J/ApJ/822/81 PTF stellar rotation periods for Pleiades members (Covey+, 2016)
Why are rapidly rotating M dwarfs in the Pleiades so (infra)red? New period
measurements confirm rotation-dependent color offsets from the cluster sequence.
Covey K.R., Agueros M.A., Law N.M., Liu J., Ahmadi A., Laher R.,
Levitan D., Sesar B., Surace J.
<Astrophys. J., 822, 81-81 (2016)>
=2016ApJ...822...81C 2016ApJ...822...81C (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open ; Photometry, VRI ; Photometry, infrared ;
Stars, masses
Keywords: open clusters and associations: individual: M44, Pleiades -
stars: late-type - stars: low-mass - stars: rotation - starspots
Abstract:
Stellar rotation periods (Prot) measured in open clusters have
proved to be extremely useful for studying stars' angular momentum
content and rotationally driven magnetic activity, which are both age-
and mass-dependent processes. While Prot measurements have been
obtained for hundreds of solar-mass members of the Pleiades,
measurements exist for only a few low-mass (<0.5 M☉) members of this
key laboratory for stellar evolution theory. To fill this gap, we
report Prot for 132 low-mass Pleiades members (including nearly 100
with M=<0.45 M☉), measured from photometric monitoring of the
cluster conducted by the Palomar Transient Factory in late 2011 and
early 2012. These periods extend the portrait of stellar rotation at
125 Myr to the lowest-mass stars and re-establish the Pleiades as a
key benchmark for models of the transport and evolution of stellar
angular momentum. Combining our new Prot with precise BVIJHK photometry
reported by Stauffer et al. (2007, J/ApJS/172/663) and Kamai et al.
(2014, J/AJ/148/30), we investigate known anomalies in the photometric
properties of K and M Pleiades members. We confirm the correlation
detected by Kamai et al. between a star's Prot and position relative
to the main sequence in the cluster's color-magnitude diagram. We find
that rapid rotators have redder (V-K) colors than slower rotators at
the same V, indicating that rapid and slow rotators have different
binary frequencies and/or photospheric properties. We find no
difference in the photometric amplitudes of rapid and slow rotators,
indicating that asymmetries in the longitudinal distribution of
starspots do not scale grossly with rotation rate.
Description:
We monitored the Pleiades using time allocated to two PTF Key
Projects: the PTF/M-dwarfs survey (Law et al. 2011ASPC..448.1367L 2011ASPC..448.1367L,
2012ApJ...757..133L 2012ApJ...757..133L) and the PTF Open Cluster Survey (POCS; Agueros et al.
2011ApJ...740..110A 2011ApJ...740..110A; Douglas et al. 2014, J/ApJ/795/161). PTF was a
time-domain experiment using the robotic 48-inch Samuel Oschin (P48)
telescope at Palomar Observatory, CA, and involved real-time
data-reduction and transient-detection pipelines and a dedicated
follow-up telescope. The PTF infrastructure is described in Law et al.
(2009PASP..121.1395L 2009PASP..121.1395L); we focus here on the components associated with
the P48, which we used to conduct our monitoring campaign. The P48 is
equipped with the CFH12K mosaic camera, which was significantly
modified to optimize its performance on this telescope. The camera has
11 working CCDs, which cover a 7.26 square degree field of view with
92 megapixels at 1" sampling (Rahmer et al. 2008SPIE.7014E..4YR). Under
typical observing conditions (1.1" seeing), it delivers 2" full-width
half-maximum images that reach a 5σ limiting R∼21 mag in 60 s
(Law et al. 2010SPIE.7735E..3ML).
Objects:
---------------------------------------------
RA (ICRS) DE Designation(s)
---------------------------------------------
03 47 00 +24 07.0 Pleiades = M 45
---------------------------------------------
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table4.dat 114 132 POCS Pleiades Periods
table5.dat 79 119 Periods For Field Stars Observed During PTF
Pleiades Campaign
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See also:
I/258 : Pleiades positions and proper motions (Wang+, 1996)
J/A+AS/100/607 : Very low mass proper motion members in Pleiades
(Hambly+, 1993)
J/ApJS/85/315 : F, G and K dwarf stars of the Pleiades (Soderblom+ 1993)
J/A+A/323/139 : K magnitude of Pleiades low-mass binaries (Bouvier+ 1997)
J/A+A/329/101 : Masses of Pleiades members (Raboud+ 1998)
J/MNRAS/313/347 : Pleiades low-mass stars and brown dwarfs (Pinfield+, 2000)
J/MNRAS/342/1241 : Low-mass stars in M45 and M44 (Pinfield+, 2003)
J/A+A/416/125 : RI photometry in alpha Per and Pleiades (Deacon+, 2004)
J/ApJS/172/663 : Infrared observations of the Pleiades (Stauffer+, 2007)
J/MNRAS/380/712 : ZYJHK photometry in Pleiades (Lodieu+, 2007)
J/MNRAS/408/475 : HATNet Pleiades Rotation Period Catalogue (Hartman+, 2010)
J/MNRAS/422/1495 : UKIDSS Galactic Clusters Survey Pleiades members
(Lodieu+ 2012)
J/AJ/148/30 : BVI photometry of 350 Pleiades stars (Kamai+, 2014)
J/ApJ/795/161 : Activity and rotation in Praesepe and the Hyades
(Douglas+, 2014)
J/A+A/577/A148 : The Seven Sisters DANCe. I. Pleiades (Bouy+, 2015)
J/A+A/596/A113 : The Seven Sisters DANCe. II. Pleiades (Barrado+, 2016)
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 16 A16 --- 2MASS 2MASS identifier (HHMMSSss-DDMMSSs)
18- 28 F11.8 deg RAdeg Right Ascension in decimal degrees (J2000)
30- 40 F11.8 deg DEdeg Declination in decimal degrees (J2000)
42- 46 F5.2 mag Vmag ? Johnson V-band magnitude
48- 55 A8 --- SourceV Source of V photometry (Kamai, Stauffer) (1)
57- 61 F5.2 mag Kmag K-band magnitude
63- 66 F4.2 mag e_Kmag ? Uncertainty in Kmag
68- 75 A8 --- SourceK Source of K photometry (2MASS, DANCe,
Stauffer, UKIDSS)
77- 81 F5.2 mag V-K ? V-K color index
83- 86 F4.2 Msun Mass Mass
88 I1 --- Bin [0/1]? Photometric binary candidate flag
(0=no, 1=yes)
90- 93 F4.2 d Prot1 POCS rotation period
95-100 F6.2 --- Power POCS periodogram peak power
102-105 F4.2 --- Amp POCS photometric amplitude
107-109 I3 --- Epoch [291/339] POCS epoch
111-114 F4.2 d Prot2 ? HATnet rotation period
--------------------------------------------------------------------------------
Note (1): Source as follows:
Kamai = Kamai et al. 2014 (J/AJ/148/30);
Stauffer = Stauffer et al. 2007 (J/ApJS/172/663).
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 F11.8 deg RAdeg Right Ascension in decimal degrees (J2000)
13- 23 F11.8 deg DEdeg Declination in decimal degrees (J2000)
25- 29 F5.2 mag Rptf PTF R-band magnitude
31- 35 F5.3 mag e_Rptf Uncertainty in Rptf
37- 40 F4.2 d Prot POCS rotation period
42- 47 F6.2 --- Power POCS periodogram peak power
49- 52 F4.2 --- Amp POCS photometric amplitude
54- 56 I3 --- Epoch [291/338] POCS epoch
58- 77 A20 --- Star Star name (or comment)
79 A1 --- n_Star [ab] Note on Star (1)
--------------------------------------------------------------------------------
Note (1): Note as follows:
a = These are non-members with Prot measured by Hartman et al.
(2010, J/MNRAS/408/475). The Prot derived here and in that work agree
to better than 1% for all these stars;
b = Known RR Lyrae.
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History:
From electronic version of the journal
(End) Tiphaine Pouvreau [CDS] 13-Feb-2018