Four famous mists of breathtaking beauty: Eagle, Omega, Trifid and Lagoon
Nebula: a star-forming cloud of gas and dust [neb-yuh-luh].
mists [neb-yuh-lee, -lahy] is a noun with plural nebulae.
The Eagle Nebula (which contains the pillars of creation), the Omega Nebula, the Trifid Nebula and the Lagoon Nebula are all known for their breathtaking beauty.
A team of astronomers in the 1950s used rough distance measurements for some of the stars in these nebulae to deduce the existence of Sagittarius.
Some of the first evidence for the spiral structure of our galaxy came from their research.
Astronomers have discovered that these nebulae are part of a substructure in the arm that is angled differently from the rest of the arm, according to a new study.
The density with which spiral arms wind around a galaxy is an important property.
The angle of inclination of the arm is used to determine this characteristic.
The angle of inclination of a circle is 0 degrees, and the angle of inclination of a spiral increases as the spiral opens.
The firing arm is thought to form a spiral with a pitch angle of about 12 degrees, but the protruding structure has a pitch angle of almost 60 degrees, according to most models.
Similar structures protruding from the arms of other spiral galaxies are known as spores or feathers.
For decades, researchers have wondered whether our Milky Way spiral arms are also dotted with these structures, or whether they are relatively slippery.