---
title: "The Kepler-255 system"
url: "https://spacecatalog.org/system/kepler-255"
release: "DR1"
licence: "No licence stated; acknowledgement requested"
citation: "This research has made use of the NASA Exoplanet Archive, which is operated by the California Institute of Technology, under contract with the National Aeronautics and Space Administration under the Exoplanet Exploration Program. Cite Christiansen et al. (2025), Planetary Science Journal (doi:10.3847/PSJ/ade3c2), and the literature reference given with each value."
---

# The Kepler-255 system

Kepler-255 is a star in Cygnus, 3433 ly away, with 3 known planets. Their orbits run from 0.0192 to 0.0920 AU. All of them were detected by transit.

## The planets, innermost first

| Planet | Orbit (AU) | Period | Radius | Mass | Equilibrium T |
| --- | --- | --- | --- | --- | --- |
| [d](https://spacecatalog.org/object/kepler-255-d) | 0.0192 | 1.046 d | 1.32 R⊕ | 2.3 M⊕ | 1710 K |
| [b](https://spacecatalog.org/object/kepler-255-b) | 0.0630 | 5.715 d | 1.55 R⊕ | 3.02 M⊕ | 971 K |
| [c](https://spacecatalog.org/object/kepler-255-c) | 0.0920 | 9.946 d | 2.99 R⊕ | 9.22 M⊕ | 807 K |

Every figure is the planet's composite parameter from the [NASA Exoplanet Archive (Planetary Systems Composite Parameters)](https://exoplanetarchive.ipac.caltech.edu/cgi-bin/TblView/nph-tblView?app=ExoTbls&config=PSCompPars), one consistent set per world. Semi-major axes are orbits about the star, not distances from Earth.

This research has made use of the NASA Exoplanet Archive, which is operated by the California Institute of Technology, under contract with the National Aeronautics and Space Administration under the Exoplanet Exploration Program. Cite Christiansen et al. (2025), Planetary Science Journal (doi:10.3847/PSJ/ade3c2), and the literature reference given with each value.

## The host star

| Quantity | Value |
| --- | --- |
| MASS | 0.867 M☉ |
| RADIUS | 0.933 R☉ |
| SURFACE TEMPERATURE | 5573 K |
| LUMINOSITY | 0.757 L☉ |
| DISTANCE FROM EARTH | 3433 ly |
| APPARENT MAGNITUDE | 15.70 |
| CONSTELLATION | Cygnus |
| STARS IN SYSTEM | 1 |

The star itself: https://spacecatalog.org/object/kepler-255

The page itself, with the orbits drawn: https://spacecatalog.org/system/kepler-255