Skywatch Line for Monday and Tuesday August 21st, and 22nd, 2023
This is the Dudley Observatory’s Skywatch Line for Monday and Tuesday August 21st, and 22nd, written by Joe Slomka.
The Sun sets at 7:48 PM; night falls at 9:33. Dawn begins at 4:24 AM and ends with the Sun rising at 6:09.
Monday’6-day-old Moon rises at 11:10 AM, by 8:20 PM it is 16° high in southwestern Virgo, 26% illuminated, 30 arc-seconds in size and sets at 10:04 PM. Tuesday’s slightly fatter Moon, moves to Libra, rising at 12:16 PM, 18° high, same size, but 36% lit and sets at 10:27.
Mars barely hangs on as an evening planet; in Virgo, it shines with 1st magnitude, a slim 3 arc-seconds, 4° high by 8:30 PM and sets at 8:50. Saturn is now an evening planet in eastern Aquarius, rising at 8:05 PM, zero magnitude, almost 19 arc-seconds and 4° high at 8:30 PM. Saturn continues retrograde travel, which means that it appears to back up against the stars. Neptune, 22 degrees behind Saturn, rises in Pisces at 8:54 PM, glimmers with 8th magnitude, a tiny 2 arc-seconds and 44° highest at 2:30 AM.
A easier object is Comet 103P/Hartley, which lies in Andromeda, glowing with 9th magnitude, 83% lit, 8° at 8:30 PM and highest with 79° altitude at 5:30 AM.
Aries houses Jupiter and Uranus. Gas Giant Jupiter makes its appearance at 10:49 PM, glistens with minus 2 magnitude, a huge 42 arc-seconds and highest with 62° at 5:30 AM. Wednesday’s pre-dawn presents telescopic events. The moon Europa begins an eclipse at 12:06 AM which ends at 2:30; its occultation starts at 2:51 and ends at 5:07. The Great Red Spot (a giant storm) becomes visible at 1:06. Uranus follows 7° behind Jupiter, rising at 11:06 PM, 3 arc-seconds, and is 37° highest at 5:30 AM. Eastern Venus peeks above Cancer’s horizon at 5:28 AM, blazing with 4th magnitude, 55 arc-seconds, and is only 2° high at 5:30 AM.
Midnight sees the rise of two star clusters: Pleiades and Hyades. The Pleiades rise first and resemble a mini dipper, while the Hyades, rising an hour later, form the face of Taurus, the Bull. In Greek myth, the Hyades and Pleiades are related, both daughters of Atlas and Aethra; both seven in number. The name Hyades derives either from the story of the sisters mourning the death of their brother Hyas, or from the Greek verb “to rain,” since the Hyades’ rise heralded the rainy season. They were placed in the sky as a reward for babysitting the infant god Bacchus. The Hyades is the second closet cluster to Earth, second to the Ursa Major cluster. It is about 400 million years old. This cluster is about 150 light-years away and part of the “Taurus Moving Cluster” of stars that are heading towards the star Betelgeuse. The bright star Aldebaran is not a member of this group, and actually midway between Earth and the Hyades. Aldebaran is a giant star, about forty times the Sun’s size and about 125 times brighter.