05/11/2020 – Ephemeris – Looking out of the Milky Way in May

This is Ephemeris for Monday, May 11th. Today the Sun will be up for 14 hours and 41 minutes, setting at 9:00, and it will rise tomorrow at 6:17. The Moon, 3 days before last quarter, will rise at 1:51 tomorrow morning.

When it’s finally dark enough to see the stars in a dark sky at the end of astronomical twilight at 11 p.m. the question might be: “Where did the Milky Way go?” The band of the Milky Way is actually nearly ringing the horizon. Part of it runs through the W shaped constellation of Cassiopeia, just above the northern horizon. But the great amount of the Earth’s atmosphere we have to look through that low in the sky dims it to invisibility. The Milky Way is what we see of our galaxy, or more accurately our part of our galaxy whose shape has the rough proportions of a pancake. Remember, we’re in it. In spring we’re mostly looking through the thin side past relatively nearby stars to the intergalactic space beyond.

The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

The Dome of the sky on May 15, 2020 at 11 pm with the Milky Way at its lowest in the sky. Credit my LookingUp program.

Our place in the Milky Way. Note that we appear to be in a barred spiral galaxy. The arms are numbered and named. 3kpc is the 3 kiloparsec arm. 3kpc = 9,780 light years. The Sun is about 27,000 light years from the center. Credit NASA and Wikimedia Commons, via EarthSky.org.

The summer and winter Milky Way viewing directions. During Spring and Autumn, we look out the sides to the universe beyond. Credit Credit: NASA with annotations by Bob King at Universe Today.