scholarly journals Encounters involving planetary systems in birth environments: the significant role of binaries

2020 ◽  
Vol 499 (1) ◽  
pp. 1212-1225
Author(s):  
Daohai Li ◽  
Alexander J Mustill ◽  
Melvyn B Davies
Keyword(s):  
Solar System ◽  
Significant Role ◽  
Cross Sections ◽  
Binary Stars ◽  
Open Cluster ◽  
Planetary Systems ◽  
The Sun ◽  
Crowded Environments ◽  
Stellar Density

ABSTRACT Most stars form in a clustered environment. Both single and binary stars will sometimes encounter planetary systems in such crowded environments. Encounter rates for binaries may be larger than for single stars, even for binary fractions as low as 10–20 per cent. In this work, we investigate scatterings between a Sun–Jupiter pair and both binary and single stars as in young clusters. We first perform a set of simulations of encounters involving wide ranges of binaries and single stars, finding that wider binaries have larger cross-sections for the planet’s ejection. Secondly, we consider such scatterings in a realistic population, drawing parameters for the binaries and single stars from the observed population. The scattering outcomes are diverse, including ejection, capture/exchange, and collision. The binaries are more effective than single stars by a factor of several or more in causing the planet’s ejection and collision. Hence, in a cluster, as long as the binary fraction is larger than about 10 per cent, the binaries will dominate the scatterings in terms of these two outcomes. For an open cluster of a stellar density 50 pc−3, a lifetime 100 Myr, and a binary fraction 0.5, we estimate that Jupiters of the order of 1 per cent are ejected, 0.1 per cent collide with a star, 0.1 per cent change ownership, and 10 per cent of the Sun–Jupiter pairs acquire a stellar companion during scatterings. These companions are typically thousands of au distant and in half of the cases (so 5 per cent of all Sun–Jupiter pairs), they can excite the planet’s orbit through Kozai–Lidov mechanism before being stripped by later encounters. Our result suggests that the Solar system may have once had a companion in its birth cluster.

3. Beautiful theories, ugly facts

2021 ◽  
pp. 31-46
Author(s):  
Raymond T. Pierrehumbert
Keyword(s):  
Angular Momentum ◽  
Solar System ◽  
Planetary Systems ◽  
Protoplanetary Disk ◽  
Newtonian Gravity ◽  
The Sun ◽  
French Mathematician ◽  
Modern Form

‘Beautiful theories, ugly facts’ evaluates the theories on planetary systems, particularly the Solar System. In 1734, the Swedish polymath Emmanuel Swedenborg proposed that the Sun and all the planets condensed out of the same ball of gas, in what is probably the earliest statement of the nebular hypothesis. The nebular hypothesis entered something close to its modern form in the hands of the French mathematician Pierre-Simon Laplace, who in 1796 made the clear connection to Newtonian gravity. The angular momentum problem and the structure of a protoplanetary disk, the formation of rocky cores, and the gravitational accretion of gas in the disk also come under this topic.

scholarly journals 11. The Role of Protoplanets in the Formation of the Solar System

1977 ◽  
Vol 39 ◽  
pp. 569-571
Author(s):  
I. P. Williams
Keyword(s):  
Solar System ◽  
Refractory Material ◽  
The Sun ◽  
Resisting Medium ◽  
Solar Composition ◽  
Roche Limit ◽  
Natural Outcome

A likely origin of the asteroids (and possibly, of the comets?) is the natural outcome of the following scenario that we propose for the formation of the planets. Protoplanets of similar mass and solar composition will segregate in three different ways: For those far enough from the sun (like Uranus and Neptune), the segregation of icy grains releases enough energy to drive the remaining gases to infinity. For all other planets, the segregation of refractory material only does not release enough energy to disrupt the protoplanet; however, while spiraling inwards in a resisting medium, the terrestrial protoplanets cross their Roche limit and lose their gaseous outer layers. Asteroids (or comets) could therefore originate from the disruption of protoplanets before the settling of their refractory (or icy) grains is completed.

scholarly journals ASTROD AND ASTROD I — OVERVIEW AND PROGRESS

2008 ◽  
Vol 17 (07) ◽  
pp. 921-940 ◽  
Author(s):  
WEI-TOU NI
Keyword(s):  
Gravitational Field ◽  
Solar System ◽  
Gravitational Waves ◽  
Binary Stars ◽  
Precise Determination ◽  
The Sun ◽  
Free System ◽  
Dynamic Distribution ◽  
Magnitude Improvement

In this paper, we present an overview of ASTROD (Astrodynamical Space Test of Relativity using Optical Devices) and ASTROD I mission concepts and studies. The missions employ deep-space laser ranging using drag-free spacecraft to map the gravitational field in the solar-system. The solar-system gravitational field is determined by three factors: the dynamic distribution of matter in the solar system; the dynamic distribution of matter outside the solar system (galactic, cosmological, etc.) and gravitational waves propagating through the solar system. Different relativistic theories of gravity make different predictions of the solar-system gravitational field. Hence, precise measurements of the solar-system gravitational field test these relativistic theories, in addition to gravitational wave observations, determination of the matter distribution in the solar-system and determination of the observable (testable) influence of our galaxy and cosmos. The tests and observations include: (i) a precise determination of the relativistic parameters β and γ with 3–5 orders of magnitude improvement over previous measurements; (ii) a 1–2 order of magnitude improvement in the measurement of G; (iii) a precise determination of any anomalous, constant acceleration Aadirected towards the Sun; (iv) a measurement of solar angular momentum via the Lense-Thirring effect; (v) the detection of solar g-mode oscillations via their changing gravity field, thus, providing a new eye to see inside the Sun; (vi) precise determination of the planetary orbit elements and masses; (vii) better determination of the orbits and masses of major asteroids; (viii) detection and observation of gravitational waves from massive black holes and galactic binary stars in the frequency range 50 μHz to 5 mHz; and (ix) exploring background gravitational waves. The baseline scheme of ASTROD is to have two spacecraft in separate solar orbits and one spacecraft near the Earth–Sun L1/L2 point carrying a payload of a proof mass, two telescopes, two 1–2 W lasers with spares, a clock and a drag-free system ranging coherently among one another using lasers. ASTROD I is a first step towards ASTROD. Its scheme is to have one spacecraft in a Venus-gravity-assisted solar orbit, ranging optically with ground stations with less ambitious, but still significant scientific goals.

scholarly journals DIVISION III: PLANETARY SYSTEMS SCIENCES

2008 ◽  
Vol 4 (T27A) ◽  
pp. 149-153
Author(s):  
Edward L. G. Bowell ◽  
Karen J. Meech ◽  
Iwan P. Williams ◽  
Alan P. Boss ◽  
Guy J. Consolmagno ◽  
...  
Keyword(s):  
Solar System ◽  
Extrasolar Planets ◽  
Planetary Systems ◽  
The Sun ◽  
Division Iii ◽  
Astronomical Research ◽  
The Universe

Division III's activities focus on a broad range of astronomical research on bodies in the solar system (excluding the Sun), on extrasolar planets, and on the search for life in the Universe.

Sherlock Holmes: Chemist

2013 ◽  
Author(s):  
James O'Brien
Keyword(s):  
Organic Chemistry ◽  
Solar System ◽  
The Sun ◽  
The Moon ◽  
Sherlock Holmes ◽  
Interest In Research ◽  
Working Out ◽  
The Brain

The previous chapter discussed Sherlock Holmes as a scientifically oriented detective. He was also knowledgeable about science in general. Practically every story contains at least some mention of one of the sciences. Having explored how Holmes used science in his detective work, we now look at his interest in research and his love of things scientific. In The “Gloria Scott” (GLOR), one of just two of the sixty stories narrated by Holmes instead of Watson, he says, “during the first month of the long vacation. I went up to my London rooms where I spent seven weeks working out a few experiments in organic chemistry.” Watson tells us in The Three Students (3STU) that without his chemicals, Holmes was “an uncomfortable man.” So there are clear indications that Holmes was devoted to science and that his first love was chemistry (see figure 4.1).Commentators disagree about Holmes’s chemistry abilities. Most praise Holmes as a chemist (see Cooper 1976; Gillard 1976; Graham 1945; Holstein1954; Michell and Michell 1946). The most notable critic of Holmes’s chemistry is Isaac Asimov. His objections are discussed in section 4.4. Dr. Watson even disagrees with himself about Holmes the chemist! Before Watson even meets Holmes, at the very outset of A Study in Scarlet (STUD), he is told by Young Stamford that Holmes is “a first-class chemist.” Stamford then performs the historic role of introducing Holmes and Watson. It doesn’t take Watson long to realize that his new roommate is a unique mixture of knowledge and ignorance. When he learns in STUD that Holmes is unfamiliar with the Copernican theory and the composition of the solar system, Watson is stunned. . . . Holmes: you say we go round the sun. If we went round the moon it would not make a pennyworth of difference to me or to my work. Watson: But the Solar System. Holmes: What the deuce is it to me?. . . Holmes believes the brain has a limited capacity. Therefore useless facts like the nature of the solar system should be forgotten, lest they crowd out important things.

scholarly journals C/O vs. Mg/Si ratios in solar type stars: The HARPS sample

2018 ◽  
Vol 614 ◽  
pp. A84 ◽  
Author(s):  
L. Suárez-Andrés ◽  
G. Israelian ◽  
J. I. González Hernández ◽  
V. Zh. Adibekyan ◽  
E. Delgado Mena ◽  
...  
Keyword(s):  
Solar System ◽  
Planetary Systems ◽  
Elemental Abundance ◽  
The Other ◽  
High Mass ◽  
The Sun ◽  
Solar Type ◽  
Low Mass

Context. Aims. We aim to present a detailed study of the magnesium-to-silicon and carbon-to-oxygen ratios (Mg/Si and C/O) and their importance in determining the mineralogy of planetary companions. Methods. Using 499 solar-like stars from the HARPS sample, we determined C/O and Mg/Si elemental abundance ratios to study the nature of the possible planets formed. We separated the planetary population in low-mass planets (<30 M⊙) and high-mass planets (>30 M⊙) to test for a possible relation with the mass. Results. We find a diversity of mineralogical ratios that reveal the different kinds of planetary systems that can be formed, most of them dissimilar to our solar system. The different values of the Mg/Si and C/O can determine different composition of planets formed. We found that 100% of our planetary sample present C/O < 0.8. 86% of stars with high-mass companions present 0.8 > C/O > 0.4, while 14% present C/O values lower than 0.4. Regarding Mg/Si, all stars with low-mass planetary companion showed values between one and two, while 85% of the high-mass companion sample does. The other 15% showed Mg/Si values below one. No stars with planets were found with Mg/Si > 2. Planet hosts with low-mass companions present C/O and Mg/Si similar to those found in the Sun, whereas stars with high-mass companions have lower C/O.

Chemical evolution of planetary materials in a dynamic solar nebula

2019 ◽  
Vol 15 (S350) ◽  
pp. 152-157
Author(s):  
Fred J. Ciesla
Keyword(s):  
Solar System ◽  
Chemical Evolution ◽  
Planet Formation ◽  
Solar Nebula ◽  
Planetary Systems ◽  
Protoplanetary Disks ◽  
Complete Picture ◽  
The Sun ◽  
Laboratory Studies ◽  
Planetary Materials

AbstractAs observational facilities improve, providing new insights into the chemistry occurring in protoplanetary disks, it is important to develop more complete pictures of the processes that shapes the chemical evolution of materials during this stage of planet formation. Here we describe how primitive meteorites in our own Solar System can provide insights into the processes that shaped planetary materials early in their evolution around the Sun. In particular, we show how this leads us to expect protoplanetary disks to be very dynamic objects and what modeling and laboratory studies are needed to provide a more complete picture for the early chemical evolution that occurs for planetary systems.

scholarly journals Statistical Properties of Extrasolar Planets

2004 ◽  
Vol 202 ◽  
pp. 3-11 ◽  
Author(s):  
R. Paul Butler ◽  
Geoffrey W. Marcy ◽  
Debra A. Fischer ◽  
Steven S. Vogt ◽  
C. G. Tinney ◽  
...  
Keyword(s):  
Detection Limit ◽  
Solar System ◽  
Mass Distribution ◽  
Binary Stars ◽  
Extrasolar Planets ◽  
Statistical Properties ◽  
The Sun ◽  
Eccentric Orbits ◽  
Nearby Stars ◽  
Solar Type

The emerging statistical properties from the first 50 extrasolar planets are startlingly different from the picture that was imagined prior to 1995. About 0.75% of nearby solar type stars harbor jovian planets in 3 to 5 day circular orbits. Another ∽7% of stars have jupiter–mass companions orbiting in eccentric orbits within 3.5 AU. The mass distribution of substellar companions rises abruptly near 5 MJup and continues increasing down to the detection limit near 1 MJup-Orbital eccentricities correlate positively with semimajor axes, even for planets beyond the tidal circularization zone within 0.1 AU, distinguishing planets from binary stars. The planet bearing stars are metal–rich relative to both nearby stars and to the Sun. Analogs of Solar System planets have not been detected to date as they require precision of 3 m s−1 maintained for more than a decade.

Urpaqtar sabaqtastyǵy arqyly ulttyq bіregeılіktі saqtaýdaǵy dіnı nanymdardyń rólі [The Role of Religious Beliefs in the Preservation of National Identity Through the Succession of Generations]

2020 ◽  
Vol 3 (117) ◽  
pp. 49-59
Author(s):  
B.Z. Imanmoldayeva ◽  
Keyword(s):  
National Identity ◽  
Significant Role ◽  
Religious Beliefs ◽  
Point Of View ◽  
The Sun ◽  
Basic Functions ◽  
Spiritual Unity

This article analyzes the worldview of our nation formed by generations. The analysis was conducted from the philosophical point of view and on the basis of the particular family’s attitude towards ancient Turk religious beliefs and preservation of national identity. The article also discusses the evidences of ancient people’s faith left on old Turkic manuscripts, and its trail left on the mentality of further generations. Moreover, it was found that the perception of the blue wolf totem, played a significant role in the preservation of the national identity. It was also revealed that a succession of generation to the Sun (Mitra), in ancient Turk worships, has a significance in keeping spiritual unity. As a result, the basic functions of preserving a national identity through succession of faith across generations were suggested. Бұл мақалада халқымыздың дүниетанымындағы ұрпақтар сабақтастығы туралы идеялар сараланды. Оның жеке отбасынан бастау алып, ұлт руханияты арқылы жүзеге асатындығына шолу жасалды, көне түркілік діни сенімдердің ұлттық бірегейлікті сақтай отыра, ұрпақтан-ұрпаққа сабақтасатындығы философиялық тұрғыдан талданды. Көне тәңіршілдік сенімнің көне түркі жазба ескерткіштеріндегі көріністерінің ұрпақтар арқылы жалғасқан менталитеттік көріністері сарапталды. Сонымен қатар, көк бөрі тотемінің көнеден бері сабақтасқан дүниетанымдық қырлары да ұлттық бірегейлікті сақтауға айтарлықтай ықпал еткендігі дәйектелді. Күнге (Митра) табыну дәстүрлері көне түркілік руханияттық бірегейлікті сақтауда айтарлықтай қызмет атқарғандығы да бұл сенімнің сабақтасқандығы бойынша ашып көрсетілді. Нәтижесінде, діни сенімдердің ұрпақтар сабақтастығы арқылы ұлттық бірегейлікті сақтаудағы негізгі қызметтері ұсынылды.

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