Spectroscopy Archives

Modeled mixtures of magnesium rich pyroxenes and olivines plotted alongside the spectrum of 267 Tirza and 1268 Libya. The addition of pyroxene to the olivine mixtures changes the behavior of the spectrum at long wavelengths, broadening this emission feature from the distinct emission peak(s) seen in the spectra of olivine and pyroxene alone. Spectral features of olivine are marked in light green and of pyroxenes are marked in dark purple to highlight commonalities with the asteroid spectra. The feature at 19.5 µm is common to both olivine and pyroxene. The spectrum of 267 Tirza in particular shows evidence of both olivine and pyroxene. All mixtures shown here contain both amorphous and crystalline silicates mixed in a 3:1 ratio, while the proportion of olivine and pyroxene is varied. The shaded grey box highlights the location of a known artefact in the SL Spitzer data (the SL teardrop). Spectra of crystalline silicates are sourced from Koike et al. (2003) and Chihara et al. (2002), spectra of amorphous silicates are derived from optical constants from J¨ager et al. (1994); Dorschner et al. (1995) and J¨ager et al. (2003) (see text for modeling details and silicate compositions). -- astro-ph.EP

Astrochemistry, Astrogeology, Comets and Asteroids, Imaging & Spectroscopy, Meteorites & Asteroids, Status Report

Comparative Mid-Infrared Spectroscopy of Dark, Primitive Asteroids: Does Shared Taxonomic Class Indicate Shared Silicate Composition?

by Keith CowingMay 1, 2024May 1, 2024

Primitive asteroids with low albedos and red slopes in the visible and near infrared (VNIR) are found in both the Main Belt and the Jupiter Trojan clouds.

Astronomy & Telescopes, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Gas Giants, Imaging & Spectroscopy, Press Release

Clouds Blanket The Night Side Of The Hot Exoplanet WASP-43b

by Keith CowingMay 1, 2024May 1, 2024

Using the James Webb Space Telescope (JWST), a team of astronomers, including scientists from MPIA, constructed a global temperature map of the hot, gas giant exoplanet WASP-43b. The nearby parent […]

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.

This artist’s concept shows what the hot gas giant exoplanet WASP-43 b could look like. WASP-43 b is a Jupiter-sized planet that orbits a star roughly 280 light-years away, in the constellation Sextans. The planet orbits at a distance of about 0.014 AU (1.3 million miles), completing one circuit in about 19.5 hours. Because it is so close to its star, WASP-43 b is probably tidally locked: its rotation rate and orbital period are the same, such that one side faces the star at all times. -- ESA

Astrochemistry, Astrogeology, Astronomy & Telescopes, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Exoplanets, -moons, -comets, Gas Giants, Imaging & Spectroscopy, Mapping, Geodesy, Cartography, Bathymetry, Press Release

Webb Maps Weather On Hot Gas-giant Exoplanet WASP-43b

by Keith CowingApril 30, 2024April 30, 2024

An international team of researchers has successfully used NASA’s James Webb Space Telescope to map the weather on the hot gas-giant exoplanet WASP-43 b.

Astrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Imaging & Spectroscopy, Status Report

Rotational Spectrum and First Interstellar Detection of 2-Methoxyethanol Using ALMA Observations of NGC 6334I

by Keith CowingApril 29, 2024April 29, 2024

We use both chirped-pulse Fourier transform and frequency modulated absorption spectroscopy to study the rotational spectrum of 2-methoxyethanol in several frequency regions ranging from 8.7-500 GHz.

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 […]

log(N/O) vs. 12+log(O/H) diagram. The color bars indicate the 𝜎frac value (left panel) and the H𝛼 fluxes in units of 10−17 erg/s/cm2 /spaxel (right panel) for each object in our sample -- astro-ph.GA

Astrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Imaging & Spectroscopy, Status Report

Chemical Abundances Of LINER Galaxies — Nitrogen Abundance Estimations

by Keith CowingApril 26, 2024April 26, 2024

In this work, we investigated the nitrogen and oxygen abundances in a sample of galaxies with Low Ionization Nuclear Emission Regions (LINERs) in their nucleus.

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.

Distribution of confirmed exoplanets in mass-period space. Planets with spectroscopic measurements that constrain their atmospheric properties are shown as dark points, those without are shown as light points. This review article focuses on atmospheric characterization of transiting exoplanets, i.e. the dark purple pentagon symbols. Solar system planets are shown as yellow circles for context. Both the radial velocity and transit techniques are most sensitive to detecting massive planets on close-in orbits, while the direct imaging technique is most sensitive to young, self-luminous planets on relatively wide orbits. Figure adapted from Currie et al. (2023). -- astro-ph.EP

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

Transiting Exoplanet Atmospheres In The Era of JWST

by Keith CowingApril 25, 2024April 25, 2024

The field of exoplanet atmospheric characterization has recently made considerable advances with the advent of high-resolution spectroscopy from large ground-based telescopes and the commissioning of the James Webb Space Telescope […]

Spectroscopy

Comparative Mid-Infrared Spectroscopy of Dark, Primitive Asteroids: Does Shared Taxonomic Class Indicate Shared Silicate Composition?

Clouds Blanket The Night Side Of The Hot Exoplanet WASP-43b

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

Webb Maps Weather On Hot Gas-giant Exoplanet WASP-43b

Rotational Spectrum and First Interstellar Detection of 2-Methoxyethanol Using ALMA Observations of NGC 6334I

Detectability of Surface Biosignatures for Directly-Imaged Rocky Exoplanets

Chemical Abundances Of LINER Galaxies — Nitrogen Abundance Estimations

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

Transiting Exoplanet Atmospheres In The Era of JWST

Astrobiologist Dale Andersen’s Antarctic Field Report: 20 Oct 2026: Wheels Down In Cape Town

Astrobiology Primer

The Evolution Of Oxygen, Temperature, And Marine Aerobic Habitat For Animals Over The Last Billion Years Of Earth History

Icy Ocean Planet Recon: Saildrone Research Fleet To Circle Antarctica For 5 Years

Water As We’ve Never Known It: Testing Water Beyond Earth-like Conditions