J/AJ/152/114 Pleiades members with K2 light curves. II. (Rebull+, 2016)
Rotation in the Pleiades with K2. II. Multiperiod stars.
Rebull L.M., Stauffer J.R., Bouvier J., Cody A.M., Hillenbrand L.A.,
Soderblom D.R., Valenti J., Barrado D., Bouy H., Ciardi D.,
Pinsonneault M., Stassun K., Micela G., Aigrain S., Vrba F., Somers G.,
Gillen E., Collier Cameron A.
<Astron. J., 152, 114-114 (2016)>
=2016AJ....152..114R 2016AJ....152..114R (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open
Keywords: galaxies: clusters: individual: Pleiades - stars: rotation
Abstract:
We use K2 to continue the exploration of the distribution of rotation
periods in Pleiades that we began in Paper I. We have discovered
complicated multiperiod behavior in Pleiades stars using these K2
data, and we have grouped them into categories, which are the focal
part of this paper. About 24% of the sample has multiple, real
frequencies in the periodogram, sometimes manifesting as obvious
beating in the LCs. Those having complex and/or structured periodogram
peaks, unresolved multiple periods, and resolved close multiple
periods are likely due to spot/spot group evolution and/or latitudinal
differential rotation; these largely compose the slowly rotating
sequence in P versus (V-Ks)0 identified in Paper I. The fast
sequence in P versus (V-Ks)0 is dominated by single-period stars;
these are likely to be rotating as solid bodies. Paper III continues
the discussion, speculating about the origin and evolution of the
period distribution in the Pleiades.
Description:
The observations and methods are discussed in detail in Paper I
(Rebull et al. 2016, Cat. J/AJ/152/113). Here we simply summarize the
main points.
Members of the Pleiades were observed in K2 campaign 4, which lasted
for 72 days. All of the stars in this sample were observed in the
long-cadence (∼30 minute exposure) mode.
We looked for periods using the Lomb-Scargle (LS; Scargle
1982ApJ...263..835S 1982ApJ...263..835S) approach.
For stars of the mass range considered here, the periods that we
measure are, by and large, starspot-modulated rotation periods. Spot
modulation is the simplest explanation for sinusoidal (or
sinusoidal-like) variations where there are changes over an entire
orbital phase.
We assembled a catalog of literature data for our targets. The most
important values obtained from this search are (V-Ks)0 (measured
or inferred; see Paper I, Rebull et al. 2016, Cat. J/AJ/152/113) and
membership (see Paper I). Cross-identifications between the EPIC
number, R.A./decl., and common literature names are in Paper I.
Out of the 1020 light curves of candidate Pleiades members from which
we started, there are 775 high-confidence members, with 51 more
lower-confidence members (for a total of 826 members).
Out of those 775 (best members), 716 (92.4%) have at least one
measured period that we believe in the overwhelming majority of cases
to be a rotation period and due to starspots. Including the
lower-confidence members, 759/826 (91.9%) have at least one measured
period (see Table2).
The period distribution is strongly peaked at P<1day with typical
amplitudes of ∼0.03mag.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 172 759 Periods, supporting data, and light-curve
categories for periodic Pleiades
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See also:
J/AJ/152/113 : Pleiades members with K2 light curves. I. (Rebull+, 2016)
J/AJ/152/115 : Pleiades members with K2 light curves. III. (Stauffer+, 2016)
J/A+A/577/A148 : The Seven Sisters DANCe. I. Pleiades (Bouy+, 2015)
J/A+A/560/A4 : Rotation periods of active Kepler stars (Reinhold+, 2013)
J/MNRAS/408/475 : HATNet Pleiades Rotation Period Catalogue (Hartman+, 2010)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 9 I9 --- EPIC Number in the Ecliptic Plane Input Catalog
(EPIC) for K2
11- 28 A18 --- IAU IAU designation (HHMMSS.ss+DDMMSS.s; J2000)
30- 37 F8.5 deg RAdeg Right Ascension in decimal degrees (J2000)
39- 46 F8.5 deg DEdeg Declination in decimal degrees (J2000)
48- 70 A23 --- OName Other identifier (Alias)
72- 76 F5.2 mag Vmag [6.73/20.71]? Apparent V band Vega magnitude, if
observed
78- 82 F5.2 mag Ksmag [6.25/14.45] Apparent Ks band Vega magnitude, if
observed
84- 88 F5.2 mag (V-K)0 [-0.2/7.2] Dereddened (V-Ks)0 color index
(vmk0) (1)
90- 96 F7.4 d Prot [0.035/22.2] Primary period (taken to be rotation
period) (P1)
98-103 F6.4 d Per2 [0.031/9.61]? Secondary period (P2)
105-110 F6.4 d Per3 [0.036/5.97]? Tertiary period (P3)
112-118 F7.4 d Per4 [0.03/10.99]? Quaternary period (P4)
120-124 F5.3 mag Amp [0.001/0.56] Amplitude of the 10th to 90th
percentile (ampl)
126-129 A4 --- Mm Membership indicator flag (best or ok) (memb) (2)
131-136 A6 --- P Indicator of whether single or multiperiod star
(single or multi) (single/multi-P)
138-140 A3 --- dd Indicator of whether or not it is double-dip
light curve (yes or no)
142-144 A3 --- ddm Indicator of whether or not it is a moving
double-dip light curve (yes or no) (ddmoving)
146-148 A3 --- shch Indicator of whether or not it is a shape
changer (yes or no)
150-152 A3 --- beat Indicator of whether or not the full light
curve has beating visible (yes or no)
154-156 A3 --- cpeak Indicator of whether or not the power spectrum
has a complex, structured and/or wide peak
(yes or no)
158-160 A3 --- resc Indicator of whether or not there are resolved
close periods in the power spectrum
(yes or no) (resclose)
162-164 A3 --- resd Indicator of whether or not there are resolved
distant periods in the power spectrum
(yes or no) (resdist)
166-168 A3 --- dScu Indicator of whether or not the power spectrum
and period suggest that this is a δ
Scuti pulsator (yes or no) (pulsator)
170-172 A3 --- cloud Indicator of whether or not the phased light
curve has narrow, angular dips (yes or no)
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Note (1): Directly observed if Vmag and Ksmag exist or inferred.
Note (2): See Paper I (Rebull et al. 2016, Cat. J/AJ/152/113) for full details
about the following membership codes:
best = Highest confidence member;
ok = Lower confidence member;
(NM = Non-member).
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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
Stauffer et al., Paper III 2016AJ....152..115S 2016AJ....152..115S, Cat. J/AJ/152/115
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] 12-Dec-2016