Space Codex / Exoplanet reference
Published exoplanet measurements
TOI-198 b
TOI-198 b orbits TOI-198 once every 10.2152 days. The system is about 77.3845 light-years from Earth.
Archive retrieved November 1, 2026 (America/New_York). The selected paper and archive update dates appear below.
The recorded orbit
The selected archive solution gives an orbital period of 10.2152 days, or 0.0279677 Earth years. Its reported semimajor axis is 0.0675 AU. That orbital scale is 0.174374 times Mercury's semimajor axis. The listed eccentricity is 0.15. The period measures a year on this planet. It does not establish the length of its rotation or the duration of daylight.
Read how orbital period, size, and eccentricity fit together.
Size and mass
The radius parameter is 1.36 (+0.13 / −0.13) Earth radii. Radius describes size; it does not specify the mass or the atmospheric composition. The mass parameter is 3.17 (+0.64 / −0.65) Earth masses. Its archive provenance is Mass. The source lists a bulk-density parameter of 6.89 (+4.27 / −2.78) g/cm³. Different interior mixtures can overlap in density; the value does not identify a unique surface.
The host star and received light
The host is cataloged as TOI-198. Its reported effective temperature is 3801 K. Its reported radius is 0.418 solar radii. Its reported mass is 0.417 solar masses. The planet's incident-flux parameter is 7.2 (+2.4 / −1.4) times Earth's received stellar flux. The equilibrium-temperature entry is 456 (+34 / −27) K. This is a model quantity, not a measured surface temperature. The available stellar and orbital entries do not establish a breathable atmosphere, surface water, or life.
What a habitable-zone claim does and does not mean · How a star changes over time.
Other planets around TOI-198
The fetched archive contains 1 selected default planet record for this host. This is the retrieved record set, and additional or revised discoveries may appear in later research.
| Planet | Period (days) | Radius (Earth) | Mass parameter (Earth) | Mass definition |
|---|---|---|---|---|
| TOI-198 b | 10.2152 (+1.1e-05 / −1e-05) | 1.36 (+0.13 / −0.13) | 3.17 (+0.64 / −0.65) | Mass |
Earth comparison
| Quantity | Reported value or conversion | Comparison |
|---|---|---|
| Orbital period | 10.2152 days | 0.0279677 Earth years |
| System distance | 23.7262 parsecs | 77.3845 light-years |
| Orbital scale | 0.0675 (+0.0067 / −0.0082) | AU; Earth = 1 |
| Radius | 1.36 (+0.13 / −0.13) | Earth radii; Earth = 1 |
| Mass parameter | 3.17 (+0.64 / −0.65) | Earth masses; check mass definition |
| Received stellar flux | 7.2 (+2.4 / −1.4) | Earth flux; Earth = 1 |
Conversions use rounded central values. They are navigation aids for the data, not additional observations. Uncertainties for the original parameters remain in the next table.
Measurement table
| Parameter | Value and reported uncertainty | Unit or definition |
|---|---|---|
| Orbital period | 10.2152 (+1.1e-05 / −1e-05) | days |
| Semimajor axis | 0.0675 (+0.0067 / −0.0082) | AU |
| Radius | 1.36 (+0.13 / −0.13) | Earth radii |
| Mass parameter | 3.17 (+0.64 / −0.65) | Earth masses |
| Orbital eccentricity | Upper limit: 0.15 | dimensionless |
| Orbital inclination | 89.63 (+0.24 / −0.32) | degrees |
| Equilibrium temperature | 456 (+34 / −27) | K; model estimate |
| Incident flux | 7.2 (+2.4 / −1.4) | Earth flux |
| Bulk density | 6.89 (+4.27 / −2.78) | g/cm³ |
| Host effective temperature | 3801 (+100 / −100) | K |
| Host radius | 0.418 (+0.029 / −0.029) | solar radii |
| Host mass | 0.417 (+0.045 / −0.045) | solar masses |
| Host metallicity | -0.66 (+0.1 / −0.1) | dex; archive abundance definition |
| Host age | Lower limit: 1 | billion years |
| Host luminosity | -1.484 (+0.013 / −0.013) | log10 solar luminosity |
| Host surface gravity | 4.81 (+0.1 / −0.1) | log10 cm/s² |
| Host rotation period | 48.5 | days |
| System distance | 23.7262 (+0.02655 / −0.02655) | parsecs |
Parentheses show the reported upper and lower uncertainties when both are supplied. Bounds are explicitly labeled. A missing entry means unavailable in this solution, not zero. The confidence convention belongs to the source paper.
Research record and limitations
| Record | Value |
|---|---|
| Planetary reference | Zapatero Osorio et al. 2026 |
| Discovery method | Transit |
| Discovery year | 2023 |
| Discovery facility | Transiting Exoplanet Survey Satellite (TESS) |
| Mass provenance | Mass |
| Host stars in system | 1 |
| Archive system planet count | 1 |
| Planetary solution publication date | 2026-02 |
| Row update date | 2026-04-09 |
| Archive release date | 2026-04-09 |
Source: NASA Exoplanet Archive overview for TOI-198 b, Planetary Systems table, default solution. The collection excludes entries flagged controversial at retrieval. A selected default is a published reference choice, not a claim that every parameter is the latest estimate in all literature.
This profile documents measurements and their scope. It is separate from the 3D planet catalog and does not create a sponsorship placement or a new explorer destination.