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Comment by callamdelaney | Hacker News Reader

Just because it's bigger doesn't mean that the gravity is higher.

Correct, but it’s mass (weight) is 3x higher than earth’s, and since gravity is proportional to mass, you’d likely be much heavier there. If the radius of the planet was the same as earth’s, the gravity would be 3x higher, but if it’s bigger than earth, it might not be as bad. The formula is g= m/r^2 , where m is the mass of the planet and r is the radius of the planet.

r^2 is around 2.3 for the alleged size so it won't be too big a difference.

Damn I'm gonna have to get serious about that diet before visiting :'(

The gravity on the surface should be 3,02÷(1,55^(2)) times the gravity on earth. It is equal to ~1.257 so it's about 25% higher.

Yeah, but look at its period:

>>>ts mass is 3.02 Earths, it takes 19.3 days to complete one orbit of its star, and is 0.083 AU from its star. Its discovery was announced in 2023

https://i.imgur.com/ghLnFrH.png

What would gravity be on that thing, it doesnt say what its circadian rhythm is.. so how long is a day, if a "year" is 19 earth days (or is the period in 'day' local-solar-system-days?)

Orbital period is in Earth days. The same as when we say the orbital period of Venus is 225 days even though a Venetian day is longer than that.

It'd be pretty messy to instead define things in the database in object relative terms, particularly when you usually know things like the orbital period with significantly more accuracy than rotational velocity.

Well yeah, Venus is in our solar system.

Thanks, though - I wasn’t sure if we always use a local reference but then au is as local a unit as possible at these scales.

It's probably tidally locked, so the day will be the same as the year.

”Its mass is 3.02 Earths.”

Right, but you also have to account for density when calculating surface gravity.

TOI-715 b has a log g value of 5.0 +/- 0.2. Earth is 2.992.

Good to know. Thanks!

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