Barnard's Star Archives - Astrobiology

Wavelength distributions of candidate spectral lines retained at each step of the line-selection procedure. The histograms show the initial linelist (light), lines retained after automated vetting (intermediate), and the final manually vetted sample (dark). The shaded background regions indicate approximate wavelength ranges for the Y, J, H, and K-bands.-- [astro-ph.SR]

Stellar Cartography

Elemental Abundances of Cool Stars: A Spectroscopic Framework Applied to Five Planet-Host Stars

by Keith CowingSeptember 23, 2026September 23, 2026

[astro-ph.SR] Stellar elemental abundances provide important constraints on the chemical environments from which planets form. M and late-K dwarfs are prime targets for the characterization of small exoplanets, yet their […]

The black line shows the empirical high-S/N template spectrum of Proxima Centauri (left) and Barnard’s Star (right). In the top panel, the green curve shows the median spectrum obtained by taking the median flux at each wavelength across the full grid of PHOENIX M-dwarf spectra, while the shaded region denotes the corresponding 1σ envelope. Comparing this range of model spectra with the empirical M-dwarf spectra demonstrates that the PHOENIX models do not adequately reproduce the observed spectra. The middle and bottom panels show either empirical templates or postellar spectral samples constructed from synthetic SPIRou observations of the respective stars at different S/N regimes. For the postellar spectra, the 1σ, 2σ, and 3σ intervals are shown, highlighting the uncertainties recovered on individual spectral feature. -- [astro-ph.EP]

Exoplanets, -moons, -comets

POSTELLAR: Posterior Stellar Spectrum Sampling – An Alternative to Approximate Stellar Spectra for Exoplanetary Analysis

by Keith CowingSeptember 10, 2026September 10, 2026

[astro-ph.EP] We present a novel approach to perform posterior sampling of the underlying stellar spectrum in high-resolution spectroscopic observations.

Atmosphere loss of Barnard’s Star planets, under various assumptions of planet masses, bulk densities, and initial atmospheric mass fraction. The mass range tested for a given planet is between its minimum mass (based on RV data; B25) and 2.5 times the minimum mass (see Section 2). The bulk densities ρ, used to calculate planet radius in the evolution models, span a liberal range: the Solar system rocky planets have densities between 3.93 g cm−3 (Mars) and 5.51 g cm−3 (Earth). No matter what assumptions are made, the planets are completely stripped of their atmospheres within 2 Gyr. The atmospheres survive longer if the planets are more massive, denser, farther from the star, and begin with a larger atmospheric mass fraction. - MNRAS

Planets Orbiting Barnard’s Star Seem To Be Small, Strange, And Utterly Uninhabitable

by Keith CowingJuly 16, 2026July 16, 2026

[University of Cambridge] Scientists have painted the most detailed portrait yet of the planetary system orbiting Barnard’s Star – the Sun’s closest neighbour after Alpha Centauri, just under six light-years […]

Atmosphere loss of Barnard’s Star planets, under various assumptions of planet masses, bulk densities, and initial atmospheric mass fraction. The mass range tested for a given planet is between its minimum mass (based on RV data; B25) and 2.5 times the minimum mass (see Section 2). The bulk densities 𝜌, used to calculate planet radius in the evolution models, span a liberal range: the Solar System rocky planets have densities between 3.93 g cm−3 (Mars) and 5.51 g cm−3 (Earth). No matter what assumptions are made, the planets are completely stripped of their atmospheres within 2 Gyr. The atmospheres survive longer if the planets are more massive, denser, farther from the star, and begin with a larger atmospheric mass fraction. — astro-ph.EP

The Barnard’s Star Planetary System: Stability, Composition, and Evolution of Four Sub-Earth Exoplanets

by Keith CowingJune 24, 2026June 24, 2026

Barnard’s Star is the nearest single star to the Sun (1.8 pc), and hosts four recently-discovered planets.

The three-dimensional MHD stellar wind solution for Barnard’s Star. Color contours represent number density values, while selected magnetic field lines are also shown. The solid white circle marks the orbit of the planet. -- astro-ph.EP

Astronomy & Telescopes, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Habitable Zones, Mars, Status Report

Atmospheric Escape Rates from Mars – If it Orbited an Old M-Dwarf Star

by Keith CowingMarch 13, 2026March 13, 2026

Atmospheric escape is an important process that influences the evolution of planetary atmospheres. A variety of physical mechanisms can contribute to escape from an atmosphere, including thermal escape, ion escape, […]

The average total power of individual airport radar systems, averaged over one-hour intervals as seen from Barnard’s Star. -- Royal Astronomical Society

Astrobiology (general), Barnard's Star, Intelligence & Language, Interstellar, Press Release, Proxima Centauri, SETI & Technosignatures

How Airports Could Help Aliens Spot Earth

by Keith CowingJuly 9, 2025July 9, 2025

Radar systems used by civilian airports and military operations are inadvertently revealing our existence to potential advanced alien civilisations, new research shows.

This plot shows the current sensitivity of detecting planets around Barnard's Star using the MAROON-X Red channel and ESPRESSO data. -- The Astrophysical Journal Letters

Astronomy & Telescopes, Barnard's Star, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report

Four Planets Discovered Around Barnard’s Star

by Keith CowingMay 27, 2025May 27, 2025

Astronomers confirm the existence of small, hot and likely rocky planets by observing the subtle gravitational wobbles of the star they orbit.

This map shows the geographic distribution of the mobile towers of planet Earth, represented by red dots. The map contains more than 30 million individual data points, most of which overlap at this resolution. -- astro-ph.EP

Alpha Centauri, Astronomy & Telescopes, Barnard's Star, Biosignatures & Paleobiology, Intelligence & Language, SETI & Technosignatures, Status Report

Simulation Of The Earth’s Radio Leakage From Mobile Towers As Seen From Selected Nearby Stellar Systems

by Keith CowingMay 26, 2025May 26, 2025

Mobile communication towers represent a relatively new but growing contributor to the total radio leakage associated with planet Earth.

This plot shows the current sensitivity of detecting planets around Barnard’s Star using the MAROON-X Red channel and ESPRESSO data. -- astro-ph.EP

Astronomy & Telescopes, Barnard's Star, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Press Release, Stellar Cartography

Four Sub-Earth Planets Orbiting Barnard’s Star From MAROON-X And ESPRESSO

by Keith CowingMarch 17, 2025March 17, 2025

Barnard’s Star is an old, single M dwarf star that comprises the second-closest extrasolar system. It has a long history of claimed planet detections from both radial velocities and astrometry.

Artist's impression of the view from one of the planets orbiting Barnard's Star. [International Gemini Observatory/NOIRLab/NSF/AURA/R. Proctor/J. Pollard; CC BY 4.0]

Astronomy & Telescopes, Barnard's Star, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Press Release

Barnard’s Star Hosts Four Tiny Planets

by Keith CowingMarch 13, 2025March 13, 2025

Just 6 light-years away, Barnard’s Star is a well-studied 10-billion-year-old M dwarf with a mass of 0.16 solar mass. Finding exoplanets around Barnard’s Star has been something of a white […]