These comparison images of the core of the globular cluster 47 Tucanae (NGC104) were taken with the COSTAR Corrected Faint Object Camera to show the improvement In performance when compared to images taken with the uncorrected camera.
(left)
The pre-COSTAR image was taken on 27 October 1993 using the F/96 mode. Even prior to the servicng mission this was considered an impressive HST image. The star density is high and none of the stars are bright enough to show the halo caused by a flaw in Hubble's primary mirror.
(right)
The COSTAR-corrected image was taken on l0th January 1994 reveals stellar images that are crisp and clean, and stellar magnitudes and colors can be accurately measured. (The pre-COSTAR image was rotated and magnified to match the scale and orientation of the COSTAR-corrected image, and both images are 14 arcseconds on a side).
A preliminary analysis of the data reveals the apparent presence of white dwarf stars in the image. Prior to the Hubble observation white dwarfs have generally been too dim to be seen within such a cluster. A globular cluster is a tight aggregate of thousands to millions of very old stars.
White dwarfs are the earth-sized remains of ordinary stars like the Sun. Finding them in a known globular cluster allows accurate estimates of their age and provides clues to reconstructing their history.
Credits
Dr. R. Jedrzejewski (STScI) NASA, ESA| About The Object | |
|---|---|
| Object Name | 47 Tucanae, NGC 104 |
| R.A. Position | 00h 24m 5.19s |
| Dec. Position | -72° 4' 49.9" |
| 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. |
