The MONS project is the scientific payload of the Danish mission Rømer, which is scheduled for launch in 2004. The chief goal of the experiment is to investigate oscillations in nearby stars to probe their interiors. The main camera will acquire high-accuracy photometry of two dozen primary targets over a period of one to two months. MONS is also equipped with two star trackers (which point 180 degrees apart) that will observe hundreds of other stars in their wide fields. More detailed information about MONS can be found here.

Among a myriad of other scientific benefits, MONS will make major contributions to the field of eclipsing binaries. The long time series photometry will yield excellently phase-covered light curves of known eclipsing binaries and lead to the discovery of over a hundred of new ones. In addition, because of the stability and the accuracy of the photometric measurements, MONS can potentially detect transits of Jupiter-size planets. These two aspects of the MONS mission just described here will be studied by the Planets and Eclipsing Binaries Group.

Eclipsing Binaries with MONS

Eclipsing binaries are valuable astrophysical laboratories that have a number of useful applications. To name a few, eclipsing binaries yield stellar masses and radii that define the mass-luminosity law and allow the test of stellar structure and evolution models, they also provide information on magnetic activity and starspots, mass loss processes, binary star evolution, accretion, ...

The light curves observed by MONS, both because of their dense phase coverage and their photometric accuracy, will permit the determination of reliable stellar properties and the study of events such as starspot migration. To learn more about what MONS can do for eclipsing binaries please click here.

Planet Transits with MONS

Until not long ago, the planets of the Solar System were the only known to exist. In 1991, three Earth-sized planets were detected orbiting a binary pulsar. Four years later, the first discovery of a planet orbiting a normal main sequence star was announced. Since then, over 60 planets have already been discovered, all with masses larger than that of Saturn.

Planet detections so far have only been sucessful using radial velocity techniques. A breakthough ocurred when two independent groups announced in 2000 the detection of a planet transiting across the star HD209458. This planet, however, was already known to exist from radial velocity measurements. The detection of planetary transits lies well within the capabilitites of MONS. For more information on this please click here.

Invitation to Join

If you are interested in collaborating with the Planets and Eclipsing Binaries Group, we encourage you to contact us. Your ideas and help will be most welcome.

A list of the current members of the group and their contact addresses can be found here.

Useful Links

Home Page of the MONS Science Consortium

Other MONS Science Groups:

Eclipsing binaries and planets:

Related missions and projects:

These pages were last updated: April 24, 2001

Ignasi Ribas (