scholarly journals How does the mass and activity history of the host star affect the population of low-mass planets?

2021 ◽  
Author(s):  
Daria Kubyshkina ◽  
Aline Vidotto
Keyword(s):  
Comparative Study ◽  
Massive Stars ◽  
Intermediate Mass ◽  
Planetary Evolution ◽  
Atmospheric Escape ◽  
The Past ◽  
Strongly Connected ◽  
History Of ◽  
Low Mass ◽  
Host Stars

<p>The evolution of the atmospheres of low and intermediate-mass planets is strongly connected to the physical properties of their host stars. The types and the past activities of planet-hosting stars can, therefore, affect the overall planetary population. We perform a comparative study of sub-Neptune-like planets orbiting stars of different masses and different evolutionary histories. As a model of atmospheric evolution, we employ our own framework combining planetary evolution in MESA with a realistic prescription of the escape of hydrogen-dominated atmospheres. We discuss general patterns of the evolved population as a function of planetary and stellar parameters. The final populations look qualitatively similar in terms of the atmospheres' survival around different stars, but quantitatively different, with this difference accentuated for planets orbiting more massive stars. We will discuss the potential input from different atmospheric escape mechanisms in shaping these populations.</p>

scholarly journals How does the mass and activity history of the host star affect the population of low-mass planets?

2021 ◽  
Vol 504 (2) ◽  
pp. 2034-2050
Author(s):  
Daria Kubyshkina ◽  
Aline A Vidotto
Keyword(s):  
Mass Star ◽  
Intermediate Mass ◽  
Solar Mass ◽  
Planetary Evolution ◽  
The Past ◽  
Strongly Connected ◽  
History Of ◽  
Low Mass ◽  
Host Stars ◽  
Atmospheric Mass

ABSTRACT The evolution of the atmospheres of low- and intermediate-mass planets is strongly connected to the physical properties of their host stars. The types and the past activities of planet-hosting stars can, therefore, affect the overall planetary population. In this paper, we perform a comparative study of sub-Neptune-like planets orbiting stars of different masses and different evolutionary histories. We discuss the general patterns of the evolved population as a function of parameters and environments of planets. As a model of the atmospheric evolution, we employ the own framework combining planetary evolution in Modules for Experiments in Stellar Astrophysics (mesa) with the realistic prescription of the escape of hydrogen-dominated atmospheres. We find that the final populations look qualitatively similar in terms of the atmospheres survival around different stars, but qualitatively different, with this difference accentuated for planets orbiting more massive stars. We show that a planet has larger chances of keeping its primordial atmosphere in the habitable zone of a solar-mass star compared to M or K dwarfs and if it starts the evolution having a relatively compact envelope. We also address the problem of the uncertain initial temperatures (luminosities) of planets and show that this issue is only of particular importance for planets exposed to extreme atmospheric mass losses.

scholarly journals Commission 35: Stellar Constitution: (Constitution Des Etoiles)

2000 ◽  
Vol 24 (1) ◽  
pp. 201-218
Author(s):  
J.-P. Zahn ◽  
D. VandenBerg ◽  
R. Canal ◽  
C. Chiosi ◽  
W. Dziembowski ◽  
...  
Keyword(s):  
White Dwarfs ◽  
Massive Stars ◽  
Atomic Diffusion ◽  
Intermediate Mass ◽  
Low Mass Stars ◽  
The Past ◽  
Intermediate Mass Stars ◽  
Low Mass

Our Commission decided to proceed as before, with a rather comprehensive report, while focusing on the subjects where most progress has been achieved during the past three years. The colleagues who kindly contributed to it are W. Dziembowski (helio- and aster-oseismology), J. Guzik (intermediate-mass stars), G. Meynet (massive stars), G. Michaud (atomic diffusion), D. VandenBerg (low mass stars), G. Vauclair (white dwarfs), J.-P. Zahn (convection, rotational mixing).

scholarly journals Commission 35: Stellar Constitution (Constitution Des Étoiles)

1997 ◽  
Vol 23 (1) ◽  
pp. 293-302
Keyword(s):  
Massive Stars ◽  
Solar Neutrinos ◽  
Atomic Diffusion ◽  
Intermediate Mass ◽  
The Past ◽  
Intermediate Mass Stars ◽  
Stellar Convection ◽  
Substantial Progress ◽  
Low Mass

This report focuses on a few subjects where substantial progress has been achieved during the past three years. Several colleagues were asked to describe what they consider as the highlights in their field, and we are very grateful to them for their prompt and competent response. They covered the following topics: massive stars (A. Maeder), intermediate mass stars (P. Demarque), low mass objects (G. Chabrier), stellar convection (H. Spruit), atomic diffusion (G. Michaud), rotational mixing (J.-P. Zahn), helioseismology (S. Basu) and solar neutrinos (E. Schatzman). J.-P. Zahn was responsible for collecting and editing their contributions.

scholarly journals The refuge of a dying variant within the grammar: Patterns of change and continuity in the Spanish verbal periphrasishaber de + infinitive over the past two centuries

2015 ◽  
Vol 27 (1) ◽  
pp. 89-116 ◽  
Author(s):  
José Luis Blas Arroyo ◽  
Javier Vellón Lahoz
Keyword(s):  
Comparative Study ◽  
Detailed Analysis ◽  
20Th Century ◽  
Language Change ◽  
Explanatory Power ◽  
The Past ◽  
History Of ◽  
Selection Of

AbstractBased on a corpus of ego-documents (private letters, diaries, memoirs) from the 19th and the first half of the 20th centuries, this paper presents a variationist comparative study to determine the fate of the modal periphrasishaber de + infinitive in the history of modern Spanish. Detailed analysis of the envelope of variation enables us to show that, despite an abrupt decline in the selection ofhaber derelative totener que, both ‘to have to’, grammatical environments that favor its use remain in the mid-20th century. Many of the factor groups and the hierarchy of constraints during this period are similar to those that operated in previous periods. Nevertheless, a generalized decrease in the explanatory power of these factor groups, as well as some divergent patterns within several of these groups are also observed, mainly as a result of the fact thathaber de + infinitive is increasingly relegated to some restricted areas of the grammar and lexicon. Based on these results, some theoretical implications for changing rates and constraints in language change and grammaticalization are discussed.

Two Paths to the Past: A Comparative Study of the Last Fifty Years ofAmerican Antiquityand theAmerican Journal of Archaeology

1985 ◽  
Vol 50 (2) ◽  
pp. 452-463 ◽  
Author(s):  
Stephen L. Dyson
Keyword(s):  
Comparative Study ◽  
Intellectual History ◽  
Fiftieth Anniversary ◽  
American Antiquity ◽  
Past Time ◽  
The Past ◽  
The Future ◽  
History Of ◽  
Time Future

The fiftieth anniversary of a journal, especially one as important and influential asAmerican Antiquity, is a time for celebration. It is also a moment for reflection both on the achievements of the past and the potential for the future. Major journals are mirrors of the intellectual history of the disciplines that they represent. They are also both intentionally or unintentionally shapers and trendsetters of that discipline. Time past, time present, and time future become inextricably woven in a consideration of their printed pages.

scholarly journals Definitions, Summary, and Some Issues

2002 ◽  
Vol 12 ◽  
pp. 179-181
Author(s):  
Peter S. Conti
Keyword(s):  
Spectral Type ◽  
Massive Star ◽  
Massive Stars ◽  
Mass Star ◽  
Mass Limit ◽  
Physical Processes ◽  
Intermediate Mass ◽  
Observable Quantity ◽  
Low Mass ◽  
Final Evolution

This Joint Discussion has been titled Massive Star Birth. Perhaps it is appropriate here to define what we mean by a massive star. The very word massive suggests we consider aminimummassMbelow which one would speak of low (or intermediate) mass evolution, and above which is the realm of massive stars. It is natural to take this mass limit as that in which a (single) star will end its life as a supernova: 8M⊙. This corresponds to a (minimum) luminosityLof a few × 103L⊙, a (minimum)Teff of 20000 K, and a ZAMS spectral type of about B1.5V. Note that this mass division refers to the final evolution of a star, and might well have nothing to do with difference in physical processes between massive and low mass starbirth. For example, the minimumTeff for a star to produce an UCHII region, a readily observable quantity, corresponds to aTeffcloser to 30000 K and a mass of 15M⊙.

scholarly journals Close-in Sub-Neptunes Reveal the Past Rotation History of Their Host Stars: Atmospheric Evolution of Planets in the HD 3167 and K2-32 Planetary Systems

2019 ◽  
Vol 879 (1) ◽  
pp. 26 ◽  
Author(s):  
D. Kubyshkina ◽  
P. E. Cubillos ◽  
L. Fossati ◽  
N. V. Erkaev ◽  
C. P. Johnstone ◽  
...  
Keyword(s):  
Planetary Systems ◽  
Atmospheric Evolution ◽  
The Past ◽  
History Of ◽  
Host Stars

scholarly journals Mass loss and evolution of massive stars

1981 ◽  
Vol 59 ◽  
pp. 229-253
Author(s):  
C. Chiosi
Keyword(s):  
Mass Loss ◽  
Stellar Wind ◽  
Evolutionary History ◽  
Massive Stars ◽  
Observational Evidence ◽  
Common Occurrence ◽  
Theoretical Understanding ◽  
The Past ◽  
History Of ◽  
The Subject

In the past few years both growing observational evidence and theoretical understanding have shown that mass loss by stellar wind is a common occurrence in the evolutionary history of many types of star. Recent reviews on the subject may be found in Conti (1978), Cassinelli (1979), Conti and Mc Cray (1980), Hutchings (1980a), de Loore (1979, 1980) and Sreenivasan (1979).Therefore, in this paper we will concentrate only on those observational and theoretical aspects of the problem that demand further investigation.

scholarly journals s-Process Enrichment in Low-Mass Agb Stars

1989 ◽  
Vol 106 ◽  
pp. 176-195 ◽  
Author(s):  
R. Gallino
Keyword(s):  
Solar System ◽  
Massive Stars ◽  
Agb Stars ◽  
Intermediate Mass ◽  
Low Mass Stars ◽  
Temporal Behaviour ◽  
Physical Conditions ◽  
Intermediate Mass Stars ◽  
Low Mass ◽  
Main Component

AbstractAfter a brief description of the developments of the theory of s-process nucleosynthesis, the difficulties recently encountered in envisaging reliable astrophysical conditions for obtaining a solar-system distribution of s-isotopes are discussed. In particular, while the reaction 22Ne(α, n)25Mg may account for the nucleosynthesis of the weak s-component in massive stars, it fails to reproduce the main s-component in intermediate mass stars. The efficiency of the alternative reaction 13C(α, n)160 occurring in low mass stars during recurring thermal instabilities of the He shell is then analyzed. It is shown that, contrary to previous expectations, the 13C source well reproduces the main component, provided that realistic physical conditions are assumed for the temporal behaviour of the pulse and the effect of the light n-absorbers (especially 12C) is properly taken into account. The results satisfactorily compare with the constraints of the classical s-analysis. Key observational evidences also appear to be in agreement with this scenario.

scholarly journals Folkways Lonto Leok Budaya Manggarai dalam Terang Pemikiran William Sumner Tentang Masyarakat Sebagai Kerjasama Antagonistic

2021 ◽  
Vol 4 (1) ◽  
pp. 411-421
Author(s):  
Mathias Jebaru Adon
Keyword(s):  
Comparative Study ◽  
The Past ◽  
History Of ◽  
Collective Deliberation ◽  
Regional Cultures ◽  
The Republic ◽  
Interpretive Method

As a large nation consisting of various regional cultures, Indonesia has various folkways, which are the skills and local wisdom of the Indonesian people. In Manggarai culture, one folkway that is most famous is lonto leok. Lonto leok is the life principle of the Manggarai community which expresses a sense of unity and oneness as a group of people. Therefore, this study aims to reveal the value of togetherness contained in folkways lonto leok. The methodology used is an interpretive method of the phenomenon of living with the Manggarai community in a comparative study with William Graham Sumner's thinking about society as an antagonistic collaboration. This study reveals that the Manggarai community was born from the antagonistic collaboration between tribes who fought each other in the past, which then united to form the Manggarai community as it is today. These historical traces are clearly revealed in the folkways lonto leok, which means collective deliberation. This study contributes to understanding the history of the unity of the Republic of Indonesia and how this unity is maintained.

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