Question about Class F stars

I’ve been working on a hard science fiction project and I’ve been trying to figure out several things.

- How far away would a planet have to be if it was orbiting a Class F star (specifically 2.0 the luminosity of Sol) and be within the habitual zone to the point of having similar temperatures to Earth?

- And, how would that effect the seasons (assuming this world has a similar axial tilt to Earth.)

The only thing I've managed to discover about Class F stars is that plants on a planet in orbit around a Class F star would be orange or red instead of green.

Originally posted by Autokrat
- How far away would a planet have to be if it was orbiting a Class F star (specifically 2.0 the luminosity of Sol) and be within the habitual zone to the point of having similar temperatures to Earth?

Lets see.

For a star with double the luminosity of Sol at 1AU it looks twice as bright and at 2AU it looks half as bright as Sol (inverse square law).

So the apparent luminosity should be the same at 1.41 AU.

Originally posted by Autokrat
- And, how would that effect the seasons (assuming this world has a similar axial tilt to Earth.)

The seasons would be identical, just longer.

Originally posted by Autokrat
The only thing I've managed to discover about Class F stars is that plants on a planet in orbit around a Class F star would be orange or red instead of green.

Why is that?

Oh and it should be "affect", not "effect", might come in handy during the writing of the story.

Originally posted by Symmetric Chaos
Lets see.

For a star with double the luminosity of Sol at 1AU it looks twice as bright and at 2AU it looks half as bright as Sol (inverse square law).

So the apparent luminosity should be the same at 1.41 AU.

The seasons would be identical, just longer.

Why is that?

Thanks for the help. The reason the plants would be orange and red is because apparently chlorophyll wouldn't be as efficient for photosynthesis due to the different wavelengths of light from a Class F star. I'm not sure what would replace it, but from all the sites I've visited I found the same thing that plants would use some kind or orange or red pigment.

Originally posted by Symmetric Chaos
Lets see.

For a star with double the luminosity of Sol at 1AU it looks twice as bright and at 2AU it looks half as bright as Sol (inverse square law).

So the apparent luminosity should be the same at 1.41 AU.

The seasons would be identical, just longer.

You beat me to it. Good work.

Originally posted by Symmetric Chaos
Why is that?

A class F star is hotter than a class G. Our sun is a class G. The hotter the star, the higher up the spectrum the star's light is. A class F would be a mostly white star.

So, a different "material" would have to be used to collect the sunlight.

I would think that black would be the best choice in any form of "visible" light stars.

So, it would be mavrophyll? lulz.

There could also be materials in the mavrophyll that would absorb light out side of the visible spectrum. That would be even cooler.

As to what he's talking about, I'm not sure. The reasons for not using the "green" portions of the EMS are not factually known beyond stupid purple bacteria from back in the day. Hell, there are things out there like red algae that don't use Red as much as the green plants do. It's just something that happened.

Geeks.

Originally posted by Autokrat
I’ve been working on a hard science fiction project...

Originally posted by Mindship
Worldbuilding? Novel?

Worldbuilding for a book yes.

Cool. Enjoy.

Originally posted by dadudemon

There could also be materials in the mavrophyll that would absorb light out side of the visible spectrum. That would be even cooler.

As to what he's talking about, I'm not sure. The reasons for not using the "green" portions of the EMS are not factually known beyond stupid purple bacteria from back in the day. Hell, there are things out there like red algae that don't use Red as much as the green plants do. It's just something that happened.

I vaguely remember you and I having a similar discussion before and also discussing Silicon rather than Carbon based life.

Originally posted by jaden101
I vaguely remember you and I having a similar discussion before and also discussing Silicon rather than Carbon based life.

Yup.

The algae discussion was one we had about oceanic deserts in the conspiracy forum about the "bloop". The other one we discussed about carbon based and silicon based lifeforms, occurred in here, the GDF, in the thread about life on mars and the Phoenix Rover.

Originally posted by Rogue Jedi
Geeks.

Says you.

Originally posted by tom_servo
Says you.

Thanks for sharing this valuable information