Related papers: Making Habitable Worlds: Planets Versus Megastruct…
Massive stars are at the core of our observations of the Universe up to the reionization epoch, both through their intense ionizing fluxes and through the energetic end products that release fresh elements into the interstellar medium. Our…
Stars and planets form, live, and evolve in unison. Throughout the life of a star, dusty circumstellar discs and stellar outflows influence the further evolution of both the star(s) and their orbiting planet(s). Planet-forming discs, winds…
We use the existence of habitable planets to impose anthropic requirements on the fine structure constant, $\alpha$. To this effect, we present two considerations that restrict its value to be very near the one observed. The first, that the…
Main sequence stars are commonly surrounded by debris disks, composed of cold dust continuously replenished by a reservoir of undetected dust-producing planetesimals. In a planetary system with a belt of planetesimals (like the Solar…
We investigate a new class of habitable planets composed of water-rich interiors with massive oceans underlying H2-rich atmospheres, referred to here as Hycean worlds. With densities between those of rocky super-Earths and more extended…
By the 2040s, the exoplanet field will have moved from the discovery of a few thousand planets to hundreds of thousands, thanks to Gaia DR5, TESS, PLATO, Roman, and their successors. At that stage, the key bottleneck will no longer be…
The discovery of exoplanets has both focused and expanded the search for extraterrestrial intelligence. The consideration of Earth as an exoplanet, the knowledge of the orbital parameters of individual exoplanets, and our new understanding…
Several processes can cause the shape of an extrasolar giant planet's shadow, as viewed in transit, to depart from circular. In addition to rotational effects, cloud formation, non-homogenous haze production and movement, and dynamical…
Determining habitable zones in binary star systems can be a challenging task due to the combination of perturbed planetary orbits and varying stellar irradiation conditions. The concept of "dynamically informed habitable zones" allows us,…
Due to their extremely small luminosity compared to the stars they orbit, planets outside our own Solar System are extraordinarily difficult to detect directly in optical light. Careful photometric monitoring of distant stars, however, can…
Planets are common objects in the Universe, observationally as well as theoretically. However, the standard theory of their formation encounters many difficulties, such as dust fall and disk lifetime problems. We positively analyze them,…
We introduce a mathematical framework for statistical exoplanet population and astrobiology studies that may help directing future observational efforts and experiments. The approach is based on a set of differential equations and provides…
Planetary systems formed in clusters may be subject to stellar encounter flybys. Here we create a diverse range of representative planetary systems with different orbital scales and planets' masses and examine encounters between them in a…
A Dyson ring is a hypothetical megastructure, that a very advanced civilization would build around a star to harness more of its energy. Satellite propagation is of high priority in such a vast world where distances could very well be…
Several studies, observational and theoretical, suggest that planetary systems with only rocky planets should be the most common in the Universe. We study the diversity of planetary systems that might form around Sun-like stars in low-mass…
The compositions of stars and planets are connected, yet, the definition of "habitability" and the "habitable zone" only take into account the physical relationship between the star and planet. Planets, however, are made truly habitable by…
Galaxies represent the visible fabric of the Universe and there has been considerable progress recently in both observational and theoretical studies. The underlying goal is to understand the present-day diversity of galaxy forms, masses…
Doppler planet searches revealed that many giant planets orbit close to their host star or in highly eccentric orbits. These and subsequent observations inspired new theories of planet formation that invoke gravitation interactions in…
There is growing observational evidence for some kind of interaction between stars and close-in extrasolar giant planets. Shkolnik et al. reported variability in the chromospheric Ca H and K lines of HD 179949 and upsilon And that seemed to…
The presence of giant planets influences potentially habitable worlds in numerous ways. Massive celestial neighbors can facilitate the formation of planetary cores and modify the influx of asteroids and comets towards Earth-analogs later…