Multiplicity of M-dwarfs of the solar vicinity

Haute-Provence and La Silla Observatories


  • A Grenoble - Geneva observatories collaboration

  • Members:

      Grenoble: Xavier Delfosse, Jean-Luc Beuzit, Christian Perrier, Lydie Marchal
      Geneva: Michel Mayor, Stephane Udry, Damien Segransan

    • Telescope: 1.93-m at OHP

    • Detector: Elodie

    • Time allocation: 12 nights per semester

    • Sample:

    • A sample of ~120 M-dwarf stars from the CNS3 catalogue

    • Northern sky: delta > -16

    • Limit distance: 9 pc

    • Limit magnitude: mv < 15

    • Volume limited until spectral type M5.5V and with extension to M6.5V

    • Results and discoveries:

    • Gliese 876

      • - A planet around an M dwarf
        - The closest extrasolar planet

    • New detections
    • The third detached M-dwarf eclipsing binary:

      • - Mass determination with a 0.3% accuracy

    • Precise mass determination by combining visual and spectroscopic Data

      • - Elodie high-precision radial velocities
        - PUE'O (CFHT) and ADONIS (ESO) adaptive optics imaging
        - ~ 10 accurate new mass determinations
        - Mass determinations with a 3-4% accuracy
        - Accurate masses of very low mass stars. IV. Improved mass-luminosity relations A&A paper
        - Accurate masses of very low mass stars. III. 16 new or improved masses A&A paper
        - Accurate masses of very low mass stars. II. The very low mass triple system GL 866 A&A paper
        - Accurate masses of very low mass stars. I. GL 570BC (0.6 M_sun+0.4 M_sun) A&A paper

    • By products

    • Programme extension in the southern sky

    • Sample:

        - ~ 100 more stars in the south
        - ~ same specifications as for the northern sample

    • FEROS

        - Wawelength extension in the red with regard to Coralie
        - Installed on the ESO-Bresilian 1.5-m telescope at La Silla
        - Programme status: application for observational time
    • Coralie

        - Rotation and chromospheric activity of the sample stars
        - Follow up of the FEROS interesting brighter sources

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