1999/06/08 by D. M. Terndrup, Donald M. Terndrup, Anita Krishnamurthi +3 · 2 citations
Physics and Astronomy · #Astro and Planetary Science #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #Brown dwarf #Geometry #Physics #Pleiades #Rotation (mathematics) #Rotation period #Stars #Stellar rotation #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/301061
13 pages, four figures. Accepted for publication in AJ
arxiv created 1999/06/08 · openalex publication_date 1999/10/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We have photometrically monitored (Cousins I C ) eight low-mass stars and brown dwarfs that are probable members of the Pleiades. We derived rotation periods for two of the stars—HHJ 409 and CFHT-PL 8—to be 0.258 and 0.401 days, respectively. The masses of these stars are near 0.4 and 0.08 M ⊙ , respectively; the latter is the second such object near the hydrogen-burning boundary for which a rotation period has been measured. We also observed HHJ 409 in V . The relative amplitude in the two bands shows that the spots in that star are about 200 K cooler than the stellar effective temperature of 3560 K and have a filling factor on the order of 13%. With one possible exception, the remaining stars in the sample do not show photometric variations larger than the mean error of measurement. We also examined the M9.5 V disk star 2MASS J0149090+295613, which had previously exhibited a strong flare event, but we did not detect any photometric variation.