Guest Author - Lea Terry

The Milky Way, home to our solar system, is one of an estimated 100 billion galaxies in the visible universe. However, from Earth we can only a small portion of the Milky Way, and scientists are still learning what our galaxy looks like from the outside. In fact, new observations have revealed a previously unknown star cluster--right in our own galaxy.

The observations were made with the European Southern Observatory's New Technology Telescope at La Silla, Chile. The new images revealed a cluster of approximately 100,000 stars located 30,000 light-years away. The cluster, FSR 1735, previously appeared as nothing more than a cloud of dust and gas, so astronomers believe it is a fairly new cluster. The cluster’s mass is thought to be 65,000 times that of the Sun, and about seven light-years wide. The cluster was found during a search for globular clusters in the Galactic Plane, an area of space rich in stars, and in which the Milky Way is located.

About Globular Clusters

Star clusters, also called globular clusters, are among the oldest objects in the universe, and are spherical groups of stars bound together by gravity. There are 150 known globular clusters in the Milky Way, but because they are usually obscured by dense clouds of dust and gas, they are difficult to locate. The infrared radiation they emit is often the only clue to their existence.

About the Milky Way

Galaxies are huge regions of space consisting of stars, planets, nebulae, gas, dust, empty space, and according to many theories, a black hole at the center. Spiral galaxies, such as the Milky Way, are the most common type of galaxy, accounting for about 75 percent of bright galaxies. The Milky Way is approximately 100,000 light-years in diameter and 2,000 light-years thick. At its center lies a flattened, rotating disk of interstellar clouds in which young, massive stars have been forming for about 10 million years. Our solar system lies in the Orion arm, one of the Milky Way’s four spiraling arms. The Milky Way is visible on clear summer nights, in locations far removed from city lights, and appears as a region of light stretching across the sky. Early stargazers thought it resembled a river of milk, hence its name--The Milky Way.