NASA's James Webb Telescope Captures Image of Cold Exoplanet 14 Herculis c

On June 11, 2025, NASA's James Webb Space Telescope (JWST) made a significant breakthrough in exoplanet research by successfully imaging the frigid exoplanet 14 Herculis c, located approximately 60 light-years from Earth. This image was captured using Webb's Near-Infrared Camera (NIRCam) during the 246th meeting of the American Astronomical Society held in Anchorage, Alaska. The image reveals a complex planetary system that defies typical orbital patterns, providing insights into the dynamics of exoplanets and their formation processes.

14 Herculis c is one of the coldest exoplanets imaged to date, with temperatures hovering around 26 degrees Fahrenheit (approximately -3 degrees Celsius). Despite the discovery of nearly 6,000 exoplanets, only a select few have been directly imaged, predominantly those with extreme temperatures. This achievement underscores the advanced capabilities of the JWST, which is renowned for its sensitivity in the infrared spectrum, as noted by William Balmer, a graduate student at Johns Hopkins University and co-first author of the related study published in The Astrophysical Journal Letters.

Research indicates that 14 Herculis c is approximately seven times the mass of Jupiter and orbits its host star, 14 Herculis, in a highly elliptical path. Unlike our solar system, where planets orbit on a relatively flat plane, the two known planets in this system exhibit a crossing orbital configuration, resembling an 'X.' This misalignment suggests a turbulent formation history, potentially involving the ejection of a third planet during the system's early development. Balmer stated, "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 light from 14 Herculis was obscured by a coronagraph, allowing researchers to focus on the planet itself, a technique that highlights Webb's innovative approach to exoplanet imaging. By measuring the brightness of 14 Herculis c at a wavelength of 4.4 microns, researchers are gaining insights into the planet's atmospheric dynamics. Daniella C. Bardalez Gagliuffi, co-first author from Amherst College, explained, "If a planet of a certain mass formed 4 billion years ago, then cooled over time because it doesn't have a source of energy keeping it warm, we can predict how hot it should be today."

However, the findings from the JWST also reveal unexpected results. The observed brightness at this wavelength was fainter than anticipated for an object of this mass and age, attributed to a phenomenon known as carbon disequilibrium chemistry, typically observed in brown dwarfs. Bardalez Gagliuffi noted, "This exoplanet is so cold, the best comparisons we have that are well-studied are the coldest brown dwarfs. In those objects, we see carbon dioxide and carbon monoxide existing at temperatures where we should see methane. This is explained by churning in the atmosphere."

The JWST's imaging of 14 Herculis c marks a pivotal point in exoplanet studies, offering a glimpse into a planetary system that could inform our understanding of the formation and evolution of not just distant worlds but also our own solar system. As researchers continue to analyze this data, future spectroscopic studies are expected to further illuminate the atmospheric characteristics and formation pathways of 14 Herculis c, contributing to a broader understanding of planetary systems across the galaxy.

The James Webb Space Telescope, a collaboration between NASA, the European Space Agency (ESA), and the Canadian Space Agency (CSA), remains at the forefront of space exploration, addressing longstanding astronomical questions and paving the way for future discoveries.