James Webb telescope finds one of the coldest, oldest planets
What's the story
The James Webb Space Telescope (JWST) has made a major discovery by directly imaging a distant, frigid planet in an alien solar system.
The exoplanet, known as 14 Herculis c or 14 Her c for short, is located about 60 light-years away from Earth in the constellation Hercules.
It appears as a faint orange dot in the new JWST image due to heat radiating from its atmosphere.
Planet profile
A frigid world
Astronomers estimate that 14 Her c formed around four billion years ago, and has a frigid atmospheric temperature of just -3°C.
It orbits its star at a distance of about 2.2 billion kilometers, roughly 15 times farther than Earth is from the Sun.
If placed in our solar system, it would sit between Saturn and Uranus.
Orbital anomalies
Unusual layout of the 14 Herculis system
Unlike the orderly orbits of planets in our solar system, the 14 Herculis system is dramatically misaligned.
Its two known planets, including the 14 Her c, orbit at angles of around 40 degrees to each other, creating an "X"-like crossing pattern around their star.
This unusual layout may have been caused by the early ejection of a third massive planet from the system.
Imaging difficulties
Why imaging cold exoplanets is challenging
Directly imaging exoplanets is a major technical challenge as they shine thousands of times fainter than their host stars.
Most directly imaged exoplanets are hot, young gas giants that emit just enough infrared light to stand out from their stars' glare.
However, colder and older planets like 14 Her c are usually too dim to detect.
Imaging breakthrough
How astronomers captured image of 14 Her c
The tilted, off-kilter orbit of 14 Her c proved beneficial for direct imaging.
Scientists used JWST's specialized starlight-blocking device called a coronagraph to isolate the planet's faint infrared glow.
Despite its estimated age of around four billion years and mass of about seven times that of Jupiter, the planet appeared significantly fainter than expected in the JWST image.