J/AJ/152/115 Pleiades members with K2 light curves. III. (Stauffer+, 2016)
Rotation in the Pleiades with K2. III. Speculations on origins and evolution.
Stauffer J., Rebull L., Bouvier J., Hillenbrand L.A., Collier-Cameron A.,
Pinsonneault M., Aigrain S., Barrado D., Bouy H., Ciardi D., Cody A.M.,
David T., Micela G., Soderblom D., Somers G., Stassun K.G., Valenti J.,
Vrba F.J.
<Astron. J. 152, 115 (2016)>
=2016AJ....152..115S 2016AJ....152..115S (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open ; Stars, masses ; Stars, diameters ; Reddening ;
Effective temperatures
Keywords: open clusters and associations: individual: Pleiades - stars: rotation
Abstract:
We use high-quality K2 light curves for hundreds of stars in the
Pleiades to better understand the angular momentum evolution and
magnetic dynamos of young low-mass stars. The K2 light curves provide
not only rotational periods but also detailed information from the
shape of the phased light curve that was not available in previous
studies. A slowly rotating sequence begins at (V-Ks)0∼1.1
(spectral type F5) and ends at (V-Ks)0∼3.7 (spectral type K8),
with periods rising from ∼2 to ∼11 days in that interval. A total of
52% of the Pleiades members in that color interval have periods within
30% of a curve defining the slow sequence; the slowly rotating
fraction decreases significantly redward of (V-Ks)0=2.6. Nearly
all of the slow-sequence stars show light curves that evolve
significantly on timescales less than the K2 campaign duration. The
majority of the FGK Pleiades members identified as photometric
binaries are relatively rapidly rotating, perhaps because binarity
inhibits star-disk angular momentum loss mechanisms during
pre-main-sequence evolution. The fully convective late M dwarf
Pleiades members (5.0<(V-Ks)0<6.0) nearly always show stable light
curves, with little spot evolution or evidence of differential
rotation. During pre-main-sequence evolution from ∼3Myr (NGC2264 age)
to ∼125Myr (Pleiades age), stars of 0.3M☉ shed about half of
their angular momentum, with the fractional change in period between 3
and 125Myr being nearly independent of mass for fully convective
stars. Our data also suggest that very low mass binaries form with
rotation periods more similar to each other and faster than would be
true if drawn at random from the parent population of single stars.
Description:
Light curves for of order 1000 candidate Pleiades members were
obtained during the K2 Field 4 campaign. This represents more than
half of the known or suspected members of the cluster; most of the
members lacking K2 light curves simply fell outside the K2 field of
view, and therefore we believe that the sample of cluster members with
light curves should be relatively unbiased. The observations and
methods are discussed in detail in Paper I (Rebull et al., Cat.
J/AJ/152/113).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 79 852 Derived data for Pleiades members with K2 light
curves
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See also:
J/AJ/152/113 : Pleiades members with K2 light curves. I. (Rebull+, 2016)
J/AJ/152/114 : Pleiades members with K2 light curves. II. (Rebull+, 2016)
J/A+A/577/A148 : The Seven Sisters DANCe. I. Pleiades (Bouy+, 2015)
J/AJ/148/30 : BVI photometry of 350 Pleiades stars (Kamai+, 2014)
J/A+A/563/A45 : Pleiades cluster membership probabilities (Sarro+, 2014)
J/ApJS/208/9 : PMS stars intrinsic colors and temperatures (Pecaut+, 2013)
J/MNRAS/422/1495 : UKIDSS Galactic Clusters Survey Pleiades mem. (Lodieu+ 2012)
J/MNRAS/408/475 : HATNet Pleiades Rotation Period Catalogue (Hartman+, 2010)
J/A+A/335/183 : Pleiades low-mass stars rotational velocities (Queloz+ 1998)
J/A+A/329/101 : Masses of Pleiades members (Raboud+ 1998)
J/ApJS/85/315 : F, G and K dwarf stars of the Pleiades (Soderblom+ 1993)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 9 I9 --- EPIC Ecliptic Plane Input Catalog number
11- 33 A23 --- Name Source identifier
35- 39 F5.2 mag Ksmag [3.77/15.53] Apparent Ks band Vega magnitude
41- 45 F5.2 mag (V-K)0 [-9.11/9.21] Dereddened (V-Ks) color index
(V-Ks)0
47- 51 F5.2 Msun Mass [0.08/1.51]?=-9.99 Stellar mass
53- 57 F5.2 mag Mbol [1.08/11.3]?=-9 Bolometric magnitude (1)
59- 63 F5.2 Rsun Rad [0.19/2.37]?=-9 Stellar radius (1)
65- 68 I4 K Teff [2823/8879]?=-9 Estimated effective temperature (2)
70- 74 F5.2 --- DVmag [-1.11/2.13]?=-9.99 Binary V band magnitude
difference (ΔV)
76- 79 F4.2 mag E(B-V) [0.22/0.53]? The (B-V) color excess (3)
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Note (1): We adopted the Pecaut & Mamajek 2013 (Cat. J/ApJS/208/9) bolometric
corrections to estimate MBol, and then the Stefan-Boltzmann law to estimate
radii.
Note (2): The effective temperature estimates are based on the Pecaut & Mamajek
2013 (Cat. J/ApJS/208/9) Table5 data for main sequence stars, using B-V to
estimate Teff for the bluest stars and (V-Ks) to estimate Teff for the
reddest stars, and a weighted average of the two estimates for G and K
dwarfs.
Note (3): Given for stars with significantly larger reddening that the rest
which have to be treated separately.
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History:
From electronic version of the journal
References:
Rebull et al., Paper I 2016AJ....152..113R 2016AJ....152..113R, Cat. J/AJ/152/113
Rebull et al., Paper II 2016AJ....152..114R 2016AJ....152..114R, Cat. J/AJ/152/114
Rebull et al., Paper IV 2017ApJ...839...92R 2017ApJ...839...92R, Cat. J/ApJ/839/92
Rebull et al., Paper V 2018AJ....155..196R 2018AJ....155..196R
(End) Prepared by [AAS]; Sylvain Guehenneux [CDS] 09-Jan-2017