The TOI-178 system contains 6 exoplanets. It is located 204.50 light years away from the solar system.
| Mass | 0.65 solar masses |
| Radius | 0.65 solar radiae |
| Temperature | 4316 kelvin |
| Stellar Metallicity | -0.23 decimal exponent |
| Age | 7.1 billion years |
At 1.501 Earth masses, TOI-178 b is a so called Super Earth. Super Earths could be terrestrial worlds like Earth, but they could also be ocean worlds or terrestrial worlds wrapped in a substantial atmosphere, in which case some refer to them as Mini Neptunes.
| Mass | 1.500 Earth masses |
| Density | 5.400 grams per cubic centimeter |
| Radius | 1.152 Earth radiae |
| Semi-major Axis | 0.02607 AU |
| Eccentricity | NaN |
| Orbital Period | 1.915 days |
| Discovery Method | Transit |
| Discovery Facility | Transiting Exoplanet Survey Satellite (TESS) |
| Discovery Telescope | 0.1 m TESS Telescope |
| Discovery Instrument | TESS CCD Array |
| Discovery Date | 2021-05 |
| Reference | Leleu et al. 2021 |
At 4.773 Earth masses, TOI-178 c is a so called Super Earth. Super Earths could be terrestrial worlds like Earth, but they could also be ocean worlds or terrestrial worlds wrapped in a substantial atmosphere, in which case some refer to them as Mini Neptunes.
| Mass | 4.770 Earth masses |
| Density | 5.620 grams per cubic centimeter |
| Radius | 1.669 Earth radiae |
| Semi-major Axis | 0.037 AU |
| Eccentricity | NaN |
| Orbital Period | 3.238 days |
| Discovery Method | Transit |
| Discovery Facility | Transiting Exoplanet Survey Satellite (TESS) |
| Discovery Telescope | 0.1 m TESS Telescope |
| Discovery Instrument | TESS CCD Array |
| Discovery Date | 2021-05 |
| Reference | Leleu et al. 2021 |
With a mass below 5 Earth masses, a density of 0.976, and a semi-major axis of 0.0592 astronomical units, TOI-178 d could, potentially, be an ocean world - a planet with no dry land.
| Mass | 3.010 Earth masses |
| Density | 0.976 grams per cubic centimeter |
| Radius | 2.572 Earth radiae |
| Semi-major Axis | 0.0592 AU |
| Eccentricity | NaN |
| Orbital Period | 6.558 days |
| Discovery Method | Transit |
| Discovery Facility | Transiting Exoplanet Survey Satellite (TESS) |
| Discovery Telescope | 0.1 m TESS Telescope |
| Discovery Instrument | TESS CCD Array |
| Discovery Date | 2021-05 |
| Reference | Leleu et al. 2021 |
With a mass below 5 Earth masses, a density of 1.98, and a semi-major axis of 0.0783 astronomical units, TOI-178 e could, potentially, be an ocean world - a planet with no dry land.
| Mass | 3.860 Earth masses |
| Density | 1.980 grams per cubic centimeter |
| Radius | 2.207 Earth radiae |
| Semi-major Axis | 0.0783 AU |
| Eccentricity | NaN |
| Orbital Period | 9.962 days |
| Discovery Method | Transit |
| Discovery Facility | Transiting Exoplanet Survey Satellite (TESS) |
| Discovery Telescope | 0.1 m TESS Telescope |
| Discovery Instrument | TESS CCD Array |
| Discovery Date | 2021-05 |
| Reference | Leleu et al. 2021 |
At more than 10 Earth masses, TOI-178 f is an ice giant, a planet that is made up mostly of volatiles like water, amonia and methane, and enveloped by a dense hydrogen and helium atmosphere, much like Uranus and Neptune.
| Mass | 7.720 Earth masses |
| Density | 3.600 grams per cubic centimeter |
| Radius | 2.287 Earth radiae |
| Semi-major Axis | 0.1039 AU |
| Eccentricity | NaN |
| Orbital Period | 15.232 days |
| Discovery Method | Transit |
| Discovery Facility | Multiple Observatories |
| Discovery Telescope | Multiple Telescopes |
| Discovery Instrument | Multiple Instruments |
| Discovery Date | 2021-05 |
| Reference | Leleu et al. 2021 |
With a mass below 5 Earth masses, a density of 0.915, and a semi-major axis of 0.1275 astronomical units, TOI-178 g could, potentially, be an ocean world - a planet with no dry land.
| Mass | 3.940 Earth masses |
| Density | 0.915 grams per cubic centimeter |
| Radius | 2.870 Earth radiae |
| Semi-major Axis | 0.1275 AU |
| Eccentricity | NaN |
| Orbital Period | 20.709 days |
| Discovery Method | Transit |
| Discovery Facility | Transiting Exoplanet Survey Satellite (TESS) |
| Discovery Telescope | 0.1 m TESS Telescope |
| Discovery Instrument | TESS CCD Array |
| Discovery Date | 2021-05 |
| Reference | Leleu et al. 2021 |