Abstract
We searched the 9 M-dwarf primaries nearer than 5 pc and south of declination δ = -30° for companions with separations 1-10 AU and found none. Taken together with the 25 northern primaries studied by Henry and McCarthy (1990) the fraction of binaries and triples within the now complete sample of all M dwarfs within 5 pc is 9/34 = 26 ± 9%, and the average number of companions per system is 0.32 ± 0.10. This is lower by 2σ than the observed multiplicity fraction of 43 ± 5%, and companions per system of 0.49 ± 0.05 in the sample of nearby solar-type main sequence stars. It is also much lower than the extrapolated binary fraction among young stars in Taurus. We discuss the implications of this finding.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 159-166 |
| Number of pages | 8 |
| Journal | Astronomy and astrophysics |
| Volume | 325 |
| Issue number | 1 |
| State | Published - Sep 1 1997 |
Keywords
- Binaries: general
- Stars: low-mass
- Stars: luminosity function, mass function
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science