scholarly journals Detection of neutral atomic species in the ultra-hot Jupiter WASP-121b

2020 ◽  
Vol 494 (1) ◽  
pp. 363-377 ◽  
Author(s):  
Samuel H C Cabot ◽  
Nikku Madhusudhan ◽  
Luis Welbanks ◽  
Anjali Piette ◽  
Siddharth Gandhi
Keyword(s):  
High Resolution ◽  
Transmission Spectrum ◽  
Cross Correlation ◽  
Hydrogen Atmosphere ◽  
Chemical Processes ◽  
Thermal Inversion ◽  
Hot Jupiters ◽  
Roche Limit ◽  
Careful Treatment ◽  
Host Stars

ABSTRACT The class of ultra-hot Jupiters comprises giant exoplanets undergoing intense irradiation from their host stars. They have proved to be a particularly interesting population for their orbital and atmospheric properties. One such planet, WASP-121b, is in a highly misaligned orbit close to its Roche limit, and its atmosphere exhibits a thermal inversion. These properties make WASP-121b an interesting target for additional atmospheric characterization. In this paper, we present analyses of archival high-resolution optical spectra obtained during transits of WASP-121b. We model the Rossiter-McLaughlin effect and the Centre-to-Limb Variation and find that they do not significantly affect the transmission spectrum in this case. However, we discuss scenarios where these effects warrant more careful treatment by modelling the WASP-121 system and varying its properties. We report a new detection of atmospheric absorption from H α in the planet with a transit depth of $1.87\pm 0.11{{\ \rm per\ cent}}$. We further confirm a previous detection of the Na i doublet, and report a new detection of Fe i via cross-correlation with a model template. We attribute the H α absorption to an extended Hydrogen atmosphere, potentially undergoing escape, and the Fe i to equilibrium chemistry at the planetary photosphere. These detections help to constrain the composition and chemical processes in the atmosphere of WASP-121b.

scholarly journals Molecular cross-sections for high-resolution spectroscopy of super-Earths, warm Neptunes, and hot Jupiters

2020 ◽  
Vol 495 (1) ◽  
pp. 224-237 ◽  
Author(s):  
Siddharth Gandhi ◽  
Matteo Brogi ◽  
Sergei N Yurchenko ◽  
Jonathan Tennyson ◽  
Phillip A Coles ◽  
...  
Keyword(s):  
High Resolution ◽  
Cross Sections ◽  
Cross Correlation ◽  
High Resolution Spectroscopy ◽  
High Signal ◽  
Pressure Broadening ◽  
Spectral Signatures ◽  
Hot Jupiters ◽  
Wide Range ◽  
Infrared Spectral

ABSTRACT High-resolution spectroscopy (HRS) has been used to detect a number of species in the atmospheres of hot Jupiters. Key to such detections is accurately and precisely modelled spectra for cross-correlation against the R ≳ 20 000 observations. There is a need for the latest generation of opacities which form the basis for high signal-to-noise detections using such spectra. In this study we present and make publicly available cross-sections for six molecular species, H2O, CO, HCN, CH4, NH3, and CO2 using the latest line lists most suitable for low- and high-resolution spectroscopy. We focus on the infrared (0.95–5 μm) and between 500 and 1500 K where these species have strong spectral signatures. We generate these cross-sections on a grid of pressures and temperatures typical for the photospheres of super-Earth, warm Neptunes, and hot Jupiters using the latest H2 and He pressure broadening. We highlight the most prominent infrared spectral features by modelling three representative exoplanets, GJ 1214 b, GJ 3470 b, and HD 189733 b, which encompass a wide range in temperature, mass, and radii. In addition, we verify the line lists for H2O, CO, and HCN with previous high-resolution observations of hot Jupiters. However, we are unable to detect CH4 with our new cross-sections from HRS observations of HD 102195 b. These high-accuracy opacities are critical for atmospheric detections with HRS and will be continually updated as new data become available.

scholarly journals Atmospheric Rossiter–McLaughlin effect and transmission spectroscopy of WASP-121b with ESPRESSO

2020 ◽  
Vol 645 ◽  
pp. A24 ◽  
Author(s):  
F. Borsa ◽  
R. Allart ◽  
N. Casasayas-Barris ◽  
H. Tabernero ◽  
M. R. Zapatero Osorio ◽  
...  
Keyword(s):  
Transmission Spectrum ◽  
Cross Correlation ◽  
Correlation Technique ◽  
Radial Velocity Curve ◽  
Hot Jupiters ◽  
Exoplanetary Atmospheres ◽  
Vertical Winds ◽  
Cross Correlation Technique ◽  
In Transit ◽  
Very High

Context. Ultra-hot Jupiters are excellent laboratories for the study of exoplanetary atmospheres. WASP-121b is one of the most studied; many recent analyses of its atmosphere report interesting features at different wavelength ranges. Aims. In this paper we analyze one transit of WASP-121b acquired with the high-resolution spectrograph ESPRESSO at VLT in one-telescope mode, and one partial transit taken during the commissioning of the instrument in four-telescope mode. Methods. We take advantage of the very high S/N data and of the extreme stability of the spectrograph to investigate the anomalous in-transit radial velocity curve and study the transmission spectrum of the planet. We pay particular attention to the removal of instrumental effects, and stellar and telluric contamination. The transmission spectrum is investigated through single-line absorption and cross-correlation with theoretical model templates. Results. By analyzing the in-transit radial velocities we were able to infer the presence of the atmospheric Rossiter–McLaughlin effect. We measured the height of the planetary atmospheric layer that correlates with the stellar mask (mainly Fe) to be 1.052 ± 0.015 Rp and we also confirmed the blueshift of the planetary atmosphere. By examining the planetary absorption signal on the stellar cross-correlation functions we confirmed the presence of a temporal variation of its blueshift during transit, which could be investigated spectrum-by-spectrum thanks to the quality of our ESPRESSO data. We detected significant absorption in the transmission spectrum for Na, H, K, Li, Ca II, and Mg, and we certified their planetary nature by using the 2D tomographic technique. Particularly remarkable is the detection of Li, with a line contrast of ~0.2% detected at the 6σ level. With the cross-correlation technique we confirmed the presence of Fe I, Fe II, Cr I, and V I. Hα and Ca II are present up to very high altitudes in the atmosphere (~1.44 Rp and ~2 Rp, respectively), and also extend beyond the transit-equivalent Roche lobe radius of the planet. These layers of the atmosphere have a large line broadening that is not compatible with being caused by the tidally locked rotation of the planet alone, and could arise from vertical winds or high-altitude jets in the evaporating atmosphere.

scholarly journals High-resolution transmission spectroscopy of MASCARA-2 b with EXPRES

2020 ◽  
Vol 641 ◽  
pp. A120 ◽  
Author(s):  
H. Jens Hoeijmakers ◽  
Samuel H. C. Cabot ◽  
Lily Zhao ◽  
Lars A. Buchhave ◽  
René Tronsgaard ◽  
...  
Keyword(s):  
High Resolution ◽  
Transmission Spectrum ◽  
Line Shape ◽  
Cross Correlation ◽  
Correlation Method ◽  
Spin Orbit ◽  
Shape Variation ◽  
Echelle Spectrograph ◽  
Transmission Spectroscopy ◽  
Different Temperatures

We report detections of atomic species in the atmosphere of MASCARA-2 b, using the first transit observations obtained with the newly commissioned EXPRES spectrograph. EXPRES is a highly stabilized optical echelle spectrograph, designed to detect stellar reflex motions with amplitudes down to 30 cm s−1, and has recently been deployed at the Lowell Discovery Telescope. By analyzing the transmission spectrum of the ultra-hot Jupiter MASCARA-2 b using the cross-correlation method, we confirm previous detections of Fe I, Fe II, and Na I, which likely originate in the upper regions of the inflated atmosphere. In addition, we report significant detections of Mg I and Cr II. The absorption strengths change slightly with time, possibly indicating different temperatures and chemistry in the day- and nightside terminators. Using the effective stellar line-shape variation induced by the transiting planet, we constrain the projected spin-orbit misalignment of the system to 1.6 ± 3.1 degrees, consistent with an aligned orbit. We demonstrate that EXPRES joins a suite of instruments capable of phase-resolved spectroscopy of exoplanet atmospheres.

Studies of the atmosphere of ultra-hot Jupiter TOI-1431b/MASCARA-5b

2021 ◽  
Author(s):  
Monika Stangret ◽  
Enric Palle ◽  
Núria Casasayas-Barris ◽  
Mahmoud Oshagh
Keyword(s):  
High Resolution ◽  
Cross Correlation ◽  
Giant Planets ◽  
High Resolution Spectroscopy ◽  
Polar Orbit ◽  
Hot Jupiters ◽  
History Of ◽  
F Stars ◽  
Suitable Object ◽  
Hot Jupiter

<p>Ultra-hot Jupiters are defined as giant planets with equilibrium temperatures larger than 2000 K. Most of them are found orbiting bright A-F stars, making them extremely suitable object to study their atmospheres using high-resolution spectroscopy.</p> <p>TOI-1431b, also known as MASCARA-5b, a newly discovered planet with the temperature of 2375 K is a prefect example of ultra-hot Jupiter. We studied this object using three transit observations obtained with high-resolution spectrographs HARPS-N and EXPRES. Analysis of Rossiter-McLaughlin effect shows that the planet is in the polar orbit, which speaks about an interesting dynamical history, and perhaps indicating the presence of more than one planet in the early history of this system. Applying the cross-correlation and transmission spectroscopy method, we find no evidence of atoms and molecules in this planet. There results are at odds with the other studies of similar UHJs orbiting bright stars, where various species have been found.</p>

scholarly journals Detection of Na, K, and Hα absorption in the atmosphere of WASP-52b using ESPRESSO

2020 ◽  
Vol 635 ◽  
pp. A171 ◽  
Author(s):  
G. Chen ◽  
N. Casasayas-Barris ◽  
E. Pallé ◽  
F. Yan ◽  
M. Stangret ◽  
...  
Keyword(s):  
High Resolution ◽  
Transmission Spectrum ◽  
Orbital Motion ◽  
Telescope Array ◽  
Hot Jupiters ◽  
Velocity Shift ◽  
Very Large Telescope ◽  
Cloudy Atmosphere ◽  
Excess Absorption ◽  
Hot Jupiter

WASP-52b is a low-density hot Jupiter orbiting a moderately active K2V star. Previous low-resolution studies have revealed a cloudy atmosphere and found atomic Na above the cloud deck. Here we report on the detection of excess absorption at the Na doublet, the Hα line, and the K D1 line. We derived a high-resolution transmission spectrum based on three transits of WASP-52b, observed with the ultra-stable, high-resolution spectrograph ESPRESSO at the Very Large Telescope array. We measured a line contrast of 1.09 ± 0.16% for Na D1, 1.31 ± 0.13% for Na D2, 0.86 ± 0.13% for Hα, and 0.46 ± 0.13% for K D1, with a line FWHM range of 11–22 km s−1. We also found that the velocity shift of these detected lines during the transit is consistent with the planet’s orbital motion, thus confirming their planetary origin. We did not observe any significant net blueshift or redshift that could be attributed to planetary winds. We used activity indicator lines as control but found no excess absorption. However, we did notice signatures arising from the Center-to-Limb variation (CLV) and the Rossiter-McLaughlin (RM) effect at these control lines. This highlights the importance of the CLV + RM correction in correctly deriving the transmission spectrum, which, if not corrected, could resemble or cancel out planetary absorption in certain cases. WASP-52b is the second non-ultra-hot Jupiter to show excess Hα absorption after HD 189733b. Future observations targeting non-ultra-hot Jupiters that show Hα could help reveal the relation between stellar activity and the heating processes in the planetary upper atmosphere.

scholarly journals A spectral survey of an ultra-hot Jupiter

2019 ◽  
Vol 627 ◽  
pp. A165 ◽  
Author(s):  
H. J. Hoeijmakers ◽  
D. Ehrenreich ◽  
D. Kitzmann ◽  
R. Allart ◽  
S. L. Grimm ◽  
...  
Keyword(s):  
Transmission Spectrum ◽  
Cross Correlation ◽  
Chemical Characterization ◽  
Blue Shift ◽  
Spectral Lines ◽  
Absorption Lines ◽  
Correlation Technique ◽  
Dwarf Stars ◽  
Hot Jupiters ◽  
Short Period

Context. KELT-9 b exemplifies a newly emerging class of short-period gaseous exoplanets that tend to orbit hot, early type stars – termed ultra-hot Jupiters. The severe stellar irradiation heats their atmospheres to temperatures of ~4000 K, similar to temperatures of photospheres of dwarf stars. Due to the absence of aerosols and complex molecular chemistry at such temperatures, these planets offer the potential of detailed chemical characterization through transit and day-side spectroscopy. Detailed studies of their chemical inventories may provide crucial constraints on their formation process(es) and evolution history. Aims. We aim to search the optical transmission spectrum of KELT-9 b for absorption lines by metals using the cross-correlation technique. Methods. We analysed two transit observations obtained with the HARPS-N spectrograph. We used an isothermal equilibrium chemistry model to predict the transmission spectrum for each of the neutral and singly ionized atoms with atomic numbers between three and 78. Of these, we identified the elements that are expected to have spectral lines in the visible wavelength range and used those as cross-correlation templates. Results. We detect (>5σ) absorption by Na I, Cr II, Sc II and Y II, and confirm previous detections of Mg I, Fe I, Fe II, and Ti II. In addition, we find evidence of Ca I, Cr I, Co I, and Sr II that will require further observations to verify. The detected absorption lines are significantly deeper than predicted by our model, suggesting that the material is transported to higher altitudes where the density is enhanced compared to a hydrostatic profile, and that the material is part of an extended or outflowing envelope. There appears to be no significant blue-shift of the absorption spectrum due to a net day-to-night side wind. In particular, the strong Fe II feature is shifted by 0.18 ± 0.27 km s−1, consistent with zero. Using the orbital velocity of the planet we derive revised masses and radii of the star and the planet: M* = 1.978 ± 0.023 M⊙, R* = 2.178 ± 0.011 R⊙, mp = 2.44 ± 0.70 MJ and Rp = 1.783 ± 0.009 RJ.

scholarly journals The atmosphere of WASP-76b seen with CARMENES: looking for CaII IRT and HeI

2021 ◽  
Author(s):  
Núria Casasayas-Barris ◽  
Jaume Orell-Miquel ◽  
Monika Stangret ◽  
Lisa Nortmann ◽  
Fei Yan ◽  
...  
Keyword(s):  
High Resolution ◽  
Transmission Spectrum ◽  
Potential Candidate ◽  
Hot Jupiters ◽  
Transmission Spectroscopy ◽  
Follow Up Studies ◽  
Ionised Calcium

<p>Currently, one of the most used techniques to study the atmosphere of the exoplanets is transmission spectroscopy by means of high-resolution facilities (R > 10<sup>5</sup>). This methodology has led to the detection of several species in the atmosphere of exoplanets, showing that ultra-hot Jupiters (T<sub>eq</sub> > 2000 K) are one of the most intriguing exoplanets, possessing the richest atmospheres measured to date. Here, using two transit observations with the high-resolution spectrograph CARMENES, we study the atmosphere of one of the most famous ultra-hot Jupiters: WASP-76b. We take advantage of the redder wavelength coverage of CARMENES, in comparison with the facilities used in previous studies of this same planet, and focus our analysis on the CaII IRT triplet at 850nm and the metastable HeI triplet at 1083nm. In line with recent studies, we detect ionised calcium in the atmosphere of WASP-76b and, additionally, find possible evidence of HeI. We contextualise our findings with previous atmospheric studies of other ultra-hot Jupiters and, in particular, with those showing the presence of CaII and HeI absorption in their transmission spectrum. We show that this planet is a potential candidate for further follow up studies of the HeI lines using high-resolution spectrographs located at larger telescopes, such as CRIRES+.</p>

Modelling high-resolution transmission spectra of the ultra-hot jupiter wasp-76b with 3D Monte-Carlo radiative transfer

2020 ◽  
Author(s):  
Joost Wardenier ◽  
Vivien Parmentier ◽  
Graham Lee
Keyword(s):  
Monte Carlo ◽  
High Resolution ◽  
Radiative Transfer ◽  
Cross Correlation ◽  
Circulation Model ◽  
High Spectral Resolution ◽  
Cloud Formation ◽  
Time Varying ◽  
Hot Jupiters ◽  
3D Monte Carlo

<div class="c-message_kit__gutter"> <div class="c-message_kit__gutter__right" data-qa="message_content"> <div class="c-message_kit__blocks c-message_kit__blocks--rich_text"> <div class="c-message__message_blocks c-message__message_blocks--rich_text"> <div class="p-block_kit_renderer" data-qa="block-kit-renderer"> <div class="p-block_kit_renderer__block_wrapper p-block_kit_renderer__block_wrapper--first"> <div class="p-rich_text_block" dir="auto"> <div class="p-rich_text_section">Ultra-hot Jupiters are tidally-locked gas giants with two chemical regimes: on the scorching dayside molecular species are dissociated and metals are ionised, while the permanent nightside is cool enough for cloud formation to occur. This means that the abundances of particular chemical species, such as iron, will exhibit a sharp gradient across the terminator region, which can be probed by transmission spectroscopy. We present a state-of-the-art 3D Monte-Carlo radiative transfer framework, adapted from Lee et al. (2017, 2019), that allows for the 3D modelling of high-resolution spectra of ultra-hot Jupiters. We use this tool to post-process the output of the SPARC/MITgcm global circulation model, with the aim to better understand how inhomogeneous chemistry, clouds and Doppler shifts due to atmospheric dynamics impact the appearance of a transit spectrum and its cross-correlation signal.</div> <div class="p-rich_text_section"> </div> <div class="p-rich_text_section">In this talk, we apply our model to the transit of WASP-76b, for which Ehrenreich et al. (2020) recently presented a time-varying iron signature at high spectral resolution. The observation suggests that iron condenses on the nightside of the planet. We show that different parts of the limb lead to very different cross-correlation signals and we show that the relative contributions from the east and west limb change during the transit, resulting in a time-varying cross-correlation signal. Finally, we explore different atmospheric scenarios for WASP-76b and we demonstrate that the occurrence of iron condensation, combined with the specific time-varying geometry during the transit, can quantitatively reproduce the Ehrenreich et al. (2020) result.</div> </div> </div> </div> </div> </div> </div> </div> <div class="c-message_actions__container c-message__actions" role="group" aria-label="Message shortcuts" data-qa="message-actions"> </div>

Fe I and Fe II in the atmosphere of Ultra-hot Jupiter MASCARA-2b

2020 ◽  
Author(s):  
Monika Stangret ◽  
Núria Casasayas-Barris ◽  
Enric Palle ◽  
Fei Yan ◽  
Alejandro Sánchez-López ◽  
...  
Keyword(s):  
Cross Correlation ◽  
Theoretical Models ◽  
High Resolution Spectroscopy ◽  
Atmospheric Transmission ◽  
Hot Jupiters ◽  
Residual Noise ◽  
The Earth ◽  
Exoplanetary Atmospheres ◽  
Host Stars ◽  
Hot Jupiter

<p>Thanks to the different Doppler velocities of the Earth, the host star and the planet using high-resolution spectroscopy we are able to detect and characterise exoplanetary atmospheres. Exoplanetary signal is buried in the residual noise, however by preforming cross-correlation of atmospheric transmission model and hundreds of atmospheric lines the signal can be increase. Studying the atmospheres of ultra-hot Jupiters, objects with the temperature higher than 2200K which orbit close to their host stars, gives us great laboratory to study chemistry of the exoplanets. MASCARA-2b also known as KELT-20b with the temperature of 2230 K is a perfect example of ultra hot Jupiter. We studied this object using three transit observations obtained with HARPS-North. Using cross-correlation method we detected strong absorption of Fe I and FeII, which agrees with theoretical models. Additionally, because of the fast rotation of the star, the crosscorrelation residuals show strong Rossiter-MacLaughlin effect.</p>

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