Proxima Centauri Archives

CO2 transit spectra for aquaplanets from Group C with varying pN2 (purple), Group A (black), and Group B with 0.1 bar CO2. Although the Group B simulation has two orders of magnitude more CO2, its transit amplitude is smaller than those of the Group C simulations due to the geometries of the systems. However, note that our GCM simulations only include a troposphere; if CO2 is well-mixed on a real planet, spectral features could extend much higher. -- astro-ph.EP

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

Water Vapour Transit Ambiguities for Habitable M-Earths

by Keith CowingFebruary 21, 2024February 20, 2024

We have shown in a recent study, using 3D climate simulations, that dayside land cover has a substantial impact on the climate of a synchronously rotating temperate rocky planet such […]

We select 10 and 5 candidate planets around nearby stars for ELT/HARMONI and ELT/METIS, respectively. As the spatial resolution of ELT/HARMONI is smaller than the plotting range, we only show the spatial resolution for ELT/METIS as the vertical dotted blue line. Planets located to the right of the dotted line are suitable planets for ELT/METIS. All colored points are suitable planets for ELT/HARMONI. The size of the colored point is proportional to the planet radius. The color of the point is based on the equilibrium temperature. All colored data points are the candidate planets listed in Table 1. Selection criteria can be found in Section 2.1. The gray points are other exoplanets from NEA that are less suitable for direct imaging with ELT. -- Ohio State University

Astrochemistry, Astronomy & Telescopes, Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Press Release, Proxima Centauri

Biosignatures: Looking For Signs Of Life Among Exoplanet Atmospheres

by Keith CowingFebruary 1, 2024February 1, 2024

The next generation of advanced telescopes could sharpen the hunt for potential extraterrestrial life by closely scrutinizing the atmospheres of nearby exoplanets, new research suggests.

Shining brightly in this Hubble image is our closest stellar neighbour: Proxima Centauri. -- Wikipedia

Exoplanets, -moons, -comets, Proxima Centauri, Status Report

Motion of Planetesimals In The Hill Sphere Of The Star Proxima Centauri

by Keith CowingFebruary 1, 2024February 1, 2024

The motion of planetesimals initially located in the feeding zone of the planet Proxima Centauri c, at distances of 500 AU from the star to the star’s Hill sphere radius […]

Gas column density of the Phantom hydrodynamical simulation of the circumstellar discs in the binary Alpha Centauri. The stars start at apoastron: A is in the top left corner, and B is in the bottom right corner. From left to right and top to bottom, we show the system at different evolutionary stages: 0, 0.5, 1, 1.5, 2.0, 2.5, 3, and 5 Pb , where Pb is a binary orbital period. The red dots represent the stars of Alpha Centauri. -- astro-ph.EP

Alpha Centauri, Exoplanets, -moons, -comets, Proxima Centauri, Status Report

Alpha Centauri: Disc Dynamics, Planet Stability, Detectability

by Keith CowingJanuary 31, 2024January 30, 2024

Alpha Centauri is a triple stellar system, and it contains the closest star to Earth (Proxima Centauri). Over the last decades, the stars in Alpha Cen and their orbits have […]

Signal-to-noise of the fiducial planet simulation. The top panel shows two slices of the CCF cube, one in the plane on the sky and one along the velocity axis. The bottom panels show the same two slices separated for clarity with pink dashed lines indicating the expected position of the signal. The region covered by the FPM is greyed-out. The bottom left panel shows the signal-to-noise for the spaxels along spaxel 푥 = 0 for different velocities relative to the exoplanet’s velocity. The bottom right panel shows the signalto-noise of all the spaxels at a Doppler shift equal to the exoplanet’s velocity. The yellow star in the bottom right panel indicates the location of the star. Note that this injected fiducial exoplanet does not represent Proximab. -- astro-ph.EP

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

Behind The Mask: Can HARMONI@ELT Detect Biosignatures In The Reflected Light Of Proxima b?

by Keith CowingJanuary 19, 2024January 19, 2024

Proxima b is a rocky exoplanet in the habitable zone of the nearest star system and a key test case in the search for extraterrestrial life.

Alpha Centauri, Exoplanets, -moons, -comets, Habitable Zones, Proxima Centauri, Status Report

Orbital Stability And Secular Dynamics Of The Proxima Centauri Planetary System

by Keith CowingJanuary 18, 2024January 18, 2024

The two innermost planets of the Proxima Centauri system are separated by just 0.02 au, inducing strong gravitational interactions between them.

Artist’s impression of swarm passing by Proxima Centauri and Proxima b. The swarm’s extent is ∼10 larger than the planet’s, yet the ∼5000-km spacing is such that one or more probes will come close to or even impact the planet (flare on limb). It should be possible to do transmission spectroscopy with such swarms. Green 432/539-nm beams are coms to Earth; red 12,000-nm laser beacons are for intra-swarm probe-to-probe coms. Conceptual artwork courtesy of Michel Lamontagne, P.Eng. -- astro-ph.IM

AI - Data - Apps - Cybernetics, Cubesats and smallsats, Missions & Hardware, Nanotechnology & SynBio, Proxima Centauri, Status Report

Swarming Proxima Centauri: Optical Communication Over Interstellar Distances

by Keith CowingDecember 22, 2023December 22, 2023

Interstellar communications are achievable with gram-scale spacecraft using swarm techniques introduced herein if an adequate energy source, clocks and a suitable communications protocol exist.

Explosive cryovolcanism in the form of geyser-like plumes on two of our solar system's ocean worlds. Left: Cryovolcanic eruptions at the south pole of Saturn's moon Enceladus (credit: NASA/JPL-Caltech/SSI). Right: Hubble Space Telescope UV observations of cryovolcanic eruptions at the south pole of Jupiter's moon Europa (credit: NASA/L. Roth). By facilitating the transport of liquid water and energy between their interiors and surfaces, similar activity could create habitable environments on cold ocean planets. - NASA/Astrophysical Journal

Astrogeology, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Icy Worlds, Press Release, Proxima Centauri, TRAPPIST-1, Water/Hycean Worlds & Oceanography

Some Icy Exoplanets May Have Habitable Oceans And Geysers

by Keith CowingDecember 13, 2023

A NASA study expands the search for life beyond our solar system by indicating that 17 exoplanets (worlds outside our solar system) could have oceans of liquid water, an essential […]

Internal ocean probabilities of the investigated exoplanets. The colour bar depicts the probability of each planet having a liquid water reservoir in its interior. Red colours imply a high probability, while planets with dark blue circles are less likely to have internal oceans. The HZ, shown as a green band only for illustrative purposes, was calculated based on stellar parameters from theoretical stellar evolution models. -- astro-ph.EP

Astrochemistry, Astrogeology, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Exoplanets, -moons, -comets, Habitable Zones, Icy Worlds, Proxima Centauri, Status Report, TRAPPIST-1, Water/Hycean Worlds & Oceanography

Water Content Of Rocky Exoplanets In The Habitable Zone

by Keith CowingDecember 4, 2023December 4, 2023

In this study we investigated the interiors of rocky exoplanets in order to identify those that may have large quantities of water.

Astronomy & Telescopes, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Proxima Centauri, Status Report, TRAPPIST-1

Detecting Biosignatures in Nearby Rocky Exoplanets using High-Contrast Imaging and Medium-Resolution Spectroscopy with Extremely Large Telescope

by Keith CowingNovember 30, 2023November 30, 2023

In the upcoming decades, one of the primary objectives in exoplanet science is to search for habitable planets and signs of extraterrestrial life in the universe.