Bob Moler's Ephemeris Blog

This is Bob Moler with Ephemeris for Monday, August 7th. Today the Sun will be up for 14 hours and 25 minutes, setting at 9:00, and it will rise tomorrow at 6:36. The Moon, 1 day before last quarter, will rise at 12:06 tomorrow morning.

Looking due south and low in the sky at 11 pm, now is one of my favorite asterisms, the Teapot of the constellation Sagittarius. Sagittarius, classically, represents a centaur with a bow and arrow aimed at the heart of the constellation Scorpius to its west. I can find the bow and arrow here, but the half man, half horse figure of the centaur eludes me. However, the stout little teapot of the children’s song is quite obvious, with its base, lid on top, handle to the left and the spout to the right. To make things more realistic, the bright Milky Way seems to rise like steam from its spout. The Teapot is an asterism, an informal constellation. As the night goes on, the Teapot moves westward and appears to tilt, pouring its tea on the southwestern horizon.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT –4 hours). They may be different for your location.

Addendum

Sagittarius-Teapot finder animation for 11 pm, August 7, 2023. I’ve omitted all the lines in Sagittarius except the teapot stars from Stellarium, so there are more lines connecting the stars, most too far south to really spot easily from our latitude (45 degrees north). Click or tap on the image to enlarge it. Created using Stellarium and GIMP.

Named stars that are shown in the image above are Nunki, from an ancient tablet of thirty stars – The proclaimer of the sea. This is because the next four constellations to the east are water constellations: Capricornus, the sea goat; Aquarius, the water bearer; Pisces the fish; and Piscis Australis, the southern fish. Antares, in Scorpius, is of course the Rival of Mars, due to its reddish hue, and Mars passes Antares regularly on its journey through the Zodiac. An archer has to have his bow. Kaus Australis is the southern bow star. The star above that is Kaus Media, the middle bow star. And the star above and left of that is Kaus Borealis, the northern bow star. The constellation art that comes with Stellarium doesn’t match up with the stars of the bow.

The five stars on the left side of the Teapot is another asterism called the Milk Dipper.

Sagittarius in a short time exposure with added annotations. This would be later in the evening, around midnight. The “M” designations are objects in Charles Messier’s catalog created in the latter half of the 18th century. LSSC is the Large Sagittarius Star Cloud, SSSC is the Small Sagittarius Star Cloud. These will be easily visible in binoculars. Credit Bob Moler.