NASA's Webb telescope glimpses coldest exoplanet yet found: What to know about gas giant

USA Today

3 days ago

NASA's Webb telescope glimpses coldest exoplanet yet found: What to know about gas giant An exoplanet 60 light-years away from Earth, known as 14 Herculis c, is thought to be as cold as 26 degrees Fahrenheit.
"Abnormal, chaotic and strange" are just a few adjectives astronomers are using to describe a perplexing planetary system located 60 light-years from Earth.
And for one of the two exoplanets orbiting the system's central star, you can add this descriptor: Cold. Surprisingly frigid, in fact.
NASA's James Webb Space Telescope recently turned its attention to the distant planetary system in our Milky Way galaxy to gather new and unexpected insights for a team of researchers. Using Webb's near-infrared camera (NIRCam), which shows reflected light, the team was able to image one of two known planets surrounding a star known as 14 Herculis.
Among the nearly 6,000 exoplanets so far discovered, those that have been imaged tend to be incredibly hot – with temperatures at times reaching into thousands of degrees Fahrenheit.
But that wasn't the case for this exoplanet, known as 14 Herculis c. Not only is 14 Herculis c not hot at all, it's uncommonly cold.
The exoplanet is so cold, in fact, that the team of researchers claims it is the coldest one imaged to date, NASA said in a Tuesday, June 10, blog post.
Here's what to know about exoplanets, and what makes the discovery about 14 Herculis c significant.
What are exoplanets?
Exoplanets are any planets that orbit stars outside of Earth's own solar system. For that reason, these celestial bodies are sometimes also referred to as extrasolar planets.
Some, called rogue planets, don't even orbit a star, but are rather floating through the cosmos untethered.
An exoplanet known as K2-18b even achieved a degree of fame in April when a team of astronomers claimed to have found in its atmosphere "the strongest evidence yet" that life exists anywhere else besides Earth. Other scientists have since cast doubt on the findings.
Astronomers have confirmed the existence of more than 5,800 exoplanets, but billions are thought to exist, according to NASA.
New exoplanet image from NASA's Webb suggest freezing temps
Webb's new image of 14 Herculis c has given researchers insight into the exoplanet's temperature, strange orbit and atmosphere.
The exoplanet is one of at least two gas giants – both significantly bigger than Jupiter – that have been observed orbiting a central star, 14 Herculis, that is similar in age and temperature to Earth's sun, but a little less massive and not as hot. Neither orbits the host star in the same way planets in our solar system do, but instead cross each other in a pattern that resembles an "X," according to NASA.
While the other exoplanet, 14 Herculis b, has been observed before, the new data suggests 14 Herculis c, which is about seven times the mass of Jupiter, is as cold as 26 degrees Fahrenheit.
Webb has become famous for snapping gorgeous images of the cosmos, but the photo the telescope captured of 14 Herculis c is far from as eye-catching. That's because astronomers struggle to image planets orbiting stars other than our own sun. Why? The stars often outshine their planets, which tend to be a little too close to their stars.
Still, even a simple grainy image like this one depicting what appears to be a distant dot is packed with information for astronomers.
The team's findings have been accepted for publication in The Astrophysical Journal Letters and were presented Tuesday, June 10, at the 246th meeting of the American Astronomical Society in Anchorage, Alaska.
What is the James Webb Space Telescope?
The James Webb Space Telescope, which launched in 2021, far surpasses the abilities of the Hubble Space Telescope, launched 35 years ago in 1990.
Orbiting the sun rather than Earth, the Webb is outfitted with a gold-coated mirror and powerful infrared instruments to observe the cosmos like no instrument before. Since reaching the cosmos, Webb has not only facilitated countless scientific breakthroughs in astrophysics, but has produced plenty of gorgeous images of planets and other celestial objects like star-forming regions.
In March 2025, NASA also deployed into orbit its SPHEREx telescope to collect data on more than 450 million galaxies. Scientists say the SPHEREx observatory will be able to get a wider view of the galaxy – identifying objects of scientific interest that telescopes like Hubble and Webb can then go study up close.
SPHEREx officially became operational in May, constantly snapping images of the cosmos.
Eric Lagatta is the Space Connect reporter for the USA TODAY Network. Reach him at [e-mail]