J/AJ/160/38 Spitzer variability detections of 79 brown dwarfs (Vos+, 2020)
Spitzer variability properties of low-gravity L Dwarfs.
Vos J.M., Biller B.A., Allers K.N., Faherty J.K., Liu M.C., Metchev S.,
Eriksson S., Manjavacas E., Dupuy T.J., Janson M., Radigan-Hoffman J.,
Crossfield I., Bonnefoy M., Best W.M.J., Homeier D., Schlieder J.E.,
Brandner W., Henning T., Bonavita M., Buenzli E.
<Astron. J., 160, 38 (2020)>
=2020AJ....160...38V 2020AJ....160...38V
ADC_Keywords: Stars, brown dwarf; Photometry, infrared; Spectral types;
Stars, ages; Stars, diameters
Keywords: Brown dwarfs ; L dwarfs ; Atmospheric variability
Abstract:
We present Spitzer Space Telescope variability monitoring observations
of three low-gravity L dwarfs with previous detections of variability
in the near-IR: 2MASSJ0045+16, 2MASSJ0501-00, and 2MASSJ1425-36. We
detect significant periodic variability in two of our targets, 2MASS
J0045+16 and 2MASS J0501-00. We do not detect variability in 2MASS
J1425-36. Combining our new rotation periods with rotational
velocities, we calculate inclination angles of 22°±1°,
60-8+13°, and 52-13+19° for 2MASSJ0045+16,
2MASSJ0501-00, and 2MASSJ1425-36, respectively. Our three new objects
are consistent with the tentative relations between inclination,
amplitude, and color anomaly previously reported. Objects with the
highest variability amplitudes are inclined equator on, while the
maximum observed amplitude decreases as the inclination angle
decreases. We also find a correlation between the inclination angle
and (J-K)2MASS color anomaly for the sample of objects with measured
inclinations. Compiling the entire sample of brown dwarfs with Spitzer
variability detections, we find no enhancement in amplitude for young,
early-L dwarfs compared to the field dwarf population. We find a
possible enhancement in amplitude of low-gravity late-L dwarfs at
4.5µm. We do not find a correlation between amplitude ratio and
spectral type for field dwarfs or for the young population. Finally,
we compile the rotation periods of a large sample of brown dwarfs with
ages 1Myr-1Gyr and compare the rotation rates predicted by
evolutionary models assuming angular momentum conservation. We find
that the rotation rates of the current sample of brown dwarfs fall
within the expected range set by evolutionary models and breakup
limits.
Description:
We used the Infrared Array Camera (IRAC) to observe our targets in the
Channel 1 (3.6µm) and Channel 2 (4.5µm) bands as part of the
Cycle 14 Program, "Weather and Rotation of Young Brown Dwarfs"
(PID: 14019).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 184 79 Brown dwarf variability detections and upper limits
in the infrared
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See also:
J/A+A/419/249 : RJHKs photometry of sigma Ori low-mass stars (Scholz+, 2004)
J/A+A/429/1007 : RIJHK photometry of VLM objects near eps Ori (Scholz+, 2005)
J/A+A/491/889 : CoRoT-Exo-3b observations (Deleuil+, 2008)
J/A+A/502/883 : I photom. of very low mass ONC stars (Rodriguez-Ledesma+,2009)
J/ApJ/723/684 : NIRSPEC ultracool dwarf radial velocity survey (Blake+, 2010)
J/A+A/519/A98 : Transit of exoplanet WASP-21b (Bouchy+, 2010)
J/ApJS/191/389 : Photometric monitoring in σ Ori cluster (Cody+, 2010)
J/ApJS/201/19 : Hawaii Infrared Parallax Program. I. (Dupuy+, 2012)
J/ApJ/761/123 : KELT-1 photometry and spectroscopy follow-up (Siverd+, 2012)
J/ApJ/810/158 : M,L,T dwarfs fundamental parameters & SEDs (Filippazzo+, 2015)
J/ApJS/219/33 : BANYAN. VII. Candidate YMG members from BASS (Gagne+, 2015)
J/ApJ/832/58 : Spitzer/IRAC monitoring WISEJ085510.83-071442.5 (Esplin+,2016)
J/ApJS/225/10 : Kinematic analysis of M7-L8 dwarfs (Faherty+, 2016)
J/ApJ/833/96 : Hawaii infrared plx program. II. Ultracool dwarfs (Liu+, 2016)
J/ApJ/818/176 : HST/WFC3 NIR photometry of 2M1207b (Zhou+, 2016)
J/AJ/154/129 : PSYM-WIDE: planetary-mass comp. to YMG members (Naud+, 2017)
J/AJ/153/95 : Catalog of Suspected Nearby Young Stars (Riedel+, 2017)
J/A+A/629/A145 : L9-T3.5 brown dwarfs light curves (Eriksson+, 2019)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 25 A25 --- ID Target identifier
27- 38 A12 --- SpT Spectral type
40- 45 F6.3 % AJ [0.6/26]? Ground based J band amplitude
47- 51 F5.3 % e_AJ [0.04/2.4]? Uncertainty in AJ
53- 53 A1 --- l_AWFC3 [>] Limit flag on AWFC3
54- 58 F5.2 % AWFC3 [0.7/27]? WFC3 NIR amplitude
60- 63 F4.2 % e_AWFC3 [0/0.3]? Uncertainty in AWFC3
65- 65 A1 --- f_AWFC3 [t] Indicates a tentative AWFC3 value
67- 72 F6.3 % A3.6 [0.1/11]? Spitzer/IRAC 3.6micron band amplitude
74- 78 F5.3 % e_A3.6 [0/1]? Uncertainty in A3.6
80- 85 F6.3 % A4.5 [-0.45/10]? Spitzer/IRAC 4.5micron band amplitude
87- 91 F5.3 % e_A4.5 [0/1.0]? Uncertainty in A4.5
93- 98 F6.3 h Per [1.41/24]? Period
100-104 F5.3 h e_Per [0.01/5]? Uncertainty in P
106-109 I4 Myr Age [7/1000]? Age
111-115 F5.1 Myr e_Age [2.5/200]? Uncertainty in Age
117-120 F4.2 Rjup Rad [0.94/1.62]? Radius (1)
122-125 F4.2 Rjup e_Rad [0.01/0.2]? Uncertainty in R
127-127 I1 --- Comp [0/1] Is this a companion, 1=yes, 0=no
129-130 I2 deg Inc [23/90]? Inclination
132-133 I2 deg E_Inc [0/19]? Upper uncertainty in Inc
135-136 I2 deg e_Inc [1/29]? Lower uncertainty in Inc
138-184 A47 --- Ref Variability reference(s) (2)
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Note (1): Estimated radii are from Filippazzo+, 2015, J/ApJ/810/158
expect for 2MASSJ00470038+6803543 and 2MASSJ2244316+204343 which come
from Vos+, 2017ApJ...842...78V 2017ApJ...842...78V and SIMPJ013656.57+093347.3 which is
Gagne+, 2017ApJ...841L...1G 2017ApJ...841L...1G.
Note (2): References as follows:
Allers2016 = Allers+, 2016ApJ...819..133A 2016ApJ...819..133A
Apai2017 = Apai+, 2017Scien.357..683A 2017Scien.357..683A
Biller2018 = Biller+, 2018AJ....155...95B 2018AJ....155...95B
Bowler2020 = Bowler+, 2020ApJ...893L..30B 2020ApJ...893L..30B
Buenzli2012 = Buenzli+, 2012ApJ...760L..31B 2012ApJ...760L..31B
Buenzli2014 = Buenzli+, 2014ApJ...782...77B 2014ApJ...782...77B
Buenzli2015 = Buenzli+, 2015ApJ...798..127B 2015ApJ...798..127B
Clarke2008 = Clarke+, 2008MNRAS.386.2009C 2008MNRAS.386.2009C
Croll2016 = Croll+, 2016arXiv160903586C 2016arXiv160903586C
Cushing2016 = Cushing+, 2016ApJ...823..152C 2016ApJ...823..152C
Eriksson2019 = Eriksson+, 2019A&A...145....1E 2019A&A...145....1E
Esplin2016 = Esplin+, 2016, J/ApJ/832/58
Gagne2017 = Gagne+, 2017ApJ...841L...1G 2017ApJ...841L...1G
Gillon2013 = Gillon+, 2013A&A...555L...5G 2013A&A...555L...5G
Girardin2013 = Girardin+, 2013ApJ...767...61G 2013ApJ...767...61G
Heinze2013 = Heinze+, 2013ApJ...767..173H 2013ApJ...767..173H
Leggett2016 = Legett+, 2016ApJ...830..141L 2016ApJ...830..141L
Lew2016 = Lew+, 2016ApJ...829L..32L 2016ApJ...829L..32L
Manjavacas2018 = Manjavacas+, 2018AJ....155...11M 2018AJ....155...11M
Manjavacas2019 = Manjavacas+, 2019ApJ...875L..15M 2019ApJ...875L..15M
Metchev2015 = Metchev+, 2015ApJ...799..154M 2015ApJ...799..154M
Miles-Paez2019 = Milles-Paez+, 2019ApJ...883..181M 2019ApJ...883..181M
Morales-Calderon2006 = Morales-Calderon+, 2006ApJ...653.1454M 2006ApJ...653.1454M
Naud2017 = Naud+, 2007AJ....154..129N 2007AJ....154..129N
Radigan2014 = Radigan+, 2014ApJ...793...75R 2014ApJ...793...75R
Schneider2018 = Schneider+, 2018AJ....155..238S 2018AJ....155..238S
Vos2017 = Vos+, 2017ApJ...842...78V 2017ApJ...842...78V
Vos2018 = Vos+, 2018MNRAS.474.1041V 2018MNRAS.474.1041V
Vos2019 = Vos+, 2019MNRAS.483..480V 2019MNRAS.483..480V
Yang2016 = Yang+, 2016ApJ...826....8Y 2016ApJ...826....8Y
Zhou2015 = Zhou+, 2016, J/ApJ/818/176
Zhou2020 = zhou+, 2020arXiv200405168Z 2020arXiv200405168Z
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 13-Oct-2020