Alpha Centauri Archives

ADORA: A Differentiable Optical Modeling And Astrometric Retrieval Framework For SHERA

by Keith CowingAugust 25, 2026August 25, 2026

[astro-ph.EP] Motivated by recent observations suggesting rings found in debris disks are wider than those in protoplanetary disks, we consider a picture in which planetesimals formed in radially narrow dust […]

Since a binary relative astrometry mission will make one-dimensional measurements of the deflection

Exoplanets, -moons, -comets

Finding Habitable Exoplanets with Binary Relative Astrometry: Planet Detection and Characterization with the Microarcsecond Astrometric Retrieval Algorithm (MARA)

by Keith CowingAugust 24, 2026August 24, 2026

[astro-ph.EP] Binary relative astrometry is a technique to search for rocky planets in the habitable zone of nearby binary stars using 1D relative astrometry at the microarcsecond level.

Projected separation of α Centauri A and B over time

Exoplanets, -moons, -comets

Searching For Habitable Exoplanets With Relative Astrometry (SHERA). I. The Case For Searching For Planets In Binary Star Systems

by Keith CowingAugust 7, 2026August 7, 2026

[astro-ph.EP] Discovering Earth-like planets orbiting Sun-like stars was identified as a priority science goal of the Astronomy 2020 Decadal Survey.

These panels represent the Lomb-Scargle power for different activity cycle power frequencies found in the dataset of Alpha Centauri A and B. The highest power for a period > 5 years is marked by the blue dashed line which amounts to 22.2 years for Alpha Centauri A and 8.2 years for Alpha Centauri B. Bottom: These panels represent the sinusoidal fit to the MgII index data for Alpha Centauri A and B. The solar MgII index is overlaid in the figure for reference. The solar MgII index is obtained from the LISIRD website (Leise et al. 2019). -- astro-ph.SR

Alpha Centauri, Astronomy & Telescopes, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Space Weather & Heliophysics, Status Report, Stellar Cartography

Near UV Stellar Activity and Brightness Fluctuations of the Alpha Centauri AB Star System from Weeks to Decades — Inputs for Reflected Light Spectroscopy with HWO

by Keith CowingMay 27, 2026May 27, 2026

We present the most comprehensive near-ultraviolet (NUV: 2550-3255 Angstrom) activity record to date for the Alpha Centauri AB system, combining archival IUE and HST observations spanning nearly five decades with […]

Artist’s impression of the approach of a swarm towards Proxima b; at this point, a few seconds before closest approach, the swarm could be examining the planet’s nightside for techno- or bioluminescence. (This image is based on the artistic work of Dr. Mark A. Garlick.) -- astro-ph.IM

Alpha Centauri, Biosignatures & Paleobiology, Cubesats and smallsats, Exoplanets, -moons, -comets, Gaia Mission, Habitable Zones, Interstellar, Missions & Hardware, Proxima Centauri, Status Report

Science From The In Situ Exploration Of Tthe Proxima Centauri System

by Keith CowingApril 23, 2026April 23, 2026

In the future interstellar exploration at near-relativistic speeds will be possible using beamed energy laser propulsion.

The strength of indirect detection signals from an Earth-like exoplanet as a function of stellar effective temperature. Bands encompassing main sequence spectral classes A through M color coded by temperature are indicated at the top. Here, Earth-like is defined as a 1-Earth mass object in an orbit receiving irradiance equivalent to 1 AU from our Sun (the solar constant). Radial Velocity signals (solid blue line) are seen to exhibit a rapid rise in signal strength (given on the right-hand abscissa) for cooler, M dwarf systems where they become detectable with present submeter per second RV precision. On the other hand, astrometric deflection signals (colored diamond symbols) rise with host star temperature, and decline linearly with distance from values of up to several microarcseconds for the nearest stars. For convenience the plot also indicates the size of the temperate orbit modeled (in AU, left abscissa) and its corresponding orbital period (in years, also left abscissa). -- astro-ph.IM

Alpha Centauri, Astronomy & Telescopes, Biosignatures & Paleobiology, Cubesats and smallsats, Habitable Zones, Imaging & Spectroscopy, Missions & Hardware, Status Report

The TOLIMAN Mission: A Low-cost Space Telescope For High Precision Narrow-angle Astrometry

by Keith CowingMarch 18, 2026March 18, 2026

The TOLIMAN project is engaged with the construction, launch and operation of a low-cost space telescope of unorthodox optical design. Its primary science goal targets an exhaustive search for temperate-orbit […]

Age of α Centauri A and B estimated in various works. The colors of the points indicate the method: blue, classic method without seismic data; green, seismic analysis; cyan, gyrochronology; orange, chemical analysis; and red, results of this study. -- astro-ph.SR

Alpha Centauri, Astronomy & Telescopes, Status Report, Stellar Cartography

A Mapping Method Of Age Estimation For Binary Stars: Application To The Alpha Centauri System A And B

by Keith CowingFebruary 11, 2026February 11, 2026

Given the wealth of data provided by Gaia and the upcoming PLATO mission, it is essential to improve stellar models to obtain accurate stellar ages. Our objective is to apply […]

Top: an example of a chop-subtraction image pair from VLT/NEAR. Image B, following 0.05 sec after A, is subtracted to remove the detector bias, thermal background, AGPM glow, and excess low frequency noise (ELFN). Bottom: an example model of a chop-subtraction persistence residual (CSPR) of α Centauri AB. This model was generated with an offset of ∼2% of a pixel, or ∼1 mas, of the star’s position behind the coronagraph following each chop. The effects of the coronagraph, persistence non-linearity and temporal decay, and post-processing are not included in the model. The CSPR is too faint to be seen in the frames above, but is easily seen in longer integrations (see Fig. 2). -- astro-ph.IM

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

Imaging Low-mass Planets Within The Habitable Zones Of Nearby Stars With Ground-based Mid-infrared Imaging

by Keith CowingMay 26, 2025May 26, 2025

Giant exoplanets on 10-100 au orbits have been directly imaged around young stars. The peak of the thermal emission from these warm young planets is in the near-infrared (~1-5 microns), […]

α Cen’s orbit about the Galactic Centre viewed on the xy and yz planes (top row), as well as the orbits of the ejecta from α Cen viewed in a comoving frame (bottom row). Our Sun (Sol) is marked by a black hexagon and its orbital path indicated by a grey solid line (top row only). α Cen’s location and path are shown by a yellow star and blue solid line (top row only). In the bottom row, the comoving frame follows α Cen around its orbit while maintaining its orientation with the y-axis pointing towards the Galactic Centre (blue arrow) and α Cen’s velocity pointing in the -x direction (black arrow). This still frame is taken at t ≈ 3, 000 yr (that is, +3,000 years from the current epoch) after ∼ 100 Myr of integration. The colours of the ejecta represent the 3rd dimension of position, except that any particle that will at any point come within 100, 000 au of Sol are plotted in red. The full animation is available in the HTML version of this publication which shows the time evolution from t ≈ −100 Myr to t ≈ 10 Myr. The duration of the animation is 11 s. https://youtu.be/YABoYgNKr-I -- astro-ph.EP

Alpha Centauri, Comets and Asteroids, Interstellar, Meteorites & Asteroids, Panspermia, Press Release

A Case Study of Interstellar Material Delivery: Alpha Centauri

by Keith CowingFebruary 6, 2025February 6, 2025

Interstellar material has been discovered in our Solar System, yet its origins and details of its transport are unknown. Here we present α Centauri as a case study of the […]

Alpha Centauri, Astronomy & Telescopes, Biosignatures & Paleobiology, Imaging & Spectroscopy, Interstellar, Press Release

Are We Alone? University Engages Satellite Company In A Search For Life Among The Stars

by Keith CowingMarch 16, 2023March 19, 2023

The University of Sydney has signed a contract with EnduroSat, a leading provider of micro satellites and space services, to explore the question of life beyond Earth, starting with our […]

Alpha Centauri

ADORA: A Differentiable Optical Modeling And Astrometric Retrieval Framework For SHERA

Finding Habitable Exoplanets with Binary Relative Astrometry: Planet Detection and Characterization with the Microarcsecond Astrometric Retrieval Algorithm (MARA)

Searching For Habitable Exoplanets With Relative Astrometry (SHERA). I. The Case For Searching For Planets In Binary Star Systems

Near UV Stellar Activity and Brightness Fluctuations of the Alpha Centauri AB Star System from Weeks to Decades — Inputs for Reflected Light Spectroscopy with HWO

Science From The In Situ Exploration Of Tthe Proxima Centauri System

The TOLIMAN Mission: A Low-cost Space Telescope For High Precision Narrow-angle Astrometry

A Mapping Method Of Age Estimation For Binary Stars: Application To The Alpha Centauri System A And B

Imaging Low-mass Planets Within The Habitable Zones Of Nearby Stars With Ground-based Mid-infrared Imaging

A Case Study of Interstellar Material Delivery: Alpha Centauri

Are We Alone? University Engages Satellite Company In A Search For Life Among The Stars

How A Deep-sea Protein Adapts To An Extreme Environment

Fingerprints Inside Our Sun Could Reveal If It Once Swallowed A Planet

Climates Of Gl 514 b

Cosmic Radiation at Flight Altitudes Rises When the Sun Is Less Active

The History Of Enzyme Evolution Embedded In Metabolism