1. Jun 25, 2015

### cbrons

What could you tell me about humans exploring this planet? Would it be feasible? Or would it be far too dangerous? What would be the biggest problem here? I am assuming the star class means it gives off a fairly high amount of radiation.

Btw TY is "Earth years", "R" is x Earth radius, etc.

2. Jun 25, 2015

### phinds

With a radius of .82Km, this would not be a planet, it would be an asteroid, so I assume that's a typo

3. Jun 25, 2015

### Czcibor

I'm not sure whether I get those numbers correctly...

Orbital radius is 3 AU, so according to inverse square law this planet should receive 1/9 of the light that planet at 1 AU would receive...

...however Luminosity is 3.5, so roughly counting 3.5/9 of the light that Earth receive should go there...

Shouldn't such planet be rather cold? Or you boost temperature with huge amount of greenhouse gasses? Or I miss something?

4. Jun 25, 2015

### rootone

I think that if the object was that small it would be some kind of a black hole, (neutron star possibly), in which case a lot of the other parameters make little sense.

5. Jun 25, 2015

### cbrons

Sorry that was a typo. Should be 0.82 the size of Earth

6. Jun 25, 2015

### cbrons

Corrected:

7. Jun 25, 2015

Staff Emeritus
Um, the prefex T is for "tera" meaning a trillion, not "terra" meaning earth.

8. Jun 25, 2015

### Bandersnatch

The planet seems to be chosen to closely resemble Earth, so I don't see any problems. Increased gravity might be the most obvious issue affecting exploration teams, but more of a nuisance than an obstacle.
A reduced lifespan of the star puts a limit on the time the planet had to develop, though. It only had ~3.5 Gy tops to calm down geologically, develop life and produce all that free oxygen.

Following on Vanadium's comment: use the symbol ⊕ to denote Earth, just like you use ☉ for the Sun, to avoid confusion.

That seems to be within the habitable zone with high greenhouse effects. See here:
http://depts.washington.edu/naivpl/sites/default/files/index.shtml

Last edited: Jun 26, 2015
9. Jun 26, 2015

### Czcibor

You want to point me that planet is within outer edge HZ? Yes, it is. Just Cbrnos requested a tropical planet with average temperature of +32C.

If he wants a tropical planet around a hot star - sounds legit. The HZ shifted. Big part of oxygen comes from UV splitting water, what speed up oxygen catastrophe. Just such relation of luminosity and distance did not seem for me right for a hot planet.