Boötes

Boötes, pronounced boo-OH-tees, is a constellation is the northern sky. It is fairly large, ranking 13th out of 88 in terms of area. It contains Arcturus, which is the fourth brightest star in the night sky. In fact, it has a total of 29 stars above the fifth magnitude, which renders them visible to the naked eye.

Boötes can be located through finding the Big Dipper, which is a famous asterism found in Ursa Major. The handle of the Big Dipper points towards Arcturus, which will allow you to locate the rest of the constellation. Boötes resembles a kite with Arcturus found at the base of the kite.

This is a rough drawing of Boötes, with its neighbouring constellations.

Arcturus forms one corner of the Spring Triangle asterism, along with Virgo's Spica and Leo's Regulus. Arcturus is a single red giant located relatively close to us. In fact, its closest approach to us will be in 4000 years. Arcturus is thought to be an old-disk star, and appears to be moving with a group of other stars known as the Arcturus stream. The thick disk has significantly lower levels of metals, which are elements that are not hydrogen and helium, implying that it consists almost exclusively of older stars. However, its nature is still under dispute.

The Arcturus stream is not in the plane of the Milky Way galaxy, and is proposed to be a remnant of an ancient dwarf satellite galaxy, which has since being assimilated into the Milky Way.

Up next is Caelum.