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TOI-1288 c

Cold Gas Giant Habitable Zone Cepheus

TOI-1288 c is a cold gas giant orbiting TOI-1288 in the constellation Cepheus. It lies about 375 light-years from Earth and was discovered in 2022 using the radial velocity method. It orbits within the habitable zone of its star — the region where liquid water could exist on a planet's surface.

85.7×Earth mass
416 dOrbital period
0.38Earth similarity
375 lyDistance
2022Discovered

Is TOI-1288 c in the Habitable Zone?

TOI-1288 c orbits inside the conservative habitable zone of TOI-1288 — the region where a rocky planet could sustain liquid water on its surface. This makes it one of the most interesting known exoplanets in the search for life.

TOI-1288 c
Too hot Optimistic habitable zone Conservative habitable zone Too cold

Habitable zone of TOI-1288: 0.642–1.531 AU (conservative: 0.814–1.452 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 ›

Orbit and Year Length

A year on TOI-1288 c — one full orbit around TOI-1288 — lasts 416.0 Earth days, longer than an Earth year. It orbits at an average distance of 1.070 AU — comparable to the inner Solar System.

How Was TOI-1288 c Discovered?

TOI-1288 c was discovered in 2022 using the radial velocity method, with observations from Multiple Observatories.

The radial velocity method measures the subtle wobble of a star caused by the gravitational pull of an orbiting planet, visible as periodic shifts in the star's light spectrum. The size of the wobble reveals the planet's minimum mass.

How Far Away Is TOI-1288 c?

TOI-1288 c is 374.6 light-years (114.9 parsecs) from Earth. Light arriving here tonight left the planet around the year 1652. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 6,592,960 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-1288 c scores 0.38, ranking #569 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.

The Host Star: TOI-1288

TOI-1288

Surface temperature
5,388 K (Sun: 5,772 K)
Mass
0.96 M☉
Radius
0.96 R☉
Luminosity
0.7000 L☉
Age
6.5 billion years (Sun: 4.6)

The TOI-1288 Planetary System

TOI-1288 c is one of 2 known planets in the TOI-1288 system. Its siblings:

TOI-1288 c — Complete Data

Mass (best estimate)85.70 Earth masses
Orbital period416.00 days
Orbital distance1.070 AU
Earth Similarity Index0.38
Distance from Earth374.6 light-years (114.9 parsecs)
ConstellationCepheus
Discovery methodRadial Velocity
Discovery facilityMultiple Observatories
Discovery year2022

Data: NASA Exoplanet Archive, last updated 2024-07-22. Earth Similarity Index: PHL @ UPR Arecibo.

Frequently Asked Questions About TOI-1288 c

Is TOI-1288 c habitable?

TOI-1288 c orbits within the habitable zone of TOI-1288, the region where liquid water could exist on a planet's surface. It sits in the conservative habitable zone — the most promising region for habitability. Whether it is actually habitable depends on its atmosphere and composition, which remain unknown.

How far away is TOI-1288 c?

TOI-1288 c is about 375 light-years from Earth in the constellation Cepheus. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 6,592,960 years to get there.

How long is a year on TOI-1288 c?

One orbit around TOI-1288 takes 416.0 Earth days.

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