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211. L 98-59 (TOI-175) ESPRESSO observations
ID:
ivo://CDS.VizieR/J/A+A/653/A41
Title:
L 98-59 (TOI-175) ESPRESSO observations
Short Name:
J/A+A/653/A41
Date:
22 Feb 2022
Publisher:
CDS
Description:
In recent years, the advent of a new generation of radial velocity instruments has allowed us to detect lower and lower mass planets, breaking the one Earth-mass barrier. Here we report a new milestone in this context, by announcing the detection of the lightest planet measured so far using radial velocities: L 98-59 b, a rocky planet with half the mass of Venus which is part of a system composed of three known transiting terrestrial planets (planets b to d). We announce the discovery of a fourth non-transiting planet with a minimum mass of 3.06_-0.37_^+0.33^M_{Earth)_ and an orbital period of 12.796_-0.019_^+0.020^ days and report hints for the presence of a fifth non-transiting terrestrial planet. If confirmed, with a minimum mass of 2.46_-0.82_^+0.66^M_{Earth}_ and an orbital period 23.15_-0.17_^+0.60^ days, this planet would sit in the middle of the habitable zone of the L 98-59 system. L 98-59 is a bright M-dwarf located 10.6pc away. Positioned at the border of the continuous viewing zone of the James Webb space telescope, this system is destined to become a corner stone for comparative exoplanetology of terrestrial planets. The three transiting planets have transmission spectrum metrics ranging from 49 to 255 which undoubtedly make them prime targets for atmospheric characterization with the James Webb space telescope, the Hubble space telescope, Ariel or ground-based facilities like NIRPS or ESPRESSO. With equilibrium temperature ranging from 416 to 627K, they offer a unique opportunity to study the diversity of warm terrestrial planets without the unknowns associated with different host stars. L 98-59 b and c have densities of 3.6_-1.5_^+1.4^ and 4.57_-0.85_^+0.77^g/cm^3^ respectively and have very similar bulk compositions with a small iron core, representing only 12 to 14% of the total mass, and a small amount of water. However, with a density of 2.95_-0.51_^+0.79^g/cm^3^ and despite a similar core mass fraction, up to 30% of L 98-59 d's mass could be made of water.
212. L 98-59 (TOI 175) HARPS observations
ID:
ivo://CDS.VizieR/J/A+A/629/A111
Title:
L 98-59 (TOI 175) HARPS observations
Short Name:
J/A+A/629/A111
Date:
21 Oct 2021
Publisher:
CDS
Description:
L 98-59 (TIC 307210830, TOI-175) is a nearby M3 dwarf around which TESS revealed three small transiting planets (0.80, 1.35, 1.57 Earth radii) in a compact configuration with orbital periods shorter than 7.5 days. Here we aim to measure the masses of the known transiting planets in this system using precise radial velocity (RV) measurements taken with the HARPS spectrograph. We considered both trained and untrained Gaussian process regression models of stellar activity, which are modeled simultaneously with the planetary signals. Our RV analysis was then supplemented with dynamical simulations to provide strong constraints on the planets' orbital eccentricities by requiring long-term stability. We measure the planet masses of the two outermost planets to be 2.42+/-0.35 and 2.31+/-0.46 Earth masses, which confirms the bulk terrestrial composition of the former and eludes to a significant radius fraction in an extended gaseous envelope for the latter. We are able to place an upper limit on the mass of the smallest, innermost planet of <1.01 Earth masses with 95% confidence. Our RV plus dynamical stability analysis places strong constraints on the orbital eccentricities and reveals that each planet's orbit likely has e<0.1. L 98-59 is likely a compact system of two rocky planets plus a third outer planet with a lower bulk density possibly indicative of the planet having retained a modest atmosphere. The system offers a unique laboratory for studies of planet formation, dynamical stability, and comparative atmospheric planetology as the two outer planets are attractive targets for atmospheric characterization through transmission spectroscopy. Continued RV monitoring will help refine the characterization of the innermost planet and potentially reveal additional planets in the system at wider separations.
213. Main sequence hot Jupiter hosts with good astrometry
ID:
ivo://CDS.VizieR/J/AJ/158/190
Title:
Main sequence hot Jupiter hosts with good astrometry
Short Name:
J/AJ/158/190
Date:
21 Oct 2021
Publisher:
CDS
Description:
While cooler giant planets are often observed with nonzero eccentricities, the short-period circular orbits of hot Jupiters suggest that they lose orbital energy and angular momentum due to tidal interactions with their host stars. However, orbital decay has never been unambiguously observed. We use data from Gaia Data Release 2 (Cat. I/345) to show that hot Jupiter host stars have a smaller Galactic velocity dispersion than a similar population of stars without hot Jupiters. Since Galactic velocity dispersion is correlated with age, this observation implies that the population of hot Jupiter host stars is on average younger than the field population. The best explanation for this inference is that tidal interactions cause hot Jupiters to inspiral while their host stars are on the main sequence. This observation requires that the typical modified stellar tidal quality factor Q_*_^'^ for solar-type stars is in the range log_10_Q_*_^'^~<7.
214. Maintaining the Ephemeris of 20 CoRoT planets
ID:
ivo://CDS.VizieR/J/other/JAVSO/48.201
Title:
Maintaining the Ephemeris of 20 CoRoT planets
Short Name:
J/other/JAVSO/48
Date:
22 Feb 2022
Publisher:
CDS
Description:
We present 33 transit minimum times of 20 transiting planets discovered by the CoRoT space mission, which have been obtained from ground-based observations since the mission's end in 2012, with the objective to maintain the ephemeris of these planets and to identify potential transit time variations. Twelve of the observed planets are in the CoRoT fields near the galactic center and the remaining eight planets are in the fields near the anticenter. We detect indications for significant transit timing variations in the cases of CoRoT 3b, 11b, 13b, 27b. For two more planets (CoRoT 18b and 20b) we conclude that timing offsets in early follow-up observations led to ephemeris in discovery publications that are inconsistent with timings from follow-up observations in later epochs. In the case of CoRoT-20b, this might be due to the influence from a further non-transiting planet. We also note that a significant majority (23 of 33) of our reported minimum times have negative O-C values, albeit most of them are within the expected uncertainty of the ephemeris.
216. MASCARA-2 b (HD185603) light curves and spectra
ID:
ivo://CDS.VizieR/J/A+A/612/A57
Title:
MASCARA-2 b (HD185603) light curves and spectra
Short Name:
J/A+A/612/A57
Date:
21 Oct 2021
Publisher:
CDS
Description:
In this paper we present MASCARA-2 b, a hot Jupiter transiting the m_V_=7.6 A2 star HD 185603. Since early 2015, MASCARA has taken more than 1.6 million flux measurements of the star, corresponding to a total of almost 3000 hours of observations, revealing a periodic dimming in the flux with a depth of 1.3%. Photometric follow-up observations were performed with the NITES and IAC80 telescopes and spectroscopic measurements were obtained with the Hertzsprung SONG telescope. We find MASCARA-2 b orbits HD 185603 with a period of 3.474119^+0.000005^_-0.000006_ days at a distance of 0.057+/-0.006AU, has a radius of 1.83+/-0.07R_J_ and place a 99 % upper limit on the mass of <17M_J_. HD 185603 is a rapidly rotating early-type star with an effective temperature of 8980^+90^_-130_K and a mass and radius of 1.89^+0.06^_-0.05_M_sun_, 1.60+/-0.06R_sun_, respectively. Contrary to most other hot Jupiters transiting early-type stars, the projected planet orbital axis and stellar spin axis are found to be aligned with {lambda}=0.6+/-4{deg}. The brightness of the host star and the high equilibrium temperature, 2260+/-50K, of MASCARA-2 b make it a suitable target for atmospheric studies from the ground and space. Of particular interest is the detection of TiO, which has recently been detected in the similarly hot planets WASP-33 b and WASP-19 b.
217. MASCARA-2b NaI & Ha absorption lines
ID:
ivo://CDS.VizieR/J/A+A/616/A151
Title:
MASCARA-2b NaI & Ha absorption lines
Short Name:
J/A+A/616/A151
Date:
21 Oct 2021
Publisher:
CDS
Description:
We used the HARPS-North high resolution spectrograph (R=115000) at Telescopio Nazionale Galileo (TNG) to observe one transit of the highly irradiated planet MASCARA-2b/KELT-20b. Using only one transit observation, we are able to clearly resolve the spectral features of the atomic sodium (NaI) doublet and the H{alpha} line in its atmosphere, which are corroborated with the transmission calculated from their respective transmission light curves (TLC). In particular, we resolve two spectral features centred on the NaI doublet position with an averaged absorption depth of 0.17+/-0.03% for a 0.75{AA} bandwidth with line contrasts of 0.44+/-0.11% (D2) and 0.37+/-0.08% (D1). The NaI TLC have also been computed, showing a large Rossiter-McLaughlin (RM) effect, which has a 0.20+/-0.05% NaI transit absorption for a 0.75{AA} passband that is consistent with the absorption depth value measured from the final transmission spectrum. We observe a second feature centred on the H{alpha} line with 0.6+/-0.1% contrast and an absorption depth of 0.59+/-0.08% for a 0.75{AA} passband that has consistent absorptions in its TLC, which corresponds to an effective radius of R'/Rp=1.20+/-0.04. While the signal-to-noise ratio (S/N) of the final transmission spectrum is not sufficient to adjust different temperature profiles to the lines, we find that higher temperatures than the equilibrium (Teq=2260+/-50K) are needed to explain the lines contrast. Particularly, we find that the NaI lines core require a temperature of T=4210+/-180K and that H{alpha} requires a temperature of T=4330+/-520K. MASCARA-2b, like other planets orbiting A-type stars, receives a large amount of UV energy from its host star. This energy excites the atomic hydrogen and produces H{alpha} absorption, leading to the expansion and abrasion of the atmosphere. The study of other Balmer lines in the transmission spectrum would allow the determination of the atmospheric temperature profile and the calculation of the lifetime of the atmosphere with escape rate measurements. In the case of MASCARA-2b, residual features are observed in the H{beta} and H{gamma} lines, but they are not statistically significant.More transit observations are needed to confirm our findings in NaI and H{alpha} and to build up enough S/N to explore the presence of H{beta} and H{gamma} planetary absorptions.
218. MASCARA-1 b occultation and transit light curves
ID:
ivo://CDS.VizieR/J/A+A/658/A75
Title:
MASCARA-1 b occultation and transit light curves
Short Name:
J/A+A/658/A75
Date:
22 Feb 2022
Publisher:
CDS
Description:
The light curves of tidally locked hot Jupiters transiting fast-rotating, early-type stars are a rich source of information about both the planet and star, with full-phase coverage enabling a detailed atmospheric characterisation of the planet. Although it is possible to determine the true spin-orbit angle Psi -- a notoriously difficult parameter to measure -- from any transit asymmetry resulting from gravity darkening induced by the stellar rotation, the correlations that exist between the transit parameters have led to large disagreements in published values of Psi for some systems. We aimed to study these phenomena in the light curves of the ultra-hot Jupiter MASCARA-1 b, which is characteristically similar to well-studied contemporaries such as KELT-9 b and WASP-33 b. We obtained optical CHaracterising ExOPlanet Satellite (CHEOPS) transit and occultation light curves of MASCARA-1 b, and analysed them jointly with a Spitzer/IRAC 4.5 micron full-phase curve to model the asymmetric transits, occultations, and phase-dependent flux modulation. For the latter, we employed a novel physics-driven approach to jointly fit the phase modulation by generating a single 2D temperature map and integrating it over the two bandpasses as a function of phase to account for the differing planet-star flux contrasts. The reflected light component was modelled using the general ab initio solution for a semi-infinite atmosphere. When fitting the CHEOPS and Spitzer transits together, the degeneracies are greatly diminished and return results consistent with previously published Doppler tomography. Placing priors informed by the tomography achieves even better precision, allowing a determination of Psi=72.1^+2.5^_-2.4_deg. From the occultations and phase variations, we derived dayside and nightside temperatures of 3062^+66^_-68_K and 1720+/-330K, respectively. Our retrieval suggests that the dayside emission spectrum closely follows that of a blackbody. As the CHEOPS occultation is too deep to be attributed to blackbody flux alone, we could separately derive geometric albedo A_g_=0.166^+0.066^_-0.068_ and spherical albedo A_s_=0.266^+0.097^_-0.100_ from the CHEOPS data, and Bond albedo A_B_=0.053^+0.083^_-0.101_ from the Spitzer phase curve. Although small, the Ag and As indicate that MASCARA-1 b is more reflective than most other ultra-hot Jupiters, where H^-^ absorption is expected to dominate. Where possible, priors informed by Doppler tomography should be used when fitting transits of fast-rotating stars, though multi-colour photometry may also unlock an accurate measurement of Psi. Our approach to modelling the phase variations at different wavelengths provides a template for how to separate thermal emission from reflected light in spectrally resolved James Webb Space Telescope phase curve data.
219. MASCARA-3b radial and light curves
ID:
ivo://CDS.VizieR/J/A+A/631/A76
Title:
MASCARA-3b radial and light curves
Short Name:
J/A+A/631/A76
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report the discovery of MASCARA-3b, a hot Jupiter orbiting its bright (V=8.33) late F-type host every 5.55149+/-0.00001-days in an almost circular orbit (e=0.050^+0.020^_-0.017_). This is the fourth exoplanet discovered with the Multi-site All-Sky CAmeRA (MASCARA), and the first of these that orbits a late-type star. Follow-up spectroscopic measurements were obtained in and out of transit with the Hertzsprung SONG telescope. Combining the MASCARA photometry and SONG radial velocities reveals a radius and mass of 1.36+/-0.05R_Jup_ and 4.2+/-0.2M_Jup_. In addition, SONG spectroscopic transit observations were obtained on two separate nights. From analyzing the mean out-of-transit broadening function, we obtain vsini*=20.4+/-0.4km/s. In addition, investigating the Rossiter-McLaughlin effect, as observed in the distortion of the stellar lines directly and through velocity anoma lies, we find the projected obliquity to be {lambda}=1.2^+8.2^_-7.4_deg, which is consistent with alignment.
220. MASCARA-2b transmission spectra
ID:
ivo://CDS.VizieR/J/A+A/628/A9
Title:
MASCARA-2b transmission spectra
Short Name:
J/A+A/628/A9
Date:
21 Oct 2021
Publisher:
CDS
Description:
Ultra-hot Jupiters orbit very close to their host star and consequently receive strong irradiation, causing their atmospheric chemistry to be different from the common gas giants. Here, we have studied the atmosphere of one of these particular hot planets, MASCARA- 2b/KELT-20b, using four transit observations with high resolution spectroscopy facilities. Three of these observations were performed with HARPS-N and one with CARMENES. Additionally, we simultaneously observed one of the transits with MuSCAT2 to monitor possible spots in the stellar surface. At high resolution, the transmission residuals show the effects of Rossiter-McLaughlin and centre- to-limb variations from the stellar lines profiles, which we have corrected to finally extract the transmission spectra of the planet. We clearly observe the absorption features of CaII, FeII, NaI, H{alpha}, and H{beta} in the atmosphere of MASCARA-2b, and indications of H{gamma} and MgI at low signal-to-noise ratio. In the case of NaI, the true absorption is difficult to disentangle from the strong telluric and interstellar contamination. The results obtained with CARMENES and HARPS-N are consistent, measuring an H{alpha} absorption depth of 0.68+/-0.05 and 0.59+/-0.07%, and NaI absorption of 0.11+/-0.04 and 0.09+/-0.05% for a 0.75{AA} passband, in the two instruments respectively. The H{alpha} absorption corresponds to ~1.2Rp, which implies an expanded atmosphere, as a result of the gas heating caused by the irradiation received from the host star. For H{beta} and H{gamma} only HARPS-N covers this wavelength range, measuring an absorption depth of 0.28+/-0.06 and 0.21+/-0.07%, respectively. For CaII, only CARMENES covers this wavelength range measuring an absorption depth of 0.28+/-0.05, 0.41+/-0.05 and 0.27+/-0.06% for CaII {lambda}8498{AA}, {lambda}8542{AA} and {lambda}8662{AA} lines, respectively. Three additional absorption lines of FeII are observed in the transmission spectrum by HARPS-N (partially covered by CARMENES), measuring an average absorption depth of 0.08+/-0.04% (0.75{AA} passband). The results presented here are consistent with theoretical models of ultra-hot Jupiters atmospheres, suggesting the emergence of an ionised gas on the day-side of such planets. Calcium and iron, together with other elements, are expected to be singly ionised at these temperatures and be more numerous than its neutral state. The Calcium triplet lines are detected here for the first time in transmission in an exoplanet atmosphere. Description: The transmission spectra and of MASCARA-2b/KELT-20b are presented. Three transits with HARPS-North at TNG telescope were retrieved and one transit with CARMENES at 3.5 telescope at CAHA Observatory. For each spectral line the transmission spectra of MASCARA-2b/KELT-20b after correcting the CLV + RME are presented here. We note that in some cases the transmission spectrum of a specific line also includes transmission lines located close to the main spectral line (e.g. in case of NaI doublet). However, it is important to note that only the main spectral line of each file (see files name) includes the CLV+RME corrections. You need to work with specific files.

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