Stellar Cartography Archives

A 2D visual comparison of the filaments identified by DisPerSE from the DTFE density field (left) and the MCPM density field (right) in the same 10 Mpc thick slices in TNG100 at z = 0. In both panels, the underlying DM overdensity along the line of sight is represented by the blue–white color bar, and gray circles represent galaxies. The individual filament segments from DTFE and MCPM are curves colored by the average persistence value of a segment (red is less persistent, yellow is more persistent). The MCPM density field identifies the filamentary structure with significantly higher fidelity, including the less prominent filaments that the DTFE density field method misses. -- The Astronomical Journal

Astronomy & Telescopes, Gaia - Planetary Perspectives, Interstellar, Microbiology & Virology, Science Fiction, Status Report, Stellar Cartography

Filaments Of The Slime Mold Cosmic Web and How They Affect Galaxy Evolution

by Keith CowingSeptember 17, 2024September 17, 2024

We present a novel approach for identifying cosmic web filaments within the DisPerSE structure identification framework, using cosmic density field estimates from the Monte Carlo Physarum Machine (MCPM), inspired by […]

Artist’s rendition of variety of exoplanets featured in the new NASA TESS-Keck Survey Mass Catalog, the largest, single, homogenous analysis of TESS planets released by any survey thus far. Credit: W. M. Keck Observatory/Adam Makarenko

Alpha Centauri, Astrogeology, Beta Pictoris, Ceres, Exoplanets, -moons, -comets, Gas Giants, Icy Worlds, Jupiter, Lava / magma ocean / Volcanic Worlds, Mapping, Geodesy, Cartography, Bathymetry, Mars, Mercury, Neptune, Pluto, Proxima Centauri, Saturn, Status Report, tau Ceti, TRAPPIST-1, Uranus, Venus, Water/Hycean Worlds & Oceanography

Classifications For Exoplanet and Exoplanetary Systems

by Keith CowingSeptember 17, 2024September 17, 2024

When a star is described as a spectral class G2V, we know its approximate mass, temperature, age, and size. At more than 5,700 exoplanets discovered, it is a natural developmental […]

llustration of possible system evolutionary histories under the Close-NE (a– c) and Wide-NE (d–f) models. Objects and orbits are not drawn to scale. Separations are representative values. (a) Initial configuration: close-in brown dwarf and wide-orbit planet. (b) Orbits expand due to host-star mass loss. AGB host star overflows Roche Lobe. Brown dwarf enters common envelope. (c) Common envelope ejected as brown dwarf orbit reduces to 0.2 au. Planetary orbit further expands. (d) Initial configuration: close-in planet and wide-orbit brown dwarf. (e) Orbits expand due to host-star mass loss. Brown dwarf and planet avoid interacting with the AGB host star. (f) Orbits continue to expand. -- astro-ph.EP

Exoplanets, -moons, -comets, Status Report, Stellar Cartography

An Earth-Mass Planet and a Brown Dwarf in Orbit Around a White Dwarf

by Keith CowingSeptember 6, 2024September 6, 2024

Terrestrial planets born beyond 1-3 AU have been theorized to avoid being engulfed during the red-giant phases of their host stars.

Distribution in logarithmic scale of planetary masses against the host stellar metallicities. -- astro-ph.IM

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

ODUSSEAS: Upgraded Version With New Reference Scale and Parameter Determinations for 82 Planet-host M Dwarf Stars in SWEET-Cat

by Keith CowingAugust 30, 2024August 29, 2024

Aims: Obtaining accurate derivations of stellar atmospheric parameters is crucial in the fields of stellar and exoplanet characterization. We present the upgraded version of our computational tool ODUSSEAS with a […]

New image from the James Webb Space Telescope spectroscopic survey of NGC1333. CREDIT ESA/Webb, NASA & CSA, A. Scholz, K. Muzic, A. Langeveld, R. Jayawardhana larger image

Astronomy & Telescopes, Brown Dwarfs, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Interstellar, Press Release, Stellar Cartography

In Six New Rogue Worlds, Webb Telescope Finds More Star Birth Clues

by Keith CowingAugust 28, 2024August 27, 2024

The James Webb Space Telescope has spotted six likely rogue worlds—objects with planetlike masses but untethered from any star’s gravity—including the lightest ever identified with a dusty disk around it.

Top: Measured instrumental drift over the course of solar observations for each of three days. Bottom: Measured solar RVs after accounting for measured instrumental drift. The NEID DRP does an excellent job of removing the short-term transients in wavelength calibration following the daily refill of the liquid nitrogen dewar. The RMS RV from a smoothed version of the instrument drift (after the initial large transient) is 0.052–0.055 m s−1 . However, an observed trend in solar RVs over the course of each day is described in §4.1. The solar RVs are potentially subject to additional systematic effects not probed by the etalon in the calibration fiber. These effects could include pointing, coupling-related behaviors with the solar feed or sci-cal fiber drift, and differential extinction. -- astro-ph.SR

Exoplanets, -moons, -comets, Habitable Zones, Press Release, Space Weather & Heliophysics, Stellar Cartography

Earths Within Reach: Evaluation of Strategies for Mitigating Solar Variability Using 3.5 years Of NEID Sun-as-a-Star Observations

by Keith CowingAugust 28, 2024August 27, 2024

We present the results of Sun-as-a-star observations by the NEID Solar Telescope at WIYN Observatory, spanning January 1, 2021 through June 30, 2024. We identify 117,060 observations which are unlikely […]

Left: Final PSF-subtracted images of LO Peg obtained with Super-RDI. North is up and east is to the left. The image and color bar are depicted in linear scale in normalized analog to digital units and have been smoothed using a Gaussian kernel with a 1.5 pixel standard deviation (40% of the width of the instrumental PSF) to average out high-frequency noise. Right: Parallactic angle of individual frames obtained across the entire observation sequence. Presented as insets are three representative de-rotated pre-processed frames (north is up and east is to the left) in the sequence showing that the point source in our final PSF-subtracted image rotates across the sequence as expected for a speckle. -- astro-ph.EP

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

Efficiently Searching for Close-in Companions Around Young M Dwarfs Using a Multi-year PSF Library

by Keith CowingAugust 28, 2024August 27, 2024

We present Super-RDI, a unique framework for the application of reference star differential imaging (RDI) to Keck/NIRC2 high-contrast imaging observations with the vortex coronagraph.

The data source: http://www.johnstonsarchive.net/astro/nearstar.html The coordinate scales are marked in light years. The third dimension is shown with color (with pink being closest to the viewer, and cyan the farthest). The mass of a star is shown with the size of its circle, and of the font. Inter-stellar distances shorter than 10 light years are shown as lines. The longer the distance, the dimmer is the line. Source -- Wikipedia

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

Multiplicity Of Stars With Planets In The Solar Neighbourhood

by Keith CowingJuly 30, 2024

Aims: We intended to quantify the impact of stellar multiplicity on the presence and properties of exoplanets.

This illustration depicts a binary star system consisting of a dense neutron star and a normal Sun-like star (upper left). Using data from the European Space Agency's Gaia mission, astronomers found several systems like this one, in which the two bodies are widely separated. Because the bodies in these systems are far apart, with separations on average 300 times the size of a Sun-like star, the neutron star is dormant—it is not actively stealing mass from its companion and is thus very faint. To find these hidden neutron stars, the scientists used Gaia observations to look for a wobble in the Sun-like stars caused by a tugging action of the orbiting neutron stars. These are the first neutron stars discovered purely due to their gravitational effects. As depicted in this illustration, the intense gravity of the compact neutron star—which is about 100,000 times smaller than the Sun-like star yet heavier—warps our view of the sky around it, producing a distorted mirrored view of the nearby star. Credit: Caltech/R. Hurt (IPAC)

Astronomy & Telescopes, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Press Release, Radiation, Space Weather & Heliophysics, Stellar Cartography

Sun-like Stars Have Been Found Orbiting Hidden Companions

by Keith CowingJuly 29, 2024July 29, 2024

Most stars in our universe come in pairs. While our own Sun is a loner, many stars like our Sun orbit similar stars, while a host of other exotic pairings […]

Rogue planet seen in visible light - ESO

Astronomy & Telescopes, Brown Dwarfs, Exoplanets, -moons, -comets, Gas Giants, Imaging & Spectroscopy, Status Report, Stellar Cartography

Predicting The Galactic Population Of Free-floating Planets From Realistic Initial Conditions

by Keith CowingJuly 22, 2024July 22, 2024

We present the first prediction for the mass distribution function of Galactic free-floating planets (FFPs) that aims to accurately include the relative contributions of multiple formation pathways and stellar populations.