J/AJ/163/247 HIRES, PEPSI & TRES radial velocities of V1298 Tau (Johnson+, 2022)
An Aligned Orbit for the Young Planet V1298 Tau b.
Johnson M.C., David T.J., Petigura E.A., Isaacson H.T., Van Zandt J.,
Ilyin I., Strassmeier K., Mallonn M., Zhou G., Mann A.W., Livingston J.H.,
Luger R., Dai F., Weiss L.M., Mocnik T., Giacalone S., Hill M.L., Rice M.,
Blunt S., Rubenzahl R., Dalba P.A., Esquerdo G.A., Berlind P., Calkins M.L.,
Foreman-Mackey D.
<Astron. J., 163, 247 (2022)>
=2022AJ....163..247J 2022AJ....163..247J
ADC_Keywords: Exoplanets; Stars, variable; Spectra, optical; Radial velocities
Keywords: Exoplanets ; Exoplanet dynamics ; High resolution spectroscopy ;
Starspots ; Pre-main sequence
Abstract:
The alignment of planetary orbits with respect to the stellar rotation
preserves information on their dynamical histories. Measuring this
angle for young planets helps illuminate the mechanisms that create
misaligned orbits for older planets, as different processes could
operate over timescales ranging from a few megayears to a gigayear. We
present spectroscopic transit observations of the young exoplanet
V1298 Tau b; we update the age of V1298 Tau to be 28±4Myr based on
Gaia EDR3 measurements. We observed a partial transit with Keck/HIRES
and LBT/PEPSI, and detected the radial velocity anomaly due to the
Rossiter-McLaughlin effect. V1298 Tau b has a prograde, well-aligned
orbit, with λ=4-10+7deg. By combining the spectroscopically
measured vsini* and the photometrically measured rotation period of
the host star we also find that the orbit is aligned in 3D,
ψ=8-7+4deg. Finally, we combine our obliquity constraints with
a previous measurement for the interior planet V1298 Tau c to
constrain the mutual inclination between the two planets to be
imut=0deg±19deg. This measurements adds to the growing number of
well-aligned planets at young ages, hinting that misalignments may be
generated over timescales of longer than tens of megayears. The number
of measurements, however, is still small, and this population may not
be representative of the older planets that have been observed to
date. We also present the derivation of the relationship between imut,
λ, and i for the two planets.
Description:
We observed a partial transit of V1298 Tau b on 2019 October 24 UT
with the 10m Keck I telescope on Maunakea, Hawaii, USA, and the High
Resolution Echelle Spectrometer (HIRES) spectrograph. We used the C2
decker, with a slit of 0.861" width and 14.0" height, yielding a
resolving power of R∼60000. The spectra span from 3646 to 7984Å,
although the velocities are derived from the 5000-6000Å region.
We observed the same transit with the Potsdam Echelle Polarimetric and
Spectroscopic Instrument (PEPSI) at the 2x8.4m Large Binocular
Telescope (LBT) on Mount Graham, Arizona, USA. We used PEPSI's
R=120000 mode and cross-dispersers III and V (covering 4800-5441Å
and 6278-7419Å).
We obtained 21 epochs of observations of V1298 Tau using the
Tillinghast Reflector Echelle Spectrograph (TRES) on the 1.5m
telescope at the Fred Lawrence Whipple Observatory (FLWO), Arizona,
USA. Nine epochs were obtained over the two weeks prior to the transit
event on 24 October 2019 UT, and 12 were obtained on the night of the
transit. TRES is a fiber-fed echelle with a spectral resolving power
of R∼44000 over the wavelength range 3850-9100Å.
Objects:
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RA (2000) DE Designation(s) (Period)
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04 05 19.59 +20 09 25.6 V1298 Tau = V* V1298 Tau (P=24d)
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 35 129 Radial velocities of V1298 Tau
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See also:
I/337 : Gaia DR1 (Gaia Collaboration, 2016)
J/ApJ/723/L223 : Radial velocities of HAT-P-11 (Winn+, 2010)
J/ApJ/757/18 : Radial velocities 16 hot Jupiter host stars (Albrecht+, 2012)
J/other/Nat/486.375 : Stellar parameters of KOI stars (Buchhave+, 2012)
J/MNRAS/474/2094 : Inferring proba. stellar rotation periods (Angus+, 2018)
J/AJ/156/271 : The stellar membership of the Taurus SFR (Luhman, 2018)
J/AJ/159/19 : SOAR TESS survey. I. (Ziegler+, 2020)
J/AJ/162/137 : Minerva-Australis radial velocity of AU Mic (Addison+, 2021)
J/AJ/162/292 : Radial velocity & transit photometry TOI-1431 (Addison+, 2021)
J/A+A/650/A66 : DS Tuc A radial velocity curve (Benatti+, 2021)
J/AJ/162/110 : Gaia EDR3 census of Taurus-Auriga complex (Krolikowski+, 2021)
J/AJ/161/119 : The TESS-Keck survey. IV. Rvel for WASP-107 (Rubenzahl+, 2021)
J/AJ/161/171 : THYME. V. Discovering stellar association (Tofflemire+, 2021)
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 14 F14.6 d BJD [2458765/2458798] Barycentric Julian Date at TDB
16- 21 F6.1 m/s RVel [-479/290] Barycentric-corrected radial velocity
23- 27 F5.1 m/s e_RVel [5/148] Uncertainty in RVel
29- 35 A7 --- Instr Instrument used (1)
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Note (1): Instruments as follows:
HIRES = HIRES spectrograph on 10m Keck 1, including 52 spectra calibrated
with I2 cell and 8 additional spectra acquired within 20 days of
the transit night.
PEPSI B = Potsdam Echelle Polarimetric and Spectroscopic Instrument on
the 2x8.4m Large Binocular Telescope, blue arm.
PEPSI R = Potsdam Echelle Polarimetric and Spectroscopic Instrument on
the 2x8.4m Large Binocular Telescope, red arm.
TRES = Tillinghast Reflector Echelle Spectrograph, FLWO 1.5m telescope.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 21-Sep-2022