# # Program information file # PROGRAM_ID 2022A027 PROGRAM_TITLE Eruptions from Young Stars: Following the next outburst from V347 Aurigae PROGRAM_INV1 Michael Connelley PROGRAM_INV2 Scott Dahm PROGRAM_INV3 Lynne Hillenbrand PROGRAM_INV4 PROGRAM_INV5 PROGRAM_SCICAT stellar PROGRAM_ABSTRACT_BEG A major problem in the study of star formation is accounting for how stars gain most of their mass. The accretion rates of most young stars are far too low to accumulate the final mass of the star in the allotted time. The prevailing solution is that most of the mass is accreted in outburst events. Since these events are unpredictable, we wait until a survey detects a major event to trigger follow up observations. However, by the time the object has brightened enough to be sure that it is experiencing a major outburst well above normal variability, the critical earliest phase of the event has been missed. V347 Aurigae is an extremely young star that has recently been found to have large [>2 magnitudes] periodic [155 days] outbursts. For the first time, we can predict the next major outburst for a well characterized young star, which should happen at end of this November. Combined with on-going monitoring in 2021B, observations in 2022A will comprise a complete photometric and spectroscopic record of this event. Most importantly, we will be able to observe the spectroscopic changes as the star transitions from its quiescent to eruptive state. We will see how and when the infrared dust emission, accretion rate, outflows, and overall luminosity change. With this information, we will first classify the outburst, and compare it to similar outbursts of other young stars. We will estimate the total mass accreted to test whether outbursts can account for the total mass of the star. We will also see how observables like the dust temperature and accretion change in response to a major disruption to the circumstellar disk. PROGRAM_ABSTRACT_END