J/AJ/163/40 KELT-9 radial velocity with LBT/PEPSI (Pai Asnodkar+, 2022)
KELT-9 as an Eclipsing Double-lined Spectroscopic Binary: A Unique and Self-
consistent Solution to the System.
Pai Asnodkar A., Wang Ji, Gaudi B.S., Cauley P.W., Eastman J.D., Ilyin I.,
Strassmeier K., Beatty T.
<Astron. J., 163, 40 (2022)>
=2022AJ....163...40P 2022AJ....163...40P
ADC_Keywords: Exoplanets; Stars, double and multiple; Spectra, optical;
Spectra, infrared; Radial velocities
Keywords: Exoplanet astronomy ; Exoplanet atmospheres ; Exoplanets
Abstract:
Transiting hot Jupiters present a unique opportunity to measure
absolute planetary masses due to the magnitude of their radial
velocity signals and known orbital inclination. Measuring planet mass
is critical to understanding atmospheric dynamics and escape under
extreme stellar irradiation. Here we present the ultrahot Jupiter
system KELT-9 as a double-lined spectroscopic binary. This allows us
to directly and empirically constrain the mass of the star and its
planetary companion without reference to any theoretical stellar
evolutionary models or empirical stellar scaling relations. Using data
from the PEPSI, HARPS-N, and TRES spectrographs across multiple
epochs, we apply least-squares deconvolution to measure out-of-transit
stellar radial velocities. With the PEPSI and HARPS-N data sets, we
measure in-transit planet radial velocities using transmission
spectroscopy. By fitting the circular orbital solution that captures
these Keplerian motions, we recover a planetary dynamical mass of
2.17±0.5MJ and stellar dynamical mass of 2.11±0.78M☉,
both of which agree with the discovery paper. Furthermore, we argue
that this system, as well as systems like it, are highly
overconstrained, providing multiple independent avenues for
empirically cross-validating model-independent solutions to the system
parameters. We also discuss the implications of this revised mass for
studies of atmospheric escape.
Description:
We observed two transits of KELT-9 b with the high-resolution echelle
spectrograph Polarimetric and Spectroscopic Instrument (PEPSI) on the
Large Binocular Telescope (LBT) (two 8.4m mirrors, effective aperture
of 11.8m) in Arizona. PEPSI has a blue arm (nominally 3830-5440Å)
and a red arm (nominally 5440-9070Å) with six cross-dispersers for
full optical coverage. In this work, we use high-resolution data from
the blue arm taken with cross-disperser 3 (∼4750-5430Å, R=50000)
exclusively because of negligible telluric contamination.
In this work, we apply the classical techniques used to analyze SB2s
to the KELT-9 system using observations from PEPSI spectrograph on LBT
and the HARPS-N spectrograph on the Telescopio Nazionale Galileo
(TNG). We utilize the original Tillinghast Reflector Echelle
Spectrograph (TRES) data (Gaudi+, 2017Natur.546..514G 2017Natur.546..514G) as well as
additional velocities from higher-precision spectrographs.
Objects:
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RA (2000) DE Designation(s) (Period)
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20 31 26.35 +39 56 19.8 KELT-9 = HD 195689 (P=1.48111890d)
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
fig1.dat 41 242 Stellar radial velocity curve of the KELT-9 system
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See also:
I/337 : Gaia DR1 (Gaia Collaboration, 2016)
J/other/A+ARV/18.67 : Accurate masses and radii of normal stars (Torres+, 2010)
J/A+A/600/A30 : Limb-darkening for TESS satellite (Claret, 2017)
J/A+A/627/A165 : KELT-9 b atmos. model transm. spectra (Hoeijmakers+, 2019)
J/A+A/631/A34 : KELT-9b radial velocity curve (Borsa+ 2019)
Byte-by-byte Description of file: fig1.dat
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Bytes Format Units Label Explanations
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1- 8 F8.5 --- Phase [-0.46/0.49] Planet's orbital phase (mid-transit=0)
10- 16 F7.3 km/s RVel [-21.9/-15.1] Stellar radial velocity
18- 22 F5.3 km/s e_RVel [0.2/3] Lower uncertainty on stellar RVel
24- 28 F5.3 km/s E_RVel [0.1/2] Upper uncertainty on stellar RVel
30- 41 A12 --- Set Dataset associated with measurement
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 05-Apr-2022