Scattered light may reveal the existence of ringed exoplanets

ABSTRACT Rings around giant exoplanets (hereafter ‘exorings’) are still a missing planetary phenomenon among the vast number of discovered planets. Despite the fact that there exist a large number of methods for identifying and characterizing these exorings, none of them has been successful to date. Most of those efforts focus on the photometric signatures produced by rings around transiting exoplanets; thus, little interest has been intended for the detectable signatures that non-transiting ringed planets might cause owing to the excess of scattered starlight from both their atmosphere and the considerably large surface of their (hypothetical) ring system. This extra scattering produced by exorings would occur at an orbital location defined here as ‘the summer solstice’ of a stellar light curve. In this letter, we develop a first-order model to estimate the photometric signatures of non-transiting exorings, and predict their detectability by using present and future facilities. We also show how, besides the discovery itself, our model can be used to constrain orbital and physical parameters of planet–ring systems.

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Stochasting modeling of planetary ring systems

International Astronomical Union Colloquium ◽

10.1017/s025292110010154x ◽

1984 ◽

Vol 75 ◽

pp. 461-469 ◽

Cited By ~ 1

Author(s):

Robert W. Hart

Keyword(s):

Maximum Entropy ◽

Ring System ◽

The Sun ◽

Ultimate State ◽

Interparticle Interactions ◽

Ring Systems ◽

First Order ◽

Planetary Ring ◽

Insight Into

ABSTRACTThis paper models maximum entropy configurations of idealized gravitational ring systems. Such configurations are of interest because systems generally evolve toward an ultimate state of maximum randomness. For simplicity, attention is confined to ultimate states for which interparticle interactions are no longer of first order importance. The planets, in their orbits about the sun, are one example of such a ring system. The extent to which the present approximation yields insight into ring systems such as Saturn's is explored briefly.

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A first-order model of thermal lensing of laser propagation in the eye and implications for laser safety

International Laser Safety Conference ◽

10.2351/1.5056578 ◽

2005 ◽

Cited By ~ 2

Author(s):

Robert J. Thomas ◽

Rebecca L. Vincelette ◽

Gavin D. Buffington ◽

Amber D. Strunk ◽

Michael A. Edwards ◽

...

Keyword(s):

Thermal Lensing ◽

Order Model ◽

Laser Safety ◽

First Order ◽

Laser Propagation

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SN2017ein: bolometric light curve and physical parameters

Physical Sciences and Technology ◽

10.26577/phst-2017-1-118 ◽

2017 ◽

Vol 4 (1) ◽

pp. 15-19

Author(s):

P.S. Tadjimuratov ◽

◽

D. Mirzakulov ◽

Keyword(s):

Light Curve ◽

Physical Parameters

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An extensive photometric study of the Blazhko RR Lyrae star RZ Lyr*

Monthly Notices of the Royal Astronomical Society ◽

10.1111/j.1365-2966.2012.20772.x ◽

2012 ◽

Vol 423 (2) ◽

pp. 993-1005 ◽

Cited By ~ 11

Author(s):

J. Jurcsik ◽

Á. Sódor ◽

G. Hajdu ◽

B. Szeidl ◽

Á. Dózsa ◽

...

Keyword(s):

Light Curve ◽

Light Curves ◽

Stellar Structure ◽

Time Base ◽

Photometric Method ◽

Physical Parameters ◽

Component Solution ◽

Rr Lyrae ◽

Curve Variation ◽

Type Variable

Abstract The analysis of recent, extended multicolour CCD and archive photoelectric, photographic and visual observations has revealed several important properties of RZ Lyr, an RRab-type variable exhibiting large-amplitude Blazhko modulation. On the time base of ∼110 yr, a strict anticorrelation between the pulsation- and modulation-period changes is established. The light curve of RZ Lyr shows a remarkable bump on the descending branch in the small-amplitude phase of the modulation, similarly to the light curves of bump Cepheids. We speculate that the stellar structure temporally suits a 4:1 resonance between the periods of the fundamental and one of the higher order radial modes in this modulation phase. The light-curve variation of RZ Lyr can be correctly fitted with a two-modulation-component solution; the 121-d period of the main modulation is nearly but not exactly four times longer than the period of the secondary modulation component. Using the inverse photometric method, the variations in the pulsation-averaged values of the physical parameters in different phases of both modulation components are determined.

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New Data on the Eclipsing Binary V1848 Ori and Improved Orbital and Light Curve Solutions

Open Astronomy ◽

10.1515/astro-2020-0013 ◽

2020 ◽

Vol 29 (1) ◽

pp. 72-80 ◽

Cited By ~ 1

Author(s):

Fatemeh Davoudi ◽

Atila Poro ◽

Fahri Alicavus ◽

Afshin Halavati ◽

Saeed Doostmohammadi ◽

...

Keyword(s):

Binary System ◽

Light Curve ◽

Mass Function ◽

Light Curves ◽

Complete Analysis ◽

Physical Parameters ◽

Mass Ratio ◽

Third Body ◽

Eclipsing Binary

AbstractNew observations of the eclipsing binary system V1848 Ori were carried out using the V filter resulting in a determination of new times of minima and new ephemeris were obtained. We presented the first complete analysis of the system’s orbital period behavior and analysis of O-C diagram done by the GA and MCMC approaches in OCFit code. The O-C diagram demonstrates a sinusoidal trend in the data; this trend suggests a cyclic change caused by the LITE effect with a period of 10.57 years and an amplitude of 7.182 minutes. It appears that there is a third body with mass function of f (m3) = 0.0058 M⊙ in this binary system. The light curves were analyzed using the Wilson-Devinney code to determine some geometrical and physical parameters of the system. These results show that V1848 Ori is a contact W UMa binary system with the mass ratio of q = 0.76 and a weak fillout factor of 5.8%. The O’Connell effect was not seen in the light curve and there is no need to add spot.

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Design and Development of Lubricating Material Database and Research on Performance Prediction Method of Machine Learning

Scientific Reports ◽

10.1038/s41598-019-56776-2 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 3

Author(s):

Dan Jia ◽

Haitao Duan ◽

Shengpeng Zhan ◽

Yongliang Jin ◽

Bingxue Cheng ◽

...

Keyword(s):

Machine Learning ◽

High Performance ◽

Prediction Method ◽

Lubricating Oil ◽

Physical Parameters ◽

First Principle ◽

Vast Number ◽

First Principle Calculation ◽

Lubricating Material ◽

Machine Learning Model

AbstractLong developing period and cumbersome evaluation for the lubricating materials performance seriously jeopardize the successful development and application of any database system in tribological field. Such major setback can be solved effectively by implementing approaches with high throughput calculation. However, it often involves with vast number of output files, which are computed on the basis of first principle computation, having different data format from that of their experimental counterparts. Commonly, the input, storage and management of first principle calculation files and their individually test counterparts, implementing fast query and display in the database, adding to the use of physical parameters, as predicted with the performance estimated by first principle approach, may solve such setbacks. Investigation is thus performed for establishing database website specifically for lubricating materials, which satisfies both data: (i) as calculated on the basis of first principles and (ii) as obtained by practical experiment. It further explores preliminarily the likely relationship between calculated physical parameters of lubricating oil and its respectively tribological and anti-oxidative performance as predicted by lubricant machine learning model. Success of the method facilitates in instructing the obtainment of optimal design, preparation and application for any new lubricating material so that accomplishment of high performance is possible.

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Application of two approaches to model chlorine residuals in Severn Trent Water Ltd (STW) distribution systems

Water Science & Technology ◽

10.2166/wst.1997.0227 ◽

1997 ◽

Vol 36 (5) ◽

pp. 317-324 ◽

Cited By ~ 6

Author(s):

M.J. Rodriguez ◽

J.R. West ◽

J. Powell ◽

J.B. Sérodes

Keyword(s):

Distribution System ◽

Distribution Systems ◽

Treatment Plant ◽

Residual Chlorine ◽

Ann Model ◽

Order Model ◽

First Order ◽

Chlorine Decay ◽

Artificial Neural Network Ann ◽

Key Parameter

Increasingly, those who work in the field of drinking water have demonstrated an interest in developing models for evolution of water quality from the treatment plant to the consumer's tap. To date, most of the modelling efforts have been focused on residual chlorine as a key parameter of quality within distribution systems. This paper presents the application of a conventional approach, the first order model, and the application of an emergent modelling approach, an artificial neural network (ANN) model, to simulate residual chlorine in a Severn Trent Water Ltd (U.K.) distribution system. The application of the first order model depends on the adequate estimation of the chlorine decay coefficient and the travel time within the system. The success of an ANN model depends on the use of representative data about factors which affect chlorine evolution in the system. Results demonstrate that ANN has a promising capacity for learning the dynamics of chlorine decay. The development of an ANN appears to be justifiable for disinfection control purposes, in cases when parameter estimation within the first order model is imprecise or difficult to obtain.

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