What it’s like to stand here
KELT-23 A b
weight
1.36 g
sun
30.0× wider
sky
warm white

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

KELT-23 A b

KELT-23 A b is a confirmed gas-giant exoplanet 412 ly from Earth in the constellation Ursa Minor, discovered in 2019 by KELT-North.

Transit: spotted by the tiny, repeating dip in its star’s light each time the planet crosses in front of it.

KELT-23 A
host star
14.83 R⊕
radius
298 M⊕
mass · measured
2.3 days
orbital period
1288°C (2350°F)
avg temp
Human scale

KELT-23 A b is a giant ball of gas with no solid surface to stand on; you would simply sink into ever-thicker cloud. Its yellow, Sun-like star looks 30.0× wider than ours, bathing the cloud tops in warm white light. A year passes in just 2.3 days, and at an estimated 1288°C (2350°F) it is hot enough to melt rock.

1.36 g
surface gravity (no solid surface · measured mass)
2.3 days
one year, in Earth time
30.0× wider
how big its sun looks vs ours
warm white
midday sky tint
0.7×
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 KELT-23 A b
Earth Similarity Index0.07#5,443 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
NO GROUND: A DRIFTER, NOT A WALKER

There is no ground here to grow up on, only bottomless sky. A child could never stand, walk, or even fall to a surface, because there isn't one. Under 1.4 times Earth's gravity and pressure that only climbs the deeper you go, anything built for this world would not look human at all: picture something closer to a deep-sea creature than a person, broad and buoyant, drifting through the cloud decks with no need for legs and no floor to land on.

Body plan
Floating, not upright
With no surface and no fixed up or down, a skeleton built for standing would be useless; a drifting, gas-filled body would not.
Build
Broad and pressure-hardened
Pressure rises without limit toward the interior, so anything alive would have to be built like a deep-sea animal, not a land one.

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 a thin, helium-fast squeak.

There is no surface to stand on; this is the sound at the cloud tops, where the air is mostly hydrogen and helium, the lightest gases there are. Sound races through them at about 2,811 metres per second, 8.3 times its Earth speed, flipping a voice into a thin, cartoon-helium squeak. The temperature behind that number is this world's computed equilibrium temperature; its real atmosphere is unknown. The demo plays the shift capped at 1.8x; the real effect would be even stronger.

sound speed ≈ 2811 m/s · 8.26× Earth

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
☆☆☆☆
Do not travel
  • !At about 1288°C (2350°F), the daytime side glows: metals run liquid and any atmosphere is being torn away.
  • !There is nowhere to land: no ground, no deck, only cloud that thickens into crushing pressure.
  • !Its star delivers about 991 times the sunlight Earth gets, a blinding, sterilizing glare.
  • !Earth-similarity index 0.07: this world has almost nothing in common with our own.

A playful read of KELT-23 A b’s measured and computed values, not a real advisory.

How long to get there · 412 ly away
Jet airliner
494 million years
dies en route1000-yr cryo: fails
Parker Solar Probethe fastest craft ever built
642,259 years
dies en route1000-yr cryo: fails
Light speed
412 years
dies en route1000-yr cryo: survives
Warp 10
150 days
arrives thriving
Folding spacetimeinstant, plus 1 hr of paperwork
1 hour
arrives thriving
Size vs Earth
EarthKELT-23 A b is 15× 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
SMALL TELESCOPE NEEDED
Host-star brightnessmag 10.3
ConstellationUrsa Minor
To see the host star4-6" (100-150 mm) telescope
Gear bridge

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

Common questions

What is the gravity on KELT-23 A b?

KELT-23 A b is a gas giant with no solid surface to stand on. At its cloud tops, gravity pulls about 1.4 times as hard as Earth's.

How far is KELT-23 A b from Earth?

KELT-23 A b lies about 412 light-years from Earth.

How long would it take to get to KELT-23 A b?

At the speed of NASA's Parker Solar Probe, the fastest craft ever built, the journey would take about 642,259 years.

How hot is KELT-23 A b?

KELT-23 A b's equilibrium temperature, the balance it reaches from its star's light alone before any greenhouse warming, is about 1288°C (2350°F).

How long is a year on KELT-23 A b?

KELT-23 A b completes one orbit of its star in 2.3 days.

Illustration generated from KELT-23 A b's confirmed parameters, not a photograph.