Retrieving the atmospheric properties of directly imaged planets

2020 ◽  
Author(s):  
Paul Mollière ◽  
Keyword(s):  
Formation Process ◽  
Giant Planets ◽  
Analysis Method ◽  
Atmospheric Models ◽  
Atmospheric Physics ◽  
Atmospheric Structure ◽  
Cloud Models ◽  
Modeling Uncertainties ◽  
Gas Giant ◽  
Shed Light

<p>Young gas giant planets still glow hot from formation, sometimes even showing signs of active accretion. Studying the atmospheres of these directly imaged planets may help placing constraints on how they formed, which may also shed light on the formation process of the planetary systems they reside in. In general, this may be achieved by connecting atmospheric to planetary composition, and planetary composition to planet formation. In my talk I will present our work that investigates the first step of this process, namely constraining the atmospheric abundances of gas giant exoplanets via free retrievals of GRAVITY, SPHERE and GPI observations. Free retrievals work by parameterizing the atmospheric structure as much as possible when calculating spectra, thereby allowing the data to constrain the atmosphere’s state. This relaxes the need for a model to fulfill given assumptions which may not accurately describe the atmospheric physics, due to modeling uncertainties and oversimplifications. At the same time caution is required because unphysical atmospheric models can potentially lead to excellent fits to spectroscopic observations. I will show why including clouds and scattering is crucial for the analysis of directly imaged planets, what the effects of using inappropriate cloud models are, and outline the next steps to develop this analysis method further.</p>

scholarly journals Direct detection of exoplanets in the 3–10 μm range with E-ELT/METIS

2014 ◽  
Vol 14 (2) ◽  
pp. 279-289 ◽  
Author(s):  
Sascha P. Quanz ◽  
Ian Crossfield ◽  
Michael R. Meyer ◽  
Eva Schmalzl ◽  
Jenny Held
Keyword(s):  
Direct Detection ◽  
Equilibrium Temperature ◽  
Giant Planets ◽  
Large Telescope ◽  
Atmospheric Models ◽  
Orbital Inclination ◽  
Planet Surface ◽  
Scientific Potential ◽  
Gas Giant ◽  
Made In

AbstractWe quantify the scientific potential for exoplanet imaging with the mid-infrared E-ELT Imager and Spectrograph (METIS) foreseen as one of the instruments of the European Extremely Large Telescope (E-ELT). We focus on two main science cases: (1) the direct detection of known gas giant planets found by radial velocity (RV) searches; and (2) the direct detection of small (1–4 R⊕) planets around the nearest stars. Under the assumptions made in our modelling, in particular on the achievable inner working angle and sensitivity, our analyses reveal that within a reasonable amount of observing time METIS is able to image >20 already known, RV-detected planets in at least one filter. Many more suitable planets with dynamically determined masses are expected to be found in the coming years with the continuation of RV-surveys and the results from the GAIA astrometry mission. In addition, by extrapolating the statistics for close-in planets found by Kepler, we expect METIS might detect ≈10 small planets with equilibrium temperatures between 200 and 500 K around the nearest stars. This means that (1) METIS will help constrain atmospheric models for gas giant planets by determining for a sizable sample their luminosity, temperature and orbital inclination; and (2) METIS might be the first instrument to image a nearby (super-) Earth-sized planet with an equilibrium temperature near that expected to enable liquid water on a planet surface.

scholarly journals Rapid Formation of Gas-giant Planets via Collisional Coagulation from Dust Grains to Planetary Cores

2021 ◽  
Vol 922 (1) ◽  
pp. 16
Author(s):  
Hiroshi Kobayashi ◽  
Hidekazu Tanaka
Keyword(s):  
Protoplanetary Disks ◽  
Central Star ◽  
Giant Planets ◽  
Solar Systems ◽  
Evolution Path ◽  
Planetary Cores ◽  
Rapid Formation ◽  
Gas Giant ◽  
Planetary Migration ◽  
Gas Accretion

Abstract Gas-giant planets, such as Jupiter, Saturn, and massive exoplanets, were formed via the gas accretion onto the solid cores, each with a mass of roughly 10 Earth masses. However, rapid radial migration due to disk–planet interaction prevents the formation of such massive cores via planetesimal accretion. Comparably rapid core growth via pebble accretion requires very massive protoplanetary disks because most pebbles fall into the central star. Although planetesimal formation, planetary migration, and gas-giant core formation have been studied with a lot of effort, the full evolution path from dust to planets is still uncertain. Here we report the result of full simulations for collisional evolution from dust to planets in a whole disk. Dust growth with realistic porosity allows the formation of icy planetesimals in the inner disk (≲10 au), while pebbles formed in the outer disk drift to the inner disk and there grow to planetesimals. The growth of those pebbles to planetesimals suppresses their radial drift and supplies small planetesimals sustainably in the vicinity of cores. This enables rapid formation of sufficiently massive planetary cores within 0.2–0.4 million years, prior to the planetary migration. Our models shows the first gas giants form at 2–7 au in rather common protoplanetary disks, in agreement with the exoplanet and solar systems.

scholarly journals Architecture in the Islamic Vision

2020 ◽  
Vol 6 (1) ◽  
pp. 1-6
Author(s):  
Yehia Hassan Wazeri
Keyword(s):  
Content Analysis ◽  
Building Materials ◽  
Town Planning ◽  
Analysis Method ◽  
The Earth ◽  
Content Analysis Method ◽  
The World ◽  
Holy Quran ◽  
The Holy Quran ◽  
Shed Light

The Qur’an contains about eighteen verses that refer to the architecture of the earth. Nearly two hundred elements (terminologies) of architecture and town planning have been mentioned in the Quran. This paper aims to present examples from the Quran to shed light on the Islamic vision of architecture and art. It uses content analysis method to achieve the objective of the research. The analysis is done by studying and discussing verses of the Holy Quran, which is related to architecture and urbanism. One of the most important results of this research is to give distinct architectural and urban examples, include the following: building materials, environmental architecture, houses of insects, visual illusions in architecture, and the centrality of Mecca to the world. All of them is explained in the Qur’an verses, such as Al-Baqarah, An-Naml, An-Nahl, Al-Kahf, and Al-Fajr. 

scholarly journals Planetesimal Accretion onto Growing Proto–Gas Giant Planets

2007 ◽  
Vol 666 (1) ◽  
pp. 447-465 ◽  
Author(s):  
Ji‐Lin Zhou ◽  
Douglas N. C. Lin
Keyword(s):  
Giant Planets ◽  
Gas Giant

scholarly journals Performance Evaluation of an Ironmaking System with Environmental Costs

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Huimin Liu ◽  
Qiqiang Li
Keyword(s):  
Formation Process ◽  
Carbon Dioxide Emissions ◽  
Environmental Costs ◽  
Analysis Method ◽  
Analysis Model ◽  
Total Cost ◽  
Iron Smelting ◽  
System Product ◽  
Environmental Emissions ◽  
Exergoeconomic Analysis

This paper proposes an exergoeconomic analysis method that considers environmental costs to make up for the lack of description of environmental costs in the traditional matrix model exergoeconomic analysis method. This method tracks the formation process of the product cost through life cycle and makes a useful exploration for revealing the true cost of the system product. According to actual needs, the principles for the construction of environmental emissions of products are proposed, and a detailed exergoeconomic analysis model is established by taking the iron smelting system as an example. Through calculation and analysis, the formation process and change rule of unit exergoeconomic cost of products in the system are revealed. Especially, considering the exergoeconomic cost of carbon emissions, the results show that the three most influential substances are sinter, coke, and pellets. When carbon dioxide emissions are considered, the total cost will increase by 165.3 CNY/t iron, and unit exergoeconomic cost gradually increases with the progress of the production process.

scholarly journals Mechanisms for Limiting the Depth of Zonal Winds in the Gas Giant Planets

2020 ◽  
Vol 890 (1) ◽  
pp. 61 ◽  
Author(s):  
Ulrich R. Christensen ◽  
Johannes Wicht ◽  
Wieland Dietrich
Keyword(s):  
Giant Planets ◽  
Zonal Winds ◽  
Gas Giant

scholarly journals SEARCHING FOR GAS GIANT PLANETS ON SOLAR SYSTEM SCALES: VLT NACO/APP OBSERVATIONS OF THE DEBRIS DISK HOST STARS HD172555 AND HD115892

2011 ◽  
Vol 736 (2) ◽  
pp. L32 ◽  
Author(s):  
Sascha P. Quanz ◽  
Matthew A. Kenworthy ◽  
Michael R. Meyer ◽  
Julien H. V. Girard ◽  
Markus Kasper
Keyword(s):  
Solar System ◽  
Giant Planets ◽  
Debris Disk ◽  
Gas Giant ◽  
Host Stars

scholarly journals Investigating the planet–metallicity correlation for hot Jupiters

2019 ◽  
Vol 491 (3) ◽  
pp. 4481-4487
Author(s):  
Ares Osborn ◽  
Daniel Bayliss
Keyword(s):  
Radial Velocity ◽  
Giant Planet ◽  
Giant Planets ◽  
Similar Process ◽  
Wide Field ◽  
Hot Jupiters ◽  
Galaxy Model ◽  
Gas Giant ◽  
Correlation Consistent

ABSTRACT We investigate the giant planet–metallicity correlation for a homogeneous, unbiased set of 217 hot Jupiters taken from nearly 15 yr of wide-field ground-based surveys. We compare the host star metallicity to that of field stars using the Besançon Galaxy model, allowing for a metallicity measurement offset between the two sets. We find that hot Jupiters preferentially orbit metal-rich stars. However, we find the correlation consistent, though marginally weaker, for hot Jupiters ($\beta =0.71^{+0.56}_{-0.34}$) than it is for other longer period gas giant planets from radial velocity surveys. This suggests that the population of hot Jupiters probably formed in a similar process to other gas giant planets, and differ only in their migration histories.

scholarly journals On the Formation of Gas Giant Planets on Wide Orbits

2006 ◽  
Vol 637 (2) ◽  
pp. L137-L140 ◽  
Author(s):  
Alan P. Boss
Keyword(s):  
Giant Planets ◽  
Gas Giant
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