ground support for MOST, COROT, Chandra, XMM, GAIA, KEPLER & DARWIN


Magnetic fields of the seismology targets of MOST, CoRoT and Kepler

For both cool and hot stars on which MOST, CoRoT & Kepler are focussing or will focus, a spectropolarimetric follow-up is needed. For cool stars, ground-based spectropolarimetry provides us with unprecedented insight into dynamo processes; dynamo magnetic fields are known to impact significantly physical processes at work both in stellar interiors (eg mixing, differential rotation) and in the immediate circumstellar environment (eg winds), thus potentially affecting the internal structure and evolution that we aim at studying through seismology. For hot stars, magnetic fields also interfere with pulsations, winds and atmospheric abundances and must be also taken into account for a proper modelling of seismology data.
Ground-based spectropolarimetric observations are also useful to model activity-induced photometric variations (eg starspots and differential rotation) that the light-curves contain.

Magnetic properties of FGK reference stars in the GAIA sample

By studying magnetic fields of a number of FGK reference stars in the GAIA sample through ground-based spectropolarimetry, we can try to correlate angular position and radial velocity variations to magnetically induced surface activity. The sample should be large enough to investigate potential dependence with convective depth, rotation rate and metallicity.

Magnetic properties of bright X-ray sources observed with Chandra/XMM

The very successfull Chandra Orion Ultradeep Project (COUP, eg Getman et al 2005, ApJS 160, 319) and XMM-Newton Extended Survey of the Taurus molecular cloud (XEST, eg Gudel et al 2007, A&A 468, 353) are very good examples of what X-ray observations can tell us about magnetic activity. Coordinated spectropolarimetric monitoring and X-ray observations, eg to explore the magnetic properties of X-ray emitting stars in the Orion Nebula Cluster (ONC) and Taurus Molecular Cloud (TMC), would be highly useful to explore in more details how X-ray emission relate to magnetic fields in various types of stars.

Ground support for MOST/CoRoT/Kepler exoplanet sample and ground preparation for DARWIN

Follow-up spectropolarimetric ground observations of stars whose planets were detected by MOST/CoRoT can also provide us with unprecendented information on how planets form, migrate and interact with their host star and parent accretion disc. Spectropolarimetric observations (especially in the nIR, eg with SPIRou) can also be used to investigate radial velocity variations and activity phenomena in M dwarfs, as a preparation to DARWIN and a contribution to the target-selection effort.

Related threads and associated Large Program

This research shares obvious links with other main threads of MagIcS; the aim is to use the techniques and discoveries derived in the other threads and adapt them to the needs of the various space projects that can benefit from it. The first issue of this research thread (regarding the magnetic fields of stars in the spacescrafts seismology samples) are the main focus of a Large Program with ESPaDOnS - this program was not awared time in 2008a and will be resubmitted later on.

Core team and collaborators

Thread coordinators: C Catala, C Soubiran, G Walker, J Matthews
Agency/Country Core team Collaborators
F Baglin, Bouret, Catala, Crifo, Deleuil, Delfosse, Donati, Hubert, Martayan, Montmerle, Moutou, Neiner, Soubiran Grosso
O Aigrain, Cameron, Fremat, Fridlund, Gregory, Hussain, Jardine, Kochukhov Udry, Preibisch
C Matthews, Walker
H Shkolnik
USA Cohen, Gagné Feigelson