Planet hotter than the Sun discovered outside Solar System
Unlike “our” Jupiter, hot Jupiters orbit very close to their stars, complete a full orbit in just a few days or even hours, and – as their name suggests – have extremely high surface temperatures.
In Short
- The binary system comprises two dwarfs
- Newly discovered system features a star-orbiting object similar to a hot Jupiter
- Findings of the study have been published in Nature Astronomy
Scientists have discovered a celestial system that could provide unprecedented insights into the atmospheres of hot Jupiters and the evolution of planets and stars.
Hot Jupiters are a class of exoplanets that share physical similarities with Jupiter, but orbit much closer to their stars, resulting in extremely high surface temperatures.
Despite their intrigue within the astrophysics community, these exoplanets are challenging to study due to the glare from their nearby stars.
Findings of the study have been published in the journal Nature Astronomy.
The system, located approximately 1,400 light years away, consists of two celestial bodies and was identified in data from the European Southern Observatory’s Very Large Telescope in Chile.
The newly discovered system features a star-orbiting object similar to a hot Jupiter, but significantly hotter.
"We’ve identified a star-orbiting hot Jupiter-like object that is the hottest ever found, about 2,000 degrees hotter than the surface of the Sun," says lead author Dr. Na’ama Hallakoun, a postdoctoral researcher at the Weizmann Institute of Science.
Unlike typical hot Jupiters, this object can be studied as it is considerably larger than its host star, which is 10,000 times fainter than a regular star.
The binary system comprises two 'dwarfs' - a white dwarf, the remnant of a Sun-like star after it has depleted its nuclear fuel, and a brown dwarf, an object with a mass between that of a gas giant like Jupiter and a small star.
Brown dwarfs, often referred to as failed stars, are dense enough to withstand the gravitational pull of their stellar partners.
The brown dwarf in this system exhibits a phenomenon known as “tidal locking,” where one side of the planet permanently faces the star, leading to extreme temperature differences between the two hemispheres.
The dayside temperature ranges between 7,250 and 9,800 Kelvin (about 7,000 and 9,500 Celsius), hotter than any known giant planet, while the nightside temperature is between 1,300 and 3,000 Kelvin (about 1,000 and 2,700 Celsius).
This discovery offers a unique opportunity to study the effect of extreme ultraviolet radiation on planetary atmospheres, which plays a crucial role in various astrophysical environments and can significantly impact both stellar and planetary evolution.
Future high-resolution spectroscopic observations of this hot Jupiter-like system may reveal how highly irradiated conditions impact atmospheric structure, contributing to our understanding of exoplanets elsewhere in the universe.