TOI-4034 b
TOI-4034 b is a hot Jupiter orbiting TOI-4034 in the constellation Cepheus. It lies about 2,430 light-years from Earth and was discovered in 2026 using the transit method.
How Big Is TOI-4034 b?
TOI-4034 b has a radius of 17.71 times that of Earth, or 1.58 times the radius of Jupiter. Its mass is 277 times that of Earth, giving it a density of 0.28 g/cm³ — closer to gas planets like Jupiter (1.33 g/cm³).
Is TOI-4034 b in the Habitable Zone?
TOI-4034 b orbits inside the inner edge of the habitable zone of TOI-4034. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of TOI-4034: 1.418–3.331 AU (conservative: 1.796–3.158 AU), per Kopparapu et al. (2014). Earth orbits the Sun at 1 AU.
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Temperature on TOI-4034 b
The equilibrium temperature of TOI-4034 b is about 1,907 K (1,634 °C) — hot enough to melt many metals. 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-4034 b — one full orbit around TOI-4034 — lasts just 43.3 hours, shorter than Mercury's 88-day year. It orbits at an average distance of 0.033 AU — closer to its star than Mercury is to the Sun.
How Was TOI-4034 b Discovered?
TOI-4034 b was discovered in 2026 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-4034 b?
TOI-4034 b is 2,430.3 light-years (745.1 parsecs) from Earth. Light arriving here tonight left the planet about 2,430 years ago. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 42,773,280 years to make the journey.
The Host Star: TOI-4034
TOI-4034
- Surface temperature
- 5,891 K (Sun: 5,772 K)
- Mass
- 1.19 M☉
- Radius
- 1.83 R☉
- Age
- 5.7 billion years (Sun: 4.6)
Planetary System
TOI-4034 b is the only planet known to orbit TOI-4034 so far.
TOI-4034 b — Complete Data
| Radius | 17.710 Earth radii (1.580 Jupiter radii) |
|---|---|
| Mass | 276.51 Earth masses (0.870 Jupiter masses) |
| Density | 0.28 g/cm³ (Earth: 5.51) |
| Orbital period | 1.80 days |
| Orbital distance | 0.033 AU |
| Equilibrium temperature | 1,907 K (1,634 °C) |
| Distance from Earth | 2,430.3 light-years (745.1 parsecs) |
| Constellation | Cepheus |
| Discovery method | Transit |
| Discovery facility | Transiting Exoplanet Survey Satellite (TESS) |
| Discovery year | 2026 |
Data: NASA Exoplanet Archive, last updated 2026-07-02. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About TOI-4034 b
Is TOI-4034 b habitable?
No — TOI-4034 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is TOI-4034 b?
TOI-4034 b is about 2,430 light-years from Earth in the constellation Cepheus. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 42,773,280 years to get there.
How big is TOI-4034 b compared to Earth?
TOI-4034 b has 17.71 times the radius of Earth and about 277 times its mass.
How long is a year on TOI-4034 b?
One orbit around TOI-4034 takes 1.8 Earth days — short enough that 203 of its years would fit into one Earth year.
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