A comprehensive study of the WASP-74 planetary system

2020 ◽  
Author(s):  
Rafael Luque ◽  
Keyword(s):  
High Resolution ◽  
Transmission Spectrum ◽  
Rayleigh Scattering ◽  
Near Infrared ◽  
Planetary System ◽  
Spin Axis ◽  
Physical Parameters ◽  
First Time ◽  
Orbital Axis ◽  
Comprehensive Study

<p>In this work, we present new transit observations of the hot Jupiter WASP-74 b using the high-resolution spectrograph HARPS-N and the multi-color simultaneous imager MuSCAT2. The new data allow us to refine the orbital properties of the planet, the physical parameters of the host star, and reveal some properties about the planet's atmosphere using different techniques. We measure, for the first time, the sky-projected angle between the stellar spin-axis and the planet’s orbital axis, which is compatible with an orbit well-aligned with the equator of the host star. We build up an observational low-resolution transmission spectrum from the optical to the near-infrared of the planet using all the available transit photometry for this planet. Our joint reanalysis shows a slope in the transmission spectrum steeper than expected from Rayleigh scattering alone and no signs of strong optical absorbers such as TiO and/or VO, in disagreement with previous claims of the presence of these gases in the atmosphere of WASP-74 b.</p>

scholarly journals Obliquity measurement and atmospheric characterisation of the WASP-74 planetary system

2020 ◽  
Vol 642 ◽  
pp. A50 ◽  
Author(s):  
R. Luque ◽  
N. Casasayas-Barris ◽  
H. Parviainen ◽  
G. Chen ◽  
E. Pallé ◽  
...  
Keyword(s):  
High Resolution ◽  
Transmission Spectrum ◽  
Rayleigh Scattering ◽  
Planetary System ◽  
Spin Axis ◽  
Absorption Feature ◽  
Spectral Features ◽  
Transmission Spectra ◽  
First Time ◽  
Orbital Axis

We present new transit observations of the hot Jupiter WASP-74 b (Teq ~ 1860 K) using the high-resolution spectrograph HARPS-N and the multi-colour simultaneous imager MuSCAT2. We refined the orbital properties of the planet and its host star and measured its obliquity for the first time. The measured sky-projected angle between the stellar spin-axis and the orbital axis of the planet is compatible with an orbit that is well-aligned with the equator of the host star (λ = 0.77 ± 0.99 deg). We are not able to detect any absorption feature of Hα or any other atomic spectral features in the high-resolution transmission spectra of this source owing to low S/N at the line cores. Despite previous claims regarding the presence of strong optical absorbers such as TiO and VO gases in the atmosphere of WASP-74 b, new ground-based photometry combined with a reanalysis of previously reported observations from the literature show a slope in the low-resolution transmission spectrum that is steeper than expected from Rayleigh scattering alone.

scholarly journals Twisted Jets from L1551 IRS5

2001 ◽  
Vol 200 ◽  
pp. 261-264
Author(s):  
Yoichi Itoh
Keyword(s):  
Infrared Spectroscopy ◽  
High Resolution ◽  
Spatial Variation ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Infrared Imaging ◽  
Close Vicinity ◽  
Jet Structure ◽  
First Time ◽  
Bright Emission

We have carried out high-resolution near-infrared imaging observations of a protostar L1551 IRS 5 with the Subaru Telescope. The jet structure of IRS5 is resolved into two independent jets for the first time from the ground. Successive near-infrared spectroscopy has revealed that the jet emission is dominated by [Fe II] lines in the J and H-bands. While the visual-extinction reaches more than 20 mag in the close vicinity of IRS 5, it decreases rapidly at ∼1″ from IRS 5 and remains constant around 7 mag at larger distances. The twisted structure and bright emission knots are intrinsic to the jets, not due to a spatial variation of the extinction.

scholarly journals Orbital misalignment of the super-Earth π Men c with the spin of its star

2021 ◽  
Vol 502 (2) ◽  
pp. 2893-2911 ◽  
Author(s):  
Vedad Kunovac Hodžić ◽  
Amaury H M J Triaud ◽  
Heather M Cegla ◽  
William J Chaplin ◽  
Guy R Davies
Keyword(s):  
Time Series ◽  
High Resolution ◽  
Radial Velocity ◽  
Gaussian Processes ◽  
Giant Planet ◽  
Spin Axis ◽  
Physical Parameters ◽  
Eccentric Orbit ◽  
High Eccentricity ◽  
Migration History

ABSTRACT Planet–planet scattering events can leave an observable trace of a planet’s migration history in the form of orbital misalignment with respect to the stellar spin axis, which is measurable from spectroscopic time-series taken during transit. We present high-resolution spectroscopic transits observed with ESPRESSO of the close-in super-Earth π Men c. The system also contains an outer giant planet on a wide, eccentric orbit, recently found to be inclined with respect to the inner planetary orbit. These characteristics are reminiscent of past dynamical interactions. We successfully retrieve the planet-occulted light during transit, and find evidence that the orbit of π Men c is moderately misaligned with the stellar spin axis with λ = − 24${_{.}^{\circ}}$0 ± 4${_{.}^{\circ}}$1 ($\psi = {26{_{.}^{\circ}} 9}^{+5{_{.}^{\circ}}8 }_{-4{_{.}^{\circ}}7 }$). This is consistent with the super-Earth π Men c having followed a high-eccentricity migration followed by tidal circularization, and hints that super-Earths can form at large distances from their star. We also detect clear signatures of solar-like oscillations within our ESPRESSO radial velocity time series, where we reach a radial velocity precision of ∼20 cm s−1. We model the oscillations using Gaussian processes (GPs) and retrieve a frequency of maximum oscillation, $\nu _\mathrm{max}{} = 2771^{+65}_{-60}\, \mu \mathrm{Hz}$. These oscillations make it challenging to detect the Rossiter–McLaughlin effect using traditional methods. We are, however, successful using the reloaded Rossiter–McLaughlin approach. Finally, in the appendix, we also present physical parameters and ephemerides for π Men c from a GP transit analysis of the full Transiting Exoplanet Survey Satellite Cycle 1 data.

scholarly journals A study of AGB stars in LMC clusters

2008 ◽  
Vol 4 (S256) ◽  
pp. 397-402
Author(s):  
Thomas Lebzelter ◽  
Michael T. Lederer ◽  
Sergio Cristallo ◽  
Oscar Straniero ◽  
Kenneth H. Hinkle
Keyword(s):  
High Resolution ◽  
Stellar Evolution ◽  
Near Infrared ◽  
Mass Range ◽  
Asymptotic Giant Branch ◽  
Agb Stars ◽  
Near Infrared Spectra ◽  
Model Predictions ◽  
First Time ◽  
Late Stages

AbstractLMC clusters offer an outstanding opportunity to investigate the late stages of stellar evolution of stars in the mass range between 1.5 and 2 M⊙. In this presentation we will focus on our results on mixing events during the evolution along the Asymptotic Giant Branch (AGB). Surface abundances have been determined for a number of cluster AGB stars from high resolution near infrared spectra. We show for the first time the evolution of C/O and 12C/13C ratios along a cluster AGB. The change of both quantities due to dredge up events is compared with model predictions. Our results indicate the late occurrence of a moderate extra-mixing in some cases.

scholarly journals Physical parameters of T dwarfs derived from high-resolution near-infrared spectra

2009 ◽  
Vol 501 (3) ◽  
pp. 1059-1071 ◽  
Author(s):  
C. del Burgo ◽  
E. L. Martín ◽  
M. R. Zapatero Osorio ◽  
P. H. Hauschildt
Keyword(s):  
High Resolution ◽  
Infrared Spectra ◽  
Near Infrared ◽  
Physical Parameters ◽  
Near Infrared Spectra

scholarly journals Feasibility of Cloud Screening Using Proxy Photon Pathlength Distributions Derived from High-Resolution Spectra in the Near Infrared

2010 ◽  
Vol 27 (1) ◽  
pp. 135-146 ◽  
Author(s):  
D. M. O’Brien ◽  
Igor Polonsky ◽  
Philip Stephens ◽  
Thomas E. Taylor
Keyword(s):  
High Resolution ◽  
Rayleigh Scattering ◽  
Near Infrared ◽  
Distribution Functions ◽  
High Resolution Spectrum ◽  
Direct Path ◽  
Clear Sky ◽  
Moderate Resolution ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
Clear Cases

Abstract High-resolution spectra of reflected sunlight in the 2-μm absorption band of CO2 are simulated at the top of the atmosphere using cloud profiles and particle sizes from CloudSat analyzed meteorology from ECMWF, surface bidirectional distribution functions over land derived from the Moderate Resolution Imaging Spectroradiometer (MODIS), and a facet model of ocean reflectance. It is argued that in clear sky the photons will follow the direct path from sun to surface to satellite, because Rayleigh scattering is negligible at 2 μm, so the distribution of photon pathlengths will be a δ function. A proxy for the photon pathlength distribution under any sky condition is recovered from the high-resolution spectrum by representing the distribution as a weighted sum of δ functions. Scenes are classified as clear or cloudy according to how closely the distribution approximates the ideal single δ function for the direct path. The algorithm has an efficiency of approximately 75%, meaning that 25% of the clear cases will be rejected as cloudy. For scenes that pass the clear-sky test, the probability that the prediction will be correct is typically 95%. The algorithm appears to be robust, insensitive to instrument noise and to errors in the surface pressure and profiles of temperature and water vapor. The efficiency and confidence level of the algorithm are almost unchanged for bright surfaces such as sun glint.

scholarly journals Physical parameters of a sample of M dwarfs from high-resolution near-infrared spectra

2011 ◽  
Vol 16 ◽  
pp. 04006 ◽  
Author(s):  
C. del Burgo ◽  
R. Deshpande ◽  
E.L. Martín ◽  
M.R. Zapatero Osorio ◽  
S. Witte ◽  
...  
Keyword(s):  
High Resolution ◽  
Infrared Spectra ◽  
Near Infrared ◽  
Physical Parameters ◽  
M Dwarfs ◽  
Near Infrared Spectra

scholarly journals HST/STIS transmission spectrum of the ultra-hot Jupiter WASP-76 b confirms the presence of sodium in its atmosphere

2020 ◽  
Vol 637 ◽  
pp. A76 ◽  
Author(s):  
C. von Essen ◽  
M. Mallonn ◽  
S. Hermansen ◽  
M. C. Nixon ◽  
N. Madhusudhan ◽  
...  
Keyword(s):  
High Resolution ◽  
Transmission Spectrum ◽  
Rayleigh Scattering ◽  
Equilibrium Temperature ◽  
Atmospheric Transmission ◽  
Space Telescope ◽  
Atomic Sodium ◽  
The One ◽  
Imaging Spectrograph ◽  
Hot Jupiter

We present an atmospheric transmission spectrum of the ultra-hot Jupiter WASP-76 b by analyzing archival data obtained with the Space Telescope Imaging Spectrograph (STIS) on board the Hubble Space Telescope (HST). The dataset spans three transits, two with a wavelength coverage between 2900 and 5700 Å, and the third one between 5250 and 10 300 Å. From the one-dimensional, time dependent spectra we constructed white and chromatic light curves, the latter with typical integration band widths of ~200 Å. We computed the wavelength dependent planet-to-star radii ratios taking into consideration WASP-76’s companion. The resulting transmission spectrum of WASP-76 b is dominated by a spectral slope of increasing opacity towards shorter wavelengths of amplitude of about three scale heights under the assumption of planetary equilibrium temperature. If the slope is caused by Rayleigh scattering, we derive a lower limit to the temperature of ~870 K. Following-up on previous detection of atomic sodium derived from high resolution spectra, we re-analyzed HST data using narrower bands centered around sodium. From an atmospheric retrieval of this transmission spectrum, we report evidence of sodium at 2.9σ significance. In this case, the retrieved temperature at the top of the atmosphere (10−5 bar) is 2300−392+412 K. We also find marginal evidence for titanium hydride. However, additional high resolution ground-based data are required to confirm this discovery.

Ground state molecular parameters of phosphine, PH3, from the simultaneous analysis of the high-resolution infrared, microwave and submillimeterwave spectra

1985 ◽  
Vol 50 (11) ◽  
pp. 2480-2492 ◽  
Author(s):  
Soňa Přádná ◽  
Dušan Papoušek ◽  
Jyrki Kauppinen ◽  
Sergei P. Belov ◽  
Andrei F. Krupnov ◽  
...  
Keyword(s):  
Fourier Transform ◽  
High Resolution ◽  
Ground State ◽  
Unitary Transformation ◽  
Point Of View ◽  
Acoustic Detection ◽  
Molecular Parameters ◽  
Microwave Spectrometer ◽  
Fourier Transform Spectra ◽  
First Time

Fourier transform spectra of the ν2 band of PH3 have been remeasured with 0.0045 cm-1 resolution. Ground state combination differences from these data have been fitted simultaneously with the microwave and submillimeterwave data to determine the ground state spectroscopical parameters of PH3 including the parameters of the Δk = ± 3n interactions. The correlation between the latter parameters has been discussed from the point of view of the existence of two equivalent effective rotational operators which are related by a unitary transformation. The ΔJ = 0, +1, ΔK = 0 (A1 ↔ A2, E ↔ E) rotational transitions in the ν2 and ν4 states have been measured for the first time by using a microwave spectrometer and a radiofrequency spectrometer with acoustic detection.

scholarly journals Molecules in the Magellanic Clouds

1991 ◽  
Vol 148 ◽  
pp. 415-420 ◽  
Author(s):  
R. S. Booth ◽  
Th. De Graauw
Keyword(s):  
High Resolution ◽  
Molecular Clouds ◽  
Short Review ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Magellanic Clouds ◽  
Giant Molecular Clouds ◽  
Interstellar Molecules ◽  
First Time ◽  
Excitation Conditions

In this short review we describe recent new observations of millimetre transitions of molecules in selected regions of the Magellanic Clouds. The observations were made using the Swedish-ESO Submillimetre Telescope, SEST, (Booth et al. 1989), the relatively high resolution of which facilitates, for the first time, observations of individual giant molecular clouds in the Magellanic Clouds. We have mapped the distribution of the emission from the two lowest rotational transitions of 12CO and 13CO and hence have derived excitation conditions for the molecule. In addition, we have observed several well-known interstellar molecules in the same regions, thus doubling the number of known molecules in the Large Magellanic Cloud (LMC). The fact that all the observations have been made under controlled conditions with the same telescope enables a reasonable intercomparison of the molecular column densities. In particular, we are able to observe the relative abundances among the different isotopically substituted species of CO.

Sign in / Sign up

Export Citation Format

Share Document