Your Eyes In Space Open the simulation

Exoplanet · gas giant

TOI-3877 b

TOI-3877 b is a gas giant orbiting the star TOI-3877. Its year lasts 4.12 Earth days. It was discovered in 2025 by the Transit method.

Host starTOI-3877
Distance1,610 light-years (493.8 pc)
Orbital period4.12 days
Orbital radius0.0529 AU
Eccentricity0.220
Radius11.7 R⊕ · 1.04 R♃
Mass99.8 M⊕ · 0.314 M♃
Density0.342 g/cm³
Surface gravity0.732 × Earth
Equilibrium temperature1,445 K (1,172 °C)
Stellar flux received729 × Earth
Discovery methodTransit
Discovery year2025
Discovered byTransiting Exoplanet Survey Satellite (TESS)

Habitable zone

Inside the inner edge of the habitable zone: it receives 729 times the light the Earth does, too hot to keep liquid water on its surface.

Its star in the sky

In the planet's sky its star is a disc 14° across: 27 times the Sun as we see it from Earth.

In the sky

A telescope is needed to see it: its apparent magnitude is 12.34. Visible from the whole Northern Hemisphere and south to latitude 56° S. North of latitude 56° N it never sets. It stands highest at midnight in March, the best time to observe it.

Light's journey

The light you see tonight set out around the year 416. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 29 million years.

Open in the simulation

Data: NASA Exoplanet Archive, PSCompPars. Its look in the simulation is a rendering based on the measured radius, mass and temperature.