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Exoplanet · Neptune-like planet

TOI-421 c

TOI-421 c is a Neptune-like planet orbiting the star TOI-421. Its year lasts 16.1 Earth days. It was discovered in 2020 by the Transit method.

Host starTOI-421
Distance244.0 light-years (74.8 pc)
Orbital period16.1 days
Orbital radius0.117 AU
Eccentricity0.190
Radius5.09 R⊕ · 0.454 R♃
Mass14.1 M⊕ · 0.0444 M♃
Density0.59 g/cm³
Surface gravity0.544 × Earth
Equilibrium temperature635 K (362 °C)
Stellar flux received34.3 × Earth
Discovery methodTransit
Discovery year2020
Discovered byTransiting Exoplanet Survey Satellite (TESS)

Habitable zone

Inside the inner edge of the habitable zone: it receives 34.3 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 10.02. Visible from the whole Southern Hemisphere and north to latitude 76° N. South of latitude 76° S it never sets. It stands highest at midnight in December, the best time to observe it.

Light's journey

The light you see tonight set out around the year 1782. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 4.3 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.