PV Gap

Debra Said:

The following figures show four stages that occur during the formation of a one-solar-mass star.?

We Answered:

3. main-sequence star (hottest)
2. protostar with jets.
1. Contraction cloud trapping infrared light
4. molecular-cloud fragment (coolest).

Isaac Said:

what is the escape velocity of a 1 solar mass neutron star and how does that compare with the speed of light?

We Answered:

Escape velocity is given by
v = sqrt (2GM/r)
M is 1 solar mass, r is the radius of the neutron star which is typically in the 10-20km range.
The escape velocity must be less than the speed of light or the object would be a black hole.
It must be pretty high tho'

Derek Said:

Calculate the radius of a 10 solar mass star?

We Answered:

The Schwarzschild radius of a black hole is defined such that the escape velocity equals c. Viz,

GMm/r = 1/2mc^2

rearrange to find r:

r = 2GM/c^2

So plug in M=10*(2e30), c=3e8, and G=6.67e-11

Micheal Said:

how likely could a solar system have been formed with 2 planets in the living zone?

We Answered:

The more luminous the star the larger the habitable zone. See here for instance: http://astronomy.nmsu.edu/holtz/a110/res…
And with a larger habitable zone the chances that *two* planets are formed inside it increase. Furthermore, more massive stars might also have a more massive planetary disk, again increasing the chances of planets.

Bobby Said:

four stages that occur during the formation of a one-solar-mass star.?

We Answered:

1. Molecular-cloud fragment
2. Contracting cloud trapping infared light
3. Protostar with jets
4. Main-sequence star

All stars start out as giant molecular clouds more commonly referred to as the interstellar medium. This medium then contracts. Then it forms a protostar (proto here being a suffix meaning before). This protostar emits jets along its axis of rotation as matter gets sucked into it from the contracting cloud. It then is considered a main sequence star after it has finished forming so long as its mass and temperature are around the conditions of a main sequence (which a solar mass star would have).

Hope that helps! :)

Brandon Said:

What distance is in the warm zone around a 100 solar mass star?

We Answered:

You're looking at many tens or hundreds of AU, but even then such a star will be billowing off charged particles and emitting deadly radiation. They're just not good places for life whatsoever. Besides, the star would explode before life had even gotten a foothold.