WISE 0855−0714, also known as WISE J085510.83−071442.5, is a substellar object located approximately 7.4 light-years from Earth in the constellation Hydra. Discovered in 2013 by astronomer Kevin Luhman using data from NASA's Wide-field Infrared Survey Explorer (WISE), it is notable for being the coldest known brown dwarf, with an effective temperature around 250 K (−23°C or −9°F). This temperature is comparable to that of Jupiter, making WISE 0855−0714 a compelling subject of study for astronomers interested in understanding the characteristics of cold, Jupiter-like objects beyond our solar system.

Discovery and Classification

WISE 0855−0714 was first detected in 2010 during WISE's primary mission to survey the entire sky in infrared wavelengths. However, its true nature was not recognized until 2013, when Luhman identified its unusually high proper motion in WISE images. Subsequent observations with the Spitzer Space Telescope and the Gemini North telescope confirmed its status as a substellar object. The International Astronomical Union (IAU) classifies it as a Y4-type brown dwarf, placing it among the coldest known substellar objects. Its mass is estimated to be between 3 and 10 Jupiter masses, positioning it below the 13 Jupiter mass threshold for deuterium fusion, which is the defining characteristic of brown dwarfs. This mass range suggests that WISE 0855−0714 is a free-floating planetary-mass object, often referred to as a "rogue planet." ([en.wikipedia.org](

Physical Characteristics

WISE 0855−0714's proximity to Earth and its low temperature make it an excellent candidate for studying the properties of cold, Jupiter-like objects. Its effective temperature of approximately 250 K (−23°C or −9°F) is similar to that of Jupiter, which has an average temperature of about 130 K (−143°C or −225°F). This temperature is low enough that WISE 0855−0714 is nearly invisible in visible light, emitting primarily in the infrared spectrum. Its luminosity is extremely faint, making it challenging to detect without specialized infrared telescopes. ([en.wikipedia.org](

Atmospheric Composition and Cloud Formation

Studies of WISE 0855−0714's atmosphere have provided valuable insights into the cloud formation processes of cold, Jupiter-like objects. Observations suggest the presence of water clouds or ice in its atmosphere, similar to those found on Jupiter. These findings are based on the object's infrared spectrum, which indicates the presence of water vapor and ice clouds. The detection of such clouds in a cold, free-floating object like WISE 0855−0714 offers a unique opportunity to study cloud formation and atmospheric dynamics in environments similar to those of gas giant planets. ([science.nasa.gov](

Search for Exomoons

Given its mass and proximity, WISE 0855−0714 has been a target for searches for exomoons—moons orbiting exoplanets or free-floating objects. A team of researchers conducted a deep search using the James Webb Space Telescope (JWST) to detect potential exomoons around WISE 0855−0714. Despite extensive observations, no transits indicative of exomoons were detected. This result suggests that if exomoons exist around WISE 0855−0714, they are either too small to produce detectable transits or absent altogether. The absence of detected exomoons provides valuable information about the formation and evolution of such systems. ([en.wikipedia.org](

Significance in Exoplanet Research

WISE 0855−0714 serves as a crucial benchmark in the study of exoplanets and brown dwarfs. Its low temperature and proximity allow astronomers to study the atmospheric properties and cloud formation processes of cold, Jupiter-like objects in detail. The absence of detected exomoons also offers insights into the dynamics of such systems. Additionally, the study of WISE 0855−0714 contributes to our understanding of the formation and evolution of planetary systems, particularly those involving free-floating objects. Its unique characteristics make it an invaluable object of study in the field of exoplanet research. ([en.wikipedia.org](

Future Observations and Research

Ongoing and future observations of WISE 0855−0714, particularly with advanced instruments like the JWST, are expected to provide deeper insights into its atmospheric composition, cloud dynamics, and potential for hosting exomoons. Such studies will enhance our understanding of cold, Jupiter-like objects and their role in the broader context of planetary system formation and evolution. The continued study of WISE 0855−0714 remains a priority for astronomers aiming to unravel the mysteries of substellar objects and their environments. ([en.wikipedia.org](

Sources

  • NASA Science — Astronomers find water clouds in cold Jupiter-like object —
  • Wikipedia — WISE 0855−0714 —
  • NASA Science — WISE J033605.05-014350.4 b —
  • arXiv — Flux and Color of WISE 0855-0714 —
  • arXiv — Temperature constraints on the coldest brown dwarf known WISE 0855-0714 —