---
title: "The NN Ser system"
url: "https://spacecatalog.org/system/nn-ser"
release: "DR1"
licence: "No licence stated; acknowledgement requested"
citation: "This research has made use of the NASA Exoplanet Archive, which is operated by the California Institute of Technology, under contract with the National Aeronautics and Space Administration under the Exoplanet Exploration Program. Cite Christiansen et al. (2025), Planetary Science Journal (doi:10.3847/PSJ/ade3c2), and the literature reference given with each value."
---

# The NN Ser system

NN Ser is a WD Wolf-Rayet star in Serpens, 1682 ly away, with 2 known planets. Their orbits run from 3.39 to 5.35 AU. All of them were detected by eclipse timing variations.

## The planets, innermost first

| Planet | Orbit (AU) | Period | Radius | Mass | Equilibrium T |
| --- | --- | --- | --- | --- | --- |
| [d](https://spacecatalog.org/object/nn-ser-d) | 3.39 | 7.885 yr | 13.30 R⊕ | 725 M⊕ | — |
| [c](https://spacecatalog.org/object/nn-ser-c) | 5.35 | 19.13 yr | 12.60 R⊕ | 2330 M⊕ | — |

Every figure is the planet's composite parameter from the [NASA Exoplanet Archive (Planetary Systems Composite Parameters)](https://exoplanetarchive.ipac.caltech.edu/cgi-bin/TblView/nph-tblView?app=ExoTbls&config=PSCompPars), one consistent set per world. Semi-major axes are orbits about the star, not distances from Earth.

This research has made use of the NASA Exoplanet Archive, which is operated by the California Institute of Technology, under contract with the National Aeronautics and Space Administration under the Exoplanet Exploration Program. Cite Christiansen et al. (2025), Planetary Science Journal (doi:10.3847/PSJ/ade3c2), and the literature reference given with each value.

## The host star

| Quantity | Value |
| --- | --- |
| CLASS | WD Wolf-Rayet star |
| SPECTRAL TYPE | WD |
| MASS | 0.535 M☉ |
| SURFACE TEMPERATURE | 57 000 K |
| DISTANCE FROM EARTH | 1682 ly |
| APPARENT MAGNITUDE | 16.94 |
| CONSTELLATION | Serpens |
| STARS IN SYSTEM | 2 |

The star itself: https://spacecatalog.org/object/nn-ser

The page itself, with the orbits drawn: https://spacecatalog.org/system/nn-ser