HARPS Archives - Page 5 of 5 - Astrobiology

The evolution of orbital plane and the change of impact parameter of TOI-1338 b’s primary and secondary transits. Top: the evolution of impact parameters of primary (red) and secondary transit (blue) integrated from the best-fit model. It shows that TOI-1338 b will permanently transit the primary star but hardly transit the secondary star. Bottom: the skyprojection view of the orbits of binary and TOI-1338 b. The orbit of TOI-1338 b is integrated 7000 days to show the effect of nodal precession due to interactions with binary stars. The size of the point scales with the line-of-sight distance, thus smaller points are behind the binary orbits. The red and blue regions show the crossing area of stellar disks of primary and secondary stars, accounting for the binary orbital motions. Transits can occur when the planet orbit and the stellar crossing area are intersected. The aspect ratio is 70:1. Due to the small mutual inclination of TOI-1338 b, the variation range of planetary inclination is very small, thus its orbit will always intersect the primary star’s orbital crossing region. The secondary star has a smaller radius, thus the stellar and planetary orbits are not mutually intersected, precluding potential transitability. -- astro-ph.EP

Astronomy & Telescopes, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report

Photo-dynamical Analysis of Circumbinary Multi-planet System TOI-1338: a Fully Coplanar Configuration with a Puffy Planet

by Keith CowingApril 30, 2024April 30, 2024

TOI-1338 is the first circumbinary planet system discovered by TESS. It has one transiting planet at P∼95 day and an outer non-transiting planet at P∼215 day complemented by RV observation.

Overview of our samples. (a): the distribution of orbital period and stellar mass(p-𝑀∗) of all samples, the colors denote the equilibrium temperature of each giant planet (from blue to red corresponds to 100 K to 4000K, where pink dotted line and dark blue dotted line mark the position of 0.1𝑎snow and 1.0𝑎snow of different host stars; (b): the distribution of planetary mass and effective temperature of host star( 𝑚p-𝑇eff) of our giant planets samples, detection completeness shown as color contours from 0.0 to 1.0 in steps of 0.1. -- astro-ph.EP

Astronomy & Telescopes, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Gas Giants, Imaging & Spectroscopy, Status Report

Mutual Occurrence Ratio of Planets. I. New Clues to Reveal Origins of Hot- and Warm-Jupiter from the RV Sample

by Keith CowingApril 20, 2024April 20, 2024

Many studies have analyzed planetary occurrence rates and their dependence on the host’s properties to provide clues to planet formation, but few have focused on the mutual occurrence ratio of […]

Phase-folded light curves from TESS (upper panels) and CHEOPS (lower panels) measurements. The best-fit model of the transit is plotted in black for HD 15337 b (left) and HD 15337 c (right). The bottom panels for each instrument show the residuals of the best-fit model. We over-plot the binned light curves and residuals with 20-min bins. -- astro-ph.EP

Astronomy & Telescopes, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report

Precise Characterisation Of HD 15337 With CHEOPS: A Laboratory For Planet Formation And Evolution

by Keith CowingMarch 26, 2024March 26, 2024

We aim to constrain the internal structure and composition of HD 15337 b and c, two short-period planets situated on opposite sides of the radius valley, using new transit photometry […]

Mass-radius diagram of transiting exoplanets with well established mass and radius from the NASA Exoplanet archive along with some theoretical composition curves (Zeng et al. 2019). The purple squares highlight the transiting planets orbiting K-dwarfs. The green blobs show the mass and radius posteriors (1- and 2-σ contours) of TOI–238 b and c. The planets of the solar system are included as reference. -- astro-ph.EP

Astronomy & Telescopes, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report

TESS and ESPRESSO Discover A Super-Earth And A Mini-Neptune Orbiting The K-dwarf TOI-238

by Keith CowingFebruary 7, 2024February 7, 2024

The number of super-Earth and mini-Neptune planet discoveries has increased significantly in the last two decades thanks to transit and radial velocity surveys. When it is possible to apply both […]

Direct imaging visibility of the five planets in the HD 134606 system. Left panel: top down view of the system with CHZ (bright green) and OHZ (dark green) overlaid. Right panel: sky projected view of the system with 60◦ orbital inclination. IWA and IWA0.5 are represented by the bright and dark shaded disks, respectively. Orbits are color coded if they are above the 1×10−10 flux ratio with 60◦ inclination. Inner four planetary orbits are too compact to be shown with detail on this scale. -- astro-ph.EP

Astronomy & Telescopes, Exoplanets, -moons, -comets, Habitable Zones, Status Report

Revised Architecture And Two New Super-Earths In The HD 134606 Planetary System

by Keith CowingFebruary 1, 2024February 1, 2024

Multi-planet systems exhibit a diversity of architectures that diverge from the solar system and contribute to the topic of exoplanet demographics. Radial velocity (RV) surveys form a crucial component of […]

Best-fit model from combined fit, showing K2 (top) and TESS data (middle). The three planets are illustrated with different colors. The bottom panel presents phase folds of K2 and TESS data with the transit model. -- astro-ph.EP

Astronomy & Telescopes, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report

The Compact Multi-planet System GJ 9827 Revisited With ESPRESSO

by Keith CowingJanuary 16, 2024January 16, 2024

GJ 9827 is a bright, nearby K7V star orbited by two super-Earths and one mini-Neptune on close-in orbits. The system was first discovered using K2 data and then further characterized […]

Results of Global Climate Model (GCM) simulations of LHS 1140 b assuming an Earth-like atmosphere (1 bar N2, 400 ppm CO2; panels a, c, d, e) and a thick CO2-dominated atmosphere (5 bar CO2; panels b, f, g, h). Panels a, b: Surface temperature maps of LHS 1140 b. The black line indicates the line of stability between liquid water and sea ice. The extent of the ice-free ocean strongly depends on the amount of CO2 in the atmosphere. Panels c, d, e, f, g, and h: Vertical profiles of the atmospheric temperatures, water vapor, and cloud mixing ratios (both H2O and CO2 ice clouds). The solid bold lines indicate the global mean vertical profiles and the dotted lines indicate terminator vertical profiles (impacting transit spectra). -- astro-ph.EP

Astronomy & Telescopes, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report, Water/Hycean Worlds & Oceanography

New Mass and Radius Constraints On The LHS 1140 Planets — LHS 1140 b Is Either A Temperate Mini-Neptune Or A Water World

by Keith CowingOctober 30, 2023October 30, 2023

LHS 1140 b and c are two small temperate exoplanets transiting a nearby M4.5 dwarf. The planetary system was observed with multiple facilities since its discovery in 2017, including MEarth, […]

Mass-radius diagram showing confirmed planets with mass uncertainties < 20% in grey circles, with TOI-544 b shown as the black circle. Left: the coloured tracks show different potential planet compositions from Zeng et al. (2019), assuming a planetary equilibrium temperature of 1000 K. The dashed lines show compositions of an Earth-like rocky core surrounded by a layer of H-He in varying percentages by mass, the solid lines show water world compositions with varying water mass fractions, the dotted lines show rocky and Earth-like rocky compositions. TOI-544 b is closest to the tracks with 100% H2O and 50% H2O with 50% rock. Right: the same as the left panel but the the dashed lines show compositions of an Earth-like rocky core surrounded by a layer of H-He in varying percentages by mass from Lopez & Fortney (2014) using the models for a 10Gyr planet, with solar metalicity and flux of 10F⊕, the solid lines show compositions from Aguichine et al. (2021) of irradiated ocean worlds with varying water mass fractions, and the dotted lines show the same rocky and Earth-like rocky compositions from Zeng et al. (2019). TOI-544 b is closest to models with either 30% water mass fraction, or a rocky core with a Hydrogen envelope of between 0.5 - 1%. The data is downloaded from the NASA Exoplanet Archive. -- astro-ph.EP

Astronomy & Telescopes, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Exploration Gear & Tech, Habitable Zones, Icy Worlds, Imaging & Spectroscopy, Status Report, Water/Hycean Worlds & Oceanography

TOI-544 b: A Potential Water-world Inside The Radius Valley In A Two-planet System

by Keith CowingOctober 24, 2023October 24, 2023

We report on the precise radial velocity follow-up of TOI-544 (HD 290498), a bright K star (V=10.8), which hosts a small transiting planet recently discovered by the Transiting Exoplanet Survey […]

Overview of the TOI-1338/BEBOP-1 system

Astronomy & Telescopes, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Status Report

The First Circumbinary Planet Discovered With Radial Velocities

by Keith CowingFebruary 26, 2023February 26, 2023

We report the detection of a gas-giant planet in orbit around both stars of an eclipsing binary star system that also contains the smaller, inner transiting planet TOI-1338b.