Quantifying the Observational Effort Required for the Radial Velocity Characterization of TESS Planets

ABSTRACT We calculate the conversion from non-adiabatic, non-radial oscillations tidally induced by a hot Jupiter on a star to observable spectroscopic and photometric signals. Models with both frozen convection and an approximation for a perturbation to the convective flux are discussed. Observables are calculated for some real planetary systems to give specific predictions. The photometric signal is predicted to be proportional to the inverse square of the orbital period, P−2, as in the equilibrium tide approximation. However, the radial velocity signal is predicted to be proportional to P−1, and is therefore much larger at long orbital periods than the signal corresponding to the equilibrium tide approximation, which is proportional to P−3. The prospects for detecting these oscillations and the implications for the detection and characterization of planets are discussed.

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Densified Pupil Spectrograph as High-precision Radial Velocimetry: From Direct Measurement of the Universe’s Expansion History to Characterization of Nearby Habitable Planet Candidates

The Astronomical Journal ◽

10.3847/1538-3881/ac397b ◽

2022 ◽

Vol 163 (2) ◽

pp. 63

Author(s):

Taro Matsuo ◽

Thomas P. Greene ◽

Mahdi Qezlou ◽

Simeon Bird ◽

Kiyotomo Ichiki ◽

...

Keyword(s):

Radial Velocity ◽

Direct Measurement ◽

High Precision ◽

Resolving Power ◽

Line Of Sight ◽

High Dispersion ◽

Velocity Measurements ◽

Habitable Planet ◽

Airy Disk

Abstract The direct measurement of the universe’s expansion history and the search for terrestrial planets in habitable zones around solar-type stars require extremely high-precision radial-velocity measures over a decade. This study proposes an approach for enabling high-precision radial-velocity measurements from space. The concept presents a combination of a high-dispersion densified pupil spectrograph and a novel line-of-sight monitor for telescopes. The precision of the radial-velocity measurements is determined by combining the spectrophotometric accuracy and the quality of the absorption lines in the recorded spectrum. Therefore, a highly dispersive densified pupil spectrograph proposed to perform stable spectroscopy can be utilized for high-precision radial-velocity measures. A concept involving the telescope’s line-of-sight monitor is developed to minimize the change of the telescope’s line of sight over a decade. This monitor allows the precise measurement of long-term telescope drift without any significant impact on the Airy disk when the densified pupil spectra are recorded. We analytically derive the uncertainty of the radial-velocity measurements, which is caused by the residual offset of the lines of sight at two epochs. We find that the error could be reduced down to approximately 1 cm s−1, and the precision will be limited by another factor (e.g., wavelength calibration uncertainty). A combination of the high-precision spectrophotometry and the high spectral resolving power could open a new path toward the characterization of nearby non-transiting habitable planet candidates orbiting late-type stars. We present two simple and compact highly dispersed densified pupil spectrograph designs for cosmology and exoplanet sciences.

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An ultra-short period rocky super-Earth orbiting the G2-star HD 80653

Astronomy and Astrophysics ◽

10.1051/0004-6361/201936689 ◽

2020 ◽

Vol 633 ◽

pp. A133 ◽

Cited By ~ 2

Author(s):

G. Frustagli ◽

E. Poretti ◽

T. Milbourne ◽

L. Malavolta ◽

A. Mortier ◽

...

Keyword(s):

Radial Velocity ◽

Thermal Emission ◽

Earth Planet ◽

Period Orbit ◽

Short Period ◽

Orbital Phase ◽

Solar Type ◽

Radial Velocity Data

Ultra-short period (USP) planets are a class of exoplanets with periods shorter than one day. The origin of this sub-population of planets is still unclear, with different formation scenarios highly dependent on the composition of the USP planets. A better understanding of this class of exoplanets will, therefore, require an increase in the sample of such planets that have accurate and precise masses and radii, which also includes estimates of the level of irradiation and information about possible companions. Here we report a detailed characterization of a USP planet around the solar-type star HD 80653 ≡EP 251279430 using the K2 light curve and 108 precise radial velocities obtained with the HARPS-N spectrograph, installed on the Telescopio Nazionale Galileo. From the K2 C16 data, we found one super-Earth planet (Rb = 1.613 ± 0.071 R⊕) transiting the star on a short-period orbit (Pb = 0.719573 ± 0.000021 d). From our radial velocity measurements, we constrained the mass of HD 80653 b to Mb = 5.60 ± 0.43 M⊕. We also detected a clear long-term trend in the radial velocity data. We derived the fundamental stellar parameters and determined a radius of R⋆ = 1.22 ± 0.01 R⊙ and mass of M⋆ = 1.18 ± 0.04 M⊙, suggesting that HD 80653 has an age of 2.7 ± 1.2 Gyr. The bulk density (ρb = 7.4 ± 1.1 g cm−3) of the planet is consistent with an Earth-like composition of rock and iron with no thick atmosphere. Our analysis of the K2 photometry also suggests hints of a shallow secondary eclipse with a depth of 8.1 ± 3.7 ppm. Flux variations along the orbital phase are consistent with zero. The most important contribution might come from the day-side thermal emission from the surface of the planet at T ~ 3480 K.

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Following the TraCS of exoplanets with Pan-Planets: Wendelstein-1b and Wendelstein-2b

Astronomy and Astrophysics ◽

10.1051/0004-6361/202037715 ◽

2020 ◽

Vol 639 ◽

pp. A130

Author(s):

C. Obermeier ◽

J. Steuer ◽

H. Kellermann ◽

R. P. Saglia ◽

Th. Henning ◽

...

Keyword(s):

Surface Temperature ◽

Radial Velocity ◽

Thermal Emission ◽

Dwarf Star ◽

Statistical Characterization ◽

Hot Jupiters ◽

Eclipse Observations ◽

Short Period ◽

Hot Jupiter

Hot Jupiters seem to get rarer with decreasing stellar mass. The goal of the Pan-Planets transit survey was the detection of such planets and a statistical characterization of their frequency. Here, we announce the discovery and validation of two planets found in that survey, Wendelstein-1b and Wendelstein-2b, which are two short-period hot Jupiters that orbit late K host stars. We validated them both by the traditional method of radial velocity measurements with the HIgh Resolution Echelle Spectrometer and the Habitable-zone Planet Finder instruments and then by their Transit Color Signature (TraCS). We observed the targets in the wavelength range of 4000−24 000 Å and performed a simultaneous multiband transit fit and additionally determined their thermal emission via secondary eclipse observations. Wendelstein-1b is a hot Jupiter with a radius of 1.0314−0.0061+0.0061 RJ and mass of 0.592−0.129+0.0165 MJ, orbiting a K7V dwarf star at a period of 2.66 d, and has an estimated surface temperature of about 1727−90+78 K. Wendelstein-2b is a hot Jupiter with a radius of 1.1592−0.0210+0.0204 RJ and a mass of 0.731−0.311+0.0541 MJ, orbiting a K6V dwarf star at a period of 1.75 d, and has an estimated surface temperature of about 1852−140+120 K. With this, we demonstrate that multiband photometry is an effective way of validating transiting exoplanets, in particular for fainter targets since radial velocity follow-up becomes more and more costly for those targets.

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Quality characterization of reflectivity and radial velocity observed by Indian Doppler weather radars

Journal of Applied Remote Sensing ◽

10.1117/1.jrs.11.036026 ◽

2017 ◽

Vol 11 (03) ◽

pp. 1 ◽

Cited By ~ 1

Keyword(s):

Radial Velocity ◽

Weather Radars

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Radial velocity follow-up for confirmation and characterization of transiting exoplanets

Proceedings of the International Astronomical Union ◽

10.1017/s174392130802632x ◽

2008 ◽

Vol 4 (S253) ◽

pp. 129-139 ◽

Cited By ~ 11

Author(s):

François Bouchy ◽

Claire Moutou ◽

Didier Queloz ◽

Keyword(s):

High Resolution ◽

Radial Velocity ◽

Space Mission ◽

High Resolution Spectroscopy

AbstractRadial Velocity follow-up is essential to establish or exclude the planetary nature of a transiting companion as well as to accurately determine its mass. Here we present some elements of an efficient Doppler follow-up strategy, based on high-resolution spectroscopy, devoted to the characterization of transiting candidates. Some aspects and results of the radial velocity follow-up of the CoRoT space mission are presented in order to illustrate the strategy used to deal with the zoo of transiting candidates.

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Kinematics and stellar populations of the double-barred early-type galaxy NGC357

Proceedings of the International Astronomical Union ◽

10.1017/s1743921308017493 ◽

2007 ◽

Vol 3 (S245) ◽

pp. 137-138

Author(s):

Adriana de Lorenzo-Cáceres ◽

Alexandre Vazdekis ◽

J. Alfonso L. Aguerri

Keyword(s):

Radial Velocity ◽

Stellar Population ◽

Velocity Dispersion ◽

Population Analysis ◽

Stellar Populations ◽

Abundance Ratio ◽

Complete Characterization ◽

Early Type ◽

Early Type Galaxy

AbstractWe have carried out a kinematical and stellar population analysis of the double-barred galaxy NGC357 to provide a more complete characterization of these systems and their role in the formation of galaxy bulges. We clearly identify the presence of the inner bar in the radial velocity and velocity dispersion profiles. The age, metallicity and [Mg/Fe] abundance ratio estimates are very similar to those of ellipticals of equivalent central σ. The [Mg/Fe] value for the bulge of this galaxy suggests formation timescales shorter than 1Gyr.

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Catalog for the ESPRESSO blind radial velocity exoplanet survey

Astronomy and Astrophysics ◽

10.1051/0004-6361/201834729 ◽

2019 ◽

Vol 629 ◽

pp. A80 ◽

Cited By ~ 4

Author(s):

S. Hojjatpanah ◽

P. Figueira ◽

N. C. Santos ◽

V. Adibekyan ◽

S. G. Sousa ◽

...

Keyword(s):

Radial Velocity ◽

Rotational Velocity ◽

Spectroscopic Characterization ◽

Solar Neighborhood ◽

Activity Level ◽

Contamination Level ◽

Echelle Spectrograph ◽

Chemical Abundances ◽

Blind Search

Aims. One of the main scientific drivers for ESPRESSO, Échelle SPectrograph, is the detection and characterization of Earth-class exoplanets. With this goal in mind, the ESPRESSO guaranteed time observations (GTO) Catalog identifies the best target stars for a blind search for the radial velocity (RV) signals caused by Earth-class exoplanets. Methods. Using the most complete stellar catalogs available, we screened for the most suitable G, K, and M dwarf stars for the detection of Earth-class exoplanets with ESPRESSO. For most of the stars, we then gathered high-resolution spectra from new observations or from archival data. We used these spectra to spectroscopically investigate the existence of any stellar binaries, both bound or background stars. We derived the activity level using chromospheric activity indexes using log (R′HK), as well as the projected rotational velocity v sin i. For the cases where planet companions are already known, we also looked at the possibility that additional planets may exist in the host’s habitable zone using dynamical arguments. Results. We estimated the spectroscopic contamination level, v sin i, activity, stellar parameters and chemical abundances for 249 of the most promising targets. Using these data, we selected 45 stars that match our criteria for detectability of a planet like Earth. The stars presented and discussed in this paper constitute the ESPRESSO GTO catalog for the RV blind search for Earth-class planets. They can also be used for any other work requiring a detailed spectroscopic characterization of stars in the solar neighborhood.

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