期刊
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
卷 517, 期 2, 页码 2165-2189出版社
OXFORD UNIV PRESS
DOI: 10.1093/mnras/stac2706
关键词
stars: activity; stars: fundamental parameters; stars: late-type; stars: magnetic field; stars: rotation; star-spots
资金
- Ohio State University College of Arts and Sciences
- NASA [80NSSC19K0597]
- Alfred P. Sloan Foundation
- U.S. Department of Energy Office of Science
- Center for High Performance Computing at the University of Utah
- Brazilian Participation Group
- Carnegie Institution for Science, Carnegie Mellon University
- Center for Astrophysics | Harvard Smithsonian
- Chilean Participation Group
- French Participation Group
- Instituto de Astrofisica de Canarias, The Johns Hopkins University
- Kavli Institute for the Physics and Mathematics of the Universe (IPMU) / University of Tokyo
- Korean Participation Group
- Lawrence Berkeley National Laboratory
- Leibniz Institut fur Astrophysik Potsdam (AIP)
- Max-Planck-Institut fur Astronomie (MPIA Heidelberg)
- Max-Planck-Institut fur Astrophysik (MPA Garching)
- Max-Planck-Institut fur Extraterrestrische Physik (MPE)
- National Astronomical Observatories of China
- New Mexico State University
- New York University
- University of Notre Dame
- Observatario Nacional / MCTI
- Ohio State University
- Pennsylvania State University
- Shanghai Astronomical Observatory
- United Kingdom Participation Group
- Universidad Nacional Autonoma de Mexico
- University of Arizona
- University of Colorado Boulder
- University of Oxford
- University of Portsmouth
- University of Utah
- University of Virginia
- University of Washington
- University of Wisconsin
- Vanderbilt University
- Yale University
- National Aeronautics and Space Administration
- National Science Foundation
This study measures star-spot filling fractions for 240 stars in the Pleiades and M67 open star clusters using APOGEE high-resolution H-band spectra. A modified spectroscopic pipeline is developed to solve for star-spot filling fraction and star-spot temperature contrast. The results show that this technique can recover real star-spot signals and has an impact on the filling fractions and effective temperatures of active stars.
We measure star-spot filling fractions for 240 stars in the Pleiades and M67 open star clusters using APOGEE high-resolution H-band spectra. For this work, we developed a modified spectroscopic pipeline which solves for star-spot filling fraction and star-spot temperature contrast. We exclude binary stars, finding that the large majority of binaries in these clusters (80 per cent) can be identified from Gaia DR3 and APOGEE criteria - important for field star applications. Our data agree well with independent activity proxies, indicating that this technique recovers real star-spot signals. In the Pleiades, filling fractions saturate at a mean level of 0.248 +/- 0.005 for active stars with a decline at slower rotation; we present fitting functions as a function of Rossby number. In M67, we recover low mean filling fractions of 0.030 +/- 0.008 and 0.003 +/- 0.002 for main sequence GK stars and evolved red giants, respectively, confirming that the technique does not produce spurious spot signals in inactive stars. Star-spots also modify the derived spectroscopic effective temperatures and convective overturn time-scales. Effective temperatures for active stars are offset from inactive ones by -109 +/- 11 K, in agreement with the Pecaut & Mamajek empirical scale. Star-spot filling fractions at the level measured in active stars changes their inferred overturn time-scale, which biases the derived threshold for saturation. Finally, we identify a population of stars statistically discrepant from mean activity-Rossby relations and present evidence that these are genuine departures from a Rossby scaling. Our technique is applicable to the full APOGEE catalogue, with broad applications to stellar, galactic, and exoplanetary astrophysics.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据