SCIENTIFIC ABSTRACT

THE NEW DETECTOR SATURATION LIMITS GIVEN BY THE ISOPHOT TEAM, 
HAVE IT MADE NECESSARY TO REPLACE THE BRIGHTEST TARGETS FROM OUR 
LIST BY FAINTER OBJECTS OF THE SAME TYPE. THE NEW TARGET OBJECTS 
WERE CHECKED FOR NOT BEEING OBSERVED BY OTHER PROPOSERS WITH THE 
SAME INSTRUMENT DURING THE GT.  
We propose to investigate the morphology of the circumstellar 
environment of deeply embedded intermediate- and high-mass 
young stellar objects (YSOs). There is strong indication that 
not only T Tauri stars are associated with discs but also 
intermediate- and high-mass YSOs. For a part of the target 
objects we search for emission from the outflows. The energy 
distribution will be determined for all sources of the sample. 

OBSERVATION SUMMARY
We selected six typical compact infrared sources from a compilation 
of very young and luminous YSOs. We will use ISOPHOT-C100 AND C200 to make 
small maps of the target sources at 60, 100, 135 and 200 microns with 
AOT P32. In addition, we want to measure all sources with 
PHOT-P with multi-filter photometry (AOT P03) at 3.6, 4.85, 7.3, 7.7, 
10, 12.8, 16, 20, 25, and 60 microns. At 7.3 and 25 microns, we will 
measure all targets with two larger apertures (AOT P03), to detect 
extended emission.