Stellar Cartography Archives

Light curves of the microlensing event OGLE-2015-BLG-1609 with three microlensing model topologies for positive values of the impact parameter u0. The difference between the topologies is visible only during the planetary anomaly (HJD ∼ 2457270; see Fig. 2). The photometry comes from the OGLE, MOA, RoboNet, and MiNDSTEp projects. -- astro-ph.EP

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

OGLE-2015-BLG-1609Lb: Sub-jovian Planet Orbiting A Low-mass Stellar Or Brown Dwarf Host

by Keith CowingDecember 18, 2024December 18, 2024

We present a comprehensive analysis of a planetary microlensing event OGLE-2015-BLG-1609. The planetary anomaly was detected by two survey telescopes, OGLE and MOA.

Artist's impression of a Sun-like star exhibiting a superflare as seen in visible light Credit MPS/Alexey Chizhik

Atmospheres, Climate, Weather, Biophysics, Habitable Zones, Press Release, Radiation, Space Weather & Heliophysics, Stellar Cartography

Sun-like Stars Produce Superflares Roughly One Per Century

by Keith CowingDecember 16, 2024December 16, 2024

There is no question that the Sun is a temperamental star, as alone this year’s unusually strong solar storms prove. Some of them led to remarkable auroras even at low […]

Composite images of PDS 70 in pseudo color. The left panel shows previous ALMA observations at 0.87 mm, and the right panel shows new ALMA observations at 3 mm. The composite image combines millimeter/submillimeter continuum images with ALMA (red), an infrared continuum image from W. M. Keck Observatory (green), and an optical image of a hydrogen emission line taken with the VLT (blue). The images show that the dust emissions observed with ALMA form a ring-like structure outside the planets detected by Keck and the VLT. At a wavelength of 3 mm, the dust emission can be seen prominently concentrated in the northwest direction (upper right of the image). Credit: ALMA (ESO/NAOJ/NRAO), W. M. Keck Observatory, VLT (ESO), K. Doi (MPIA)

Astrochemistry, Astrogeology, Astronomy & Telescopes, Exoplanets, -moons, -comets, Interstellar, Press Release, Stellar Cartography

ALMA Reveals the Birthplace of a Planetary System

by Keith CowingDecember 14, 2024December 14, 2024

The Atacama Large Millimeter/submillimeter Array (ALMA) has successfully observed a site of planet formation by detecting a high concentration of dust grains, a planet-forming material, outside the orbits of just-formed […]

Astronomy & Telescopes, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Icy Worlds, Mapping, Geodesy, Cartography, Bathymetry, Stellar Cartography, Water/Hycean Worlds & Oceanography

A Map Of Many Worlds: Icy And Rocky Planets

by Keith CowingDecember 9, 2024December 9, 2024

This poster visualizes over 800 known exoplanets believed to be rocky or terrestrial, arranged by the amount of heat they receive, comparing their relative sizes and providing a window to […]

Intensity raster map with averaged spectral intensity represented in log-scale. Gray dashed lines delimit the region containing the planetary limb. These represent two concentric ellipses centered at (X, Y) = (57″, 39.75″), marked with a red cross. Two vertical dashed lines were included to outline the region of the limb where the atmospheric aureole is observed. Two solid gray lines delimit the location of the solar limb. -- MDPI

Ariel Mission, Astronomy & Telescopes, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Gaia - Planetary Perspectives, Habitable Zones, Icy Worlds, Press Release, Space Weather & Heliophysics, Stellar Cartography, Terraforming & Geoengineering, Venus, Water/Hycean Worlds & Oceanography

A Rare Venus Solar Transit Helps Unravel Exoplanet Atmospheres

by Keith CowingDecember 6, 2024December 6, 2024

In the next decade, researchers will start probing the atmosphere of planets as small as Earth and Venus orbiting nearby stars. But although these two Solar System planets are similar […]

Trajectories of the Sun on the R-tbk planes for the evolving model. The orange lines show the trajectories of “trapped migrators,” while the green lines depict “untrapped migrators.” Thick lines represent the trajectories of Sun-like particles, while thin lines show orbits similar to those indicated by the thick lines. The background colors with contours indicate (a) the SFR density (ΣSFR) and (b) lethal GRB event rates (NGBR), based on the Galactic chemical evolution model (Baba et al. 2023). The black dashed lines indicate the locations of the bar’s CR and OLR radii. -- astro-ph.GA

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

Solar System Migration Points to a Renewed Concept: Galactic Habitable Orbits

by Keith CowingDecember 5, 2024December 5, 2024

Astrophysical evidence suggests that the Sun was born near 5 kpc from the Galactic center, within the corotation radius of the Galactic bar, around 6-7 kpc.

CASBI pipeline. In our analysis the Template Library is fixed to the NIHAO simulations. The choice of the Template Library incorporates all the assumptions that we make on the chemical enrichment histories of Galaxies, the dynamical effects that accreted objects undergo, and the cosmology, making this part the principal cause of possible misspecification. We sample non-repeated subhalos aiming to reproduce a Luminosity function N(< L), [17] with fixed total stellar mass budget of the halo [11]. The SBI pipeline can incorporate a Surrogate Simulator to perform the sequential version of NPE. The Observational Realism encapsulates all effects bridging the gap between simulation and observation (e.g. observational uncertainties, selection functions, realistic in-situ stars background, etc.). -- astro-ph.GA

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

CASBI – Chemical Abundance Simulation-Based Inference for Galactic Archeology

by Keith CowingNovember 27, 2024

Galaxies evolve hierarchically through merging with lower-mass systems and the remnants of destroyed galaxies are a key indicator of the past assembly history of our Galaxy. However, accurately measuring the […]

Upper panels: Cosmic star formation rate density, as computed with our extension of the SP21 model (dashed black line) and as given by the original SP21 model (dot-dashed red line). In the left panel, we further show with the empirical fit (dotted black line) to a compilation of observational data provided by Madau & Dickinson (2014) (grey data points). The right panel shows the behaviour of the SP21 model and our extended formalism in the future of the universe. As future times correspond to negative redshifts, and the cosmic star formation rate density becomes asymptotically null at arbitrarily large times, both axes switch from logarithmic to linear scale when moving from the left to the right panel. The grey hatched shaded area in the right panel excludes the non-physical region corresponding to 𝜌¤∗ < 0. Lower panels: Relative difference between the two models showed above (dashed black line), and between our formalism and the fit from Madau & Dickinson (2014) (dotted black line). The latter comparison is available only for positive redshifts (i.e., past cosmic times), as the fit represents a purely empirical fit to the data, and not a predictive theoretical model. The SP21 model agrees well with the improved method introduced in this work at high redshift, but overestimates the cosmic star formation rate density at lower redshift and in the future. In the redshift range 0 < 𝑧 < 10, both the original SP21 model and our updated formalism agree with the empirical fit within a factor of ∼ 2. -- astro-ph.CO

Astronomy & Telescopes, Status Report, Stellar Cartography

The Impact Of The Cosmological Constant On Past And Future Star Formation

by Keith CowingNovember 23, 2024November 23, 2024

We present an extended analytic model for cosmic star formation, with the aim of investigating the impact of cosmological parameters on the star formation history within the ΛCDM paradigm.

Visibility and image of WOH G64 obtained from our VLTI/GRAVITY observations. a: u3 coverage of our VLTI/GRAVITY observations of WOH G64 with the calibrated visibility color-coded. North is up, east is to the left. b: Image of WOH G64 reconstructed at 2.2 µm (with a spectral window of 0.2 µm) using IRBis with the maximum entropy regularization. North is up, east is to the left. -- Astronomy and Astrophysics

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

Stellar Cartography: The First Close-up Picture Of A Star Outside Our Galaxy

by Keith CowingNovember 21, 2024November 21, 2024

“For the first time, we have succeeded in taking a zoomed-in image of a dying star in a galaxy outside our own Milky Way,” says Keiichi Ohnaka, an astrophysicist from […]

Coordinates and properties of the 20,257 A-type stars that are used in this study. Each point is a star, with color indicating the number of sectors it has been observed by TESS. -- astro-ph.EP

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

Stellar Cartography: Small And Close-In Planets Are Uncommon Around A-type Stars

by Keith CowingNovember 21, 2024November 21, 2024

The Kepler and K2 missions enabled robust calculations of planet occurrence rates around FGKM-type stars. However, these missions observed too few stars with earlier spectral types to tightly constrain the […]