scholarly journals HOŘAVA–LIFSHITZ GRAVITY: TIGHTER CONSTRAINTS FOR THE KEHAGIAS–SFETSOS SOLUTION FROM NEW SOLAR SYSTEM DATA

2011 ◽  
Vol 20 (06) ◽  
pp. 1079-1093 ◽  
Author(s):  
L. IORIO ◽  
M. L. RUGGIERO
Keyword(s):  
Black Hole ◽  
Solar System ◽  
Lower Bounds ◽  
Modified Gravity ◽  
The Sun ◽  
Supermassive Black Hole ◽  
The Earth ◽  
Test Particles ◽  
The Galaxy ◽  
System Data

We analytically work out the perturbation Δρ induced by the Kehagias–Sfetsos (KS) spacetime solution of the Hořava–Lifshitz (HL) modified gravity at long distances on the two-body range ρ for a pair of test particles A and B orbiting the same mass M. We apply our results to the most recently obtained range residuals δρ for some planets of the solar system (Mercury, Mars, Saturn) ranged from the Earth to effectively constrain the dimensionless KS parameter ψ0 for the Sun. We obtain [Formula: see text] (Mercury), [Formula: see text] (Mars), and [Formula: see text] (Saturn). Such lower bounds are tighter than others existing in the literature by several orders of magnitude. We also preliminarily obtain [Formula: see text] for the system constituted by the S2 star orbiting the supermassive black hole (SBH) in the center of the galaxy.

scholarly journals Synchronism of the Events on the Sun and the Earth - A Sign of External Influence on the Solar System

2019 ◽  
Vol 2 (3) ◽  
Keyword(s):  
Gravitational Field ◽  
Solar System ◽  
The Sun ◽  
Additional Energy ◽  
Gravitational Effects ◽  
External Influences ◽  
The Earth ◽  
The Galaxy ◽  
Celestial Bodies ◽  
Endogenous Activity

To solve fundamental and applied problems, it is useful to detect signs of external influences on the Solar system from the synchronous responses of the Earth’s shells, using a systemic and interdisciplinary analysis of solar-terrestrial relations - taking into account, along with solar activity and GCR fluxes, the endogenous activity of the Earth due to gravitational effects on the Earth with the sides of the Moon, the Sun and other celestial bodies of the Solar system during its barycentric motion in the gravitational field of the Galaxy, as well as the effects of perturbations on the Solar system as a whole. At the same time, the mechanism, energy, cyclicity, synchronism, change in the shape of the Earth and gravity, polar asymmetry and jump-like manifestations of solar-terrestrial relations, instability of the Earth’s daily rotation become explainable. The Solar system is subject to external influences of gravity of the heavy planets of Jupiter and Saturn in the course of its barycentric motion in the gravitational field of the Galaxy, as well as the bringing in solar system of additional energy when exposed to a heterogeneous interstellar environment.

scholarly journals A strong magnetic field around the supermassive black hole at the centre of the Galaxy

Nature ◽  
2013 ◽  
Vol 501 (7467) ◽  
pp. 391-394 ◽  
Author(s):  
R. P. Eatough ◽  
H. Falcke ◽  
R. Karuppusamy ◽  
K. J. Lee ◽  
D. J. Champion ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Black Hole ◽  
Strong Magnetic Field ◽  
Supermassive Black Hole ◽  
The Galaxy

scholarly journals Matahari dalam Perspektif Sains dan Al-Qur'an

2019 ◽  
Vol 2 (1) ◽  
pp. 27-35
Author(s):  
Anisa Nur Afida ◽  
Yuberti Yuberti ◽  
Mukarramah Mustari
Keyword(s):  
Qualitative Research ◽  
Data Analysis ◽  
Solar System ◽  
Data Model ◽  
Research Method ◽  
The Sun ◽  
Data Display ◽  
The Earth ◽  
Library Research ◽  
Analysis Technique

Abstract: This study aims to determine the function of the sun in the perspective of science and al-Qur'an . The research method used is qualitative research methods with the type of research library (Library Research). This research applies data analysis technique of Milles and Huberman model, with steps: 1) data reduction; 2) data display; 3) verification. The result of this research is, the theories that science explain related to the function of the sun in accordance with what is also described in the Qur'an. Science explains that the sun as the greatest source of light for the earth can produce its own energy. This is explained in the Qur'an that the sun is described as siraj and dhiya' which means sunlight is sourced from itself, as the center of the solar system is not static but also moves this matter in the Qur'an explained in QS Yāsin verse 38, besides science and the Qur'an also equally explain that the sun can be made as a calculation of time.Abstrak: Penelitian ini bertujuan untuk mengetahui fungsi matahari dalam perspektif sains dan al-Qur’an..Metode penelitian yang digunakan yaitu metode penelitian kualitatif dengan jenis penelitian pustaka (Library Research). Penelitian ini menggunakan teknik analisis data model Milles dan Huberman, dengan langkah-langkah: 1) reduksi data; 2) display data; 3) verifikasi. Hasil dari penelitian ini yaitu, teori-teori yang sains jelaskan berkaitan dengan fungsi matahari sesuai dengan apa yang juga di jelaskan dalam al-Qur’an. Sains menjelaskan bahwa matahari sebagai sumber energi cahaya terbesar bagi bumi dapat menghasilkan energinya sendiri hal ini dijelaskan dalam al-Qur’an bahwa matahari dideskripsikan sebagai siraj dan dhiya’yang berarti sinar matahari bersumber dari dirinya sendiri, sebagai pusat tata surya matahari tidaklah statis melainkan juga bergerak hal ini dalam al-Qur’an di jelaskan dalam QS Yāsin ayat 38, selain itu sains dan al-Qur’an juga sama-sama menjelaskan bahwa matahari  dapat di jadikan sebagai perhitungan waktu serta petunjuk dari bayang-bayang.

Influence of supernovae, gamma-ray bursts, solar flares, and cosmic rays on the terrestrial environment

2008 ◽  
Author(s):  
Arnon Dar
Keyword(s):  
Solar Activity ◽  
Cosmic Rays ◽  
Gamma Ray ◽  
Cosmic Ray ◽  
Gamma Ray Bursts ◽  
The Sun ◽  
Terrestrial Environment ◽  
The Earth ◽  
The Galaxy ◽  
Threat To Life

Changes in the solar neighbourhood due to the motion of the sun in the Galaxy, solar evolution, and Galactic stellar evolution influence the terrestrial environment and expose life on the Earth to cosmic hazards. Such cosmic hazards include impact of near-Earth objects (NEOs), global climatic changes due to variations in solar activity and exposure of the Earth to very large fluxes of radiations and cosmic rays from Galactic supernova (SN) explosions and gamma-ray bursts (GRBs). Such cosmic hazards are of low probability, but their influence on the terrestrial environment and their catastrophic consequences, as evident from geological records, justify their detailed study, and the development of rational strategies, which may minimize their threat to life and to the survival of the human race on this planet. In this chapter I shall concentrate on threats to life from increased levels of radiation and cosmic ray (CR) flux that reach the atmosphere as a result of (1) changes in solar luminosity, (2) changes in the solar environment owing to the motion of the sun around the Galactic centre and in particular, owing to its passage through the spiral arms of the Galaxy, (3) the oscillatory displacement of the solar system perpendicular to the Galactic plane, (4) solar activity, (5) Galactic SN explosions, (6) GRBs, and (7) cosmic ray bursts (CRBs). The credibility of various cosmic threats will be tested by examining whether such events could have caused some of the major mass extinctions that took place on planet Earth and were documented relatively well in the geological records of the past 500 million years (Myr). A credible claim of a global threat to life from a change in global irradiation must first demonstrate that the anticipated change is larger than the periodical changes in irradiation caused by the motions of the Earth, to which terrestrial life has adjusted itself. Most of the energy of the sun is radiated in the visible range. The atmosphere is highly transparent to this visible light but is very opaque to almost all other bands of the electromagnetic spectrum except radio waves, whose production by the sun is rather small.

scholarly journals Universal interferometric signatures of a black hole’s photon ring

2020 ◽  
Vol 6 (12) ◽  
pp. eaaz1310 ◽  
Author(s):  
Michael D. Johnson ◽  
Alexandru Lupsasca ◽  
Andrew Strominger ◽  
George N. Wong ◽  
Shahar Hadar ◽  
...  
Keyword(s):  
General Relativity ◽  
Black Hole ◽  
Event Horizon ◽  
Infinite Sequence ◽  
High Order ◽  
Black Hole Mass ◽  
Tests Of General Relativity ◽  
Supermassive Black Hole ◽  
The Galaxy ◽  
Self Similar

The Event Horizon Telescope image of the supermassive black hole in the galaxy M87 is dominated by a bright, unresolved ring. General relativity predicts that embedded within this image lies a thin “photon ring,” which is composed of an infinite sequence of self-similar subrings that are indexed by the number of photon orbits around the black hole. The subrings approach the edge of the black hole “shadow,” becoming exponentially narrower but weaker with increasing orbit number, with seemingly negligible contributions from high-order subrings. Here, we show that these subrings produce strong and universal signatures on long interferometric baselines. These signatures offer the possibility of precise measurements of black hole mass and spin, as well as tests of general relativity, using only a sparse interferometric array.

Review Lecture - Long time-scale fluctuations in the evolution of the Earth

1981 ◽  
Vol 375 (1760) ◽  
pp. 1-41 ◽  
Keyword(s):  
Current Knowledge ◽  
Interstellar Matter ◽  
The Sun ◽  
Time Intervals ◽  
Interstellar Clouds ◽  
The Earth ◽  
The Galaxy ◽  
Long Time ◽  
Extended Review ◽  
Review Current

This lecture is an attempt to review current knowledge about certain terrestrial phenomena with the twofold purpose: ( a ) to discover the extent to which the behaviour of the Earth may be influenced by fluctuations in its astronomical environment, ( b ) to see if new knowledge of that environment may be gained from its influence on the Earth. Fluctuations in geomagnetism, climate, glaciation, biological extinctions, etc., are surveyed with special regard to datings and characteristic time-intervals; correlations between such fluctuations are discussed. Astronomical phenomena, within the Solar System and elsewhere in the Galaxy, that might cause terrestrial effects are reviewed. As regards astronomical effects on Earth: (i) There is a good case - not yet overwhelming - for the currently widely accepted view that fluctuations of glaciation within an ice-epoch result from changes of insolation accompanying fluctuations of the Earth’s motion relative to the Sun. Some evidence suggests that an ice-epoch may be triggered by variations of the astronomical environment encountered in the Sun’s motion relative to the Galaxy; but tectonic changes on Earth may be the main trigger. (ii) Impacts of planetesimals may be more important than hitherto recognized. Among astronomical results regarding the Sun, while the intensity of solar ‘activity’ is variable, terrestrial effects provide no confirmation that the Sun is a ‘variable star’. Regarding the Galaxy, impacting planetesimals may originate in interstellar clouds, and so provide on Earth samples of interstellar matter. Some unsolved problems emphasized by the review are listed; certain concepts that would call for consideration in any extended review are mentioned.

scholarly journals The Brightest Point in Accretion Disk and Black Hole Spin: Implication to the Image of Black Hole M87*

Universe ◽  
2019 ◽  
Vol 5 (8) ◽  
pp. 183 ◽  
Author(s):  
Vyacheslav I. Dokuchaev ◽  
Natalia O. Nazarova
Keyword(s):  
Black Hole ◽  
Event Horizon ◽  
Accretion Disk ◽  
Disk Model ◽  
Dark Region ◽  
High Resolution Image ◽  
Supermassive Black Hole ◽  
Black Hole Spin ◽  
The Galaxy ◽  
Expected Position

We propose the simple new method for extracting the value of the black hole spin from the direct high-resolution image of black hole by using a thin accretion disk model. In this model, the observed dark region on the first image of the supermassive black hole in the galaxy M87, obtained by the Event Horizon Telescope, is a silhouette of the black hole event horizon. The outline of this silhouette is the equator of the event horizon sphere. The dark silhouette of the black hole event horizon is placed within the expected position of the black hole shadow, which is not revealed on the first image. We calculated numerically the relation between the observed position of the black hole silhouette and the brightest point in the thin accretion disk, depending on the black hole spin. From this relation, we derive the spin of the supermassive black hole M87*, a = 0.75 ± 0.15 .

The Odd Couple: Quasars & Black Holes

Daedalus ◽  
2014 ◽  
Vol 143 (4) ◽  
pp. 103-113 ◽  
Author(s):  
Scott Tremaine
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Solar System ◽  
Total Mass ◽  
Host Galaxy ◽  
The Sun ◽  
Central Black Hole ◽  
Frictional Forces ◽  
The Universe

Quasars emit more energy than any other object in the universe, yet are not much bigger than our solar system. Quasars are powered by giant black holes of up to ten billion (1010) times the mass of the sun. Their enormous luminosities are the result of frictional forces acting upon matter as it spirals toward the black hole, heating the gas until it glows. We also believe that black holes of one million to ten billion solar masses – dead quasars – are present at the centers of most galaxies, including our own. The mass of the central black hole appears to be closely related to other properties of its host galaxy, such as the total mass in stars, but the origin of this relation and the role that black holes play in the formation of galaxies are still mysteries.

scholarly journals Jupiter’s decisive role in the inner Solar System’s early evolution

2015 ◽  
Vol 112 (14) ◽  
pp. 4214-4217 ◽  
Author(s):  
Konstantin Batygin ◽  
Greg Laughlin
Keyword(s):  
Solar System ◽  
Dynamical Evolution ◽  
Decisive Role ◽  
Terrestrial Planets ◽  
The Sun ◽  
Mean Motion Resonances ◽  
The Earth ◽  
Short Period ◽  
Orbital Periods ◽  
Gas Drag

The statistics of extrasolar planetary systems indicate that the default mode of planet formation generates planets with orbital periods shorter than 100 days and masses substantially exceeding that of the Earth. When viewed in this context, the Solar System is unusual. Here, we present simulations which show that a popular formation scenario for Jupiter and Saturn, in which Jupiter migrates inward from a > 5 astronomical units (AU) to a ≈ 1.5 AU before reversing direction, can explain the low overall mass of the Solar System’s terrestrial planets, as well as the absence of planets with a < 0.4 AU. Jupiter’s inward migration entrained s ≳ 10−100 km planetesimals into low-order mean motion resonances, shepherding and exciting their orbits. The resulting collisional cascade generated a planetesimal disk that, evolving under gas drag, would have driven any preexisting short-period planets into the Sun. In this scenario, the Solar System’s terrestrial planets formed from gas-starved mass-depleted debris that remained after the primary period of dynamical evolution.

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