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Abstract Gyrochronology is the empirical relation between rotation and age. NASA's Transiting Exoplanet Survey Satellite (TESS), Kepler, and K2 missions have observed thousands of wide main sequence binaries. Since components of a binary are coeval, their rotation periods should be consistent with gyrochronology models. However, the usefulness of gyrochronology depends upon reliable rotation periods. We explore the reliability of rotation period determinations for a sample of wide binary components from the TESS cycle 3. Wide binaries with the most reliable rotation period determinations provide a strong basis for testing whether the gyrochronology empirical relation derived from open clusters is also valid for field stars.
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Seven classes of rotational variables from a study of 50 000 spotted stars with ASAS-SN, Gaia , and APOGEE
ABSTRACT We examine the properties of ∼50 000 rotational variables from the ASAS-SN survey using distances, stellar properties, and probes of binarity from Gaia DR3 and the SDSS APOGEE survey. They have higher amplitudes and span a broader period range than previously studied Kepler rotators. We find they divide into three groups of main sequence stars (MS1, MS2s, MS2b) and four of giants (G1/3, G2, G4s, and G4b). MS1 stars are slowly rotating (10–30 d), likely single stars with a limited range of temperatures. MS2s stars are more rapidly rotating (days) single stars spanning the lower main sequence up to the Kraft break. There is a clear period gap (or minimum) between MS1 and MS2s, similar to that seen for lower temperatures in the Kepler samples. MS2b stars are tidally locked binaries with periods of days. G1/3 stars are heavily spotted, tidally locked RS CVn stars with periods of 10s of days. G2 stars are less luminous, heavily spotted, tidally locked sub-subgiants with periods of ∼10 d. G4s stars have intermediate luminosities to G1/3 and G2, slow rotation periods (approaching 100 d), and are almost certainly all merger remnants. G4b stars have similar rotation periods and luminosities to G4s, but consist of sub-synchronously rotating binaries. We see no difference in indicators for the presence of very wide binary companions between any of these groups and control samples of photometric twin stars built for each group.
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- PAR ID:
- 10477333
- Publisher / Repository:
- Oxford University Press
- Date Published:
- Journal Name:
- Monthly Notices of the Royal Astronomical Society
- Volume:
- 527
- Issue:
- 3
- ISSN:
- 0035-8711
- Format(s):
- Medium: X Size: p. 5588-5602
- Size(s):
- p. 5588-5602
- Sponsoring Org:
- National Science Foundation
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