with known distances and metallicities and with a wide range of age, star clusters in the magellanic clouds (mcs) offer a unique opportunity for observational studies of stellar evolution. particularly interesting are asymptotic giant branch (agb) stars, i.e., low to intermediate mass stars in the late stage of their evolution in the star clusters. the recent studies revealed a large discrepancy between the prediction of the theory and the observation. it was found that the agbs in the intermediate age clusters do not extend to the expected luminosity from the theory. this luminous agb stars deficiency might be connected to another mystery of carbon stars whose bolometric magnitudes are found 1 or 2 mag. fainter than predicted. among amendments proposed to reconcile theory to observation, the modification of the evolutionary track by mass loss seems most promising. unfortunately, however, there are little direct evidence of mass loss from agb stars in the clouds. in order to clarify the mass loss phenomenon and its effect on stellar evolution, mid-infrared observations are obviously needed. we propose to observe spectrophotometrically agb-rich clusters, ngc 1783 and ngc 419, in the mcs using isocam cvf. these clusters contain both m and c type agbs which have been studied in the visual and near-infrared. our observations will show the spectral characteristics of both types of agbs in the mid-infrared and enable us to estimate the mass loss rates of agbs with known ages. furthermore, we can establish a relationship between infrared colours to stellar types, which will help us to interpret the infrared photometric data which will be taken by our isas time proposal, ttanabe_redstar3, or by others.
Instrument
CAM01 , CAM04
Temporal Coverage
1996-03-11T14:20:41Z/1997-09-13T11:24:25Z
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.
