Young Stellar Objects

Review written by Péter Ábrahám
Team: P. Ábrahám, E. Elek, Cs. Kiss, S. Király, Á. Kóspál, M. Kun, A. Moór, L. Mosoni, Zs. Regály, J. Szulágyi


Stars are formed by gravitational collapse of dense gas condensations in the interstellar space. Figure 1 is an image of the Elephant's Trunk Nebula (a globule in IC 1396) where protostars are visible as bright redish dots mostly along the southern rim of the globule.

A protostar collects its mass via accretion. Due to angular momentum constrains the infalling material cannot reach directly the stellar surface but flows through a flattened circumstellar structure. Such a disk is seen... (more)

15 years after the first high quality data set of IRAS, the Infrared Space Observatory (ISO) made a significant new contribution to the study of the infrared SEDs of pre-main sequence stars. At KISAG we work on the collection, analysis, and publication of all infrared photometric data of young stars obtained with ISOPHOT, the photometer on-board ISO. The ISOPHOT results are compared and combined with data from other infrared data sets ( IRAS, MSX, 2MASS). A description of this long-term programme can be found in Ábrahám (2002). We are also interested in variability studies of pre-main-sequence stars both at optical and infrared wavelengths. Our third major topic is related to the history and spatial distribution of star formation in individual star forming regions.

On-going projects

Title Participants Project Page
ISOPHOT-S mid-infrared spectral atlas of YSOs Ábrahám, P., Kun, M., Acosta-Pulido, J.A., Henning, Th., Leinert, Ch., Przygodda, F.
Photometric catalog of infrared observations of YSOs obtained with ISOPHOT Ábrahám, P., Moór, A., Csizmadia, Sz., Csengeri, T., Juhász, A., Kóspál, Á.
Mid-infrared observations of YSOs with UKIRT/MAX Juhász, A., Ábrahám, P., Ligori, S.
Temporal variations of UX Orionis stars at infrared wavelengths Juhász, A., Ábrahám, P., Prusti, T.
Star formation in the LDN 1251 dark cloud Kun, M., Prusti, T., Ábrahám, P., Moór, A.
Star formation in the LDN 1188 dark cloud Könyves, V., Moór, A., Kiss, Cs., Ábrahám, P.
Circumstellar structure of binary TTauri stars Csengeri, T., Ábrahám, P., Leinert, Ch.


Previous projects

Title Participants Project Page
The disappearing act of KH 15D: photometric results from 1995 to 2004 Hamilton, C.M., Herbst, W., Vrba, F.J., Ibrahimov, M.A., Mundt, R., Bailer-Jones, C.A.L., Sanchez Bejar, V.J., Ábrahám, P., Kun, M., Moór, A., Benko, J., Csizmadia, S., Filippenko, A.V., Li, W.
Far-infrared photometry and mapping of Herbig Ae/Be stars with ISO Ábrahám, P., Leinert, Ch., Burkert, A., Henning, Th., Lemke, D.