This Week’s Sky at a Glance, 2023 Sept. 16 – Sept. 23
This Week’s Sky at a Glance, 2023 Sept. 16 – Sept. 23
Autumn arrives next weekend, and dedicated stargazers are happy to have the longer observing time afforded by earlier sunsets. The summer constellations appear reluctant to move on, however; emerging from twilight in nearly the same place each night because the earlier darkness masks that they rise four minutes sooner each day. But move on they do, and by mid-evening the two groups of autumn constellations lord over us.
Perseus sits below W-shaped Cassiopeia in the northeast these evenings. Cepheus is a house-shaped constellation north of Cassiopeia, and Andromeda lies with her feet below Cassiopeia and her head sharing a star with Pegasus. The asterism called the Great Square of Pegasus rises as a large diamond, a harbinger of the baseball post season. These constellations relate to a classic tale in Greek mythology, as does Cetus, playing the role of a ferocious sea monster. Cetus is actually a whale, and this segues to the second group – the water constellations.
To the southeast in evening twilight is the chevron-shaped Capricornus the sea goat. Above and left is the source of all this water; Aquarius, the water bearing servant of the Olympian gods. Saturn is situated in the middle of Aquarius, and below them is the southern fish, Piscis Austrinus with its bright star Fomalhaut. Later and further east we have Pisces the fishes with Cetus swimming below them, and well above Capricornus we see Delphinus the dolphin trying to leap back into summer.
This Week in the Solar System
Saturday’s sunrise in Moncton is at 6:58 am and sunset will occur at 7:29 pm, giving 12 hours, 31 minutes of daylight (7:02 am and 7:33 pm in Saint John). Next Saturday the Sun will rise at 7:07 am and set at 7:15 pm, giving 12 hours, 8 minutes of daylight (7:12 am and 7:20 pm in Saint John). We are one week away from the autumnal equinox.
On Saturday afternoon, while parts of the province are likely being inundated with rain, the Moon will be passing in front of Mars, making a very difficult observation impossible. Such is the hobby of astronomy. The Moon is at first quarter next Friday, leading us into Fall Astronomy Day. Venus is at its brightest this week, and on Friday Mercury will be a hand span to Venus’s lower left as it reaches greatest elongation from the Sun. Saturn rings in the evening sky in the southeast, awaiting Jupiter’s rising two hours after sunset. Neptune officially enters the evening sky as it reaches opposition on Tuesday.
The RASC NB star party at Kouchibouguac National Park takes place on Friday and Saturday of next weekend, September 22-23. Also, Astronomy Day public observing will be held at the Irving Nature Park in Saint John next Friday from 8 – 11:30 pm, with a back-up date of September 23.