is slowly lifting. Get out your scope this month and enjoy Mars as the dust settles.

Two Ice giant planets join the evening sky this month. First up is Neptune. Use binoculars tonight to spot dim (7.8 magnitude) Neptune after twilight fades. A handy star chart can be found in the September 2018 issue of Sky and Telescope magazine. Neptune will be well placed for telescope observers by 8:30 p.m. tonight and just after twilight by Halloween. About 90 minutes after Neptune rises, Uranus pops up from the eastern horizon. Look tonight about 8 p.m. to spot Uranus in the constellation Aries. Technically, Uranus is visible to the unaided eye at magnitude 5.7. However, most folks find that binoculars and a star chart help track down this gas giant.

Meteor Showers

October brings two meteor showers, one famous and one seldom observed. The Orionids Meteor Shower come from dust ejected from Comet Halley. This moderate shower generally has between 20 and 30 swift, mostly dim, meters per hour at the annual peak. This year, the Orionids will mostly be lost in the glare of a bright nearly full moon. If skies are clear, bundle up on the morning of Oct. 21 after midnight to see about 10 meteors per hour. Look toward the northeast or south southeast for best counts. If the moon is up, face away and place the moon toward your back. Highest counts and darkest skies will be found two hours before morning twilight. A seldom observed minor shower known as the Draconids or Giacobinids peaks on the night of October 8th just as the sky darkens. This shower has a history of three to five meteors per hour at best. Forecasters this year predict a wide range of peak numbers from 20 to 10 meteors per hour. Draconids meteors are relatively “slow” with speeds about 1/3 as fast as the Orionid’s meteors. This shower does not require waiting until after midnight as most showers do. Rather, it begins with best numbers just after the sky darkens or about 7:45 p.m. PDT. Bundle up and enjoy the show.

Morgan Observatory at U.C.C. (PMO)

Planned public star gazing events have concluded. Depending on weather, more evening and daytime solar events may be possible. Look for short term notices of events as weather patterns allow. Generally, only 48 to 72 hours notice will be available. So, please check the site frequently.

Please look at the Observatory website for announcements and event details at www.umpqua.edu/observatory. Observatory seating is limited and parking is available near the Tower Building at U.C.C. All events are offered without charge. Dress warmly as the nights can be chilly at the observatory.

Umpqua Astronomers Meeting

Come on October 9 at 7 p.m. to U.C.C. Wayne Crooch Hall Room 18 for the Umpqua Astronomers October meeting. Club news, monthly sky events and astronomy news will be presented. The latest techniques to observe Mercury and Venus will be given. Also, observing fall comets and a possible fall messier marathon will be discussed. If the skies are clear, bring your telescope or binoculars to a final “Tune up your Telescope night” at the observatory after the October UA meeting. Everyone interested in astronomy is welcome. Newcomers to astronomy are invited to a special pre-meeting at 6:30 p.m. to ask questions and learn about beginning astronomy. For more information visit, http://www. umpquaastronomers.org. or call 541-673-1081.

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