on statistical arguments fu ori eruptions must be very common among pre-main-sequence (pms) stars, yet only a few cases are known. consequently, this phase of pms evolution is poorly understood. a little bit more is known about ex lup outbursts because some cases are known where the same star has undergone more than one event. nevertheless, the physical reasons for an outburst are not known. two models have been presented: rotation induced mass outflow and enhanced disk accretion. the biggest predicted observable difference is in the infrared. the accretion model predicts infrared brightening prior to the maximum activity while outflow model is consistent with infrared brightening after the main activity phase. a simple infrared photometric monitoring will discriminate between the models and provide unique data necessary to understand the physics involved. the rarity of outbursts triggers most ground-based observatories to monitor the process. if an eruption occurs when iso is operational, it has to be recorded also in the wavelengths where majority of the luminosity is emitted. this too programme proposes the most basic monitoring measurements for an erupting pms star.
Instrument
CAM01 , PHT03 , PHT22 , PHT32 , PHT40 , SWS01
Temporal Coverage
1996-02-28T17:35:03Z/1997-09-22T01:40:16Z
Version
1.0
Mission Description
The Infrared Space Observatory (ISO) was the worlds 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.
European Space Agency, PRUSTI et al., 1999, 'TOO: EVOLUTION OF THE CIRCUMSTELLAR ENVIRONMENT DURING AN FU ORI OR EX LUP OUTBURST', 1.0, European Space Agency, https://doi.org/10.5270/esa-ldzv8hq
