J/AJ/160/35 NIR photometry in the T Tauri system with Keck (Schaefer+, 2020)
Orbital motion, variability, and masses in the T Tauri triple system.
Schaefer G.H., Beck T.L., Prato L., Simon &.M.
<Astron. J., 160, 35-35 (2020)>
=2020AJ....160...35S 2020AJ....160...35S (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple; Photometry, infrared
Keywords: Binary stars; Multiple stars
Abstract:
We present results from adaptive optics imaging of the T Tauri triple
system obtained at the Keck and Gemini Observatories in 2015-2019. We
fit the orbital motion of T Tau Sb relative to Sa and model the
astrometric motion of their center of mass relative to T Tau N. Using
the distance measured by Gaia, we derived dynamical masses of
MSa=2.05±0.14M☉ and MSb=0.43±0.06M☉. The
precision in the masses is expected to improve with continued
observations that map the motion through a complete orbital period;
this is particularly important as the system approaches periastron
passage in 2023. Based on published properties and recent evolutionary
tracks, we estimate a mass of ∼2M☉ for T Tau N, suggesting that
T Tau N is similar in mass to T Tau Sa. Narrowband infrared photometry
shows that T Tau N remained relatively constant between late 2017 and
early 2019 with an average value of K=5.54±0.07mag. Using T Tau N
to calibrate relative flux measurements since 2015, we found that T
Tau Sa varied dramatically between 7.0 and 8.8mag in the K band over
timescales of a few months, while T Tau Sb faded steadily from 8.5 to
11.1mag in the K band. Over the 27yr orbital period of the T Tau S
binary, both components have shown 3-4mag of variability in the K
band, relative to T Tau N.
Description:
At the Keck Observatory, natural guide star Adaptive Optics (AO)
observations were obtained using the Near InfraRed Camera 2 (NIRC2)
narrow-field camera on the Keck II Telescope.
At Gemini Observatory, observations were obtained using the Altair AO
system and the Near Infra-Red Imager (NIRI) f/32 camera. Images were
recorded in the narrowband K continuum filter during every epoch and
in narrowband H continuum and L-band emission line filters (Brα
and PAH) during some epochs.
Objects:
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RA (ICRS) DE Designation(s)
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04 21 59.4323326335 +19 32 06.439974179 T Tauri = V* T Tau
04 21 59.433 +19 32 06.42 T Tau N = NAME T Tau N
04 21 59.371 +19 32 05.95 T Tau Sa = NAME T Tau Sa
04 21 59.371 +19 32 05.95 T Tau Sb = NAME T Tau Sb
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 84 153 NIR AO measurements of T Tau triple system
table2.dat 50 35 Absolute photometry, Gemini observations
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See also:
J/ApJS/165/256 : Fluorescent H2 emission from T Tauri stars (Herczeg+, 2006)
J/A+A/479/827 : UBVR light curves of weak-line T Tauri stars (Grankin+, 2008)
J/ApJ/718/1353 : Light curve of the triple system NLTT 41135 (Irwin+, 2010)
J/ApJ/744/121 : Far-UV spectroscopy of T Tau stars (Yang+, 2012)
J/MNRAS/434/966 : Measurements of Li in T-Tauri stars (Sergison+, 2013)
J/A+A/590/A78 : NGC2264 weak-line T Tauri lithium abundances (Bouvier+, 2016)
J/AJ/152/11 : Orbits of four triple stars (Tokovinin, 2016)
J/AJ/152/198 : Periods of 4-10Myr old T Tauri mem. of Orion OB1 (Karim+,2016)
J/A+A/611/A69 : B,V and R band polarimetry of lambda Tau (Berdyugin+, 2018)
J/A+A/622/A72 : Intermediate-mass T Tau stars spectra (Villebrun+, 2019)
J/AJ/159/135 : LCs of the binary T Tauri star V582 Mon (Garcia Soto+, 2020)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 4 I4 yr Obs.Y [2015/2019] UT Year of observation
5- 7 A3 "month" Obs.M UT month of observation
8- 9 I2 d Obs.d UT day of observation
12- 20 F9.4 yr JY [2015/2020] Julian Year
23- 27 A5 --- Comp Component identification (1)
30- 35 F6.2 mas Sep [65.2/692]? Separation
38- 42 F5.2 mas e_Sep [0.4/23.7]? Error in Sep
45- 51 F7.3 deg PA [6.25/358]? Position angle
53- 58 F6.3 deg e_PA [0.03/12]? Error in PA
61- 65 A5 --- Filt Filter (2)
68- 73 F6.4 --- Fratio [0.0004/2.94] Flux ratio; f2/f1
76- 81 F6.4 --- e_Fratio [0.0003/0.57] Error in Fratio
84 A1 --- Tel Code for telescope; G=Gemini North (129
occurrences), K=Keck II (24 occurrences)
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Note (1): Component designation "X,Y" indicates that component Y was measured
relative to X.
Note (2): Filters as follows:
Kcon = K continuum filter (72 occurrences)
Hcon = H continuum filter (24 occurrences)
BrA = Brα, L-band emission line filter (54 occurrences)
PAH = PAH, L-band emission line filter (3 occurrences)
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 9 F9.4 yr JY [2017/2020] Julian Year
12 A1 --- Filt Filter (5 H-, 16 K- or 14 L-band filter)
15- 18 F4.2 mag MAGN [5.02/6.44] Absolute magnitude of T Tau N
21- 24 F4.2 mag e_MAGN [0.03/1.9] Error in MagN
27- 31 F5.2 mag MAGSa [5/13] Absolute magnitude of T Tau Sa
34- 37 F4.2 mag e_MAGSa [0.08/1.9] Error in MagSa
40- 44 F5.2 mag MAGSb [8.36/13.3] Absolute magnitude of T Tau Sb
47- 50 F4.2 mag e_MAGSb [0.2/3.5] Error in MagSb
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 12-Oct-2020