TOI-1246 d
TOI-1246 d is a puffy low-density planet orbiting the K V star TOI-1246 in the constellation Draco. It lies about 553 light-years from Earth and was discovered in 2022 using the transit method.
How Big Is TOI-1246 d?
TOI-1246 d has a radius of 3.43 times that of Earth. Its mass is 5.4 times that of Earth, giving it a density of 0.73 g/cm³ — closer to gas planets like Jupiter (1.33 g/cm³).
Is TOI-1246 d in the Habitable Zone?
TOI-1246 d orbits inside the inner edge of the habitable zone of TOI-1246. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of TOI-1246: 0.531–1.277 AU (conservative: 0.673–1.211 AU), per Kopparapu et al. (2014). Earth orbits the Sun at 1 AU.
See the full interactive habitable-zone view in the Exoplanet Explorer app ›
Temperature on TOI-1246 d
The equilibrium temperature of TOI-1246 d is about 588 K (315 °C) — hotter than anywhere on Earth. This estimate ignores any atmosphere, which could change surface temperatures dramatically — Earth's greenhouse effect adds about 33 °C.
Orbit and Year Length
A year on TOI-1246 d — one full orbit around TOI-1246 — lasts 18.7 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.132 AU — closer to its star than Mercury is to the Sun.
How Was TOI-1246 d Discovered?
TOI-1246 d was discovered in 2022 using the transit method, with observations from Transiting Exoplanet Survey Satellite (TESS).
The transit method watches a star for the tiny, regular dip in brightness that occurs when a planet crosses in front of it. The depth and timing of these dips reveal the planet's size and orbital period.
How Far Away Is TOI-1246 d?
TOI-1246 d is 552.6 light-years (169.4 parsecs) from Earth. Light arriving here tonight left the planet around the year 1474. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 9,725,760 years to make the journey.
Earth Similarity Index
The Earth Similarity Index (ESI) scores how physically similar a planet is to Earth, from 0 to 1, based on radius, density, escape velocity and surface temperature. TOI-1246 d scores 0.23, ranking #3,459 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: TOI-1246
TOI-1246
- Spectral type
- K V
- Surface temperature
- 5,151 K (Sun: 5,772 K)
- Mass
- 0.87 M☉
- Radius
- 0.86 R☉
The TOI-1246 Planetary System
TOI-1246 d is one of 4 known planets in the TOI-1246 system. Its siblings:
- TOI-1246 b (Sub Neptune)
- TOI-1246 c (Super Earth)
- TOI-1246 e (Sub Neptune)
TOI-1246 d — Complete Data
| Radius | 3.431 Earth radii (0.306 Jupiter radii) |
|---|---|
| Mass | 5.40 Earth masses (0.017 Jupiter masses) |
| Density | 0.73 g/cm³ (Earth: 5.51) |
| Orbital period | 18.65 days |
| Orbital distance | 0.132 AU |
| Equilibrium temperature | 588 K (315 °C) |
| Earth Similarity Index | 0.23 |
| Distance from Earth | 552.6 light-years (169.4 parsecs) |
| Constellation | Draco |
| Discovery method | Transit |
| Discovery facility | Transiting Exoplanet Survey Satellite (TESS) |
| Discovery year | 2022 |
Data: NASA Exoplanet Archive, last updated 2024-07-22. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About TOI-1246 d
Is TOI-1246 d habitable?
No — TOI-1246 d orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is TOI-1246 d?
TOI-1246 d is about 553 light-years from Earth in the constellation Draco. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 9,725,760 years to get there.
How big is TOI-1246 d compared to Earth?
TOI-1246 d has 3.43 times the radius of Earth and about 5.4 times its mass.
How long is a year on TOI-1246 d?
One orbit around TOI-1246 takes 18.7 Earth days — short enough that 20 of its years would fit into one Earth year.
Explore TOI-1246 d in the app
Browse, filter and compare 6,000+ exoplanets on iPhone, iPad and Apple Watch — with habitable-zone views, widgets and offline data.
