HR 8799

HR 8799

system

HR 8799 — a young, hot star ~134 light-years away in Pegasus, and a landmark of astronomy: FOUR of its giant planets have been DIRECTLY IMAGED — actual photographs of the worlds themselves, not indirect detections — and even filmed orbiting over years. Descend to see the imaged system.

Open in 3D viewSee HR 8799 in the live, interactive 3D map

Science

Classification

Type
Planetary system
Distance
~134 light-years · its real distance from the Sun
Explore
Descend to see the star and its confirmed planets

How we know

Note
A real star system, shown at its measured position in the galaxy. Its star and confirmed planets — their measured sizes and how each was found — are on the cards inside; descend to explore them. Distances follow Gaia parallax; planet data follow the NASA Exoplanet Archive.

Discovery & history

Name
A Yale Bright Star Catalogue number (HR 8799 = HD 218396); the star has no proper name.

In 2008, three planets (b, c, d) were directly imaged around HR 8799 — the first multiple-planet system ever photographed; a fourth, e, followed in 2010. Because the star is young (only ~30 million years), its giant planets are still hot and self-luminous, glowing enough in the infrared to be seen beside their star. Repeated images have since been assembled into a time-lapse of the four planets circling.

Images

A time-lapse of the four planets orbiting HR 8799, assembled from REAL telescope images (W. M. Keck Observatory) — actual photographs of the planets, not an artist's concept.
Jason Wang / Christian Marois (CC BY 3.0) · Wikimedia Commons
The HR 8799 planetary system imaged by the Hubble Space Telescope — a REAL photograph; the star's overwhelming light is masked so the planets show.
NASA / ESA / STScI (CC BY 4.0) · Wikimedia Commons

Images from open archives · credit shown per image