Stellar Cartography Archives

Full NIRSpec and MIRI spectra for EDJ183-b and Per-emb35. The the ice absorption features are shaded in color. -- astro-ph.SR

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

JOYS+ Study Of Solid State 12C/13C Isotope Ratios In Protostellar Envelopes: Observations of CO and CO2 Ice with JWST

by Keith CowingOctober 21, 2024

The carbon isotope ratio is a powerful tool for studying the evolution of stellar systems. Recent detections of CO isotopologues in disks and exoplanet atmospheres pointed towards significant fractionation in […]

The RV semi-amplitude of a Neptune-mass planet in the middle of the OHZ for each of the stars on the Mamajek & Stapelfeldt (2024) HWO target list, shown as a function of stellar effective temperature (left panel) and as a histogram (right panel). The vertical dashed line indicates the Kraft break at Teff = 6250 K, beyond which precision RV measurements become increasingly challenging due to the rapid rotation of the stars and the associated broadening of the stars’ absorption lines. The majority these hypothetical HZ Neptunes would have RV semi-amplitudes below 1.5m s−1 making them challenging detections, especially at the 100+ day orbital periods of these HZs. Long term, dedicated EPRV survey efforts would be required to detect these potential perturbers and determine what portions of each star’s HZ remains dynamically viable for Earth analog planets. For the hottest stars, similar surveys via precision astrometry could provide complementary insights into the star’s HZ inhabitants. -- astro-ph.EP

Astronomy & Telescopes, Exoplanets, -moons, -comets, Habitable Zones, Status Report, Stellar Cartography

Hic Sunt Dracones: Uncovering Dynamical Perturbers Within the Habitable Zone

by Keith CowingOctober 17, 2024October 17, 2024

The continuing exploration of neighboring planetary systems is providing deeper insights into the relative prevalence of various system architectures, particularly with respect to the solar system.

Left: A zoom-in on the stacked Kp-band image of MOA-2011-BLG-262, with the brighter source star near center and the faint lens star candidate indicated with the cross-hair. Middle: Zoomed-in frame with a single-PSF model fit to the source star and subtracted from the frame, the remaining flux comes primarily from the lens and is indicated with the cross-hair. The other bright nearby stars are also subtracted with the same PSF model. Right: Zoomed-in frame with the PSF model fit and subtracted from the source and lens stars. North is up, East is left in all frames. Note there are several faint ambient field stars that are at or below the default detection threshold in DAOPHOT. -- astro-ph.EP

Astronomy & Telescopes, Exoplanets, -moons, -comets, Gaia Mission, Gas Giants, Imaging & Spectroscopy, Interstellar, Status Report, Stellar Cartography

A Candidate High-Velocity Exoplanet System In The Galactic Bulge

by Keith CowingOctober 16, 2024November 16, 2024

We present an analysis of adaptive optics (AO) images from the Keck-I telescope of the microlensing event MOA-2011-BLG-262. The original discovery paper by Bennett et al. 2014 reports two distinct […]

[C/Fe], [N/Fe], and [O/Fe] abundances and C/O and N/O ratios as functions of [Fe/H] for observed dwarfs (left panel) and giants (right panel). Thin disc planet-hosting stars are represented by green circles, while pink circles indicate stars from the thick disc. Circles filled with both colours represent "in between stars" to thin and thick discs. The (coloured) diamond symbols represent the planets-hosts from Tautvaišiene et al. ˙ (2022). The comparison sample results are taken from Stonkute et al. (2020); Tautvaišien ˙ e et al. (2022) and indicated by empty grey squares (thin ˙ disc) and triangles (thick disc). -- astro-ph.SR

Astrochemistry, Astronomy & Telescopes, Imaging & Spectroscopy, Status Report, Stellar Cartography

Chemical Composition of Planetary Hosts: C, N, and a-element Abundances

by Keith CowingOctober 12, 2024

Accurate atmospheric parameters and chemical composition of planet-hosting stars are crucial for characterising exoplanets and understanding their formation and evolution.

The left panel is Hubble's actual view of Uranus – the planet is a light blue sphere, with a white circle covering the right half of the planet (the southern pole). The right panel is the actual view of Uranus from New Horizons. The planet appears as a tiny whiteish dot. -- STSCI/NASA/SwRI (larger image)

Astrogeology, Astronomy & Telescopes, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Gas Giants, Ice Giant, Icy Worlds, Imaging & Spectroscopy, Mapping, Geodesy, Cartography, Bathymetry, Missions & Hardware, Press Release, Stellar Cartography, Uranus

Exoplanet Analysis Practice Using Uranus, Hubble, And New Horizons

by Keith CowingOctober 10, 2024May 12, 2025

NASA’s Hubble Space Telescope and New Horizons spacecraft simultaneously set their sights on Uranus recently, allowing scientists to make a direct comparison of the planet from two very different viewpoints. […]

Top: The high-resolution spectrum of the T-dwarf Gl229 B analyzed using ExoJAX2 (Kawashima et al. submitted) with ∼ 108 total molecular absorption lines considered. The blue solid line shows the median value, while the blue shaded regions indicate the 95% credible interval. Black points represent the observed Subaru/IRD data. The periodic increases in the residuals observed correspond to the gaps between orders. Bottom: Medium-resolution transmission spectrum of WASP-39 b analyzed using ExoJAX2 and the HMC-NUTS method. The black solid line represents the model derived from the median values of each parameter obtained through MCMC sampling, with the 95% credible interval shaded in gray. The blue points show the observed planetary radii from JWST NIRSpec/G395H observations. The vertical axis on the left shows the planetary radius, while the vertical axis on the right displays the corresponding pressure. The contributions of CO, CO2, H2O, SO2, gray clouds, and collision-induced absorption (CIA) are represented by colored shading with an offset of -0.01 Rs. -- astro-ph.SR

AI - Data - Apps - Cybernetics, Apps - Games, Astronomy & Telescopes, Brown Dwarfs, Imaging & Spectroscopy, Status Report, Stellar Cartography

Differentiable Modeling of Planet and Substellar Atmosphere: High-Resolution Emission, Transmission, and Reflection Spectroscopy with ExoJAX2

by Keith CowingOctober 10, 2024October 10, 2024

Modeling based on differentiable programming holds great promise for astronomy, as it can employ techniques such as Hamiltonian Monte Carlo, gradient-based optimization, and other machine learning techniques.

The uGMRT image (blue contours) of the GJ 1151 field at 218 MHz overlaid on the ZTF zg band image (epoch J2021.17). The red circle marks the position of GJ 1151 at the time of observations (epoch J2021.21), and the green circle marks the position of the radio source detected with LOFAR (epoch J2014.454) -- astro-ph.EP

Space Weather & Heliophysics, Status Report

uGMRT Survey of EXoplanets Around M-dwarfs (GS-EXAM): Radio observations of GJ 1151

by Keith CowingOctober 5, 2024October 5, 2024

Coherent radio emission with properties similar to planetary auroral signals has been reported from GJ 1151, a quiescent, slow-rotating mid-M star, by the LOFAR Two-metre (120-170 MHz) Sky Survey (LoTSS).

Gigantic infrared map of the Milky Way, ESO Larger images

Astronomy & Telescopes, Imaging & Spectroscopy, Press Release, Stellar Cartography

ESO Telescope Captures The Most Detailed Infrared Map Ever Of Our Home Galaxy

by Keith CowingSeptember 27, 2024September 27, 2024

Astronomers have published a gigantic infrared map of the Milky Way containing more than 1.5 billion objects ― the most detailed one ever made. Using the European Southern Observatory’s VISTA […]

GaiaPMEX constraints on mass and sma of a candidate companion around β Pictoris. Same caption as Fig. 19. The yellow and pink dots show the properties of the known exoplanet companions b & c in this system, with smab=9.8±0.4 au and mb=10–11 MJ , and smac=2.7±0.02 au and Mc=7.8±0.4 MJ (Lagrange et al. 2020). -- astro-ph.SR

Astronomy & Telescopes, Exoplanets, -moons, -comets, Gaia Mission, Imaging & Spectroscopy, Missions & Hardware, Status Report, Stellar Cartography

Searching For Substellar Companion Candidates With Gaia. I. Introducing The GaiaPMEX Tool

by Keith CowingSeptember 26, 2024November 16, 2024

The Gaia mission is expected to yield the detection of several thousands of exoplanets, perhaps at least doubling the number of known exoplanets. Although the harvest is expected to occur […]

Left: The planet radius and equilibrium temperature for the 159 massive exoplanets (0.5MJ < mass < 10MJ ) with homogeneous high precision [Fe/H]. Right panel is the radius anomaly vs. the equilibrium temperature for the same planets. The line is the best fit of a power law. -- astro-ph.EP

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

SWEET-Cat: A View On The Planetary Mass-radius Relation

by Keith CowingSeptember 20, 2024September 20, 2024

SWEET-Cat (Stars With ExoplanETs Catalogue) was originally introduced in 2013, and since then, the number of confirmed exoplanets has increased significantly. A crucial step for a comprehensive understanding of these […]