Related papers: Habitable Zones Around Main-Sequence Stars: New Es…
Over the course of the past decade, advances in the radial velocity and transit techniques have enabled the detection of rocky exoplanets in the habitable zones of nearby stars. Future observations with novel methods are required to…
Since there are several ways planets can survive the giant phase of the host star, we examine the habitability and detection of planets orbiting white dwarfs. As a white dwarf cools from 6000 K to 4000 K, a planet orbiting at 0.01 AU would…
Understanding planetary habitability requires a comparative approach that explores the divergent evolutionary outcomes of Earth and Venus. The Habitable Worlds Observatory (HWO) will be uniquely positioned to conduct a statistical and…
Feedbacks that can destabilize the climates of synchronously-rotating rocky planets may arise on planets with strong day-night surface temperature contrasts. Earth-like habitable-zone (HZ) planets maintain stable surface liquid water over…
Among the most highly valued of exoplanetary discoveries are those of terrestrial planets found to reside within the Habitable Zone (HZ) of the host star. In particular, those HZ planets with relatively bright host stars will serve as…
A radiative-convective climate model is used to calculate stratospheric temperatures and water vapor concentrations for ozone-free atmospheres warmer than that of modern Earth. Cold, dry stratospheres are predicted at low surface…
Determining planetary habitability is a complex matter, as the interplay between a planet's physical and atmospheric properties with stellar insolation has to be studied in a self consistent manner. Standardized atmospheric models for…
White and brown dwarfs are astrophysical objects that are bright enough to support an insolation habitable zone (IHZ). Unlike hydrogen-burning stars, they cool and become less luminous with time, and hence their IHZ moves in with time. The…
The aim of my dissertation is to investigate habitability in extra-Solar Systems. Most of the time, only planets are considered as possible places where extraterrestrial life can emerge and evolve, however, their moons could be inhabited,…
The recently discovered exoplanet Gl581d is extremely close to the outer edge of its system's habitable zone, which has led to much speculation on its possible climate. We have performed a range of simulations to assess whether, given…
In the outer regions of the habitable zone, the risk of transitioning into a globally frozen "snowball" state poses a threat to the habitability of planets with the capacity to host water-based life. We use a one-dimensional energy balance…
Aims: The planetary system around the M star Gliese 581 consists of a hot Neptune (Gl 581b) and two super-Earths (Gl 581c and Gl 581d). The habitability of this system with respect to the super-Earths is investigated following a concept…
The habitability of a planet is influenced by both its parent star and the properties of its local stellar neighborhood. Potential threats to habitability from the local stellar environment mainly arise from two factors: cataclysmic events…
There are four different stable climate states for pure water atmospheres, as might exist on so-called "waterworlds". I map these as a function of solar constant for planets ranging in size from Mars size to 10 Earth-mass. The states are:…
The conditions that a planet must fulfill to be habitable are not precisely known. However, it is comparatively easier to define conditions under which a planet is very likely not habitable. Finding such conditions is important as it can…
M dwarfs host most of the exoplanets in the local Milky Way. Some of these planets, ranging from sub-Earths to super-Jupiters, orbit in their stars' habitable zones (HZs), although many likely possess surface environments that preclude…
When searching for inhabited exoplanets, understanding the boundaries of the habitable zone around the parent star is key. If life can strongly influence its global environment, then we would expect the boundaries of the habitable zone to…
Kepler-452b is currently the best example of an Earth-size planet in the habitable zone of a sun-like star, a type of planet whose number of detections is expected to increase in the future. Searching for biosignatures in the supposedly…
Planetary climate can be affected by the interaction of the host star spectral energy distribution with the wavelength-dependent reflectivity of ice and snow. Here we explore this effect using a one dimensional (1-D), line-by-line,…
Habitability is usually defined as the requirement for a terrestrial planet's atmosphere to sustain liquid water. This definition can be complemented by the dynamical requirement that other planets in the system do not gravitationally…