TESS Archives

RV time-series (top) and phase-folded plots for TOI 4633 b (lower left) and TOI 4633 c (lower right). SOPHIE (blue circles) and HIRES (orange diamonds) RV measurements are shown following the subtraction of the systemic velocities for each instrument. The light colored error bars show the uncertainties accounting for the jitter. Solid black lines show the inferred median model. Grey lines show models made with 100 random samples from the posterior distributions. -- astro-ph.EP

Astronomy & Telescopes, Citizen Science / Open Science, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Status Report

Planet Hunters TESS V: A Planetary System Around A Binary Star, Including A mini-Neptune In The Habitable Zone

by Keith CowingMay 2, 2024May 2, 2024

We report on the discovery and validation of a transiting long-period mini-Neptune orbiting a bright (V = 9.0 mag) G dwarf (TOI 4633; R = 1.05 RSun, M = 1.10 […]

An artist’s interpretation of TOI 4633 c, a Neptune-like exoplanet found orbiting the habitable zone of a sunlike star. The system contains a second star (right) and may also host another exoplanet (left). CREDIT Ed Bell for the Simons Foundation

Astronomy & Telescopes, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Citizen Science / Open Science, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Press Release

Citizen Scientists Help Discover A Habitable Zone Exoplanet In A Binary Star System

by Keith CowingMay 1, 2024May 1, 2024

A team of astronomers and citizen scientists has discovered a planet in the habitable zone of an unusual star system, including two stars and potentially another exoplanet.

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.

Light curves of EPIC 202059229 in terms of phase over time with the relative flux as color code. Left: Observations of K2. The light curve was splitted into the ∼7 rotation cycles present in the total light curve. Right: Observations of TESS. The TESS data only consists of 4.5 rotation cycles. Both panels were plotted in the same time range and the same color bar to show the light curves on the same scale. The size of the time bins is fixed on the rotation period determined from the K2 observation (Prot = 5.036 d). The difference in the size of the phase bins is caused by the different observing cadences. -- astro-ph.SR

Astronomy & Telescopes, Habitable Zones, Status Report

Long-term Stellar Activity Of M dwarfs: A Combined K2 And TESS Study Of Two Early M-type Stars

by Keith CowingApril 26, 2024April 26, 2024

Studies of the rotation and activity of M type stars are essential to enhance our understanding of stellar dynamos and angular momentum evolution.

Mean and standard deviation of outer vs inner stability borders in units of log10 of the binary semi-major axis. The color scale refers to the binary orbit eccentricity (top left), the planet’s orbital eccentricity (top right), the binary mass ratio (bottom left), and the mutual inclination (bottom right). Stability limits depend strongly on the planetary orbital eccentricity which accounts for most of the variance in the system. Stability borders also show roughly the same sensitivity to the binary star orbital eccentricity, the binary mass ratio as well as the inclination of the system. -- astro-ph.EP

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

Empirical Stability Criteria For 3D Hierarchical Triple Systems I: Circumbinary Planets

by Keith CowingApril 24, 2024April 24, 2024

In this work we revisit the problem of the dynamical stability of hierarchical triple systems with applications to circumbinary planetary orbits.

TESS Target Pixel Files showing the custom apertures used to extract the photometry of TOI-4336 A b in this work for Sectors 11, 38, and 64. -- astro-ph.EP

Astrogeology, Astronomy & Telescopes, Biosignatures & Paleobiology, Exploration Gear & Tech, Gas Giants, Habitable Zones, Imaging & Spectroscopy, Status Report

TOI-4336 A b: A Temperate Sub-Neptune Ripe For Atmospheric Characterization In A Nearby Triple M-dwarf System

by Keith CowingApril 24, 2024April 24, 2024

Small planets transiting bright nearby stars are essential to our understanding of the formation and evolution of exoplanetary systems. However, few constitute prime targets for atmospheric characterization, and even fewer […]

Stability analysis of the TOI-421 planetary system. For fixed initial conditions (Table 6), the parameter space of the system was explored by varying the orbital period Pb and the eccentricity eb of planet-b (left panel) and the eccentricities of both planets (right panel). The step size was 10−3 day in orbital period and 0.0025 in eccentricity. For each initial condition, the system was integrated over 5000 yr and a stability indicator was calculated, which involved a frequency analysis of the mean longitude of the inner planet. The chaotic diffusion was measured by the variation in the frequency (see text). Red points correspond to highly unstable orbits, while blue points correspond to orbits which are likely to be stable on a billion-years timescale. The black dots show the values of the best fit solution (Table 6). -- astro-ph.EP

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

Characterisation Of The TOI-421 Planetary System Using CHEOPS, TESS, and Archival Radial Velocity Data

by Keith CowingApril 20, 2024

The TOI-421 planetary system contains two sub-Neptune-type planets and is a prime target to study the formation and evolution of planets and their atmospheres.

This artist’s impression shows the free-floating planet CFBDSIR J214947.2-040308.9. -- ESO

Astronomy & Telescopes, Brown Dwarfs, Exoplanets, -moons, -comets, Status Report

Searching For Free-Floating Planets with TESS: I. Discovery of a First Terrestrial-Mass Candidate

by Keith CowingApril 19, 2024April 19, 2024

Though free-floating planets (FFPs) that have been ejected from their natal star systems may outpopulate their bound counterparts in the terrestrial-mass range, they remain one of the least explored exoplanet […]

Comparison of bolometric energies and durations of NUV (blue crosses) and optical (red dots) M dwarf flares from this work with those of solar and stellar flares observed with SDO/HMI (black solid stars; Namekata et al. 2017), GALEX (black astericks; Brasseur et al. 2019), DEC (solid diamonds; Webb et al. 2021) and Kepler (open triangles and open squares; Shibayama et al. 2013; Maehara et al. 2015). The cadence sizes are 45 s, 10 s, 20 s, and 1 or 30 min, respectively. The dashed and dotted lines correspond to scaling laws between flare durations and energies corresponding to either constant magnetic field (B) with varying emitting region length scale (L) or constant emitting region length scale with varying magnetic field. -- astro-ph.SR

Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Habitable Zones, Radiation, Space Weather & Heliophysics, Status Report

A Multiwavelength Survey of Nearby M dwarfs: Optical and Near-Ultraviolet Flares and Activity with Contemporaneous TESS, Kepler/K2, Swift, and HST Observations

by Keith CowingApril 19, 2024April 19, 2024

We present a comprehensive multiwavelength investigation into flares and activity in nearby M~dwarf stars. We leverage the most extensive contemporaneous dataset obtained through the Transiting Exoplanet Sky Survey (TESS), Kepler/K2, […]

Figure (a) and (c) show the initial light curve and the river plot for TOI-4622, respectively. The light curve is folded over seven transits and the river plot shows the evolution of the noisy periodic transit signals over the course of the entire light curve. Figure (b) and (d) show the denoised versions of these plots after the implementation of SSA. The SNR of the transit has increased from 13.37 to 15.59. -- astro-ph.EP

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

Singular Spectrum Analysis of Exoplanetary Transits

by Keith CowingApril 9, 2024April 9, 2024

Transit photometry is currently the most efficient and sensitive method for detecting extrasolar planets (exoplanets) and a large majority of confirmed exoplanets have been detected with this method.

TESS

Planet Hunters TESS V: A Planetary System Around A Binary Star, Including A mini-Neptune In The Habitable Zone

Citizen Scientists Help Discover A Habitable Zone Exoplanet In A Binary Star System

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

Long-term Stellar Activity Of M dwarfs: A Combined K2 And TESS Study Of Two Early M-type Stars

Empirical Stability Criteria For 3D Hierarchical Triple Systems I: Circumbinary Planets

TOI-4336 A b: A Temperate Sub-Neptune Ripe For Atmospheric Characterization In A Nearby Triple M-dwarf System

Characterisation Of The TOI-421 Planetary System Using CHEOPS, TESS, and Archival Radial Velocity Data

Searching For Free-Floating Planets with TESS: I. Discovery of a First Terrestrial-Mass Candidate

A Multiwavelength Survey of Nearby M dwarfs: Optical and Near-Ultraviolet Flares and Activity with Contemporaneous TESS, Kepler/K2, Swift, and HST Observations

Singular Spectrum Analysis of Exoplanetary Transits

Relevance of the Avalon Assemblage as an Astrobiological Analog for Icy Ocean Worlds

The Climate and Potential Habitability of a Warm and Oxygenated Mars

Variable X-ray flux May Explain Variable Helium Escape From The Habitable-zone Exoplanet LHS 1140b

Spacetime Contactability in Galactic Civilization Networks: Contact Counts and Percolation

Surprisingly Enriched CO and CH4 in Halley-type Comet 13P/Olbers: Clues to Its Interstellar Heritage