A planet from another galaxy
•Télécharger en tant que PPTX, PDF•
1 j'aime•341 vues
A planet from another galaxy
Recommandé
Recommandé
Contenu connexe
Tendances
Tendances (20)
Similaire à A planet from another galaxy
Similaire à A planet from another galaxy (20)
Plus de Nelson Correia
Plus de Nelson Correia (20)
Dernier
Dernier (20)
A planet from another galaxy
- 2. Exoplanets For two decades, astronomers have known that there are planets beyond our Solar System, orbiting other stars, known as exoplanets. More than 1800 exoplanets have been detected. More than 90% of the stars hosting exoplanets are in the same evolutionary phase as the Sun – the main-sequence phase, during which stars burn hydrogen.
- 3. The research group at the Max Planck Institute for Astronomy in Heidelberg, Germany, detected a planet around the star HIP 13044, which has left the red giant phase, during which the star expands massively after exhausting the hydrogen. The star has now contracted again and is burning helium in its core. An extragalactic star
- 4. An extragalactic star The star belongs to a stellar stream that is known to have its origin outside our galaxy. The planet HIP 13044 b should be from another galaxy, has a mass at least 1.3 times that of Jupiter and orbits at a distance of 0.12 astronomical unit.
- 5. Detecting exoplanets Whereas the star can be seen with a telescope, the planet is too small to observe directly. We can detect the exoplanet using a technique known as radial velocity: • When the position of the stellar spectral lines change, this indicate a change in the velocity of the star (the star’s movement is the yellow line) and can reveal the presence of a planet (blue ball).
- 6. Detecting exoplanets • A positive change in radial velocity (away from us, to the left) corresponds to a shift towards the red in the spectrum; • a negative change (towards us, to the right) corresponds to a shift towards the blue.
- 7. Detecting exoplanets The light contains information about the elements in the stars atmosphere, which can be in the form of spectral lines (black lines on the coloured spectrum), that can be detected with the high-resolution spectrograph FEROS attached to the MPG/ESO 2.2-metre telescope at the European Southern Observatory’s La Silla facility in Chile.
Notes de l'éditeur
- O nº de exoplanetas deve estar atualizado – ver em http://exoplanets.eu
- Recently, our team have successfully detected a planet around the star HIP 13044, which has left the red giant phase.
- Slide com muito texto, deve-se separar ou resumir o texto This is the first time that astronomers have detected a planetary system in a stellar stream of extragalactic origin. HIP 13044 b has a mass at least 1.3 times that of Jupiter, and orbits at a distance of 0.12 astronomical unit.
- Slide com muito texto, deve-se separar ou resumir o texto whereas the star can be seen with a telescope, the planet itself is far too small to observe directly. How, then, did we detect it? Using a technique known as radial velocity By examining the stellar spectral lines at intervals, we detected changes to those lines (see diagram below). These indicate changes in the velocity of the star along the line of sight and can reveal the presence of an unseen low-mass companion, such as a planet. Deve-se colocar a imagem maior: http://www.scienceinschool.org/repository/images/issue19exoplanet3_xl.jpg
- Slide com muito texto, deve-se separar ou resumir o texto whereas the star can be seen with a telescope, the planet itself is far too small to observe directly. How, then, did we detect it? Using a technique known as radial velocity By examining the stellar spectral lines at intervals, we detected changes to those lines (see diagram below). These indicate changes in the velocity of the star along the line of sight and can reveal the presence of an unseen low-mass companion, such as a planet. Deve-se colocar a imagem maior: http://www.scienceinschool.org/repository/images/issue19exoplanet3_xl.jpg
- Devem escrever as referências do artigo