Back to Back Issues Page |
Sky And Scopes, Issue #002 -- Looking at Globular Clusters December 02, 2010 |
Hi -------------------------------------------------------
In this issue of 'Sky And Scopes'.....
1)Looking at Globular Clusters. So what are Globular clusters and where are they to be found?.. If you like this ezine maybe you could do me a big favor and 'pay it forward'. If a friend passed it on and you find it interesting, please subscribe here.... -------------------------------------------------------
Globular clusters are defined as a dense grouping of thousands to millions of stars. They are comprised of young stars at millions of years old to older stars at several billions years old. The stars in these clusters are usually very tightly bound together. They are considered deep sky objects. They are easily found in the night sky in the hours before midnight in the months of April through September and appear in your telescope as concentrated patches of gray mist. The most spectacular of all is the NGC 5139 which you can see with your naked eye because it is three times the moon's diameter. There are millions of stars that take up your viewfinder. It is truly a wondrous site to behold. If you live in or around North Carolina close to the latitude of +36 degrees, you will be able to spot it easily in the night sky. Clusters such as these are very common. In the Milky Way, there are 150 known clusters. The Andromeda galaxy could have upwards of 500. The giant elliptical galaxies, such as M87, have as many as 10,000. The really neat thing is the globular clusters contain some of the first stars that were created when time began. The major part of these clusters are found near the galactic core on the celestial sky side. Clusters contain a high density of older stars but they are not great locations for planetary systems. The orbits of the planets become unstable in the dense clusters. These clusters can be dated by viewing the temperature the coolest white dwarf stars are in the group. Common results say some of these stars are 12.7 billion years old or older.
Happy Viewing..............
See you next month! Michael https://www.telescopes-for-amateur-astronomers.com |
Back to Back Issues Page |