Stellar Contamination Archives

Normalized white light curves of TRAPPIST-1 c and TRAPPIST-1 b observed with JWST/NIRSpec PRISM during their quasi-simultaneous transits on July 9, 2024. Top panel: A schematic of the geometry of the quasi-simultaneous transits is displayed at the top. The blue circles represent the data points after removing the systematics model (a combination of a linear slope and a Gaussian Process, see Section 3.2). The solid black line indicates the fitted transit model. The data have been binned in time from the original 10,208 integrations to the 341 points shown here to accommodate the computation of the Gaussian Process systematics model. Horizontal lines labeled S1 through S5 mark the time bins used in the out-of-transit stellar analysis (see Section 3.1). The inset displays a histogram of the residuals after subtracting the combined transit and systematics model, compared to a Gaussian distribution with a standard deviation equal to the mean measurement error plus a fitted white noise term. Bottom panel: Residuals after subtracting both the transit and systematic models. -- astro-ph.EP

Astrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biophysics, Imaging & Spectroscopy, Interstellar, Status Report

Stellar Contamination Correction Using Back-to-Back Transits of TRAPPIST-1 b and c

by Keith CowingDecember 24, 2024December 24, 2024

Stellar surface heterogeneities, such as spots and faculae, often contaminate exoplanet transit spectra, hindering precise atmospheric characterization.

The Bayes Factor resulting from the difference between the ln(E) of the stellar activity model minus that of the base model, divided by Case number. For an explanation of the data sets considered in each Case, we refer the reader to Table 1. The coloured thresholds indicate the strength of the evidence, with negative values favouring the base model over the contamination model. Multiple solutions might be found by the retrieval in certain scenarios, however here we present either the solution with the highest Bayesian evidence if both models appear physically motivated, or the most physically motivated of the two solutions. -- astro-ph.EP

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

A Population Analysis of 20 Exoplanets Observed from the Optical of the Near-infrared Wavelengths with HST: Evidence for Widespread Stellar Contamination

by Keith CowingApril 26, 2024April 26, 2024

We present a population study of 20 exoplanets, ranging from Neptune-like to inflated hot-Jupiter planets, observed during transit with the STIS and WFC3 instruments aboard the Hubble Space Telescope.

Stellar Contamination

Stellar Contamination Correction Using Back-to-Back Transits of TRAPPIST-1 b and c

A Population Analysis of 20 Exoplanets Observed from the Optical of the Near-infrared Wavelengths with HST: Evidence for Widespread Stellar Contamination

Training For Astrobiology Spelunking On Mars

Mars Perseverance Rover’s Panoramic View of Broom Point

Planets Orbiting Barnard’s Star Seem To Be Small, Strange, And Utterly Uninhabitable

Experimental Astrochemistry And Machine Learning Unravel The Formation Of Oxygen-bearing Organic Molecules In Extraterrestrial Ices

Bacteria Form Herds To Survive Predators, Offering Fresh Insight Into Earth’s Carbon Cycle