Observing programme

STARS can measure simultaneously a very large number of sources within its field of view. A subset of these targets will form the core programme designed to achieve the major scientific objectives of the mission. These primary targets are stars down to from which the micromag flux variations exhibited by solar-type stars in open clusters will be detected, and down to from which 5 micromag flux variations might be detected. These stars are mainly:

• Members of open clusters, encompassing the entire mass range of the main sequence, including ,
• Selected field stars adequately sampling the Hertzsprung-Russell diagram, including Population II stars and super-metal-rich stars typical of the galactic bulge,
• Binaries with good mass determinations,
• Sources from the ROSAT and EUVE archives,
• Massive stars, including Cephei stars and Wolf-Rayet stars: potential supernova progenitors,
• Stars from the CaII HK Mount Wilson project,
• Scuti stars,
• Rapidly oscillating Ap stars.

Other targets will be allocated through a Guest Investigator programme. These secondary targets comprise a wide variety of possible sources, such as:

• Same type of stars as above but fainter than those for which the core programme can be carried out,
• White dwarfs, Am and Boo stars, PMS stars, Be stars, central stars in planetary nebulae,
• Close binary stars, for studying mass exchange, cataclysmic variation; occultation imaging.

STARS will observe a field continuously for at least one month in order to measure oscillation frequencies with sufficient precision for the diagnosis of the interior structure to be carried out.