- How to find and observe NGC457 (TOTS#3) (eyesonthesky.com)
NGC 457 is an open cluster within our own Milky Way galaxy. It is over 7,900 light years from Earth, so the photons from it reaching your eye in a telescope left that cluster about the time copper was first being used in the Middle East. The estimated age is about 21 million years, making it one of the younger star clusters in our galaxy. Here is how to locate it.
- Globular cluster (Wikipedia)
A globular cluster is a spheroidal conglomeration of stars that is bound together by gravity, with a higher concentration of stars towards their centers. They can contain anywhere from tens of thousands to many millions of member stars, all orbiting in a stable, compact formation. Globular clusters are similar in form to dwarf spheroidal galaxies, and the distinction between the two is not always clear. Their name is derived from Latin globulus (small sphere). Globular clusters are occasionally known simply as “globulars”.