---
title: "The π Men system"
url: "https://spacecatalog.org/system/hd-39091"
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 π Men system

π Men is a G0V yellow main-sequence star in Mensa, 59.74 ly away, with 3 known planets. Their orbits run from 0.0684 to 3.28 AU. All but one were detected by radial velocity.

## The planets, innermost first

| Planet | Orbit (AU) | Period | Radius | Mass | Equilibrium T |
| --- | --- | --- | --- | --- | --- |
| [c](https://spacecatalog.org/object/pi-men-c) | 0.0684 | 6.268 d | 2.02 R⊕ | 3.63 M⊕ | 1170 K |
| [d](https://spacecatalog.org/object/pi-men-d) | 0.506 | 124.6 d | 3.72 R⊕ | 13.4 M⊕ | 444 K |
| [HD 39091 b](https://spacecatalog.org/object/hd-39091-b) | 3.28 | 5.719 yr | 12.30 R⊕ | 4480 M⊕ | 173 K |

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 | G0V yellow main-sequence star |
| SPECTRAL TYPE | G0V |
| MASS | 1.026 M☉ |
| RADIUS | 1.203 R☉ |
| SURFACE TEMPERATURE | 5856 K |
| LUMINOSITY | 1.61 L☉ |
| DISTANCE FROM EARTH | 59.74 ly |
| APPARENT MAGNITUDE | 5.65 |
| CONSTELLATION | Mensa |

The star itself: https://spacecatalog.org/object/hd-39091

The page itself, with the orbits drawn: https://spacecatalog.org/system/hd-39091