imaging Archives

Left: NIRCam F356W detection of the Fomalhaut C debris disk in scattered light resulting from the MCRDI procedure (Section 4). The image has been smoothed by a gaussian kernel with FWHM of 6.7 pixels (3× the PSF FWHM). The inner software mask has a radius of 1. ′′5 and covers the region of significant residual speckle noise. Logarithmically-spaced black contours are drawn above the maximum for the color stretch to show the peak location of the bright south-western background source. Right: As the image on the left, but with silver contours showing the 1–5 σ levels for the ALMA detection of the disk reported in Cronin-Coltsmann et al. (2021). The gold arrows extend from the locations of the two assumed background sources modeled in Cronin-Coltsmann et al. (2021), showing their expected displacement due to the proper motion of Fomalhaut C (Gaia Collaboration et al. 2022). Both predicted positions are consistent with sources detected in the 2022 NIRCam data, supporting their identity as unassociated background objects. -- astro-ph.EP

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

JWST/NIRCam Detection of the Fomalhaut C Debris Disk in Scattered Light

by Keith CowingMay 2, 2024September 5, 2025

Observations of debris disks offer important insights into the formation and evolution of planetary systems. Though M dwarfs make up approximately 80% of nearby stars, very few M-dwarf debris disks […]

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

SPHERE RefPlanets: Search For Epsilon Eridani b And Warm Dust

by Keith CowingMay 1, 2024August 13, 2025

We carried out very deep VLT/SPHERE imaging polarimetry of the nearby system Eps Eri based on 38.5 hours of integration time with a 600 – 900 nm broadband filter to […]

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

Current Laboratory Performance Of Starlight Suppression Systems, And Potential Pathways To Desired Habitable Worlds Observatory Exoplanet Science Capabilities

by Keith CowingApril 30, 2024April 30, 2024

We summarize the current best polychromatic (10 to 20 % bandwidth) contrast performance demonstrated in the laboratory by different starlight suppression approaches and systems designed to directly characterize exoplanets around […]

Reflectance spectra of all four microbes with biosignatures and wavelength regions annotated. Colors represent regions of the visible wavelength range, and the gray area represents the near-infrared region of the electromagnetic spectrum. Annotated biosignatures for black microbial mat include a chlorophyll absorption feature and a photosynthetic red edge. Orange microbial mat also has a photosynthetic red edge in addition to chlorophyll, phycocyanin, and carotenoid absorptions. Biosignatures within the Arthrobacter sp. spectrum include carotenoids, 43 and Ectothiorhodospira sp. str. BSL-9 has both carotenoid and bacteriochlorophyll-a absorptions. -- astro-ph.EP

Analog Studies, Arctic / Antarctic / Alpine, Biogeochemical Cycles & Geobiology, Biophysics, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Extremeophiles and Extreme Environments, Imaging & Spectroscopy, Microbiology & Virology, Status Report

Detectability of Surface Biosignatures for Directly-Imaged Rocky Exoplanets

by Keith CowingApril 26, 2024April 26, 2024

Modeling the detection of life has never been more opportune. With next generation space telescopes, like the currently developing Habitable Worlds Observatory (HWO) concept, we will begin to characterize rocky […]

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.

Graphical illustration of potential scenarios leading to potentially detectable abiotic O2 and/or O3. Circle molecules identify spectrally active species such as O4 (O2-O2 collisionally induced absorption) that could be used to fingerprint the origin(s) of O2 and/or O3, while the red strike-through indicates species that should be absent. Modern Earth is distinguished by the combination of spectrally active O2, O3, H2O, CO2, and CH4 together with low levels of CO. See section “False Positives for Oxygen and Ozone Biosignatures” in this text for additional details. This figure is reproduced from Meadows et al. (2018) under Creative Commons Attribution License CC-BY. Graphic artist: R. Hasler. -- astro-ph.EP

Astronomy & Telescopes, Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Gaia - Planetary Perspectives, Habitable Zones, Icy Worlds, Imaging & Spectroscopy, Status Report

An Overview Of Exoplanet Biosignatures

by Keith CowingApril 25, 2024April 25, 2024

This chapter reviews proposed exoplanet biosignatures, including their biological origins, observable features, atmospheric sinks, and potentially confounding abiotic sources.

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.

Depths of the eighteen strongest lines in the transit spectra, as well as the metastable helium and calcium infrared triplet lines. The results are shown for the models with a fixed density at the planet radius (right column of Fig. 3). Our computational radial domain extends to 8Rp, corresponding to a maximum absorption of 16.9%, which is reached by various spectral lines. Lines originating from metal atoms (solid) and singly charged ions (dashed) tend to become stronger up to 10x solar metallicity, and then become weaker. Lines originating from doubly or higher charged metal ions (dotted and dash-dotted) keep growing stronger as the metallicity increases. -- astro-ph.EP

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

The Open-source Sunbather Code: Modeling Escaping Planetary Atmospheres And Their Transit Spectra

by Keith CowingApril 24, 2024April 24, 2024

Atmospheric escape is thought to significantly influence the evolution of exoplanets, especially for sub-Jupiter planets on short orbital periods. Theoretical models predict that hydrodynamic escape could erode the atmospheres of […]

Reflectance spectra of purple and blue-green cyanobacteria (top), PNSB (N = 10) (middle), and, PSB (N = 12) (bottom) where N denotes the number of samples. Labels of main pigments identified: (a) Chl-a Soret band, (b) Carotenoids, (c) Chl-a Qx band, (d) Phycobilins, (e) Chl-a Qy band, (f) BChl-a Soret band, (g) BChl-a, b Qx band, (h) BChl-a Qy band, and (i) BChl-b Qy band. Dry samples (right) show a stronger reflectance than fresh samples (left), water absorption features at 1490 and 1900 nm are stronger in the fresh samples. The reflectance of the culture medium alone is shown as a dotted line for control.

Astrochemistry, Astronomy & Telescopes, Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Icy Worlds, Imaging & Spectroscopy, Microbiology & Virology, Status Report, Water/Hycean Worlds & Oceanography

Purple Is The New Green: Biopigments And Spectra Of Earth-like Purple Worlds

by Keith CowingApril 18, 2024April 18, 2024

With more than 5,500 detected exoplanets, the search for life is entering a new era. Using life on Earth as our guide, we look beyond green landscapes to expand our […]

Variable stars of the catalog in the “period–amplitude” plane classified by type: eclipsing EA, EW, EB|EW, EP|BD|EA; pulsating RR, DSCT|GDOR|SXPHE (designated DGS), LPV; rotating rot, as well as a group of unambiguously unidentified types EW|rot|DGS|RR (see text for description). -- astro-ph.SR

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

Catalog Of Variable Stars In The WD 0009+501 and GRW +708247 Fields Based On Photometric Survey Data On Transiting Exoplanets

by Keith CowingApril 18, 2024April 18, 2024

We present a catalog of 150 variable stars, including 13 stars with exoplanet candidates. 37 stars were identified as variables for the first time.

imaging

JWST/NIRCam Detection of the Fomalhaut C Debris Disk in Scattered Light

SPHERE RefPlanets: Search For Epsilon Eridani b And Warm Dust

Current Laboratory Performance Of Starlight Suppression Systems, And Potential Pathways To Desired Habitable Worlds Observatory Exoplanet Science Capabilities

Detectability of Surface Biosignatures for Directly-Imaged Rocky Exoplanets

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

An Overview Of Exoplanet Biosignatures

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

The Open-source Sunbather Code: Modeling Escaping Planetary Atmospheres And Their Transit Spectra

Purple Is The New Green: Biopigments And Spectra Of Earth-like Purple Worlds

Catalog Of Variable Stars In The WD 0009+501 and GRW +708247 Fields Based On Photometric Survey Data On Transiting Exoplanets

A Martian Horizon Last Monday Afternoon

Habitable-zone Earths At The Detection Frontier: Measured Completeness And False-alarm Rate Of A Transit Pipeline For The PLATO M-dwarf Sample

A Homogeneous Survey Of JWST MIRI Transmission Spectra Of 10 Exoplanets

Retrieving Ocean Glint Reflectance Signatures From Directly Imaged Earth-like Exoplanets

Analytical Platform (Microsampling, Catapulting, Trapping, and LIBS) for the Characterization of Discrete Domains in Samples of Astrochemical Interest