New approaches to asteroseismology

Just as we know our Earth`s interior from the analysis of earthquakes, the interior of stars can be inferred from modelling their pulsations ("starquakes"). This scientific method is called asteroseismology and it has resulted in spectacular successes when being applied to our Sun and to some end products of stellar evolution, white dwarf stars". Consequently, it is of high interest to apply asteroseismology to other pulsating stars as weIl. Several classes of pulsator, mostly normal stars between 1.5 to 15 times the mass oft he Sun, are well suited for this technique, but its practical application turned out to be difficult so far. The reason is that the astrophysical infonnation these stars offer is harder to decipher compared to the stars already solved. This project provides new and improved ways to gain the necessary knowledge about the stellar pulsations required for their successful modelling. The first idea incorporates a search for stars which show two complementary types of pulsation simultaneously. We have already discovered one such star in the Southem Hemisphere and we could unravel a large fraction of its secrets. Now it is time to look for related objects in the North, The second approach consists of obtaining data of unprecedented quantity and quality for another group of pulsating star, which have not yet had the attention they deserve, through worldwide collaborations. The results we expect will enable us to explore the deep interior oft hese objects for the fIrst time.

Just as we know our Earth`s interior from the analysis of earthquakes, the interior of stars can be inferred from modelling their pulsations ("starquakes"). This scientific method is called asteroseismology and it has resulted in spectacular successes when being applied to our Sun and to some end products of stellar evolution, white dwarf stars. Consequently, it is ofhigh interest to apply asteroseismology to other pulsating stars as weIl. Several classes ofpulsator, mostlynormal stars between 1.5 to 15 times the mass ofthe Sun, are well suited for this technique, but its practical application turned out to be difficult so far. The reason is that the astrophysical infonnation these stars offer is harder to decipher compared to the stars already solved. This project provides new and improved ways to gain the necessary knowledge about the stellar pulsations required for their successful modelling. The first idea incorporates a search for stars which show two complementary types of pulsation simultaneously. Wehave already discovered one such star in the Southem Hemisphere and we could unravel a large fraction of its secrets. Now it is time to look for related objects in the North, The second approach consists of obtaining data ofunprecedented quantity and quality for another group ofpulsating star, which have not yet had the attention they deserve, through worldwide collaborations. The results we expect will enable us to explore the deep interior ofthese objects for the fIrst time.