What's Up June 2009: Ancient stars in the globular cluster M-13
Transcript
Hello and welcome. I'm Jane Houston Jones at NASA's Jet Propulsion
Laboratory in Pasadena, California.
2009 is International Year of Astronomy. And each month this year we’re showcasing a great celestial object. This month it’s the Hercules Globular Cluster, which is also called M-13.
Title: M13
Jane Houston-Jones: It’s called M-13 because this object is the 13th of Charles Messier’s 1764 catalog of celestial objects.
Title: Charles Messier
Jane Houston-Jones: But Charles Messier wasn’t the discoverer of this cluster! M-13 was discovered half a century earlier by Edmund Halley.
Title: Edmund Halley
Jane Houston-Jones: A globular cluster is a collection of hundreds of thousands of ancient stars held together by gravity.
You can easily find M-13 in the "Keystone"…
Title: Keystone
Jane Houston-Jones: …of the constellation Hercules,
Title: Hercules
Jane Houston-Jones: …about a third of the way along a line drawn…
Title: M13
Jane Houston-Jones: …between Eta and Zeta Herculis.
Titles: Eta Herculis, Zeta Herculis
Title: Binoculars View
Jane Houston-Jones: M-13 will look like a round hazy glow in binoculars.
Title: Telescope View
Jane Houston-Jones: Through a telescope, you’ll see individual stars at the edge of the cluster, and a dense core of stars closer to the center.
Titles: Hubble Space Telescope, Wide Field and Planetary Camera 2
Jane Houston-Jones: The Hubble Space Telescope’s Wide Field and Planetary Camera 2 (or “WFPC2” for short) and the Advanced Camera for Surveys combined data from 1999 through 2006 to create a glittering image of this Herculean star city.
Title: Milky Way (artist’s concept)
Jane Houston-Jones: A spiral galaxy like our Milky Way is made up of three visible parts: the nucleus, the disk and the halo.
Titles: Side View, Nucleus
Jane Houston-Jones: The nucleus contains the highest density of stars in the galaxy.
Title: Disk
Jane Houston-Jones: Most of the gas and dust is contained in the disk.
Title: Halo
Jane Houston-Jones: The halo, or outer shell, is spherical and contains little gas, dust, or star formation.
Title: Globular Clusters
Jane Houston-Jones: The globular clusters found in the halo are the oldest parts of the galaxy.
Titles: Milky Way, Top View, Side View, M13, Our Sun
Jane Houston-Jones: M13 is one of 150 globular clusters in the halo of our Milky Way Galaxy.
Title: Saturn
Jane Houston-Jones: This is the last month to get a good look at Saturn in the evening sky. So, don’t miss it! The rings are narrowing to nearly edge on, and look dimmer than they did last month!
Title: To learn more about the Hercules globular cluster: astronomy2009.nasa.gov
You can read about the Hercules globular cluster on NASA's International Year of Astronomy website: astronomy2009.nasa.gov
Title: To learn more about NASA’s missions: www.nasa.gov
And you can learn all about NASA's missions at www.nasa.gov
Title: Thanks to the following for submitting images: Tom Callen, Paulo Casquinha, Karl Jennings, Morris Jones
Jane Houston-Jones: That's all for this month. I'm Jane Houston Jones.
Title: NASA, Jet Propulsion Laboratory, California Institute of Technology