TRAPPIST-1 Archives

Broadband light curves of the flare-affected transits of TRAPPIST-1b and f. The transit models are shown in orange, and the exponential fit to the integrations in both the transit and flare is shown in blue. The exponential fit is necessary to determine the shape of the transit light curve. As shown in the O-C diagrams at the bottom, we use an initial guess of c1 and c2 to fit the exponential, then subtract the exponential to obtain final values of c1 and c2. We note c1 and c2 represent the coefficients of the quadratic limb darkening equation. The first and third O-C diagrams are directly comparable and show the light curve with the final transit model removed. The middle O-C diagram shows an intermediate step in the determination of the TRAPPIST-1f transit model fit in which the initial guess on the transit model is subtracted prior to fitting and subtracting the exponential. The residuals of the middle panel therefore show the quality of the exponential fit. -- astro-ph.SR

Exoplanets, -moons, -comets, Habitable Zones, Radiation, Space Weather & Heliophysics, Status Report, TRAPPIST-1

Characterizing The Near-infrared Spectra Of Flares From TRAPPIST-1 During JWST Transit Spectroscopy Observations

by Keith CowingOctober 9, 2023October 9, 2023

We present the first analysis of JWST near-infrared spectroscopy of stellar flares from TRAPPIST-1 during transits of rocky exoplanets. Four flares were observed from 0.6–2.8 μm with NIRISS and 0.6–3.5 […]

The evolution of M dwarf X-ray activity over time. Early M dwarfs are plotted on the left, and mid-late M dwarfs on the right. Lighter-colored error bars indicate when the ‘average’ uncertainty value was applied to a target for fitting purposes. A two-component, segmented linear model was applied to each subset and is plotted. Each subset shows an initial “saturation phase” where high activity levels are sustained for a period of time, before an inflection point is reached. After this, the activity decreases at an accelerated rate. It is worth noting that many studies assume a constant level of activity during the saturation phase, where our fits indicate that a slight decrease occurs. The saturation phase is found last ∼470 Myr for the early M dwarfs and ∼2.1 Gyr for the mid-late M dwarfs. -- astro-ph.EP

Exoplanets, -moons, -comets, Habitable Zones, Radiation, Space Weather & Heliophysics, Status Report, TRAPPIST-1

Living With A Red Dwarf: X-ray, UV, And Ca II Activity-Age Relationships Of M Dwarfs

by Keith CowingOctober 9, 2023October 9, 2023

The vast majority of stars in the nearby stellar neighborhood are M dwarfs. Their low masses and luminosities result in slow rates of nuclear evolution and minimal changes to the […]

Joint constraints on the H2/He abundance and the atmospheric pressure on TRAPPIST-1 b resulting from the sequential fit of the stellar contamination and planetary atmosphere. The color shading illustrates the posterior probability density, where darker colors correspond to higher probabilities. Contours indicate the 1σ, 2σ, and 3σ Bayesian credible regions. The displayed posterior probability is marginalized over the H2O, CH4, CO, CO2, NH3, and N2 abundances. Hydrogen-dominated scenarios with high-altitude clouds are at the top left corner of the plot and cloud-free, volatile-rich, high-mean-molecular-mass atmospheres are at the bottom right. Any hydrogen-rich atmospheres without high-altitude clouds, at the bottom left, are robustly ruled out. The second horizontal axis at the top shows the mean molecular mass representative for a pure H2/H2O atmosphere. -- University of Michigan

Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Press Release, TRAPPIST-1

JWST’s First Spectrum Of A TRAPPIST-1 Planet

by Keith CowingOctober 8, 2023October 8, 2023

In a solar system called TRAPPIST-1, 40 light years from the sun, seven Earth-sized planets revolve around a cold star.

Calculated obliquity ranges for each planet, as a function of orbital semi-major axis. The obliquity range is calculated using only the |g| values for interactions of adjacent pairs of planets (e.g. TRAPPIST-1 c with TRAPPIST-1 b or with TRAPPIST-1 d) and the median obliquity for each range is plotted as a point on the range line. The planets with no possible obliquity for a given value of |g| are plotted as a dashed line. The value for Earth’s obliquity is also shown as a reference. There is a wide range of obliquity values possible for planets 0.01 − 0.4 AU from their host star. Beyond roughly 0.4 AU, non-zero obliquity due to capture in Cassini State 2 is no longer excited. -- astro-ph.EP

Exoplanets, -moons, -comets, Habitable Zones, Status Report

Plausibility Of Capture Into High-Obliquity States For Exoplanets In The M Dwarf Habitable Zone

by Keith CowingOctober 5, 2023October 4, 2023

For temperate exoplanets orbiting M dwarf hosts, the proximity of the habitable zone to the star necessitates careful consideration of tidal effects.

The TP profiles for the 6 exoEarth atmospheres (left panel) and the chemical abundance profiles for the 400 ppm exoEarth (right panel).

Astrogeology, Astronomy & Telescopes, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Status Report, Venus

Investigating The Ability Of JWST To Identify Discerning Features In exoEarth And exoVenus Transmission Spectra

by Keith CowingOctober 4, 2023October 4, 2023

The success of the Transiting Exoplanet Survey Satellite (TESS) mission has led to the discovery of an abundance of Venus Zone (VZ) terrestrial planets that orbit relatively bright host stars.

Image description: Infographic titled, “Rocky Exoplanet TRAPPIST-1 b Dayside Temperature Comparison, MIRI F1500W” showing five planets plotted along a horizontal temperature scale: Earth, TRAPPIST-1 b, Mercury, and two different models of TRAPPIST-1 b. The temperature scale is labeled in kelvins and degrees Fahrenheit, and ranges from 0 kelvins (negative 459 degrees Fahrenheit) at the left to 800 kelvins (980 degrees Fahrenheit at the right). The planets are plotted along the temperature scale at the following temperatures: Earth Measured at 290 kelvins (60 degrees Fahrenheit); TRAPPIST-1 b Measured at about 500 kelvins and 445 degrees Fahrenheit; “Mercury Measured” at 700 kelvins (800 degrees Fahrenheit). TRAPPIST-1 b Model with atmosphere is plotted at 400 kelvins (260 degrees Fahrenheit); TRAPPIST-1 b Model with no atmosphere is plotted at about 510 kelvins and 455 degrees Fahrenheit. TRAPPIST-1 b Measured is plotted at almost the same temperature as TRAPPIST-1 b Model with no atmosphere.

Astrogeology, Astronomy & Telescopes, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Press Release, TRAPPIST-1

Webb Measures The Temperature Of Rocky Exoplanet TRAPPIST-1 b

by Keith CowingOctober 2, 2023

Webb measured the dayside temperature of rocky exoplanet TRAPPIST-1 b and found it to be about 450 degrees F (227 degrees C), suggesting it has no significant atmosphere.

Best-fit system in each modeling scenario compared to the true TRAPPIST-1 system using only Filippazzo et al. (2015) priors. The symbol size corresponds to the planet size, and the color indicates albedo. Horizontal bars indicate the uncertainty on a planet’s semi-major axis. Each modeling scenario is labeled with the number of planets included, the computed evidence, and its significance against the best-fit model. We use transparency to demonstrate which models are ruled out by > 3σ confidence. The vertical dashed lines indicate the limits of our semi-major axis bounds. -- astro-ph.EP

Astronomy & Telescopes, Status Report, TRAPPIST-1

On the Effectiveness of the Planetary Infrared Excess (PIE) Technique to Retrieve the Parameters of Multiplanet Systems around M dwarfs: A Case Study on the TRAPPIST-1 System

by Keith CowingOctober 1, 2023October 1, 2023

The planetary infrared excess (PIE) technique has the potential to efficiently detect and characterize the thermal spectra of both transiting and non-transiting exoplanets. However, the technique has not been evaluated […]

The transmission spectrum atmospheric effective altitude is plotted against wavelength between 0.2 µm and 11 µm for the P19 PI (orange), P19 10% PAL (brown), P19 1% PAL (yellow), and P19 0.1% PAL (red) simulations, and the W21 PI (light blue), W21 10% PAL (blue), W21 1% PAL (lilac), and W21 0.1% PAL (grey) simulations. The non-tidally locked cases are excluded for clarity, but show little differences compared to the equivalent tidally locked case. The transit depth, in terms of contrast with respect to the star, is indicated on the right vertical axis in parts per million (ppm). The spectra are binned to a spectral resolving power of R = 250. Spectral features are indicated in grey. The wavelength range of the proposed Habitable Worlds Observatory (HWO; blue shaded region), and that of the JWST NIRSpec instrument (yellow shaded region), are shown. They overlap in the green shaded region. The wavelength range of the JWST MIRI instrument is indicated in the magenta shaded region. The wavelength spacing between 0.2 – 1 µm is changed between 1 – 11 µm in order to clearly show the UV and visible regions. The black bar represents the uncertainty that would be present on a measurement that has reached the noise floor of the instrument, where the noise floor is indicated as 5 ppm. Note this error bar is an estimate of the performance of the telescope and does not indicate a measurement. -- astro-ph.EP

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Status Report, TRAPPIST-1

Degenerate Interpretations Of O3 Spectral Features In Exoplanet Atmosphere Observations Due To Stellar UV Uncertainties: A 3D Case Study With TRAPPIST-1e

by Keith CowingOctober 1, 2023October 1, 2023

TRAPPIST-1e is a potentially habitable terrestrial exoplanet orbiting an ultra-cool M Dwarf star and is a key target for observations with the James Webb Space Telescope (JWST). One-dimensional photochemical modelling […]

Astrochemistry, Astronomy & Telescopes, Atmospheres, Climate, Weather, Habitable Zones, Imaging & Spectroscopy, Press Release, TRAPPIST-1

JWST Insights Into The Atmosphere Of Exoplanet TRAPPIST-1 b And The Star TRAPPIST-1

by Keith CowingSeptember 25, 2023September 25, 2023

Astronomers led by a team at Université de Montréal has made important progress in understanding the intriguing TRAPPIST-1 exoplanetary system, which was first discovered in 2016 amid speculation it could […]

Earth’s observed cloud-free transit transmission spectrum from Macdonald & Cowan (2019) binned to a resolution of ∆λ = 0.02 µm and fit using smarter. The data are shown in black, the best-fitting model (Model 1) spectrum is shown in white and blue, and various colors are used to indicate each molecule’s contribution to the model spectrum. The most prominent features are due to CO2 and O3, but a rich diversity of habitability indicators, biosignatures, and technosignatures are present. -- astro-ph.EP

Astronomy & Telescopes, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, SETI & Technosignatures, Status Report

Earth As A Transiting Exoplanet: A Validation Of Transmission Spectroscopy And Atmospheric Retrieval Methodologies For Terrestrial Exoplanets

by Keith CowingAugust 29, 2023August 29, 2023

The James Webb Space Telescope (JWST) will enable the search for and characterization of terrestrial exoplanet atmospheres in the habitable zone via transmission spectroscopy.

TRAPPIST-1

Characterizing The Near-infrared Spectra Of Flares From TRAPPIST-1 During JWST Transit Spectroscopy Observations

Living With A Red Dwarf: X-ray, UV, And Ca II Activity-Age Relationships Of M Dwarfs

JWST’s First Spectrum Of A TRAPPIST-1 Planet

Plausibility Of Capture Into High-Obliquity States For Exoplanets In The M Dwarf Habitable Zone

Investigating The Ability Of JWST To Identify Discerning Features In exoEarth And exoVenus Transmission Spectra

Webb Measures The Temperature Of Rocky Exoplanet TRAPPIST-1 b

On the Effectiveness of the Planetary Infrared Excess (PIE) Technique to Retrieve the Parameters of Multiplanet Systems around M dwarfs: A Case Study on the TRAPPIST-1 System

Degenerate Interpretations Of O3 Spectral Features In Exoplanet Atmosphere Observations Due To Stellar UV Uncertainties: A 3D Case Study With TRAPPIST-1e

JWST Insights Into The Atmosphere Of Exoplanet TRAPPIST-1 b And The Star TRAPPIST-1

Earth As A Transiting Exoplanet: A Validation Of Transmission Spectroscopy And Atmospheric Retrieval Methodologies For Terrestrial Exoplanets

Curiosity Mars Rover Discovers A Field Of Honeycomb Textures

Viking Science

Constraining The Lives And Times Of Exoplanets Through Evolutionary Bayesian Retrievals

Project Hephaistos — III. Characterizing Anomalous Infrared Sources Identified As Dyson-sphere Candidates

SCoRE: The Surface Composition Of Rocky Exoplanets