Skywatch Line for Friday, October 25, through Sunday, October 27, 2019

This is Dudley Observatory’s Skywatch Line for Friday, October 25, through Sunday, October 27, written by Sam Salem.

On Friday, Sun rises at 7:21am and sets at 5:58pm; the waning crescent Moon rises at 3:54am and sets at 5:05pm. The new Moon occurs on Sunday at 11:38pm.

Mars is the only bright planet to appear in the morning sky. Mars rises at 5:50am. Modesty-bright Mars may not be easy to spot in the morning sky. On Saturday, let the waning crescent moon serve as your guide to Mars. Watch for the young Moon to join up with the planets Mercury and Venus in a few to several more days.

Mercury, Venus, Jupiter and Saturn come out after sunset. Jupiter and Saturn stay out till well after nightfall. Jupiter sets a little after 8:30pm and Saturn sets around 10:20pm. Mercury and Venus sit low in the afterglow at sunset and then follow the Sun beneath the horizon shortly thereafter. Look for Venus first and then seek out Mercury with either the eye alone or binoculars. Mercury and Venus set around 6:45pm.

Try to spot planet Uranus this weekend taking advantage of these upcoming moon-free nights. Uranus, at magnitude 5.7, comes closest to Earth for the year on Sunday then reaches opposition on Monday. As Uranus lies opposite the Sun, it climbs highest up for the night at midnight, and sets in the west at sunrise. It is now shining at its brightest in our sky. Even at its brightest, Uranus is still quite faint. It is barely seen as a dim speck of light to the unaided eye. Uranus shines no more brilliantly than the sky’s faintest stars. If you have a dark sky free of light pollution, you might see Uranus with the eye alone, if you know where to look. Uranus sits in front of the rather faint constellation, Aries, though quite close to constellation Pisces border.

Zodiacal light is readily visible from a dark site in east before morning twilight for the next two weeks. The zodiacal light is also known as the false dawn. Look east, about an hour before the light of true dawn. The zodiacal light is a pyramid-shaped glow in the east before dawn, or after twilight ends in the evening. It’s even “milkier” in appearance than the starlit trail of the summer Milky Way. The zodiacal light can be seen for up to an hour or so before true dawn begins to break. Look for it about 120 to 80 minutes before sunrise. Unlike true dawn or dusk, there’s no rosy color to the zodiacal light. The reddish skies at dawn and dusk are caused by Earth’s atmosphere, and the zodiacal light originates far outside our atmosphere. The zodiacal light is sunlight reflecting off dust particles that move in the same plane as Earth and the other planets orbiting our Sun.
You are looking edgewise into our own solar system when you see the zodiacal light.

Vega is the brightest star shining high in the east after dark. Barely lower left of it is 4th-magnitude Epsilon Lyrae, the Double-Double. Epsilon forms one corner of a roughly equilateral triangle with Vega and Zeta Lyrae. The triangle is less than 2 degrees on a side, hardly the width of your thumb at arm’s length. Binoculars easily resolve Epsilon. A telescope should resolve each of Epsilon’s wide components into a tight pair. Zeta Lyrae is also a double star for binoculars. It is much tougher, but plainly resolved in any telescope. Delta Lyrae, a little below Zeta, is a much wider and easier pair, tinted deep orange and pale blue.

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