Skywatch Line for Monday and Tuesday July 8th and 9th, written by Joe Slomka
This is the Dudley Observatory’s Skywatch Line for Monday and Tuesday July 8th and 9th, written by Joe Slomka.
The Sun sets at 8:35 PM; night falls at 10:47. Dawn begins at 3:15 AM and ends with Sunrise at 5:26.
The Moon resides in western Leo on both nights and appears 30 arc-minutes in size. Monday, the 3-day-old Moon rises at 7:53 AM, by 9 PM it lies 17° high, 10% illuminated and sets at 10:41 PM. Tuesday’s Moon rises at 8:59 AM, 21° high, 16% lit; that evening, the crescent Moon trails Regulus by 6° as both sink into nightfall at 11:03 PM. Wednesday’s Moon rises at 10:03 AM.
Venus is first visible planet, 9° from the Sun, blazes with minus 4th magnitude, appears 10 arc-seconds, 2° high in the Northwest and sets at 9:08 PM. Mercury is second, appearing 12° above the Moon and 23° from the Sun, appears 6 arc-seconds in western Cancer, 65% lit, by 9 PM zero magnitude, 9° high and sets at 9:51 PM. Saturn, in southern Aquarius, shines with 1st magnitude, 18 arc-seconds, 3° high, and sets at 11:31 PM. Neptune, 10° from Saturn, inhabits Pisces, 8th magnitude, 2 arc-seconds, 40° high in the Southeast and sets at 11:51 PM.
Red Planet Mars rises in Aries at 1:57 AM, glistens with 1st magnitude, 5 arc-seconds, 90% illuminated and 29° high at 4 AM. Eastern Taurus shares Uranus with Jupiter. Uranus rises at 2:08 AM, 5th magnitude, 3 arc-seconds and 20° high at 4 AM. Giant Jupiter, 14° from Uranus, rises at 2:56 AM, flashes with minus 2nd magnitude, a large 34 arc-seconds and 11° high.
On January 1st 1801, Giuseppe Piazzi discovered the first Dwarf Planet, 1Ceres, floating between Mars and Jupiter in the Asteroid Belt. It is small, but close enough for observers to spot it with binoculars; in 2015, the Dawn spacecraft spotted water surface – a rare finding. 1Ceres rises in the low southeast at 8:49 PM, 7th magnitude, highest 18° at 12:47 AM, 10° high by 4 AM and sets at 4:45 AM.
Appropriate for the upcoming racing season, two horses appear by midnight. The largest horse is, of course, Pegasus; the smallest is Equuleus. This dim constellation is easy to find. Pegasus fly’s upside down and is easily identified as a Great Square. Two thin chains sweep northward from the upper left. If one follows the chain, binoculars reveal a large hazy oval; which is revealed, in telescopes, to be the Andromeda Galaxy – about two and a half million-light-years distant. You can see it with the naked eye under rural skies. Pegasus’ neck flows from the lower right corner and angles up. Equuleus is the small angular line of stars West of the Pegasus’ nose. A globular star cluster, M15, lies halfway between Pegasus’ nose and Equuleus. This too is easily observed in binoculars.