How to find exoplanets
So how do we find exoplanets??Space telescopes do not observe exoplanets directly, but find them indirectly. For example, when an exoplanet passes in front of a star that emits light, some of the light disappears due to the shadow., We estimate the size of this.NASA According to the method proposed by Dr. William Boruki of the Ames Institute,, Kepler·The Tess Space Telescope uses this method.
Figure 4. When an exoplanet passes in front of a star (star), the shadow momentarily dims the starlight, and this is repeated according to the orbital period of the exoplanet. This way you can find exoplanets. (Source: ESA)
There is also a way to find out by analyzing the wavelength of light..Stars move little by little due to the gravitational pull of the planets around them.. As the star moves toward Earth, it becomes more blue with shorter wavelengths., When it gets farther away, a red color with a longer wavelength appears, and this change is observed to confirm the existence of an exoplanet.. Last 2019year’s Nobel Prize in Physics 1995year 50Gas exoplanets rivaling Jupiter light-years away(51 Pegasus B)The discovery was jointly awarded by astronomers Michel Mayor and Didier Kello, who used a method of analyzing wavelengths..
Figure 5. When an exoplanet and a star (star) orbit, exoplanets can be discovered by measuring the motion of the star (wavelength change) caused by the planet’s gravity. This motion causes the light from the star to appear slightly bluer as it moves toward Earth and slightly redder as it moves away (the Doppler effect).
Most exoplanets have been discovered in these two ways. However, this method is useless if the exoplanets are far from the star.. In this case, the gravitational lensing effect is used..The gravitational lensing effect is a phenomenon in which space-time is bent when there is a celestial body with gravity, and the celestial body behind it is distorted as if it were magnified by a lens, and the brightness is different.. This method is particularly useful for locating celestial bodies similar in size to Earth..
Figure 6. As one star crosses behind another, the nearby star acts like a lens, refracting light and changing its brightness. This is called the gravitational lensing effect, and this method can be used to find exoplanets. This is because if an exoplanet exists around a nearby star, the planet’s gravity will change the star’s brightness. (Source: ESA)
Over time, methods for observing exoplanets have become increasingly diverse and precise.. A new space telescope for future observations may find other ways to find exoplanets. last year 12In addition to the James Webb Space Telescope, which was launched in 2027year NASANancy Grace Roman Space Telescope developed by2029The Ariel Space Telescope, developed by the European Space Agency in 2015, is preparing to go into space.. They explore exoplanets ‘My2of earth’Let’s see if we can find.
writing: Woohyun Kim Science Columnist/ illustration: Writer Lee Myeong-heon