These images showcase the ancient globular cluster 47 Tucanae, a dense swarm of up to a million stars.
The image at left shows the entire cluster, which measures about 120 light-years across. Located in the southern constellation Tucana, the cluster is about 16,700 light-years away. The image is part of the Digitized Sky Survey (DSS) and was taken by the UK Schmidt Telescope at Siding Spring Observatory in New South Wales, Australia. The white rectangular box outlines the view taken by NASA's Hubble Space Telescope.
That image, shown at right, captures close-up views of thousands of cluster stars. The large, bright stars in the image are red giants. These stars have puffed up to several times their normal size because they have exhausted their nuclear fuel and are near the end of their lives. The image was taken by Hubble's Advanced Camera for Surveys.
Astronomers used these Hubble observations, along with archival Hubble data, of 47 Tucanae to accurately measure changes in positions of more than 30,000 cluster stars. Based on those measurements, the astronomers pieced together the stars' histories, finding two populations of stars that have different chemical composition and that have different motions. Understanding the dynamics of the 47 Tucanae stars can yield insights into how this cluster formed its stars.
The Hubble image was taken between January and October 2010. The Schmidt telescope image was taken Oct. 12, 1977, and Sept. 9, 1989.
Credits
NASA, ESA, Digitized Sky Survey (DSS; STScI/AURA/UKSTU/AAO), H. Richer and J. Heyl (University of British Columbia), and J. Anderson and J. Kalirai (STScI)| About The Object | |
|---|---|
| Object Name | 47 Tuc, 47 Tucanae, NGC 104 |
| Object Description | Globular Cluster |
| R.A. Position | 00h 24m 5.67s |
| Dec. Position | -72° 4' 52.59" |
| Constellation | Tucana |
| Distance | 16,700 light-years (5,100 parsecs) |
| About The Data | |
| Data Description | The image was created from Hubble data from proposal : H. Richer and S. Davis (University of British Columbia), M. Rich, B. Hansen, and D. Reitzel (UCLA), J. Anderson and J. Kalirai (STScI), A. Dotter (Australian National University), G. Fahlman (Dominion Astrophysical Observatory), J. Hurley (Swinburne University of Technology), I. King (University of Washington), M. Shara (American Museum of Natural History) and P. Stetson (Dominion Astrophysical Observatory). The science team includes: H. Richer and J. Heyl (University of British Columbia), and J. Anderson (STScI). |
| Instrument | DSS (left), HST>ACS/WFC (right) |
| Exposure Dates | January - October, 2010 (right) |
| Filters | HST>ACS/WFC: F606W (V) and F814W (I) |
| About The Image | |
| Color Info | This image is a composite of separate exposures acquired by the ACS/WFC instrument. Several filters were used to sample various wavelengths. The color results from assigning different hues (colors) to each monochromatic (grayscale) image associated with an individual filter. In this case, the assigned colors are: Cyan: F606W (V) Orange: 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. |
