---
title: "The LHS 1678 system"
url: "https://spacecatalog.org/system/lhs-1678"
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 LHS 1678 system

LHS 1678 is an M2.0 V red star in Caelum, 64.83 ly away, with 3 known planets. Their orbits run from 0.0124 to 0.0400 AU. All of them were detected by transit.

## The planets, innermost first

| Planet | Orbit (AU) | Period | Radius | Mass | Equilibrium T |
| --- | --- | --- | --- | --- | --- |
| [b](https://spacecatalog.org/object/lhs-1678-b) | 0.0124 | 0.8602 d | 0.69 R⊕ | 0.35 M⊕ | 830 K |
| [c](https://spacecatalog.org/object/lhs-1678-c) | 0.0327 | 3.694 d | 0.94 R⊕ | 1.4 M⊕ | 511 K |
| [d](https://spacecatalog.org/object/lhs-1678-d) | 0.0400 | 4.965 d | 0.98 R⊕ | 0.907 M⊕ | 463 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 | M2.0 V red star |
| SPECTRAL TYPE | M2.0 V |
| MASS | 0.345 M☉ |
| RADIUS | 0.329 R☉ |
| SURFACE TEMPERATURE | 3490 K |
| LUMINOSITY | 0.0145 L☉ |
| DISTANCE FROM EARTH | 64.83 ly |
| APPARENT MAGNITUDE | 12.60 |
| CONSTELLATION | Caelum |
| STARS IN SYSTEM | 2 |

The star itself: https://spacecatalog.org/object/lhs-1678

The page itself, with the orbits drawn: https://spacecatalog.org/system/lhs-1678