Your Eyes In Space Open the simulation

Exoplanet · Neptune-like planet

TOI-1803 c

TOI-1803 c is a Neptune-like planet orbiting the star TOI-1803. Its year lasts 12.9 Earth days. It was discovered in 2025 by the Transit method.

Host starTOI-1803
Distance388.9 light-years (119.2 pc)
Orbital period12.9 days
Orbital radius0.097 AU
Eccentricity0.000
Radius4.29 R⊕ · 0.383 R♃
Mass8 M⊕ · 0.0252 M♃
Density0.419 g/cm³
Surface gravity0.435 × Earth
Equilibrium temperature588 K (315 °C)
Stellar flux received22 × Earth
Discovery methodTransit
Discovery year2025
Discovered byTransiting Exoplanet Survey Satellite (TESS)

Habitable zone

Inside the inner edge of the habitable zone: it receives 22 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 3.9° across: 7.4 times the Sun as we see it from Earth.

In the sky

A telescope is needed to see it: its apparent magnitude is 12.03. Visible from the whole Northern Hemisphere and south to latitude 55° S. North of latitude 55° 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 1637. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 6.9 million years.

Planets in the same system

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.