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Ephemeris: 07/08/2024 – The Summer Triangle dominates the eastern sky

July 8, 2024 Comments off

This is Ephemeris for Monday, July 8th. Today the Sun will be up for 15 hours and 23 minutes, setting at 9:29, and it will rise tomorrow at 6:06. The Moon, 3 days past new, will set at 11:34 this evening.

We’re two weeks into summer, and the asterism or informal constellation called the Summer Triangle can be seen in the eastern sky as it gets dark. The highest of the three bright stars is Vega in the constellation Lyra the harp, whose body is seen in a narrow parallelogram just below it. The second star of the triangle is Deneb, in Cygnus the swan, lower and left of Vega, It appears dimmer than Vega because it is by far the most distant of the three. The third star of the Summer Triangle is seen farther below and a right of Vega. It is Altair in Aquila the eagle, and the closest. Altair is 16.5 light years away, Vega is 27 light years, while Deneb may be a whopping 2,600 light years away. One light year by the way, is 6 trillion miles (9 trillion kilometers).

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

Finder animation for the Summer Triangle
Finder animation for the Summer Triangle. Created using Stellarium and GIMP.
The Milky Way in the Summer Triangle
Something that we are going to be missing in the next couple of weeks with the Moon being out in the evening will be the Milky Way that runs through the Summer Triangle. This photograph by Daniel Dell’Olmo emphasizes the Milky Way that can be seen under moonless skies.
Categories: Asterism, Ephemeris Program, Observing, Stars