![HD 219134 f: 21 Light-Years Away](https://cdn.slatesource.com/9/8/f/98fe65e4-778a-4341-9c56-0f3f5ca8b3f9.webp) # HD 219134 f: 21 Light-Years Away - [Made in Slatesource](https://slatesource.com/@steph/hd-219134-f-21-light-years-away) - By [Steph](https://slatesource.com/@steph) - Created on Sep 19, 2026 ## Super-earth around HD 219134 It is 1.31 times Earth's radius, closest in size to Earth, and 7.3 times Earth's mass. A year there lasts 22.72 days, on an orbit 3 times closer to its star than Mercury is to the Sun. Its equilibrium temperature is 523 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 1.31 Earth radii Mass 7.3 Earth masses Equilibrium temperature 523 K (measured) One year 22.72 days Orbit radius 0.1463 AU Host star HD 219134 at 4699 K Distance 21 light-years **21.3** light-years: close enough to be a follow-up target What the archive holds on this planet 0% A measured radius. Yes. A measured mass. Yes. A density, the one clue to composition. No. A semi-major axis. Yes. An observed temperature. Yes. An eccentricity, so the orbit shape is known. Yes. What the wobble gives A minimum mass, from how fast the star moves toward and away from us. HD 219134 has 6 known planets. Systems like this are the ones where architecture can be studied instead of guessed at. 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. [NASA Exoplanet Archive: every published measurement of this planet](https://exoplanetarchive.ipac.caltech.edu/overview/HD%20219134%20f?utm_source=slatesource)