The heart of the giant globular star cluster 47 Tucanae in the Hubble Space Telescope image at left reveals the glow of 200,000 stars. The green box outlines the cluster's crowded core, where Hubble spied a parade of young white dwarfs starting their slow-paced 40-million-year journey to the less populated suburbs.
White dwarfs are the burned-out relics of stars that rapidly lose mass, cool down, and shut off their nuclear furnaces. As these glowing carcasses age and shed weight, their orbits begin to expand outward from the cluster's packed downtown. This migration is caused by a gravitational tussle among stars in the cluster.
The stellar relics are too faint to be seen clearly in visible light, as shown in the Hubble image at top right. But in ultraviolet light the stars glow brightly because they are extremely hot, as shown in the image at bottom right, taken by Hubble's Wide Field Camera 3. The green circles in the image outline the brightest of the young white dwarfs spied by Hubble.
Astronomers used Hubble to analyze 3,000 white dwarfs in the cluster, located 16,700 light-years away in our Milky Way galaxy's southern constellation of Tucana. Until these Hubble observations, astronomers had never seen the dynamical conveyor belt in action. The Wide Field Camera 3 observations were taken between November 2012 and December 2013. The left-hand image and the image at top right are a blend of exposures taken by the Advanced Camera for Surveys and Wide Field Camera 3.
Credits
NASA, ESA, and H. Richer and J. Heyl (University of British Columbia, Vancouver, Canada);Acknowledgment: J. Mack (STScI) and G. Piotto (University of Padova, Italy)
| About The Object | |
|---|---|
| Object Name | 47 Tuc, 47 Tucanae, NGC 104 |
| Object Description | Globular Cluster |
| R.A. Position | 00h 24m 5.35s |
| Dec. Position | -72° 4' 53.17" |
| Constellation | Tucana |
| Distance | 16,700 light-years (5,100 parsecs) |
| About The Data | |
| Data Description | The optical/UV image of 47 Tuc was created from Hubble data from proposal , PI: J. Mack and R. Gillian (STScI) and 12311, PI: G. Piotto (University of Padova, Italy) et al. The UV image of 47 Tuc was created from Hubble data from proposal : H. Richer (University of British Columbia), A. Dotter (Australian National University), R. Goldsbury (University of British Columbia), B. Hansen (UCLA), J. Heyl (University of British Columbia), J. Kalirai (STScI/JHU), K. Woodley (University of British Columbia), and K. Sigurdson (University of California, Santa Cruz). The science team includes: J. Heyl and H. Richer (University of British Columbia), E. Antolini (Università degli Studi di Perugia, Italy), R. Goldsbury (University of British Columbia), J. Kalirai (STScI/JHU), J. Parada (University of British Columbia), and P.-E. Tremblay (STScI). |
| Instrument | HST>ACS/WFC and HST>WFC3/UVIS |
| Exposure Dates | November 2003 - September 2004, November 2010, and November 2012 - September 2013 |
| Filters | Left and Top Right Panels: ACS/WFC: F475W (B), F606W (V), F814W (I) WFC3: F275W (UV) Bottom Right Panel: WFC3: F225W (UV) and F336W (U) |
| About The Image | |
| Color Info | Left and Top Right Panels: This image is a composite of separate exposures acquired by the ACS/WFC and WFC3 instruments. 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: Blue: F475W (B) Green: F606W (V) Red: F814W (I) Purple: F275W (UV) Bottom Right Panel: This image is a composite of separate exposures acquired by the WFC3 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: F225W (UV) Yellow: F336W (U) |
| 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. |
