NASA's James Webb Space Telescope has taken its first image of a planet outside of our solar system. The telesco pe recorded four different views of HIP 65426 b, a large planet about 6 latest one takes to 12 times the mass of the planet Jupiter.
"This is a historic moment, not only for Webb but also for astronomy generally," said Sasha Hinkley, associate professor of physics and astronomy at the University of Exeter Astronomers discovered HIP 65426 b in 2017 using the European Southern Observatory's Very Large Telescope in Chile. It is a young exoplanet(系外行星) around 15 to 20 million years ole-Earth is 4.5 billion years old.
According to NASA, taking direct images of exoplanets presents a challenge because stars are much brighter than their surrounding planets-HIP65426 b is more than 10,000 times duller than its host star in the near-infrared(近红外光), and a few thousand times duller in the mid-infrared.
Webb has a near-infrared camera and mid-infrared instrument, which are both equipped with coronagraphs(日冕仪). "It was really impressive how well the Webb coronagraphs worked to suppress the light of the host star," Prof. Hinkley said. Since the planet is around 100 times further away from its host star than Earth is from the Sun, the telescope can easily separate it from the star in the image.
Although this is not the first direct image of an exoplanet taken from space, as the Hubble Space Telescope has taken direct exoplanet images previously, the image points the way to future observations that will disclose more information about exoplanets. "I think what's most exciting is that we've only just begun," said Aarynn Carter, a postdoctoral researcher at the University of California. "There are many more images of exoplanets to come that will shape our overall understanding of their physics, chemistry and formation. We may even discover previously unknown planets, too."
