TESS Archives - Page 32 of 35 - Astrobiology

The phased light curve of LTT 1445A, highlighting the transit of planet c. The detrended TESS observations are show in black and our new HST observations in orange. In blue, we show our MAP orbital solution. -- astro-ph.EP

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

HST/WFC3 Light Curve Confirms the Closest Exoplanet to Transit an M Dwarf is Terrestrial

by Keith CowingJuly 7, 2023July 7, 2023

Previous studies of the exoplanet LTT 1445Ac concluded that the light curve from the Transiting Exoplanet Survey Satellite (TESS) was consistent with both grazing and non-grazing geometries. As a result, […]

The mass-radius diagram for small planets. Data comes from the NASA Exoplanet Archive’s planetary systems table, as accessed on 2022-Nov-17 (NASA Exoplanet Archive 2022). Planets with mass and radius measurements to better than 50% and 15% fractional precision, respectively, are shown as the circles with 1σ error bars. The opacity of the points is proportional to mass measurement precision (i.e., a less precise mass measurement translates to a more transparent marker). Color corresponds to equilibrium temperature assuming zero Bond albedo and full day-night heat redistribution. Underlying contours come from Gaussian kernel density estimation (KDE) of the confirmed planets described above. The 11 transiting planets from this work are overplotted as the stars. Mass upper limits (98% confidence) are plotted for HD 25463 c (yellow star near the radius valley) and HIP 9618 c (labeled). A handful of composition curves are plotted for reference (Lopez & Fortney 2014; Zeng et al. 2016, 2019). The curves of H/He envelopes atop Earth-like cores come from Lopez & Fortney (2014) and are chosen for a planet receiving 10× Earth’s incident flux (i.e., Teq ≈ 500 K) orbiting a 10 Gyr-old, solar-metallicity star. The 50% water plus 50% Earth-like composition curve from Zeng et al. (2019) is calculated for a fixed temperature of 700 K at 100 bar, which determines the planetary model’s specific entropy. Note that familiar features of the planet radius distribution are now visible as two-dimensional features in the mass-radius plane. These include the radius valley (Fulton et al. 2017; Van Eylen et al. 2018), with center near 6 M⊕ and 1.8 R⊕, and the radius cliff (e.g., Kite et al. 2019), as seen by in the steep drop off in the number of planets around 3 R⊕. -- astro-ph.EP

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

The TESS-Keck Survey. XVI. Mass Measurements for 12 Planets in Eight Systems

by Keith CowingJune 29, 2023June 29, 2023

With JWST’s successful deployment and unexpectedly high fuel reserves, measuring the masses of sub-Neptunes transiting bright, nearby stars will soon become the bottleneck for characterizing the atmospheres of small exoplanets […]

TESS target pixel file images of TOI-2084 observed in Sector 16 (left panel) and TOI-4184 observed in Sector 1 (right panel), made by tpfplotter (Aller et al. 2020). Red dots show the location of Gaia DR3 sources, and the red shaded region shows the photometric apertures used to extract the photometric measurements. -- astro-ph.EP

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

TOI-2084 b and TOI-4184 b: Two New Sub-Neptunes Around M Dwarf Stars

by Keith CowingJune 28, 2023June 28, 2023

We present the discovery and validation of two TESS exoplanets orbiting nearby M dwarfs: TOI-2084b, and TOI-4184b. We characterized the host stars by combining spectra from Shane/Kast and Magellan/FIRE, SED […]

The result of the transit injection-and-recovery test for the planet candidate. Blue to light green represents an increasing detection possibility of its transit signal (assuming it transits). The solid blue histogram in the top panel illustrates the average number of transits within the TESS time baseline. The foreground yellow solid lines mark the six possible orbital solutions of the planet candidate found in Juliet. -- astro-ph.EP

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

A Transiting Super-Earth in the Radius Valley and An Outer Planet Candidate Around HD 307842

by Keith CowingJune 26, 2023June 26, 2023

We report the confirmation of a TESS-discovered transiting super-Earth planet orbiting a mid-G star, HD 307842 (TOI-784). The planet has a period of 2.8 days, and the radial velocity (RV) […]

Target Pixel File (TPF) from TESS sector 1 with TOI-908 marked with a white cross. Other sources from Gaia DR2 are marked with red circles sized by scaled magnitudes relative to the target, ranked by distance. The aperture mask is indicated by the red outline. -- astro-ph.EP

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

TOI-908: A Planet At The Edge Of The Neptune Desert Transiting A G-type Star

by Keith CowingJune 19, 2023June 19, 2023

We present the discovery of an exoplanet transiting TOI-908 (TIC-350153977) using data from TESS sectors 1, 12, 13, 27, 28 and 39. TOI-908 is a T = 10.7 mag G-dwarf […]

Observed and best-fit model light-curves (one transit event) for KELT-2 A b, KELT-3 b, KELT-4 A b and KELT-11 b. For each observed transit, Top: the unprocessed light-curve (cyan), light-curve after wavelet denoising (magenta), the best-fit transit model (blue). Middle: the residual after modeling without GP regression (magenta), the mean (blue) and 1-σ interval (cyan) of the best-fit GP regression model. Bottom: mean residual flux (blue). -- astro-ph.EP

Astronomy & Telescopes, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Habitable Zones, Imaging & Spectroscopy, Status Report

Precise Transit Photometry Using TESS: Updated Physical Properties for 28 Exoplanets Around Bright Stars

by Keith CowingJune 5, 2023June 5, 2023

The TESS follow-up of a large number of known transiting exoplanets provide unique opportunity to study their physical properties more precisely.

Left: HAT-P-33b observational and theoretical light curves using TESS sector 45 data; Right: The observational light curve of HAT-P-32b from this study in the 𝑉 filter and the theoretical light curve. -- astro-ph.EP

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

Ephemeris Updates For Seven Selected HATNet Survey Transiting Exoplanets

by Keith CowingJune 2, 2023June 2, 2023

We refined the ephemeris of seven transiting exoplanets HAT-P-6b, HAT-P-12b, HAT-P-18b, HAT-P-22b, HAT-P-32b, HAT-P-33b, and HAT-P-52b. We observed 11 transits from eight observatories in different filters for HAT-P-6b and HAT-P-32b.

Panel (a): radius and orbital period for all TKS planets, with stellar mass shown as a color scale. Grey background points show the distribution of planets from the CKS sample (Petigura et al. 2022). The radius gap, as defined by Petigura et al. (2022), is shown as the orange shaded region. The Hot Neptune desert, as defined by Mazeh et al. (2016), is shown as the region marked off by black dashed lines. Panel (b): same as (a), except x-axis is Sinc. Panel (c): same as (a), except x-axis is M⋆ and color scale is P. Panel (d): same as (c), except x-axis is [Fe/H]. -- astro-ph.SR

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

The TESS-Keck Survey. XV. Precise Properties of 108 TESS Planets and Their Host Stars

by Keith CowingJune 2, 2023June 2, 2023

We present the stellar and planetary properties for 85 TESS Objects of Interest (TOIs) hosting 108 planet candidates which comprise the TESS-Keck Survey (TKS) sample.

WASP-18 b, seen in an artist concept, is a gas giant exoplanet 10 times more massive than Jupiter that orbits its star in just 23 hours. Researchers used NASA’s James Webb Space Telescope to study the planet as it moved behind its star. Temperatures there reach 5,000 degrees Fahrenheit (2,700 C). Credit: NASA/JPL-Caltech (K. Miller/IPAC)

Astrochemistry, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Press Release

Webb Maps and Finds Traces of Water in an Ultra-hot Gas Giant’s Atmosphere

by Keith CowingMay 31, 2023May 31, 2023

There’s an intriguing exoplanet out there – 400 light-years out there – that is so tantalizing that astronomers have been studying it since its discovery in 2009. A year for […]

Black crosses: TESS lightcurve around the transits of planet b, after phasing by the planet’s period against the adopted ephemeris and the correction against gradients in the off-eclipse sections (indicated by the orange vertical dashed lines) as described in Sect. 2. Green crosses: The same curve, after a boxcar smoothing over 100 phased data points and posterior binning over 50 points. We note that the average time-increment between the binned points is 126 seconds, which is very similar to the 120 s temporal resolution of TESS lightcurves. The red curve is the transit model generated with UTM/UFIT, described in Appendix C. -- astro-ph.EP

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

TOI-1416: A Ssystem With A Super-Earth Planet With A 1.07d Period

by Keith CowingMay 31, 2023May 31, 2023

TOI 1416 (BD+42 2504, HIP 70705) is a V=10 late G or early K-type dwarf star with transits detected by TESS. Radial velocities verify the presence of the transiting planet […]