Orbit10 AU, about 24 yearsabout Saturn's distance from the Sun[1]
Temperature≈ 1 600–1 700 K (1 330–1 430 °C)heat left over from its formation[2]
Day lengthabout 8–9 hoursfirst exoplanet day ever measured, 2014[2]
Ageabout 23 million yearsthe star's age; the planet may be younger[2]
Discovered2008direct imaging, VLT; Lagrange et al.[2]
About the image. Drawn as a young giant glowing dull orange-red inside an edge-on dust disk. The planet's temperature and the disk's orientation are measured; telescopes see the planet only as a point of light, so its surface is imagined.
0.2×as wide as our Sun looks from Earth
9%of the light Earth gets
No ground: the view from the cloud tops
The sky from Beta Pictoris b
Beta Pictoris would look 0.2× as wide as the Sun does from Earth, smaller than our Sun, and the planet gets 9% of the light Earth gets from the Sun.
Its colour comes from its surface temperature of 8 039 K (7 770 °C); the Sun's is about 5 772 K (5 500 °C).
Beta Pictoris b spins fast: its day lasts about 8 to 9 hours, the first day length ever measured for an exoplanet.
Apparent size = star radius ÷ orbit; light = size² × (temperature ÷ 5 772 K)⁴. Both from the values on this page. The landscape is imagined.
Most exoplanets are known only from what they do to their star: a dip in its light or a wobble in its motion. Beta Pictoris b is one of the few that has been photographed. It shows up as a faint point of light beside Beta Pictoris, a young star in the southern sky that you can see with the naked eye.
Found in an old picture
The planet was hiding in an image taken in 2003 with the Very Large Telescope in Chile. When Anne-Marie Lagrange’s team re-processed it in 2008, they spotted a faint source near the star. In late 2009 and early 2010 they saw it again, now on the other side of the star, proving it was an orbiting planet. It orbits at about 10 AU, roughly Saturn’s distance from the Sun, and takes about 24 years to go around.
A baby planet
Beta Pictoris is only about 23 million years old, and the planet may have finished forming just a few million years ago. It is still hot from its own formation, around 1 600 to 1 700 K (1 430 °C), and glows in infrared light, its atmosphere thick with dust and clouds. It lies almost exactly in the plane of the star’s enormous dust disk, which is seen nearly edge-on from Earth, and is aligned with a warp in the disk’s inner part.
The first exoplanet day
In 2014 Ignas Snellen and colleagues measured how the planet’s light is smeared by its spin and worked out that its equator moves at about 25 kilometres per second. That makes its day about 8 hours long, the first day length ever measured for an exoplanet. Later measurements, including one with the James Webb Space Telescope, put it at about 9 hours. A second planet, Beta Pictoris c, orbits closer to the star.
How far out it would be
Beta Pictoris b goes around once every 24 years, at 10.07 AU from its star. Dashed circles show Jupiter and Saturn around the Sun, on the same scale.
Beta Pictoris b: atmosphere, still hot from its formation. Logarithmic scale from 100 K to 10 000 K. Reference values: NASA, IAU.
How long to get there?
Beta Pictoris b is about 64 light-years away.
Light299 792 km/s64 years
Breakthrough Starshotplanned light sail, 20% of light speed320 years
Parker Solar Probefastest spacecraft so far, 192 km/s99 931 years
Voyager 1leaving the Solar System, 17 km/s1.1 million years
At Voyager 1's speed the trip would take about 14 108 human lifetimes of 80 years. Bars are on a logarithmic scale. Speeds: NASA, Breakthrough Initiatives.
Gallery
A bright white star at the centre of a long, thin, edge-on disc of pale dust, with a small reddish planet inside it, an impression of Beta Pictoris b and its debris disc. AI-generated painting.A banded orange-brown gas giant filling the right of the frame, with a small bright white star at its left edge, an impression of Beta Pictoris b. AI-generated painting.Beta Pictoris b, 3D artist's impression, rendered from the interactive model.Beta Pictoris b, 3D artist's impression, from another angle, rendered from the interactive model.Beta Pictoris b, 3D artist's impression, close-up, rendered from the interactive model.
Timeline
2003Captured in a VLT image, unnoticed for five years.
2008Spotted when the image is re-processed.
2010Seen on the other side of the star, confirming it orbits.
2014Its spin is measured: a day of about 8 hours.
Questions people ask
Has Beta Pictoris b been photographed?
Yes. It is one of the few exoplanets imaged directly, seen as a point of light beside its star.
How old is Beta Pictoris b?
Its star is about 23 million years old, and the planet may be only a few million years old.