- weight
- 1.30 g
- sun
- 18.0× wider
- sky
- bright white
Illustration computed from this world’s measured and derived values, not a photograph.
HD 77946 b
HD 77946 b is a confirmed sub-Neptune exoplanet 324 ly from Earth in the constellation Ursa Major, discovered in 2024 by Transiting Exoplanet Survey Satellite (TESS).
Transit: spotted by the tiny, repeating dip in its star’s light each time the planet crosses in front of it.
Standing on HD 77946 b, you would weigh about 30% more than you do on Earth. Its yellow-white star looks 18.0× wider than ours, bathing the surface in bright white 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 6.5 days, and at an estimated 856°C (1572°F) it is furnace-hot.
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
A little heavier than home, at 1.3 times Earth's gravity. A child raised here would likely grow a little shorter and sturdier than their Earth-raised parents, about 0.95x as tall as on Earth: a 5 ft 10 in adult could stand nearer 5 ft 7 in, with denser bones.
- Bones
- Thick and dense
- More weight to bear forces the skeleton to grow denser and stronger all through childhood.
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 856°C (1572°F), sound would travel roughly 98% 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.
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.
- !Furnace-hot at around 856°C (1572°F), with no liquid water and no shade anywhere.
- Surface gravity is close to Earth's, 1.30 times, so you would move much as you do here.
- !Its star delivers about 413 times the sunlight Earth gets, a blinding, sterilizing glare.
- !Earth-similarity index 0.19: this world has almost nothing in common with our own.
- !Likely tidally locked: one hemisphere in endless day, the other in permanent night.
A playful read of HD 77946 b’s measured and computed values, not a real advisory.
How long to get there · 324 ly away
No other confirmed planets here yet. New ones auto-appear as telescopes report.
Zoom out: star → system → (soon) galaxy arm, host black hole, and a real image of the host galaxy.
Matched telescope & eyepiece recommendations are coming. Any product links will carry a clear affiliate disclosure.
What is the gravity on HD 77946 b?
HD 77946 b's surface gravity is about 1.3 times Earth's.
How much would you weigh on HD 77946 b?
Someone who weighs 150 pounds on Earth would weigh about 195 pounds on HD 77946 b.
How far is HD 77946 b from Earth?
HD 77946 b lies about 324 light-years from Earth.
How long would it take to get to HD 77946 b?
At the speed of NASA's Parker Solar Probe, the fastest craft ever built, the journey would take about 505,883 years.
How hot is HD 77946 b?
HD 77946 b's equilibrium temperature, the balance it reaches from its star's light alone before any greenhouse warming, is about 856°C (1572°F).
How long is a year on HD 77946 b?
HD 77946 b completes one orbit of its star in 6.5 days.
Illustration generated from HD 77946 b's confirmed parameters, not a photograph.