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Ephemeris: 07/28/2026 – The size and shape of the Milky Way

July 28, 2026 Comments off

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This is Ephemeris for Tuesday, July 28th. Today the Sun will be up for 14 hours and 48 minutes, setting at 9:13, and it will rise tomorrow at 6:25. The Moon, 1 day before full, will set at 6:11 tomorrow morning.

August and September are the two months in which the Milky Way dominates the evening sky. It also dominates the sky in the winter, six months from now but we’re looking out away from the center of the Milky Way. It is dimmer, an almost invisible as a band, but we have a great number of really bright stars, including those of Orion. The Milky Way is a galaxy, a large conglomeration of stars that are arranged in a disk, with the central bulge, whose diameter is about 87,400 light years. The thickness of the disk runs from 8,500 light years near the center to 1,000 light years farther out. The sun’s location is 25 to 26,000 light years from the center. From our location within the disk it appears to be a glowing band that surrounds the sky.

The astronomical event times given in this blog are for the Traverse City/Interlochen area of Michigan (Lat 44.7° N, Long 85.7° W; EDT, UT – 4 hours) unless stated otherwise. Times will be different for other locations.

Addendum

Artist's conception of the Milky Way. From NASA/JPL/Spitzer/Cal Tech
Artist’s conception of the Milky Way. Credit: NASA/JPL/Spitzer/Cal Tech
The summer and winter Milky Way viewing directions.
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.
The span of the Milky Way across the summer sky
The span of the Milky Way across the summer sky as seen in the free Stellarium app. Specifically August 15th at 10 pm from Northern Michigan. The Milky Way has been set to its maximum brightness to show as much detail as possible. It really isn’t that bright. The horizon is only delineated by the compass points. The dark clouds of the Great Rift are also visible. The Milky Way, in Stellarium, is photo-realistic. The triangle of three bright stars above center is the Summer Triangle, Specifically, clockwise from the top star: Vega, Altair and Deneb. Large images can be truncated on the right. Click or tap on the image to enlarge and display the complete image.

Categories: Concepts, Ephemeris Program, Milky Way