Sökning: "exoplanets"

Visar resultat 1 - 5 av 32 uppsatser innehållade ordet exoplanets.

  1. 1. Effects of planetary radius contraction on scattering

    Kandidat-uppsats, Lunds universitet/Astronomi

    Författare :Viktor Hrannar Jónsson; [2020]
    Nyckelord :Physics and Astronomy;

    Sammanfattning : The observed high orbital eccentricities of many giant exoplanets is thought to be the result of gravitational scattering between planets. Outcomes of planet-planet scattering can result in some planets being lost by ejections into interstellar space, or collisions between planets or with the star. LÄS MER

  2. 2. Detecting exoplanets with machine learning : A comparative study between convolutional neural networks and support vector machines

    Kandidat-uppsats, Uppsala universitet/Institutionen för teknikvetenskaper; Uppsala universitet/Institutionen för teknikvetenskaper; Uppsala universitet/Institutionen för teknikvetenskaper; Uppsala universitet/Institutionen för teknikvetenskaper

    Författare :Jacob Tiensuu; Maja Linderholm; Sofia Dreborg; Fredrik Örn; [2019]
    Nyckelord :Machine learning; Exoplanet; Support vector machine; Convolution neuralnetwork;

    Sammanfattning : In this project two machine learning methods, Support Vector Machine, SVM, and Convolutional Neural Network, CNN, are studied to determine which method performs best on a labeled data set containing time series of light intensity from extrasolar stars. The main difficulty is that in the data set there are a lot more non exoplanet stars than there are stars with orbiting exoplanets. LÄS MER

  3. 3. Implementing an Algorithm for Spectrum Extraction of Circumstellar Objects with High-Dispersion Spectroscopy

    Master-uppsats, Stockholms universitet/Institutionen för astronomi

    Författare :Marcus Karlsson; [2019]
    Nyckelord :Astronomy; Spectroscopy; Exoplanets; Circumstellar Objects; Direct Imaging;

    Sammanfattning : In this thesis project, we study the field of high-dispersion spectroscopy and methods for extracting the spectrum of circumstellar objects such as exoplanets from the combined signal of a stellar system. One of the only techniques for detecting absorption lines in exoplanetary atmospheres is to directly image a planet and record the reflected light. LÄS MER

  4. 4. Detailed analysis of the chemical composition of stars harboring Earth-like planets

    Master-uppsats, Lunds universitet/Astronomi

    Författare :Lorena Acuña Aguirre; [2019]
    Nyckelord :Physics and Astronomy;

    Sammanfattning : Context. The planet-metallicity correlation for gaseous giants is widely accepted through spectroscopic studies. However, whether a similar correlation exists for terrestrial planets is a debated subject. LÄS MER

  5. 5. The Almighty Quasar — Destroyer of Worlds

    Kandidat-uppsats, Uppsala universitet/Observationell astrofysik

    Författare :Julia Ahlvind; [2019]
    Nyckelord :Astronomy; Habitability; Quasars; Active galactic nucleus; AGN;

    Sammanfattning : In the study of habitability of terrestrial exoplanets, both life-supporting conditions and the prevalence of transient life-threatening events need to be considered. One type of hazardous effect that has so far not received much attention is the thermal effect of a nearby active galactic nucleus (AGN), or in this particular case, the class of the AGN known as a quasar. LÄS MER