![HD 219134 d: 21 Light-Years Away](https://cdn.slatesource.com/d/b/d/dbda545a-ca24-4334-9d6d-e964ac816979.webp)

# HD 219134 d: 21 Light-Years Away

- [Made in Slatesource](https://slatesource.com/@steph/hd-219134-d-21-light-years-away)
- By [Steph](https://slatesource.com/@steph)
- Created on Sep 19, 2026

## Super-earth around HD 219134

It is 1.61 times Earth's radius, closest in size to Earth, and 16.2 times Earth's mass. A year there lasts 46.86 days, on an orbit 2 times closer to its star than Mercury is to the Sun. Its equilibrium temperature is 410 K, hotter than any desert. The host star HD 219134 runs at 4699 K with 0.81 times the Sun's mass.

journey·4 Planets

# HD 219134 from the inside out

Orbit

/

Planet

"super-Earth, 1015 K.

"super-Earth, 782 K.

"super-Earth, 523 K.

"super-Earth, 410 K.

Radius

1.61 Earth radii

Mass

16.2 Earth masses

Equilibrium temperature

410 K (measured)

One year

46.86 days

Orbit radius

0.2370 AU

Host star

HD 219134 at 4699 K

Distance

21 light-years

**21.3** light-years: close enough to be a follow-up target

The state of the record for this planet

0%

A radius from transit photometry. Yes.

A mass. Yes.

A density, the one clue to composition. No.

An orbital distance. Yes.

A temperature someone observed rather than calculated. Yes.

The shape of the orbit. Yes.

What the wobble gives

The pull of the planet on its star, which is a lower bound on its mass.

HD 219134 has 6 known planets. A crowded system is worth more than the sum of its planets: the timing of each transit constrains the others.

This planet was found by the wobble it induces in its star, which measures mass rather than size. A radius quoted for such a planet usually comes from a later transit or from a model.

Found by Roque de los Muchachos Observatory in 2015.

[NASA Exoplanet Archive: the full record for HD 219134 d](https://exoplanetarchive.ipac.caltech.edu/overview/HD%20219134%20d?utm_source=slatesource)