Spiraling In
20 NOVEMBER 2019 • SKY & TELESCOPE
270°300°OUR GALAXY
The Milky Way has a few main arms and
several smaller ones. Since this diagram’s
creation in 2008, astronomers have detect-
ed the New Arm, probably an extension of
the Scutum-Centaurus Arm. The Perseus
Arm has proved patchier (sparse sections
hazed out) and the Local Arm brighter and
longer — observers suspect it might hook
up with Perseus near 70° galactic longitude
(dotted line). Locations of familiar citizens
of the Perseus, Local, Sagittarius, and
Scutum-Centaurus arms are highlighted.1 h and Chi Persei3 Orion Nebula (M42)4 Westerlund 12 Eagle Nebula (M16) 5 Eta Carinae PERSEI^ DOUBLE:^ROTHRITTER;^ E
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