IF IT’S CLEAR
By  Fulton Wright Jr.
Prescott, AZ

Celestial events (from Sky & Telescope magazine, Astronomy magazine, and anywhere else I can find information) customized for Prescott, Arizona. 

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August 2017

On Tuesday, August 1, it is a good time to look at the lunar crater, Clavius, as libration has tipped that part of the Moon toward us. It is a big crater, located in the southern part of the Moon, near the terminator and has an arc for decreasing sized craters in it.

On Monday, August 7, at 7:33 PM the full Moon rises spoiling any chance of hunting for faint fuzzies for the night.

On Tuesday, August 15, the Moon is at third quarter phase and rises at 12:41 AM (Wednesday).

On Sunday, August 20, before midnight, three of Saturn’s brightest moons are all on the celestial west of the planet. They are (starting with the furtherest) Titan (magnitude 9.2), Rhea (magnitude 10.4), and Dione (magnitude 11.2).

On Monday, August 21, it is new Moon and you have all night to hunt for faint fuzzies. At 9:12 AM a partial eclipse of the Sun begins in Prescott. It is maximum about 10:30 AM (about magnitude .75). The show is over at 11:59 AM. For a total eclipse, you need to travel. The path of totality starts in Oregon and exits in South Carolina. I expect many Americans (and some foreigners) to crowd into the path. I plan to be in Rexburg, ID hoping for clear skies. Sky and Telescope, and Astronomy have articles about the eclipse this month. Your favorite search engine will produce more sites than you need. Many companies will sell you eye protection which you will need for the partial phases. It is already too late to get reservations in the eclipse path, but you might get some in driving distance of the path. Remember: you will need eye protection when any part of the photosphere (the bright part of the Sun) is showing unless you use a pin hole camera to project an image of the Sun. I use a #14 welder’s filter. You must not use a filter during totality if you want to see anything (and you will want to see something).

On Monday, August 28, at 11:31 PM, the first quarter Moon sets.

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September 2017

On Saturday, September 2, the Moon occults two double stars in Capricornus. The first, Pi, happens at 11:09 PM. Pi is listed as magnitudes 5.2 and 8.5, separated by 3 arc-seconds. The second, Rho, happens at 12:18 AM (Sunday). Rho is listed as magnitudes 4.8 and 6.9, separated by 2 arc-seconds. Pi emerges from the bright limb of the Moon at 12:09 AM (Sunday) and Rho at 1:33 AM (Sunday)

On Tuesday, September 5, at 6:46 PM, the full Moon rises spoiling any chance of seeing faint fuzzies for the night. As you would expect from last month’s total solar eclipse, there is almost an eclipse of the Moon this month and you can expect very flat illumination of this full Moon.

On Tuesday, September 12, the Moon occults Aldebaran. At 4:48 AM the bright limb of the Moon covers it, at 6:02 AM (during twilight) it reappears. Later that evening the Moon is at last quarter phase and rises at 11:29 PM.

On Wednesday, September 13, if you are out between 4:00 and 5:30 AM, you can see the northern part of the Moon at its best. In particular, now would be the time to hunt for those illusive craterlets in the floor of the crater Plato.

On Monday, September 18, about 5:30 AM, you can see a lot of objects lined up. Starting at the top, brilliant Venus, Regulus, the very thin crescent Moon, Mars, and Mercury form an almost vertical line. Mars and Mercury are close on September 16. Venus and Regulus are close on September 20.

On Tuesday, September 19, it is new Moon and you have all night to hunt for faint fuzzies.

On Wednesday, September 27, the Moon is at first quarter phase and sets at 11:34 PM.