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NN Ser c

Cold Gas Giant Serpens

The parameters of this planet are disputed or ambiguous in the scientific literature.

NN Ser c is a cold gas giant orbiting the WD star NN Ser in the constellation Serpens. It lies about 1,682 light-years from Earth and was discovered in 2010 using the eclipse timing variations method.

3,086×Earth mass
6,987 dOrbital period
1,682 lyDistance
2010Discovered

Is NN Ser c in the Habitable Zone?

The position of NN Ser c relative to the habitable zone of NN Ser cannot be precisely determined from the available orbital data.

Orbit and Year Length

A year on NN Ser c — one full orbit around NN Ser — lasts 6,987.0 Earth days, longer than Jupiter's 12-year orbit. Its orbit is mildly elliptical (eccentricity 0.09).

How Was NN Ser c Discovered?

NN Ser c was discovered in 2010 using the eclipse timing variations method, with observations from Multiple Observatories.

Eclipse timing variations detect a planet orbiting an eclipsing pair of stars: the planet's gravity shifts the precise moments when the stars eclipse each other.

How Far Away Is NN Ser c?

NN Ser c is 1,682.4 light-years (515.8 parsecs) from Earth. Light arriving here tonight left the planet about 1,682 years ago. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 29,610,240 years to make the journey.

The Host Star: NN Ser

NN Ser c is a circumbinary planet — it orbits around two stars at once, like Tatooine in Star Wars.

NN Ser

Spectral type
WD
Mass
0.54 M☉

The NN Ser Planetary System

NN Ser c is one of 2 known planets in the NN Ser system. Its siblings:

NN Ser c — Complete Data

Mass (best estimate)3,086.11 Earth masses
Orbital period6,987.00 days
Eccentricity0.089
Distance from Earth1,682.4 light-years (515.8 parsecs)
ConstellationSerpens
Discovery methodEclipse Timing Variations
Discovery facilityMultiple Observatories
Discovery year2010

Data: NASA Exoplanet Archive, last updated 2025-12-18. Earth Similarity Index: PHL @ UPR Arecibo.

Frequently Asked Questions About NN Ser c

Is NN Ser c habitable?

NN Ser c is not known to orbit within the habitable zone of NN Ser, and as a cold gas giant it is an unlikely candidate for life as we know it.

How far away is NN Ser c?

NN Ser c is about 1,682 light-years from Earth in the constellation Serpens. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 29,610,240 years to get there.

How long is a year on NN Ser c?

One orbit around NN Ser takes 6,987.0 Earth days.

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