Gliese 328
# Gliese 328

Gliese 328, also known as BD+02 2098, is a M-type main-sequence star located 66.9 light-years (20.5 parsecs) away in the constellation Hydra. Its surface temperature is 3989 K. Gliese 328 is depleted in heavy elements compared to the Sun, with a metallicity Fe/H index of −0.13. The age of the star is unknown. Gliese 328 exhibits an activity cycle similar to that of the Sun, with a period around 2000 d.

Multiplicity surveys did not detect any stellar companions as of 2016.

## Planetary system

In 2013, one superjovian planet, named Gliese 328 b, was discovered on a wide, eccentric orbit by the radial velocity method. The known planetary orbit is wide enough to not disrupt orbits of other bodies in the habitable zone of the star. In 2023, a second, Neptune-mass planet was discovered orbiting closer to the star.

The Gliese 328 planetary system :

| Companion (in order from star) | Mass | Semimajor axis (AU) | Orbital period (days) | Eccentricity | Inclination | Radius |
| - | - | - | - | - | - | - |
| c | ≥21.4+3.4 −3.2 $M_🜨$ | 0.657+0.026 −0.028 | 241.8+1.3 −1.7 | — | — | — |
| b | ≥2.51±0.23 $M_J$ | 4.11+0.16 −0.18 | 3771±17 | 0.227±0.015 | — | — |
