Environment around a star becoming a red giant

[SPBS]

Hello all,

 

I am hoping that you may be able to save my skin. I have tried to find the information out myself as a layman in this, but the only resources I can find are terribly basic or beyond my understanding.

 

Basically, I am writing a piece of fiction and I have a background environment within which I need certain things to occur, but they must be as plausible as possible. In order for me to accomplish this I need to know a couple of things… which is where you come in!

 

 

The environment:

 

a) A star roughly 1 solar mass has entered into its Red Giant phase and has expanded enough to make a particular planet (not earth, but roughly the same size and mass as earth) virtually uninhabitable. Most of the water on its surface has boiled away, and all the flora and fauna has died off apart from an advanced technological society that (for the intentions of the story) have recently abandoned the planet.

 

b) A Black Hole has entered the solar system and has begun devouring it piece by piece (the planet in question is on the other side of the sun until the end of the piece that I am writing).

 

The questions:

 

1) If the sun has grown enough for the water to have evaporated and the flora and fauna to have died off, would the temperature on the surface be too hot for a human being to survive for short periods of time (protected by a fictional but realistic environmental suit)?

 

2) How would the growth of the sun and possible changes in its emissions affect: a) the magnetosphere of the planet in question? And b) the radiation in orbit around the planet (for the purpose of a shuttle craft and its human passengers?

 

3) How many solar masses would the singularity at the center of the black hole have to be the equivalent of, in order to be realistic for the purpose of the story?

 

4) If the Black hole has begun dismantling the solar system already then is it already too late, and everything would be within the event horizon?

 

 

 

I appreciate any help anyone may be able to give me on this. It may be fiction but I would like to base it on as much scientific realism as I can.

 

 

Of course if I need to give any more details in order to answer the questions I will, but I have to be careful as Agents and publishers can be funny about submissions and an IP being in the public domain before they have them…

 

 

Many thanks in advance and I look forward to, hopefully, reading any replies!

[pavelcherepan]

 

 

a) A star roughly 1 solar mass has entered into its Red Giant phase and has expanded enough to make a particular planet (not earth, but roughly the same size and mass as earth) virtually uninhabitable. Most of the water on its surface has boiled away, and all the flora and fauna has died off apart from an advanced technological society that (for the intentions of the story) have recently abandoned the planet.

 

Earth has been losing water since the end of Late Heavy Bombardment and might run out of water in the next 2-3 billion years, well before Sun turning red giant. Most of the atmosphere might go as well.

 

https://en.wikipedia.org/wiki/Future_of_the_Earth#Loss_of_oceans

 

 

 

1) If the sun has grown enough for the water to have evaporated and the flora and fauna to have died off, would the temperature on the surface be too hot for a human being to survive for short periods of time (protected by a fictional but realistic environmental suit)?

 

By the time Sun-like star turns full-on Red Giant, Earth-like planet will be scorched completely with surface temperatures exceeding couple thousand degrees. And there will be lava everywhere. But if your fictional environmental suit can handle those temperatures, then no problem. You can walk on lava without sinking.

 

 

 

2) How would the growth of the sun and possible changes in its emissions affect: a) the magnetosphere of the planet in question? And b) the radiation in orbit around the planet (for the purpose of a shuttle craft and its human passengers?

 

Not sure I understand. Growth of the star would be a lengthy process spanning millions of years. As for other things: magnetosphere will be no more and radiation of some ridiculous levels. Shuttle will have to have some extremely efficient cooling to not get destroyed.

 

 

3) How many solar masses would the singularity at the center of the black hole have to be the equivalent of, in order to be realistic for the purpose of the story?

 

Reasonable number would be >3 solar masses if a black hole is a result of normal star evolution, not some crazy scientific experiment.

 

 

4) If the Black hole has begun dismantling the solar system already then is it already too late, and everything would be within the event horizon?

 

No. Black holes will rip apart objects well before reaching event horizon due to tidal forces, but that depends on the type of Black Hole. In super massive black holes you might already be inside the event horizon and still not register any effects.

[SPBS]

Thank you very much for your reply.

 

I have managed to find a few bits out from some lucky finds through searches but your answers have helped with the bits I couldn't quite find.

 

The ability for the story to be 'within reasonable plausibility' means that I will have to change a few aspects of the set up for the sequence of events. Maybe something along the lines of the sun 'just' entering the sub giant stage or something so that the luminosity has almost risen to about the 10% increase point.

 

I think I'm going to have to read a little more on black holes to get a better grasp though. The amount of times I've come up with ideas for some kind of 'grand imagery' and then found out that That it would just be outside the realms of Sci-fi and entered too far into science fantasy.

 

Damn Imagination... always runs away with me!

 

Many thanks again!