Letteratura scientifica selezionata sul tema "Habitabilité (astronomie)"

Stellar activity and planetary atmospheric properties have the potential to strongly influence habitability. To date, neither have been adequately studied in the multiverse context, so there has been no assessment of how these effects impact the probabilities of observing our fundamental constants. Here, we consider the effects of solar wind, mass loss, and extreme ultra-violet (XUV) flux on planetary atmospheres, how these effects scale with fundamental constants, and how this affects the likelihood of our observations. We determine the minimum atmospheric mass that can withstand erosion, maintain liquid surface water, and buffer diurnal temperature changes. We consider two plausible sources of Earth’s atmosphere, as well as the notion that only initially slowly rotating stars are habitable, and find that all are equally compatible with the multiverse. We consider whether planetary magnetic fields are necessary for habitability, and find five boundaries in parameter space where magnetic fields are precluded. We find that if an Earth-like carbon-to-oxygen ratio is required for life, atmospheric effects do not have much of an impact on multiverse calculations. If significantly different carbon-to-oxygen ratios are compatible with life, magnetic fields must not be essential for life, and planet atmosphere must not scale with stellar nitrogen abundance, or else the multiverse would be ruled out to a high degree of confidence.

Recent detections of potentially habitable exoplanets around sunlike stars demand increased exploration of the physical conditions that can sustain life, by whatever methods available. Insight into these conditions can be gained by considering the multiverse hypothesis; in a multiverse setting, the probability of living in our universe depends on assumptions made about the factors affecting habitability. Various proposed habitability criteria can be systematically considered to rate each on the basis of their compatibility with the multiverse, generating predictions which can both guide expectations for life’s occurrence and test the multiverse hypothesis. Here, we evaluate several aspects of planetary habitability, and show that the multiverse does indeed induce strong preferences among them. We find that the notion that a large moon is necessary for habitability is untenable in the multiverse scenario, as in the majority of parameter space, moons are not necessary to maintain stable obliquity. Further, we consider various proposed mechanisms for water delivery to the early Earth, including delivery from asteroids, both during giant planet formation and a grand tack, delivery from comets, and oxidation of a primary atmosphere by a magma ocean. We find that, depending on assumptions for how habitability depends on water content, some of these proposed mechanisms are disfavored in the multiverse scenario by Bayes factors of up to several hundred.

The term habitable is used to describe planets that can harbour life. Debate exists as to specific conditions that allow for habitability but the use of the term as a planetary variable has become ubiquitous. This paper poses a meta-level question: What type of variable is habitability? Is it akin to temperature, in that it is something that characterizes a planet, or is something that flows through a planet, akin to heat? That is, is habitability a state or a process variable? Forth coming observations can be used to discriminate between these end-member hypotheses. Each has different implications for the factors that lead to differences between planets (e.g. the differences between Earth and Venus). Observational tests can proceed independent of any new modelling of planetary habitability. However, the viability of habitability as a process can influence future modelling. We discuss a specific modelling framework based on anticipating observations that can discriminate between different views of habitability.

AbstractIn this paper, we connect ideas of the astrobiological and ecological schools to quantify habitability. We show how habitability indexes, devised using the astrobiologically inspired Quantitative Habitability Theory (QHT), can be embedded into ecological models of trophic levels. In particular, we address the problem of spatial-temporal scales. It turns out that the versatility of QHT allows to treat spatial and temporal scales typical of ecological studies. As a habitability index, we propose a new version of our Aquatic Primary Habitability, devised by some of us and formerly applied to saltwater ecosystems (both ocean and coastal) and now applied to freshwater. Although the aim of the paper is to outline the methodology rather than realism, initial steps for parameterization are considered for lakes of South-Central Chile.

In 1961, astronomer Frank Drake formulated the Drake Equation as a cornerstone for scientific discourse regarding the prevalence of communicative extraterrestrial civilizations within the Milky Way galaxy. This equation, often referred to as the “Classic Drake Equation”, outlines the key factors influencing the number of potential civilizations with which we might establish communication. This article submerges into the Drake Equation and proposes a simplified version focused on the broader detection of extraterrestrial non-intelligent life. The established terms of the equation, such as the rate of stellar formation, the fraction of stars harboring planetary systems, and the probability of such systems containing habitable planets, are re-examined and discussed. Additionally, a reevaluation of other factors is presented. Based on this revised framework, various scenarios are explored. As our technological capabilities continue to advance, the detection of biosignatures on exoplanets (incorporated into the suggested new version of the equation) is anticipated to offer insights into the search for life beyond Earth. Keywords: Drake Equation, Extraterrestrial Life, Exoplanetology, Habitability, Biomarkers, Communicative Civilizations

En décembre 2021, le télescope spatial James Webb (JWST) a été lancé marquant ledébut d'une décennie active de recherche axée sur la caractérisation des atmosphères exoplanétaires. Les premières observations de JWST suggèrent déjà la détection d'espèces simples (CO2, CH4 et H2O) et d'aérosols dans les atmosphères d'exoplanètes rocheuses. Ces observables fournissent des informations essentielles sur les processus chimiques se produisant dans l'atmosphère. Leur détection et la quantification de leur abondance peut aider à contraindre des propriétés importantes de l'atmosphère,son origine et les conditions à la surface de la planète. Dans cette thèse, je me concentre sur trois types d'observables fournissant différentes informations sur les atmosphères des exoplanètes rocheuses : les produits photochimiques en phase gaz importants pour les mondes habitables, les brumes photochimiques et leurs propriétés optiques intrinsèques, et les volatiles simples issus du dégazage volcanique pour les exoplanètes rocheuses chaudes et non habitable. A l'aide d'expériences en laboratoire et de modélisation, j'ai étudié ces différents observables pour mieux comprendre les informations qu'ils peuvent fournir et pour améliorer l'interprétation des futures données JWST. Pour les observables photochimiques en phase gaz dans les mondes habitables, j'ai évalué la formation d'eau par photochimie dans la haute atmosphère, au-dessus de la couverture nuageuse, et sa corrélation à la présence de H2 d'origine volcanique. Pour les atmosphères d'exoplanètes rocheuses plus chaudes, j'ai utilisé la modélisation combinant dégazage volcanique, chimie atmosphérique et transfert radiatif pour évaluer le lien entre les abondances moléculaires relatives des volatiles dans l'atmosphère(par exemple CO2/CO) et l'état rédox de l'intérieur de la planète. Pour comprendre l'extinction induite par les brumes photochimiques dans les atmosphères des exoplanètes, je me suis concentré sur l'influence de la composition chimique en déterminant les indices optiques d'analogues de laboratoire. J'ai évalué l'impact de la technique optique, de la composition du mélange gazeux initial et des conditions expérimentales (irradiation, température, temps de résidence du gaz) sur ces indices optiques
In december 2021, the James Webb Space Telescope (JWST) was launched marking thebeginning of an active decade of research focusing on the characterization of exoplanet atmo-spheres. The first observations of JWST already suggest the detection of simple species (CO2 ,CH4 and H2O) and aerosols in rocky exoplanet atmospheres. These observables hold crucialinformation on the chemical processes occurring in the atmosphere. Their detection and thequantification of their abundances can help constrain important properties of the atmosphere,its origin and the conditions found at the surface. In this thesis, I focus on three types of observ-ables providing different information on rocky exoplanet atmospheres : gaseous photochemicalproducts in habitable worlds, haze extinction partly set by their intrinsic optical properties,and simple volatiles tracing properties of the rocky interior in warm and non-habitable envi-ronments. Using laboratory experiments and modelling, I studied these different observablesto better understand the information they can provide and to improve future interpretationof JWST data. For gas observables in habitable worlds, I assessed the formation of watervapor by photochemistry in the upper atmosphere, above the cloud layer, and its correlationto the presence of volcanic H2 . For warmer rocky exoplanet atmospheres, I used modellingcombining geochemical outgassing, atmospheric chemistry and radiative transfer to assess thecorrelation between the observed relative molecular abundances of volatiles in the atmosphere(e.g. CO2 /CO) and the interior redox state of the planet. To understand the extinction causedby photochemical hazes in exoplanet atmospheres, I focused on the influence of the particle'scomposition by deriving the refractive indices of laboratory analogs. I assessed the impact ofthe optical technique, gas composition and experimental conditions (irradiation, temperature,residence time of the gas) on these refractive indices

Avec la découverte d'anciens réseaux de rivières sur Mars et la détection de planètes telluriques tempérées autour d'étoiles voisines, nous disposons à présent d'un terrain de jeu formidable pour explorer si la vie est abondante ou rare dans l'Univers. Mon travail de thèse vise à mieux comprendre les conditions dans lesquelles une planète peut maintenir de l'eau liquide - substrat essentiel de la vie - à sa surface. À l'aide de modèles numériques de climat 3-D, et de calculs et mesures spectroscopiques, j'ai mené pendant ma thèse deux enquêtes. Premièrement, j'ai exploré les climats passés de Mars, pour comprendre comment se sont formées les énigmatiques rivières martiennes. À part la Terre, Mars est la seule planète qui a été habitable, mais nous ne savons toujours pas pourquoi. J'ai montré que les évènements extrêmes (formation des vallées de débâcle, impacts de météorites) qui ont pourtant profondément marqué la surface de Mars ne peuvent pas expliquer à eux seuls la formation de ces réseaux fluviaux. Mes travaux de thèse ont également permis d'établir que la présence de gaz à effet de serre réduits (hydrogène, méthane) offre une solution alternative prometteuse. Deuxièmement, j'ai étudié les atmosphères possibles des exoplanètes solides et tempérées, notamment celles orbitant autour de petites étoiles comme Proxima et TRAPPIST-1. J'ai montré que certaines de ces planètes ont des caractéristiques très favorables à la présence d'eau liquide en surface. Ce résultat est d'autant plus prometteur qu'il sera possible - comme démontré dans ma thèse pour le cas de la planète Proxima b - de caractériser l'atmosphère de ces planètes avec les futurs télescopes JWST et ELTs
Ancient rivers and lakes discovered on Mars. Numerous temperate, Earth-sized exoplanets detected around nearby stars. Thanks to ground and space-based telescope observations and Solar System exploration missions, we now have a fantastic playground to explore how prevalent life is in the Universe. The main goal of my thesis work is to better understand the conditions necessary for a planet to maintain liquid water - a primary building block for life - on its surface. Using 3-D numerical climate models, as well as spectroscopic calculations and measurements, I conducted two major investigations during my thesis. First, I explored the environments of ancient Mars at multiple epochs in order to understand the conditions in which the enigmatic Martian rivers were carved. Apart from Earth, Mars is the only planet that has been habitable, but we don't know why. I showed that extreme events (outflow channel formation, meteoritic impacts) that scarred the surface of Mars cannot explain the formation of these valley networks. Nonetheless, I showed that the presence of reducing greenhouse gases such as hydrogen and methane offers a promising alternative solution. Secondly, I studied the possible atmospheres of solid, temperate exoplanets, with a particular focus on those orbiting small stars such as Proxima Centauri and TRAPPIST-1. I showed that some of these planets have characteristics that are highly favourable to the presence of liquid water on their surface. This result is really promising as it will be soon become possible - as demonstrated in my thesis for Proxima b - to characterize the atmosphere of these planets with the future JWST and ELTs astronomical observatories

Over the centuries, mankind always wondered whether other worlds existed, as well as other life forms upon their surfaces. This topic was considered “science-fiction” a few decades ago, but now it’s becoming more and more realistic: actually, different planets do exist, and some of them could bear life. Up to date, a database of more than 7000 planets or candidates is continuously updated, as current facilities keep on discovering new ones – a simple estimate suggests that in our galaxy tens of billions of new planets await to be revealed. Being extrasolar planetology a relatively new field of astrophysics, many things need to be set and done. In this case, a full characterization of the different atmospheres terrestrial exoplanets are likely to have is needed to correctly understand observational data; also, one should retrieve information about their formation and be able to presume that some form of life exists on the surface. To do that, theoretical modeling is needed: by simulating a simple imaginary exoplanet, one could have a better understanding of how all active processes interact within the system and what observable features they express so that they could be recognized when observing a real exoplanet. In this Ph.D. project, I explored the topic in various ways, starting with an overview about the detection techniques, the current knowledge about Super Earths, which are massive terrestrial exoplanets, and the concept of habitability. In the framework of a standardized, Virtual Observatory (VO) aware treatment of the exoplanets, I developed Exo-MerCat, which collects data from the most important online archives and merges the information while correcting nomenclature, status, and coordinate issues. This catalog is now a VO resource and has been positively accepted by the International Virtual Observatory Alliance (IVOA), as well as being used for PLATO and ARIEL space missions. Exo-MerCat allowed retrieving the sample of known Super Earths, which is then used as input to create a grid of atmospheric models to be run with the 1D radiative-convective model MAGRATHEA which I contributed to develop. MAGRATHEA can model Earth and Mars-like atmospheres, covering a wide range of the physical and chemical parameter space. It is able to calculate the radiative-convective equilibrium solution of an atmosphere in a very short time (a few hours of computational time), allowing us to fulfill a grid of 18000 atmospheric models of theoretical planets and 2400 ones of observed planets, as retrieved by the Exo-MerCat catalog. These models can be useful to study under which physical and atmospheric conditions it is possible to find liquid water on the surface of the planet, an essential requirement for the habitability of exoplanets. The atmospheric pressure-temperature profiles for the observed Super Earths grid, as retrieved by MAGRATHEA, were then used as an input for the Exoplanet Ozone Model to produce the corresponding ozone profile. The code is, at present, still at its early stages, but can efficiently produce the ozone profile of an atmosphere by solving the (photo-induced and thermal) chemistry of the oxygen-related species. The laboratory experiments performed at the Biology Department of the University of Padua, within the “Atmosphere in a Test-Tube project”, can benefit from the theoretical results from MAGRATHEA. The physical and chemical conditions at the surface are reproduced in the laboratory, forming exotic environments at which cyanobacteria are exposed. The study of the survival rate and the variation of the chemical composition caused by the presence of biological activity can be thus performed: this is indispensable in order to understand if, and when, a habitable planet can be actually inhabited.
Nei secoli, ci siamo sempre chiesti se esistessero altri mondi e altre forme di vita sulla superficie di questi. Questo argomento è stato considerato spesso “fantascienza” fino a pochi decenni fa, ma ora sta diventando sempre più realistico: in realtà, pianeti diversi esistono ed alcuni di essi possono ospitare la vita. Ad oggi, un archivio di più di 7000 pianeti confermati o candidati è costantemente aggiornato, al passo con gli strumenti che ne scoprono sempre di più - solo nella nostra Galassia, decine di miliardi di nuovi pianeti aspettano di essere scoperti. Essendo la planetologia extrasolare un campo relativamente nuovo dell'astrofisica, molte cose devono essere ancora studiate. In questo caso, una caratterizzazione più dettagliata delle possibili atmosfere di esopianeti di tipo terrestre è necessaria per comprendere meglio le osservazioni; inoltre, bisognerebbe ricavare informazioni sulla loro formazione e poter presumere se, ed in quali casi, forme di vita potrebbero esistere su quei pianeti. Per fare ciò, un approccio teorico è necessario: simulando un pianeta in maniera semplificata, si potrebbe avere una migliore comprensione di come tutti i processi attivi interagiscono tra loro e quali osservabili producono, affinché possano essere identificate quando si osserva un vero esopianeta. In questo progetto di Dottorato, ho esplorato l'argomento da diversi punti di vista, iniziando con una sintesi dei metodi di scoperta, di ciò che è noto ad oggi sulle Super Terre (pianeti terrestri massivi), e del concetto di abitabilità. In una prospettiva di un trattamento standardizzato dei dati, il quale possa rientrare nei canoni del Virtual Observatory (VO), ho sviluppato Exo-MerCat al fine di collezionare dati dai più importanti archivi online, incrociando le informazioni e correggendo problemi di nomenclatura, status e coordinate. Questo catalogo è ora una risorsa VO ed è stato accettato positivamente dall'International Virtual Observatory Alliance (IVOA), oltre ad essere usato per le missioni spaziali PLATO e ARIEL. Exo-MerCat ha permesso di ricavare l'insieme di Super Terre note, usato poi per creare una griglia di modelli atmosferici utilizzata dal modello 1D radiativo-convettivo MAGRATHEA, che ho contribuito a sviluppare. MAGRATHEA riesce a riprodurre atmosfere di tipo terrestre e marziano, coprendo un largo intervallo di parametri fisici e chimici. Il codice calcola il profilo di equilibrio radiativo-convettivo di una atmosfera in poche ore di tempo computazionale, consentendoci di riempire una griglia di 18000 modelli di pianeti teorici e una di 2400 modelli di pianeti osservati, ricavati dall'insieme prodotto da Exo-MerCat. Questi modelli possono essere utili per studiare sotto quali condizioni fisiche e atmosferiche è possibile trovare acqua liquida sulla superficie di un pianeta, requisito essenziale per l'abitabilità degli esopianeti. I modelli atmosferici delle Super Terre osservate ricavati da MAGRATHEA sono stati usati come input per l'Exoplanet Ozone Model al fine di produrre la concentrazione di ozono corrispondente ai profili stessi. Questo codice è, al momento, ancora preliminare, ma può riprodurre il profilo dell'abbondanza di ozono di una atmosfera risolvendo la chimica foto-indotta e termica delle specie legate all'ossigeno. I risultati teorici ottenuti dai vari codici sono utili agli esperimenti di laboratorio effettuati al Dipartimento di Biologia dell'Università di Padova. Considerando alcune atmosfere calcolate da MAGRATHEA, si possono riprodurre le condizioni fisiche e chimiche alla superficie in laboratorio, formando atmosfere esotiche ed esponendo cianobatteri a queste. Lo studio della sopravvivenza e dell'adattamento dei batteri, così come della variazione della composizione chimica causata dall'attività biologica, può essere eseguito. Ciò è indispensabile per comprendere se, e sotto quali condizioni, un pianeta abitabile può essere effettivamente abitato.

Exoplanet discovery has grown more quickly in recent years. However, the nature of their discovery leaves many unanswered in questions regarding exoplanetary habitability. Proxima Centauri b, an exoplanet which orbits the Sun's closest stellar neighbour, Proxima Centauri, was recently discovered with a subzero equilibrium temperature. Although not considered habitable based on the classical definition of the liquid water range, there may be fractions of Proxima Centauri b which are habitable. A prior study simulated the climate conditions of Proxima Centauri b until equilibrium was reached, using a variety of initial conditions. In this project, various metrics for calculating the fractional habitability of Proxima Centauri b are presented and applied to the results of the prior study's simulations. Colormaps are used to show the ice and temperature distributions that produce the calculated values of fractional habitability. The fractional habitabilities calculated show that while the value is both case and metric dependent, for the vast majority of all cases and metrics the value is nonzero implying that Proxima Centauri b is likely to have habitable regions.
Upptäckandet av exoplaneter har ökat i takt över de senaste åren. Samtidigt, på grund av sättet som de upptäcks finns många obesvarade frågor angående planeternas beboelighet. Proxima Centauri b är en exoplanet som kretsar kring solens närmsta granne, Proxima Centauri. Exoplaneten upptäcktes nyligen med en jämviktstemperatur under $0\degree$C. Trots att exoplaneten inte anses beboelig enligt klassisk definition kan det finnas delar av Proxima Centauri b som är beboeliga. En tidigare studie simulerade klimatförhållandena av Proxima Centarui b till jämvikt nåddes, med varierade begynnelsetillstånd. I detta projekt beräknas andelen av Proxima Centauri b som är beboelig genom flera olika mått för "fractional habitability". Måtten jämförs med den tidigare studien och dess simuleringar. Grafiskt åsikdligörs resultaten via färgkartor över planeten för istjocklek och yttemperatur. De beräknade värdena på Proxima Centauri b's "fractional habitability" påvisar beroende på mått och begynnelsetillstånd. Däremot, för en majoritet av både fall och mått är värdet nollskilt vilket antyder att Proxima Centauri b är delvist beboelig.

A wide range of potentially rocky transiting planets in the habitable zone (HZ) have been detected by Kepler as well as ground-based searches. The spectral type of the host star will influence our ability to detect atmospheric features with future space and ground based missions like JWST, GMT and E-ELT. For my thesis, I present a complete suit of stellar models with a stellar effective temperature ranging from Teff = 2300K to Teff = 7000K, sampling the entire FGKM stellar type range, for modeling extrasolar planets. I also have a grid of model atmospheres for an Earth-analogue planet orbiting stars and derive remotely detectable spectral atmospheric features. The UV emission from a planet's host star dominates the photochemistry and thus the resultant observable spectral features. Using the latest UV spectra obtained by Hubble as well as IUE, I model Earth-like planets for a wide range of host stars. I detail the results of activity on the primary detectable atmospheric features that indicate habitability on Earth, namely: H2O, O3, CH4, N2O and CH3Cl. I model the emergent spectra of Earth-analogue planets orbiting our grid of FGKM stars in the VIS/NIR (0.4 - 4 microns) and the IR (5 - 20 microns) range in accordance with future mission design concepts like JWST and direct detection missions like HDST/LUVOIR in the more distant horizon. We also model the amount of UV flux reaching the surface of Earth-like planets at various geological epochs ranging from a pre-biotic world through the rise of oxygen and for Earth-like planets orbiting FGKM stars at equivalent stages of evolution.
Astronomy

In the study of habitability of terrestrial exoplanets, both life-supporting conditions and the prevalence of transient life-threatening events need to be considered. One type of hazardous effect that has so far not received much attention is the thermal effect of a nearby active galactic nucleus (AGN), or in this particular case, the class of the AGN known as a quasar. In this work we investigate the thermal effect from a quasar by calculating the number of habitable terrestrial planets (HTP) in an elliptical or bulge-dominated galaxy, that goes extinct when exposed to the quasar radiation in a limited wavelength range. This is done by approximations and modelling along with pre-existing formulas and data from earlier publications. As a result, the influence by a quasar during the time span of quasar activity will have a less significant impact on the habitability in solar-type stellar systems than expected. Assuming tQSO = 108 yrs of quasar activity, results in the number of affected HTP, ≈ 1 × 105, 9 × 105 and 4 × 108 for isotropic spherical radiation and ≈ 1 × 106, 8 × 106 and 3 × 109 for a double-conical radiation. In terms of stellar mass fraction, ≈ 1.3%, 1.0%, 0.4% for isotropic radiation and ≈ 12.8%, 9.5%, 3.8% for conical, is affected. The results of this work are hoped to provide a rough estimation of the thermal impacts of a quasar on the habitability as well as to point out the most important parameters when considering this model.
I studier om beboeligheten på jordlika exoplaneter övervägs både förutsätningar för liv på planeten men även livshotande händelser i planetens närhet. En typ av farlig effekt som hit- intills inte fått mycket uppmärksamhet, är det termiska effekterna från en aktiv galaxkärna (AGN) eller som i detta fall, AGN-typen kvasar. I detta arbete studeras de termiska effekterna från en kvasar genom att beräkna antalet beboeliga jordlika exoplaneter (HTP) i en elliptisk eller bulge-dominerad galax, (bulge-centralförtätning), som blir obeboeliga då de utsätts för kvasarens strålning i ett begränsat våglängdsområde. Detta görs genom antaganden och modellering av redan befintliga formler och data från tidigare publikationer. Detta resulterar i en mindre inverkan av kvasaren på system kring sollika stjärnor än förväntat. Antaget tQSO =108 år av kvasar-aktivitet ger antal påverkade HTP, ≈ 1 × 105, 9 × 105 och 4 × 108 vid isotropisk strålning och 1 × 106, 8 × 106 och 3 × 109 vid dubbel-konisk formad strålning. Uttryckt i andel stjärnmassa motsvarar detta ≈ 1.3%, 1.0%, 0.4% för sfäriskt fall och ≈ 12.8%, 9.5%, 3.8% vid koniskt. Detta arbete hoppas kunna ge on grov uppfattning om kvasarens termiska effekter på beboligheten men även identifiera det mest betydande parametrarna i denna modell.

abstract: I present a catalog of 1,794 stellar evolution models for solar-type and low-mass stars, which is intended to help characterize real host-stars of interest during the ongoing search for potentially habitable exoplanets. The main grid is composed of 904 tracks, for 0.5-1.2 M_sol at scaled metallicity values of 0.1-1.5 Z_sol and specific elemental abundance ratio values of 0.44-2.28 O/Fe_sol, 0.58-1.72 C/Fe_sol, 0.54-1.84 Mg/Fe_sol, and 0.5-2.0 Ne/Fe_sol. The catalog includes a small grid of late stage evolutionary tracks (25 models), as well as a grid of M-dwarf stars for 0.1-0.45 M_sol (856 models). The time-dependent habitable zone evolution is calculated for each track, and is strongly dependent on stellar mass, effective temperature, and luminosity parameterizations. I have also developed a subroutine for the stellar evolution code TYCHO that implements a minimalist coupled model for estimating changes in the stellar X-ray luminosity, mass loss, rotational velocity, and magnetic activity over time; to test the utility of the updated code, I created a small grid (9 models) for solar-mass stars, with variations in rotational velocity and scaled metallicity. Including this kind of information in the catalog will ultimately allow for a more robust consideration of the long-term conditions that orbiting planets may experience. In order to gauge the true habitability potential of a given planetary system, it is extremely important to characterize the host-star's mass, specific chemical composition, and thus the timescale over which the star will evolve. It is also necessary to assess the likelihood that a planet found in the "instantaneous" habitable zone has actually had sufficient time to become "detectably" habitable. This catalog provides accurate stellar evolution predictions for a large collection of theoretical host-stars; the models are of particular utility in that they represent the real variation in stellar parameters that have been observed in nearby stars.
Dissertation/Thesis
Doctoral Dissertation Astrophysics 2017

The modern view of planets goes far beyond the usual concept of the planets as bodies of the Solar system. The discovery ofexoplanets has immeasurably expanded the understanding of the architecture and properties of planetary systems. Majoradvances have been made in the study of the planets and minor bodies of the Solar system. However, no answers havebeen received to fundamental questions about the causes of various paths of evolution and formation of planetary naturalcomplexes. To give answers to these questions, research on exoplanets is called upon, of which more than 5000 have beendiscovered to date. Exoplanet studies provide an approach to solving the key problems of stellar-planetary cosmogony —the genesis and evolution of planets as byproduct of star formation. The most urgent problems concern the formation ofplanetary systems around stars of various spectral classes; the nature of hot Jupiters; the reasons for the predominanceof super-Earths and sub-Neptunes, which are absent in the Solar system; stability of planetary systems of binary stars,including circumbinary systems. Of particular interest are terrestrial planets with orbits in zones of “potential habitability”,studies of which open a new page in astrobiology.