Proxima Centauri Archives

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 […]

XAO+PIAAN simulation scheme. -- astro-ph.IM

Astronomy & Telescopes, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Proxima Centauri, Status Report

RISTRETTO: A VLT XAO Design To Reach Proxima Cen b In The Visible

by Keith CowingSeptember 13, 2024September 13, 2024

RISTRETTO is the evolution of the original idea of coupling the VLT instruments SPHERE and ESPRESSO lovis_2016a, aiming at High Dispersion Coronagraphy. RISTRETTO is a visitor instrument that should enable […]

“Hyper-realistic” RGB images of Control at a phase of 40°, generated with PSG GlobES. Clockwise starting from the top left: (a) true color image, without BVLO. Proxima b appears orange because Proxima Centauri is a cool star which emits mostly red light in the visible. In this image, the darkest regions on the planet are oceans, and the lighter regions are ice or clouds. To identify clouds, compare with b. (b) the cloud cover fraction, with high numbers indicating grid cells mostly covered with clouds. (c) false color image of Control with BVLO. The BVLO appear purple because of Qy feature strongly absorbs in the green channel at 1um. (d) same as a, but with BVLO added (Amax = 1). The BVLO fill in the open water regions. To easily see regions of BVLO coverage, compare with purple regions in c. -- astro-ph.EP

Analog Studies, Astrochemistry, Astrogeology, Astronomy & Telescopes, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Proxima Centauri, Status Report

Detectability Simulations of a NIR Surface Biosignature on Proxima Centauri b with Future Space Observatories

by Keith CowingSeptember 11, 2024September 11, 2024

Telescope missions are currently being designed which will make direct imaging of habitable exoplanets possible in the near future, and studies are needed to quantify the detectability of biosignature features […]

Top panels: evolution of CHZ and UVH for Trappist-1, Proxima Centauri, GJ 273, GJ 163, K2-18, GJ 832, GJ 357, GJ 229A, HD 40307 and Kepler-62. In each plot the vertical gray line represents the host star age found in the literature and the relative errors (the gray shaded region around the gray line). Yellow, orange and dark orange lines represent the ages at which fraction of systems with at least one rocky planet without a primordial envelope in the CHZ is equal to 20%, 30%, 40% for each system (according to NGPPS model). The dashed line represents the time where each star settled onto the main sequence. Bottom panels: evolution of the fraction of the radial extension of the CHZ that is overlapping the radial extension of the UVZ for three different values of the NUV atmospheric transmission. -- astro-ph.EP

Biophysics, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Proxima Centauri, Radiation, Space Weather & Heliophysics, Status Report, TRAPPIST-1, Water/Hycean Worlds & Oceanography

The Time Evolution Of The Ultraviolet Habitable Zone

by Keith CowingSeptember 5, 2024September 5, 2024

For stars hosting Circumstellar Habitable Zone (CHZ) exoplanets, we investigate the time-evolution of their ultraviolet habitable zone (UHZ), the annular region around a star where an exoplanet could experience a […]

Astrochemistry, Astronomy & Telescopes, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Proxima Centauri, Status Report, TRAPPIST-1

STScI Initiates A Concerted Search For Atmospheres Around M-dwarf Exoplanets

by Keith CowingJuly 23, 2024July 23, 2024

The STScI Director, Dr. Jennifer Lotz, has accepted the primary recommendation of the Working Group on Strategic Exoplanet Initiatives , and has decided to proceed with a large-scale survey of […]

The surface temperature is displayed for the four PCb simulations used in this work: PCb PI (top left), PCb 10% PAL (top right), PCb 1% PAL (bottom left), PCb 0.1% PAL (bottom right). White arrows indicate the magnitude and direction of the surface winds. The magenta contours show surface temperatures of 273 K. For scale, a 10 m s-1 arrow is shown in the middle of the figure. -- astro-ph.EP

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Gaia - Planetary Perspectives, Habitable Zones, Proxima Centauri, Space Weather & Heliophysics, Status Report, TRAPPIST-1

Lethal Surface Ozone Concentrations Are Possible On Habitable Zone Exoplanets

by Keith CowingMay 31, 2024

Ozone (O3) is important for the survival of life on Earth because it shields the surface from ionising ultraviolet (UV) radiation. However, the existence of O3 in Earth’s atmosphere is […]

Sketch of the magnetospheric interaction in the starplanet system Proxima - Proxima b. The stellar wind velocity and the interplanetary magnetic field (IMF) streamlines (assumed to be radial–see text in Sect. 3) are drawn in green and red, respectively. Note that there are magnetic field lines from the star (yellow circle) that are connected to the exoplanet Proxima b (purple circle). The density distribution is shown as a color scale, normalized to the value of the stellar wind density, ρsw = µmpnsw (see Table 1). The sketch represents a super-Alfvénic case, where the ram pressure of the wind dominates over the stellar wind magnetic field pressure, so a bow shock is formed at the dayside of the planet. The Proxima star is beyond the limits of our simulation domain. -- astro-ph.EP

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biophysics, Exoplanets, -moons, -comets, Habitable Zones, Magnetic Fields, Electromagnetism, bioelectricity,, Proxima Centauri, Radiation, Space Weather & Heliophysics, Status Report

MHD Simulations of the Space Weather in Proxima b: Habitability Conditions and Radio Emission

by Keith CowingMay 30, 2024May 30, 2024

The habitability of exoplanets hosted by M-dwarf stars dramatically depends on their space weather. We present 3D magneto-hydrodynamic simulations to characterise the magneto-plasma environment and thus the habitability of the […]

Commercial & Private Sector, Cubesats and smallsats, Interstellar, Missions & Hardware, Proxima Centauri, Status Report

Swarming Proxima Centauri: Coherent Picospacecraft Swarms Over Interstellar Distances

by Keith CowingMay 18, 2024July 12, 2025

Tiny gram-scale interstellar probes pushed by laser light are likely to be the only technology capable of reaching another star this century. We presuppose availability by mid-century of a laser […]

Composite and difference maps for Temperature (T) at the ~22km level. (a-b) Composite maps are field medians computed from Chemistry and No-Chemistry joint co-persistence and co-dimension states (defined in Figure 4), which are >95th percentile – ‘High,’ and (c-d) the same but for states

Astronomy & Telescopes, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Press Release, Proxima Centauri

The Impact Of Ozone On Earth-like Exoplanet Climate Dynamics: The Case Of Proxima Centauri b

by Keith CowingApril 30, 2024April 30, 2024

The emergence of the James Webb Space Telescope and the development of other advanced observatories (e.g., ELTs, LIFE and HWO) marks a pivotal moment in the quest to characterize the […]

Calculated dayside surface temperature matrices for some of the studied planets. Temperatures are presented in Kelvin. N = 1 was considered, since it is not expected that any of these planets have a very thick atmosphere. -- astro-ph.EP

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Microbiology & Virology, Press Release, Proxima Centauri, Radiation, Space Weather & Heliophysics, TRAPPIST-1

How Habitable are M-dwarf Exoplanets?

by Keith CowingMarch 7, 2024March 7, 2024

How Habitable are M-dwarf Exoplanets? Modeling Surface Conditions and Exploring the Role of Melanins in the Survival of Aspergillus niger Spores Under Exoplanet-like Radiation