NASA's Hubble Space Telescope has provided astronomers with the best observational evidence to date that globular clusters sort out stars according to their mass, governed by a gravitational billiard ball game between stars. Heavier stars slow down and sink to the cluster's core, while lighter stars pick up speed and move across the cluster to its periphery.
[Left] - A photo of the globular star cluster 47 Tucanae taken with the Very Large Telescope in Chile. It is one of the densest globular clusters in the Southern Hemisphere. The cluster contains 1 million stars.
[Right] - A NASA Hubble Space Telescope color photo of the core of 47 Tucanae. Multiple photos of this region allowed astronomers to track the "behive swarm" motion of stars. Precise velocities were obtained for nearly 15,000 stars in this cluster. This image was taken with Hubble's Advanced Camera for Surveys.
The international science team was made of the following scientists: D.E. McLaughlin (University of Leicester), J. Anderson (Rice University), G. Meylan (Ecole Polytechnique Federale de Lausanne), K. Gebhardt (University of Texas at Austin), C. Pryor (Rutgers University), D. Minniti (Pontifica Universidad Catolica), and S. Phinney (Caltech).
Credits
Ground-Based Image: Very Large Telescope/European Southern Observatory, R. Kotak and H. Boffin (ESO);Hubble Image: NASA, ESA and G. Meylan (Ecole Polytechnique Federale de Lausanne
| About The Object | |
|---|---|
| Object Name | 47 Tucanae, NGC 104 |
| Object Description | Globular Cluster |
| R.A. Position | 00h 24m 5.67s |
| Dec. Position | -72° 4' 52.59" |
| Constellation | Tucana |
| Distance | This obejct is roughly 15,000 light-years (4,600 parsecs) away. |
| Dimensions | 1 arcminute (4.6 light-years or 1.4 parsecs) wide (right) |
| About The Data | |
| Data Description | The Hubble image was created from data from the following proposals: , , and : G. Meylan (Ecole Polytechnique Federale de Lausanne), D. Minniti (Universidad Catolica de Chile), S. Phinney (California Institute of Technology), C. Pryor (Rutgers University), B. Sams (Mediateam, Germany), and C. Tinney (Anglo-Australian Observatory) : R. Gilliland (STScI), D. Naef (Observatoire de Geneve), A. Sarajedini (University of Florida), S. Sigurdsson (Pennsylvania State University), D. VandenBerg (University of Victoria), T. Brown (University Corporation For Atmospheric Research), A. Burrows (University of Arizona), W. Cochran (University of Texas, Austin), P. Edmonds (Harvard University), S. Frandsen (Aarhus University), S. Vogt, P. GuhaThakurta, and D. Lin (University of California, Santa Cruz), G. Marcy (University of California, Berkeley), M. Mayor (Observatoire de Geneve), and E. Milone (University of Calgary) : R. Bohlin (STScI), G. De Marchi (ESA/STScI), and R. Gilliland (STScI) : R. Gilliland, K. Sahu, and P. Goudfrooij (STScI) : G. Meurer and H. Tran (Johns Hopkins University) : I. King (University of Washington) and J. Anderson (Rice University) The international team was made of the following scientists: D.E. McLaughlin (University of Leicester), J. Anderson (Rice University), G. Meylan (Ecole Polytechnique Federale de Lausanne), K. Gebhardt (University of Texas, Austin), C. Pryor (Rutgers University), D. Minniti (Pontifica Universidad Catolica), and S. Phinney (Caltech). |
| Instrument | ESO>VLT (left); HST>WFPC2, HST>ACS/WFC, and HST>ACS/HRC (right) |
| Exposure Dates | October 1995, November 1997, July 1999, October 1999, July 2001, April 2002, and July 2002 (right) |
| Filters | Hubble data: F300W (Wide U), F336W (U), F475W (SDSS g) For image: F475W (SDSS g), F555W (V), and F814W (I) |
| About The Image | |
| Color Info | The Hubble image is a composite of many separate exposures made by the ACS instrument on the Hubble Space Telescope using three different filters to sample broad wavelength ranges. The color results from assigning different hues (colors) to each monochromatic image. In this case, the assigned colors are: Blue: F475W (SDSS g) Green: F555W (V) Red: F814W (I) |
| Compass Image |  |
| About The Object | |
|---|---|
| Object Name | A name or catalog number that astronomers use to identify an astronomical object. |
| Object Description | The type of astronomical object. |
| R.A. Position | Right ascension – analogous to longitude – is one component of an object's position. |
| Dec. Position | Declination – analogous to latitude – is one component of an object's position. |
| Constellation | One of 88 recognized regions of the celestial sphere in which the object appears. |
| Distance | The physical distance from Earth to the astronomical object. Distances within our solar system are usually measured in Astronomical Units (AU). Distances between stars are usually measured in light-years. Interstellar distances can also be measured in parsecs. |
| Dimensions | The physical size of the object or the apparent angle it subtends on the sky. |
| About The Data | |
| Data Description |
|
| Instrument | The science instrument used to produce the data. |
| Exposure Dates | The date(s) that the telescope made its observations and the total exposure time. |
| Filters | The camera filters that were used in the science observations. |
| About The Image | |
| Image Credit | The primary individuals and institutions responsible for the content. |
| Publication Date | The date and time the release content became public. |
| Color Info | A brief description of the methods used to convert telescope data into the color image being presented. |
| Orientation | The rotation of the image on the sky with respect to the north pole of the celestial sphere. |
