Nobel Prize in Physics Awarded for Work on Cosmology

• 10.08.2019, 16:33
•  World,  No-politics

BBC

There are two methods that astronomers use to spot planets around other stars. One is the so-called transit method where scientists watch for planets as they wander across the face of their parent star, The Guardian reports.

Even though the star is but a pinprick in the heavens, sensitive telescopes can often detect the minuscule dimming of the starlight as the planet goes by and casts its shadow on the detector. It’s been extremely successful - Nasa’s Kepler’s mission is but one that has exploiting transits to find hoards of new planets.

Mayor and Queloz used a different technique. They looked at how stars are pulled around by planets that swing around them. The method exploits the Doppler effect. In this case, as a planet’s gravity pulls its star towards Earth - with its telescope-wielding astronomers - light from the star is shifted towards the blue wavelengths of the electromagnetic spectrum. The rays are basically squeezed up, making them bluer. As the planet goes around the star and pulls it backwards, the starlight is stretched out and so turns more towards the red end of the electromagnetic spectrum.