Confirmed exoplanet · Database record + computed analysis
LHS 1678 b
A confirmed world orbiting LHS 1678, 64.8 light-years away.
A sub-Earth
smaller than Earth at 0.69 Earth radii. Worlds this small are hard to detect, so every one is a catch. With 0.3 Earth masses packed into that size, its density points to rock and iron rather than gas.
The orbit
Its year lasts about 20.6 hours, making it an ultra-short-period planet skimming its star. Orbiting this tightly around a cool star, it is very likely tidally locked: one hemisphere in permanent day, the other in permanent night.
Temperature and starlight
Its equilibrium temperature (the airless-world estimate) is about 557 °C. Hotter than Venus's surface. It receives 94.3 times the starlight Earth gets.
Its sun
Its star is a red dwarf (3,490 K surface), type M2.0 V: small, dim, flare-prone, and destined to outlive the Sun many times over. The system holds 2 stars, so its skies have more than one sun. It shares the system with 2 other known planets.
How far is that, really?
At 65 light-years, tonight's light from this system left it around the year 1961. A Voyager-speed probe would need roughly 1,147,082 years to get there.
How we found it
It was found by the transit method: the planet crosses its star's face on schedule, dimming it by a tiny, repeating fraction. The dip's depth gives the planet's size. The discovery was announced in 2021 from Transiting Exoplanet Survey Satellite (TESS).
Everything above is computed from the archive’s measured values for this planet. Where a quantity is missing, the statement is omitted rather than guessed.
About this record
The measured values come from the NASA Exoplanet Archive, and any missing value has not been determined yet; the Atlas never fills gaps with guesses. More standout worlds: Proxima b, TRAPPIST-1e, K2-18 b, 55 Cancri e, and the detection methods that found them all.