ar X iv : a st ro - p h / 04 02 58 2 v 1 2 4 Fe b 20 04 Chromospheric Ca II emission in Nearby F , G , K , and M stars
نویسندگان
چکیده
We present chromospheric Ca II H & K activity measurements, rotation periods and ages for ∼1200 F-, G-, K-, and Mtype main-sequence stars from ∼18,000 archival spectra taken at Keck and Lick Observatories as a part of the California and Carnegie Planet Search Project. We have calibrated our chromospheric S values against the Mount Wilson chromospheric activity data. From these measurements we have calculated median activity levels and derived R HK, stellar ages, and rotation periods from general parameterizations for 1228 stars, ∼1000 of which have no previously published S values. We also present precise time series of activity measurements for these stars. Subject headings: stars: activity, rotation, chromospheres
منابع مشابه
ar X iv : a st ro - p h / 04 02 02 0 v 1 1 Fe b 20 04 Perspective from a Younger Generation – The Astro - Spectroscopy of Gisbert
متن کامل
ar X iv : a st ro - p h / 04 02 28 5 v 1 1 2 Fe b 20 04 1 UNIDENTIFIED GAMMA - RAY SOURCES AND MICROQUASARS
Some phenomenological properties of the unidentified EGRET detections suggest that there are two distinct groups of galactic gamma-ray sources that might be associated with compact objects endowed with relativistic jets. We discuss different models for gamma-ray production in both microquasars with low-and high-mass stellar companions. We conclude that the parent population of low-latitude and ...
متن کاملar X iv : a st ro - p h / 04 02 16 8 v 1 7 F eb 2 00 4 A search for wide ( sub ) stellar companions around extrasolar planet host stars
We present an overview of our ongoing systematic search for wide (sub)stellar companions around the stars known to host rad-vel planets. By using a relatively large field of view and going very deep, our survey can find all directly detectable stellar and massive brown dwarf companions (m>40 MJup) within a 1000 AU orbit.
متن کاملar X iv : a st ro - p h / 04 06 33 8 v 2 1 6 Ju n 20 04 Do We Know of any Maunder Minimum Stars ? 1
Most stars previously identified as Maunder minimum stars are old stars evolved off of the main sequence. Analysis of activity measurements from the California and Carnegie Planet Search program stars and Hipparcos parallaxes implies that the canonical age-chromospheric activity relation breaks down for stars older than ∼ 6 Gyr when activity is calculated from Mount Wilson S values. Stars only ...
متن کامل