NASA’s James Webb Space Telescope has captured the first direct image of an exoplanet — a planet orbiting a star other than the sun — despite it being extremely cold. The planet, called 14 Herculis c, could give scientists a new perspective on how planetary systems across the Milky Way galaxy evolve.
This image of 14 Herculis c, a planet orbiting a star 60 light-years away from Earth, was taken with ... More
As exoplanets go, o, 14 Herculis c is huge — about seven times the mass of Jupiter. It can be found between the bright stars Vega and Arcturus in the night sky tonight, in the constellation Hercules, “The Hero.” It’s about 60 light-years from the solar system.
14 Herculis c is one of the coldest exoplanets ever directly imaged by a telescope. Most directly imaged exoplanets are extremely hot, but 14 Herculis is just 26 degrees Fahrenheit (minus 3 degrees Celsius).
14 Herculis c orbits an almost sun-like star, but it's not alone. There’s a second planet closer to the host star that’s hidden by the black disk in the image, above, called a coronagraph, which the Webb Telescope uses to block out the star’s light, making its search for dim planets easier.
If it was in the solar system, 14 Herculis c would be approximately 15 times farther from the sun than Earth — about 1.4 billion miles. That would put it somewhere between the sixth planet, Saturn, and the seventh planet, Uranus.
Unlike the solar system, where all planets orbit the sun in the same plane, the two planets in the 14 Herculis star system are misaligned, with their orbital planes inclined relative to one another at an angle of about 40 degrees.
Scientists believe a third planet may have been violently ejected from the system early in its formation, resulting in the unusual misalignment. “The early evolution of our own solar system was dominated by the movement and pull of our own gas giants, [which]
The Webb Telescope’s NIRCam (Near-Infrared Camera) was able to directly image 14 Herculis c because it can capture near-infrared light — radiation just beyond the visible spectrum. That’s critical to this observation because cold objects shine brightly only in infrared light. “The colder an exoplanet, the harder it is to image, so this is a new regime of study that Webb has unlocked with its extreme sensitivity in the infrared,” said Balmer. “We are now able to add to the catalog of not just hot, young exoplanets imaged, but older exoplanets that are far colder than we’ve directly seen before Webb.”
The Webb Telescope has a primary mirror with a diameter of 21 feet/6.5 meters. It’s made from beryllium and made-up of 18 hexagonal segments, each one covered in a super-thin layer of gold that’s perfect for reflecting infrared light. It was designed to last for five-10 years, but fuel-saving during its precise launch on Christmas Day, 2021, means it’s now expected to last for up to 20 years.