LTT 1445A Archives - Astrobiology

UVIS (G280) white light curves for all three observed transits. The +1 and −1 orders are fitted separated and are shown on the top and bottom rows in red and blue, respectively. The raw light curve data are shown in dark grey, with the light grey points in the +1 order being the outlier points excluded in the white light curve fits. The model fits to the data are shown as red and blue points, and their residuals are shown individually below each plot. The full phase model, along with the systematics-removed points, are shown offset above the raw data, seen as a solid line and black points, respectively. -- astro-ph.EP

Astrochemistry, Astrogeology, Astronomy & Telescopes, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Status Report

An HST Transmission Spectrum of the Closest M-Dwarf Transiting Rocky Planet LTT 1445Ab

by Keith CowingOctober 18, 2024October 18, 2024

Which rocky exoplanets have atmospheres, and which do not? This presumably simply question is the first that must be answered in the pathway toward understanding the prevalence of nearby habitable […]

The average emission spectrum of LTT 1445A b compared to models with and without atmospheres. (Left) Forward models are shown for 100% CO2, αB = 0.1 atmospheres with at different surface pressures (ps). (Right) Planck thermal spectra are shown at 0 K (no eclipse), 431 K (αB = 0, f-factor = 1/4), 549 K (αB = 0, f-factor = 2/3), and best-fit dayside temperature (525 K). The displayed χ 2 incorporates model uncertainty from the uncertain system parameters, is for 16 degreess of freedom, and is translated into a probability with which each model can be disfavored, expressed as a number of σ in a Gaussian distribution. -- astro-ph.EP

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

The Thermal Emission Spectrum of the Nearby Rocky Exoplanet LTT 1445A b from JWST MIRI/LRS

by Keith CowingOctober 18, 2024October 18, 2024

The nearby transiting rocky exoplanet LTT 1445A b presents an ideal target for studying atmospheric retention in terrestrial planets orbiting M dwarfs. It is cooler than many rocky exoplanets yet […]

This is an artist's concept of the nearby exoplanet LTT 1445Ac, which is the size of Earth. The planet orbits a red dwarf star. The star is in a triple system, with two closely orbiting red dwarfs seen at upper right. The black dot in front of the bright light-red sphere at image center is planet LTT 1445Ac transiting the face of the star. The planet has a surface temperature of roughly 500 degrees Fahrenheit. In the foreground at lower left is another planet in the system, LTT 1445Ab. The view is from 22 light-years away, looking back toward our Sun, which is the bright dot at lower right. Some of the background stars are part of the constellation Boötes. NASA, ESA, Leah Hustak (STScI)

Astronomy & Telescopes, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Press Release

Hubble Measures the Size of the Nearest Transiting Earth-Sized Planet

by Keith CowingNovember 16, 2023November 16, 2023

NASA’s Hubble Space Telescope has measured the size of the nearest Earth-sized exoplanet that passes across the face of a neighboring star. This alignment, called a transit, opens the door […]

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, […]

TPF of LTT 1445

Astronomy & Telescopes, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Press Release

Planetary System Around LTT 1445A Unveiled By ESPRESSO: Multiple Planets In A Triple M-dwarf System

by Keith CowingOctober 18, 2022

We present radial velocity follow-up obtained with ESPRESSO of the M-type star LTT 1445A (TOI-455), for which a transiting planet b with an orbital period of~5.4 days was detected by […]