<=== observer ===> "FHESSMAN",\ "Hessman, Frederic V.",\ "",\ "Universitaets-Sternwarte",\ "Geismarlandstr. 11",\ "",\ "D-37077",\ "Goettingen",\ "Germany",\ "","",\ "hessman@wotan.uni-sw.gwdg.de" <=== proposal ===> "FUORS",1,3,\ {"accretion discs","star formation"},\ {"R. Mundt (MPIA)", "D. Lemke (MPIA)", "T. Ray (DIAS)"} <=== title ===> FU Orionis stars <=== abstract ===> SCIENTIFIC ABSTRACT FU Orionis stars (FUORs) represent a rare and unique class of pre-main-sequence objects of which only about nine members are known. Most probably they consist of a T Tauri-like star surrounded by a very luminous accretion disc currently in a state of very high mass accretion (approx. 10**-4 Msun/yr). We propose to measure the spectral energy distributions of all known FUORs and FUOR candidates between 3.6 and 160 microns. With the addition of IRAS and ground-based measurements, the time evolution of these discs can be studied. These studies - combined with a comparison with other young stars - will lead to a much better understanding of the properties of FUOR discs, the physical processes in accretion discs, and hence discs around young stars in general. OBSERVATION SUMMARY We propose to measure the spectral energy distributions of almost all of the classic FUORs from 3.6 to 160 microns using the PHT-P and PHT-C photometers. Some important objects have been left out due to object complexity (Z CMa) or to spacecraft time limitations (e.g. SVS 13) and will have to be observed during the normal open observing periods. The total times for each object include equal times for object and background measurements, 180 s for target aquisition per object (added to the PHT03 times), 15 s for each instrument setup (i.e. for PHT03 and PHT22), 10 s per filter-wheel positioning, 16 s for FCS calibration per filter, and 90 s heating for the P2, P3, and C100 observations, for a total of 714 sec overhead per object (180+15+7x10+7x16+2x90=557 s for PHT03 plus aquisition, and 15+2x10+2x16+90=157 sec for PHT22). The individual integration times (target+background) for all our objects and are given in the following table. TargetName P_3.6 P4.8 P_7.3 P_11.5 P_16 P_25 P_60 C_90 C_160 Total _____________________________________________________________________________ RNO1B-SW 16 16 16 16 8 8 8 8 8 104 BBW 76 16 16 16 16 16 16 32 16 16 160 V346 NOR 8 8 8 8 8 8 8 8 8 72 V1515 CYG 8 8 8 8 8 8 16 8 8 80 V1057 CYG 8 8 8 8 8 8 8 8 8 72 V1735 CYG 16 16 8 8 8 8 8 8 8 88 L1551-IRS5 16 16 8 8 8 8 8 8 8 88 FU ORI 8 8 8 8 8 8 16 8 8 80 ___________________________________________________________________________ The total integration times for a spring/fall launch (target, background, and overhead) is 4884/4002 sec (1.36/1.11 hrs). <=== scientific_justification ===> Team : top 40% second 30% last 30% PHT : 4884 0 0 <=== autumn_launch_targets ===> 1, "PHT03", 2.0, "N", "RNO1B_SW", 0.56448, 63.20667, 1950, 0., 0., 645, 2 2, "PHT22", 2.0, "N", "RNO1B_SW", 0.56448, 63.20667, 1950, 0., 0., 173, 0 3, "PHT03", 1.0, "N", "V346_NOR", 16.48244, -44.81889, 1950, 0., 0., 613, 4 4, "PHT03", 1.0, "N", "V346_NOR", 16.48244, -44.81889, 1950, 0., 0., 173, 0 5, "PHT03", 1.0, "N", "V1515_CYG", 20.36756, 42.04444, 1950, 0., 0., 621, 6 6, "PHT22", 1.0, "N", "V1515_CYG", 20.36756, 42.04444, 1950, 0., 0., 173, 0 7, "PHT03", 1.0, "N", "V1057_CYG", 20.95173, 44.06289, 1950, 0., 0., 613, 8 8, "PHT22", 1.0, "N", "V1057_CYG", 20.95173, 44.06289, 1950, 0., 0., 173, 0 9, "PHT03", 1.0, "N", "V1735_CYG", 21.75747, 47.30222, 1950, 0., 0., 629, 10 10, "PHT22", 1.0, "N", "V1735_CYG", 21.75747, 47.30222, 1950, 0., 0., 189, 0 11, "PHT03", 1.0, "N", "L1551-5", 4.47784, 18.02814, 1950, 0., 0., 629, 12 12, "PHT22", 1.0, "N", "L1551-5", 4.47784, 18.02814, 1950, 0., 0., 189, 0 <=== spring_launch_targets ===> 1, "PHT03", 1.0, "N", "L1551-5", 4.47784, 18.02814, 1950, 0., 0., 629, 2 2, "PHT22", 1.0, "N", "L1551-5", 4.47784, 18.02814, 1950, 0., 0., 189, 0 3, "PHT03", 1.0, "N", "BBW_76", 7.81118, -32.97869, 1950, 0., 0., 685, 4 4, "PHT22", 1.0, "N", "BBW_76", 7.81118, -32.97869, 1950, 0., 0., 189, 0 5, "PHT03", 1.0, "N", "FU_ORI", 5.71055, 9.05069, 1950, 0., 0., 621, 6 6, "PHT22", 1.0, "N", "FU_ORI", 5.71055, 9.05069, 1950, 0., 0., 173, 0 7, "PHT03", 1.0, "N", "V1515_CYG", 20.36756, 42.04444, 1950, 0., 0., 621, 8 8, "PHT22", 1.0, "N", "V1515_CYG", 20.36756, 42.04444, 1950, 0., 0., 173, 0 9, "PHT03", 1.0, "N", "V1057_CYG", 20.95173, 44.06289, 1950, 0., 0., 613, 10 10, "PHT22", 1.0, "N", "V1057_CYG", 20.95173, 44.06289, 1950, 0., 0., 173, 0 11, "PHT03", 1.0, "N", "V1735_CYG", 21.75747, 47.30222, 1950, 0., 0., 629, 12 12, "PHT22", 1.0, "N", "V1735_CYG", 21.75747, 47.30222, 1950, 0., 0., 189, 0