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04/12/2018 – Ephemeris – Where did the Milky Way go in the spring?

April 12, 2018 Comments off

Ephemeris for Thursday, April 12th. The Sun will rise at 7:03. It’ll be up for 13 hours and 20 minutes, setting at 8:24. The Moon, 3 days before new, will rise at 6:14 tomorrow morning.

The Bright stars of winter are sliding into the western twilight in the evening. Taking their place in the south and east are the much more sparse stars of spring. The Milky Way passes through the winter and summer skies as well as the northern autumn sky. In the spring it runs below our southern horizon. Way back 200 years ago William Herschel realized that the stars around us lie in a flattened disk, that it was deeper in the direction of the milky glow than 90 degrees from it. It wasn’t until a bit less than 100 years ago that astronomers realized that there was anything outside this disk of stars. Today we call the fuzzy objects we find out there galaxies after the Greek word for Milky Way. They were seen in the 18th and 19th centuries, but were not recognized as such.

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

Addendum

Herschel's Universe

The shape of the universe (Milky Way) as measured by William Herschel by counting stars in the eyepiece fields of his telescope pointed in various directions. The large indent on the right is caused by the Great Rift, clouds of gas and dust the block the light of the stars behind it, not the lack of stars in that direction. The Great Rift is easily seen in the summer sky running through the Milky Way.

Spring sky dome

The dome of the spring sky showing the Milky Way visible mostly on the northeastern sky. In spring, we are looking out the thin side of the Milky Way. Created using Cartes du Ciel (Sky Charts).

Some Spring Galaxies

M51 photo

The Whirlpool Galaxy, M51 in Canes Venatici. Credit Scott Anttila.

M101

The Pinwheel Galaxy, M101  near the star Mizar in the handle of the Big Dipper. Credit Scott Anttila.

Markarian Chain of galaxies in Virgo. Credit Scott Anttila.

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