What it’s like to stand here
HD 216520 b
weight
≥ 1.01 g
sun
3.8× wider
sky
amber-orange

Illustration computed from this world’s measured and derived values, not a photograph.

HD 216520 b

HD 216520 b is a confirmed sub-Neptune exoplanet 63.8 ly from Earth in the constellation Cepheus, discovered in 2020 by Multiple Observatories.

Radial Velocity: spotted by the gravitational wobble the planet tugs in its star.

HD 216520
host star
3.18 R⊕
radius
10.26 M⊕
mass · minimum (m·sin i)
35 days
orbital period
209°C (408°F)
avg temp
Human scale

Standing on HD 216520 b, you would weigh roughly almost exactly what you weigh on Earth. Its orange dwarf looks 3.8× wider than ours, bathing the surface in amber-orange light. It is likely tidally locked, so that sun never moves in the sky: one hemisphere in endless day, the other in permanent night. A year passes in just 35 days, and at an estimated 209°C (408°F) it is blistering.

≥ 1.01 g
your weight (minimum mass only)
35 days
one year, in Earth time
3.8× wider
how big its sun looks vs ours
amber-orange
midday sky tint
1.0×
how high you could jump vs Earth
likely
likely tidally locked: probably eternal day on one side, night on the other
Calculate your exact weight on HD 216520 b
Earth Similarity Index0.42#1,096 of 5,788 ranked worlds

How closely this world matches Earth in size and warmth, from 0 to 1 (Earth = 1.0). Computed by gravityfinder. See every world ranked →

What these mean: surface gravity · tidal locking · equilibrium temperature · Earth similarity

If your children grew up herea playful thought experiment
EARTH HEIGHT≈ 1.00xEARTH-RAISEDRAISED HERE
much like Earth height

Gravity close to Earth's, at about 1.0 times. A child would grow up much as they would back home.

A playful thought experiment from this world’s gravity, not a prediction about any real person. No human has ever grown up off Earth, so no one truly knows; the direction (taller in low gravity, shorter and stockier in high) follows how growing bodies respond to weight.

Hear how a voice sounds herea computed acoustic demo

Your voice would sound high and thin, almost cartoonish.

Assuming Earth-like air at this world's temperature of about 209°C (408°F), sound would travel roughly 29% faster than on Earth, so your voice would sound high and thin, almost cartoonish. The real atmosphere is unknown, so this is a best guess.

sound speed ≈ 440 m/s · 1.29× Earth · assumes Earth-like air

A real voice sample, pitch-shifted (tempo held constant) to suggest the acoustics: a playful approximation, not a precise simulation. Voice: Lingua Libre / Vealhurl, CC BY-SA 4.0.

The journey
Cosmic travel advisory
★★★☆☆
For seasoned travelers
  • !Blistering at about 209°C (408°F), far too hot for liquid water on the surface.
  • Surface gravity is close to Earth's, at least 1.01 times, so you would move much as you do here.
  • !Likely tidally locked: one hemisphere in endless day, the other in permanent night.

A playful read of HD 216520 b’s measured and computed values, not a real advisory.

How long to get there · 63.8 ly away
Jet airliner
76.5 million years
dies en route1000-yr cryo: fails
Parker Solar Probethe fastest craft ever built
99,456 years
dies en route1000-yr cryo: fails
Light speed
64 years
dies en route1000-yr cryo: survives
Warp 10
23 days
arrives thriving
Folding spacetimeinstant, plus 1 hr of paperwork
1 hour
arrives thriving
Size vs Earth
EarthHD 216520 b is 3.2× the width of Earth
Explore from here · roam the neighborhood

Zoom out: star → system → (soon) galaxy arm, host black hole, and a real image of the host galaxy.

Can you see it tonight? · observe
BINOCULARS NEEDED
Host-star brightnessmag 7.5
ConstellationCepheus
To see the host star50 mm binoculars
Gear bridge

Matched telescope & eyepiece recommendations are coming. Any product links will carry a clear affiliate disclosure.

Common questions

What is the gravity on HD 216520 b?

HD 216520 b's surface gravity is at least 1.0 times Earth's, and possibly more: its mass is only a lower bound.

How much would you weigh on HD 216520 b?

Someone who weighs 150 pounds on Earth would weigh at least 152 pounds on HD 216520 b.

How far is HD 216520 b from Earth?

HD 216520 b lies about 63.8 light-years from Earth.

How long would it take to get to HD 216520 b?

At the speed of NASA's Parker Solar Probe, the fastest craft ever built, the journey would take about 99,456 years.

How hot is HD 216520 b?

HD 216520 b's equilibrium temperature, the balance it reaches from its star's light alone before any greenhouse warming, is about 209°C (408°F).

How long is a year on HD 216520 b?

HD 216520 b completes one orbit of its star in 35 days.

Illustration generated from HD 216520 b's confirmed parameters, not a photograph.