Eruptive young stellar objects

Review written by Ágnes Kóspál
Team: P. Ábrahám, Á. Kóspál, M. Kun, A. Moór, Zs. Regály, N. Sipos, L. Mosoni


Figure 1: NASA/JPL-Caltech/T. Pyle (SSC)

Almost all young (pre-main sequence) stars exhibit semiregular or irregular brightness variations during the early phases of stellar evolution. Certain objects, however, show not only these small variations but also powerful eruptions. During these outbursts, the object can brighten by a factor of 100 in the optical wavelength regime.

These events are connected to enhanced accretion from the circumstellar disk onto the stellar surface. The image to the left is an artist's depiction of such an event. Due to the extra heat from the eruption, these objects are ideal laboratories for studying the disk structure and composition... (more)

Our work on young eruptive stars started in 2004 with the analysis of a dataset obtained with the Infrared Space Observatory on seven FU Orionis-type star. We compared the broad-band 1-200 μm spectral energy distribution of these stars obtained at two different epochs and analysed the wavelength-dependence of the observed long-term flux changes.

Although photometric infrared variability studies of young eruptive stars have remained an important topic in KISAG, we also started using other techniques as well to study these stars. These include optical, near-infrared and mid-infarared spectroscopy, near-infrared polarimetry, and mid-infrared interferometry.

Title Participants Project Page
Dust and gas observations of the extreme outburst of EX Lupi P. Abraham, M. Goto, A. Juhasz, S. Kiraly, A. Kospal, Zs. Regaly
Infrared variability of EXors A. Kospal, N. Sipos, P. Abraham, A. Moor
Mid-infrared variability spectral atlas of young stellar objects A. Kospal, P. Abraham, A. Moor, M. Kun, Ch. Leinert, Th. Henning, J. Acosta-Pulido

Previous projects

Title Participants Project Page
EX Lupi (2008-2009) Kóspál, Á.; Németh, P.; Ábrahám, P.; Kun, M.; Henden, A.; Jones, A. F.; Juhász, A.; Dullemond, C. P.; van Boekel, R.; Bouwman, J.; Henning, Th.; Moór, A.; Mosoni, L.; Sicilia-Aguilar, A.; Sipos, N.
V1647 Ori (2004-2009) Ábrahám, P., Kóspál, Á., Csizmadia, Sz., Moór, A., Kun, M., Stringfellow, G.
High-resolution polarimetry of Parsamian 21: revealing the structure of an edge-on FUOri disc (2008) Kóspál, Á.; Ábrahám, P.; Apai, D.; Ardila, D. R.; Grady, C. A.; Henning, Th.; Juhász, A.; Miller, D. W.; Moór, A.
The outburst of the eruptive young star OO Serpentis between 1995 and 2006 (2007) Kóspál, Á.; Ábrahám, P.; Prusti, T.; Acosta-Pulido, J.; Hony, S.; Moór, A.; Siebenmorgen, R.
The long-term evolution of FUors (2004) Kóspál, Á., Ábrahám, P., Csizmadia, Sz., Kun, M., Moór, A., Prusti, T., Verdugo, E.