HD 20794 Archives - Astrobiology

Left: HZ and planetary orbits in the HD 20794 system, where the orbits are labeled by planet designation. The scale of the figure is 2.9 AU along each side. Right: Variation in incident flux received by HD 20794 d during one complete orbit. For both panels, the extent of the HZ is shown in green, where light green and dark green indicate the CHZ and OHZ, respectively. -- astro-ph.EP

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

Dynamical Stability and Habitability in the HD 20794 System

by Keith CowingMay 28, 2026May 28, 2026

The Keplerian orbit of a terrestrial planet can be a significant driver in the evolution of surface conditions, as well as influencing the overall dynamics of the system.

Evolutionary tracks of HD 20794 computed with MESA

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

A Theoretical Study of the Structure and Elemental Abundances of HD 20794

by Keith CowingApril 29, 2026April 29, 2026

HD-20794 is a nearby, bright, metal-poor G-type dwarf hosting a compact planetary system, including a super-Earth near the habitable zone.

Observational HR diagram, from Hipparcos data, of stars within 10 pc of the Sun. The black box isolates the parameter range +4.0 < MV < +6.5 and +0.50 < (B-V) < +1.05 (see text) and contains the initial candidates as astrobiologically interesting stars. -- astro-ph

Astrobiology (general), Astronomy & Telescopes, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Status Report, Stellar Cartography

Astrobiologically Interesting Stars Within 10 Parsecs Of The Sun

by Keith CowingMay 25, 2025May 24, 2025

The existence of life based on carbon chemistry and water oceans relies upon planetary properties, chiefly climate stability, and stellar properties, such as mass, age, metallicity and Galactic orbits.

TESS target pixel file for HD 20794. No nearby sources are detected by the Gaia DR3 catalog up to a contrast magnitude of +6 within the TESS aperture. -- -- astro-ph.EP

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

Revisiting the Multi-planetary System of the Nearby star HD 20794: Confirmation of a Low-mass Planet in the Habitable Zone of a Nearby G-dwarf

by Keith CowingFebruary 4, 2025February 4, 2025

Close-by Earth analogs and super-Earths are of primary importance because they will be preferential targets for the next generation of direct imaging instruments. Bright and close-by G-to-M type stars are […]

RV dataset of HD 20794 for the different datasets. The HARPS RVs have been extracted using YARARA (Cretignier et al. 2021a, 2023). For ESPRESSO, RVs have been extracted with sBART (Silva et al. 2022). -- Astronomy and Astrophysics

Astronomy & Telescopes, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Press Release

A Super-Earth Laboratory For Searching Life Elsewhere In The Universe

by Keith CowingFebruary 2, 2025February 1, 2025

‘‘Are we alone in the Universe?’’ For thousands of years, this question was confined to philosophy, and it is only very recently that modern science has begun to provide solid […]

Exoplanet HD 20794 d -- University of Oxford

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Exoplanets, -moons, -comets, Habitable Zones, Press Release, Water/Hycean Worlds & Oceanography

Existence Of Exoplanet HD 20794 d In A Habitable Zone Confirmed

by Keith CowingJanuary 28, 2025January 28, 2025

An international team has confirmed the discovery of a super-Earth orbiting in the habitable zone of a nearby Sun-like star. The planet was originally detected two years ago by Oxford […]