Kepler-167e

Lore & Background

Kepler-167e was confirmed in 2016 as part of a study validating outer planets in the Kepler-167 system. The star itself hosts four known transiting exoplanets, with the inner three being super-Earths orbiting closer than Mercury is to the Sun. Kepler-167e is a long-period transiting gas giant, making it a rare example for atmospheric characterization. Observations using the Spitzer Space Telescope, published in 2019, ruled out significant transit timing variations, improving predictions for future transits. Four transits of the planet have been detected using both space-based and ground-based observations. In 2025, astronomer David Kipping and his team conducted a search for exomoons around Kepler-167e using the James Webb Space Telescope. One candidate event, which would place a moon orbit close to the Roche limit, may instead be explained by the planet passing in front of a starspot; no conclusion could be reached until the next transit in October 2027.

Reader's Guide

Kepler-167e holds significance as the first transiting Jupiter analog, providing a benchmark for studying long-period gas giants via the transit method. Its discovery and confirmation, along with the ruling out of significant transit timing variations, allow reliable predictions of future transits, facilitating follow-up observations. The planet is a target for atmospheric characterization, as its long orbital period and transiting nature offer a rare opportunity to probe the composition and structure of a cold gas giant. The 2025 exomoon search using JWST, though inconclusive, highlights ongoing interest in the system; the candidate event may be resolved with the next transit in October 2027. The presence of a companion red dwarf star at a wide separation (orbital period over 15,000 years) adds context to the system's architecture. Kepler-167e's legacy lies in demonstrating that Jupiter-like planets can be found transiting Sun-like stars, opening a window into comparative exoplanetology for temperate gas giants.

Did You Know?

• Kepler-167e is the first transiting Jupiter analog discovered.
• Its equilibrium temperature is 134 K.
• A 2025 exomoon search using JWST found one candidate event that may be a starspot crossing.
• The next transit of Kepler-167e after 2025 is predicted for October 2027.