mass loss rates along the red giant branch (rgb) and along the asymptotic giant branch (agb) are a key ingredient for a proper understanding of these evolutionary phases of low-mass stars. this program aims at deriving the mass loss rates of agb and rgb stars of different luminosities in the galactic globular cluster 47 tuc. a search for possible dust-enshrouded agb stars will also be performed in four different fields. the cluster 47 tuc is especially well suited for this study, because (i) it is the closest stellar cluster whose agb and rgb are well populated, (ii) previous studies have assigned giants to either the rgb or agb, (iii) the agb of metal-rich globular clusters like 47 tuc extends to luminosities mbol virgul - 4.6 higher than in metal-poor globular clusters, and (iv) its distance is well known. in addition, this program will provide a ([12]-[25], [25]-[60]) color-color diagram for giants of known luminosity and evolutionary state (agb or rgb), to which the colors of galactic field stars may then be compared. with such a ..rosetta stone.., it is possible to test the conjecture according to which all m giants with no excesses in the ([12]-[25], [25]-[60]) diagram are rgb stars, thus providing a powerful tool for testing the evolutionary status of field giants.
Instrument
CAM01 , PHT03 , PHT22
Temporal Coverage
1996-05-25T03:56:31Z/1996-05-26T14:11:51Z
Version
1.0
Mission Description
The Infrared Space Observatory (ISO) was the world's first true orbiting infrared observatory. Equipped with four highly-sophisticated and versatile scientific instruments, it was launched by Ariane in November 1995 and provided astronomers world-wide with a facility of unprecedented sensitivity and capabilities for a detailed exploration of the Universe at infrared wavelengths.
