J/AJ/156/275 Rotational evolution of young, binary M dwarfs (Stauffer+, 2018)
The rotational evolution of young, binary M dwarfs.
Stauffer J., Rebull L.M., Cody A.M., Hillenbrand L.A., Pinsonneault M.,
Barrado D., Bouvier J., David T.
<Astron. J., 156, 275 (2018)>
=2018AJ....156..275S 2018AJ....156..275S (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open ; Stars, double and multiple ; Stars, dwarfs ;
Stars, M-type ; Stars, pre-main sequence ; Stars, masses
Keywords: binaries: general - stars: low mass - stars: pre-main sequence -
stars: rotation
Abstract:
We have analyzed K2 light curves for more than 3000 low-mass stars in
the ∼8 Myr old Upper Sco association, the ∼125 Myr age Pleiades open
cluster, and the ∼700 Myr old Hyades and Praesepe open clusters to
determine stellar rotation rates. Many of these K2 targets show two
distinct periods, and for the lowest-mass stars in these clusters,
virtually all of these systems with two periods are photometric binaries.
The most likely explanation is that we are detecting the rotation periods
for both components of these binaries. We explore the evolution of the
rotation rate in both components of photometric binaries relative to
one another and to nonphotometric binary stars. In Upper Sco and the
Pleiades, these low-mass binary stars have periods that are much shorter
on average and much closer to each other than would be true if drawn
at random from the M dwarf single stars. In Upper Sco, this difference
correlates strongly with the presence or absence of infrared excesses
due to primordial circumstellar disks-the single-star population includes
many stars with disks, and their rotation periods are distinctively longer
on average than their binary star cousins of the same mass. By Praesepe
age, the significance of the difference in rotation rate between the single
and binary low-mass M dwarf stars is much less, suggesting that angular
momentum loss from winds for fully convective zero-age main-sequence
stars erases memory of the rotation rate dichotomy for binary and single
very low mass stars at later ages.
Description:
All of the rotation period data we use in this paper come from light
curves obtained by NASA's K2 mission. We use the periods we have previously
derived and reported in Rebull et al. (2016, J/AJ/152/113; 2016,
J/AJ/152/114) for the Pleiades, Rebull et al. (2017, J/ApJ/839/92) for
Praesepe, Rebull et al. (2018, J/AJ/155/196) for Upper Sco, and to be
reported in an upcoming paper for the Hyades (L. Rebull et al. 2018,
in preparation). In those same papers, we provide (V-Ks)0 colors for all
of the stars with periods. Where possible, we use observed V and Ks
photometry to yield the (V-Ks)0 color; where that was not possible
(primarily when there is no literature V magnitude; Ks comes from 2MASS),
we use photometry at other bands to allow us to estimate the star's
(V-Ks)0 color.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table4.dat 42 257 Upper Sco M<0.32 M☉ stars with K2 periods
table5.dat 42 286 Pleiades M<0.32 M☉ stars with K2 periods
table6.dat 42 292 Praesepe/Hyades M<0.32 M☉ stars with K2
periods
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See also:
IV/34 : K2 Ecliptic Plane Input Catalog (EPIC) (Huber+, 2017)
J/AJ/120/479 : Low-mass stars in the Upper Sco association (Ardila+, 2000)
J/MNRAS/313/347 : Pleiades low-mass stars and brown dwarfs (Pinfield+, 2000)
J/AJ/132/1517 : Spectroscopy of M dwarfs in Praesepe (Kafka+, 2006)
J/MNRAS/408/2457 : Low-mass stars and brown dwarfs in Praesepe (Baker+, 2010)
J/MNRAS/413/2218 : Stellar rotation in Hyades and Praesepe (Delorme+, 2011)
J/ApJ/795/161 : Activity and rotation in Praesepe and the Hyades
(Douglas+, 2014)
J/AJ/152/113 : Pleiades members with K2 light curves. I. Periods
(Rebull+, 2016)
J/AJ/152/114 : Pleiades members with K2 light curves. II. (Rebull+, 2016)
J/AJ/152/115 : Pleiades members with K2 light curves. III.
(Stauffer+, 2016)
J/ApJ/822/47 : K2 rotation periods for 65 Hyades members (Douglas+, 2016)
J/ApJ/839/92 : Praesepe members with K2 light curve data (Rebull+, 2017)
J/ApJ/842/83 : Praesepe members rotational periods from K2 LCs
(Douglas+, 2017)
J/AJ/155/196 : Analysis of K2 LCs for members of USco + ρ Oph
(Rebull+, 2018)
Byte-by-byte Description of file: table4.dat table5.dat table6.dat
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Bytes Format Units Label Explanations
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1- 9 I9 --- EPIC [202515599/247899959] EPIC identifier
11- 15 F5.3 mag (V-Ks)0 [5.31/6.974] Intrinsic (V-Ks) color
17- 23 F7.4 d P1 [0.0824/29.7371] First rotation period
25- 31 F7.4 d P2 [0.1126/19.2487]?=-9 Second rotation period
33- 37 F5.3 Msun Mass [0.112/0.32] Mass
39 A1 --- Disk [Y] Disk detected? (only in Table 4)
41- 42 A2 --- Cluster Cluster code (H=Hyades, Pr=Praesepe) (only in
Table 6)
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History:
From electronic version of the journal
(End) Prepared by [AAS], Tiphaine Pouvreau [CDS] 17-Apr-2019