Globular clusters were originally defined as rich, compact, nearly spherical, groups of hundreds of thousands (or even millions) of stars. the Milky Way nuclear star cluster, discuss its relation with nuclear clusters in other galaxies and point out where further research is needed. In this figure, the X and Y axes are in units of distances in kiloparsecs (1 kiloparsec = 1,000 parsecs). 1.

It takes its name from the Milky Way, the irregular luminous band of stars and gas clouds that stretches across the sky as seen from Earth. It stood to reason that because the Milky Way was disk-shaped and because spiral galaxies were disk-shaped, the Milky Way was probably a spiral galaxy. Check back soon! a. Cepheid variable b. blue supergiant c. RR Lyrae d. Sun-like.

The oldest stars (in the globular clusters) ... Our galaxy is much larger than the size of the luminous portion (globular clusters and disk) Dark matter halo dwarfs the inner halo of stars and gas estimate 2/3 of mass within the luminous region is dark matter . Kyle M. Cudworth. Check back soon! In the 1930s, astronomer R. J. Trumpler realized that the estimates of the size of the Milky Way galaxy by Kapetyn and others were off because the measurements had relied on observations in the visible wavelengths. Two ringlike structures of stars wrapping around the Milky Way's outer disk now appear to belong to the disk itself. Problem 2 Detailed observations of the structure of the Milky Way are difficult because a. the Solar System is embedded in the dust and gas of the disk. GALATIC STRUCTURE, GLOBULAR CLUSTERS. The hatched region represents the plane of the Milky Way (that is, roughly the part of the sky where the Milky Way is visible to the eye), and the X located at (0,0) marks the location of the Sun in the plane of the Milky Way. The size of the Milky Way is determined from studying _________ stars in globular clusters. In the 1930s, astronomer R. J. Trumpler realized that the estimates of the size of the Milky Way galaxy by Kapetyn and others were off because the measurements had relied on observations in the visible wavelengths. RR Lyrae. The Milky Way Center, Shape Globular cluster system Galactic coordinates Size of the Milky Way Milky Way from Iowa Milky Way from Australia Milky Way from Australia How do we locate the center of the Milky Way? a.

These objects belong to the halo of our own galaxy, the Milky Way . The size of the Milky Way is determined from studying _____ stars in globular clusters. Herschel's Milky Way: More sophisticated counting techniques yielded similar results including a careful model by Kapteyn in 1922. Milky Way Galaxy (sometimes simply called the Galaxy), large spiral system of about several hundred billion stars, one of which is the Sun. The ages of individual stars in the Milky Way can be estimated by measuring the abundance of long-lived radioactive elements such as thorium-232 and uranium-238 , then comparing the results to estimates of their original abundance, a technique called nucleocosmochronology . Rank in order of age, globular clusters with main sequence turnoffs at the following temperatures: 10,000K, 3,000K, and 6,000K.

The size of the Milky Way is determined from studying in globular clusters _____ a. standard candles b. velocities c. standard models d. expansions a. Cepheid variable b. blue supergiant c. RR Lyrae d. Sun-like

Surrounding the galactic disk is a spherical Galactic Halo of stars and globular clusters that extends farther outward, but is limited in size by the orbits of two Milky Way satellites, the Large and Small Magellanic Clouds, whose closest approach to the Galactic Center is about 180,000 ly (55 kpc). a. Cepheid variable b. blue supergiant c. RR Lyrae d. Sun-like. Two ringlike structures of stars wrapping around the Milky Way's outer disk now appear to belong to the disk itself. The size of the Milky Way is determined from studying _____ stars in globular clusters.

Problem 2 Rank, in increasing order of age, globular clusters with mainsequence turnoffs at the following temperatures.

Shapley observed a number of globular clusters and discovered that the center of the Milky Way is some distance (now known to be 8.5kpc) from the Sun. Work in the past few decades has shown that the stars in globular clusters are among the oldest stars in the Galaxy, with ages greater than 10 10 years. Nuclear star clusters The study of nuclear star clusters (NSCs) of galaxies has only become feasible from the middle of the 1990s on with the high sensitivity and spatial resolution o ered by the Hubble Space Telescope.

Globular clusters are among the oldest objects in the Milky Way, which thus set a lower limit on the age of the Milky Way. The size of the Milky Way is determined from studying _____ stars in globular clusters. Shapley's Model of the Milky Way. It stood to reason that because the Milky Way was disk-shaped and because spiral galaxies were disk-shaped, the Milky Way was probably a spiral galaxy.

Milky Way Globular Clusters This list contains all 157 Milky Way globular clusters known at the time of this writing (May-June 2011).