Can we explore white dwarfs with robotic missions?

[bostonnew]

Hi all,

If we develop the right kind of space ships, would it be possible to do non-human robotic missions to a white dwarf? What would it be like?

 

[mathman]

It would be very hot (that's why it is white) and the surface gravity would be very large (mass comparable to that of the sun in a planet sized volume).

 

[DaveC426913]

Here is an interesting little article from NASA about what it might be like on the surface of a white dwarf.

http://imagine.gsfc.nasa.gov/docs/science/know_l2/dwarfs.html

Note the 100,000g gravity. We won't be landing there anytime soon.

 

[bostonnew]

Ok, thanks.

What about red dwarfs or brown dwarfs? I'm just curious if we can ever visit a star. Do we know of any material that could withstand the kind of heat required?

 

[DaveC426913]

Ok, thanks.

What about red dwarfs or brown dwarfs? I'm just curious if we can ever visit a star. Do we know of any material that could withstand the kind of heat required?

We can certainly visit them. What would be accomplished by landing on them?

 

[Cosmo Novice]

We can certainly visit them. What would be accomplished by landing on them?

A melted spacecraft at the taxpayers expense?

I don't think conventional science can theoretically land on a star in answer to the original OP. You would need a magic technology like a star trek type "force field".

 

[Nabeshin]

Uhh, I think we are overlooking the fact that there is nothing to land on! Stars do not have a solid surface, so it's more like trying to land on Jupiter. And to get to anything resembling a solid surface, you have to go very deep down, then you have both pressure and ridiculous temperatures to contend with. Not possible, no.

 

[DaveC426913]

Uhh, I think we are overlooking the fact that there is nothing to land on! Stars do not have a solid surface,

White dwarfs are not normal stars. It is hypothesized that they do indeed have solid surfaces of crystalized carbon and oxygen under a thin atmo of hydrogen and helium.

 

[Ryan_m_b]

This reminds me of the novel Dragon's Egg by Robert Forward. In it a neutron star passes close by the solar system and humanity seizes on this opportunity to do some study and send a manned ship. Upon arrival they find that the surface is covered in life made from nuclear matter, the effect of this is that they are very small and 'chemical' reactions occur 1,000,000 times faster. Within a day some tribal life has evolved to a space faring race.

In all seriousness though the gravity will be so huge that any material capable of withstanding it is unlikely to be able to do any complex activity, in combination with the heat it's extremely unlikely that we could land some sort of vehicle. You would probably have to build the probe out of the material the star is made out of.

 

[qraal]

Ok, thanks.

What about red dwarfs or brown dwarfs? I'm just curious if we can ever visit a star. Do we know of any material that could withstand the kind of heat required?

Red dwarfs would be just cool enough for some engineering materials to endure, while brown dwarfs would be a piece of cake. The gravity is very high on both, but not impossibly so. However neither have surfaces to land on.

 

[qraal]

One possibility is the equatorial low-gee belt of a neutron star. Some are rotating fast enough to cancel most of their gravity and create conditions suitable for normal matter to exist in. Stephen Baxter has written a couple of SF stories using that concept in his Xeelee sequence.

 

[Nabeshin]

White dwarfs are not normal stars. It is hypothesized that they do indeed have solid surfaces of crystalized carbon and oxygen under a thin atmo of hydrogen and helium.

Interesting, I suppose it sort of makes sense. I'm wondering, do you know of a place to find the density profile for these compact objects? I was under the (completely unfounded) impression that they had a (relatively) large gaseous envelope and slowly transitioned to higher densities rather than a well defined surface like the Earth.

 

[qraal]

Interesting, I suppose it sort of makes sense. I'm wondering, do you know of a place to find the density profile for these compact objects? I was under the (completely unfounded) impression that they had a (relatively) large gaseous envelope and slowly transitioned to higher densities rather than a well defined surface like the Earth.

There's dozens of papers on them from the last decade alone. White dwarfs are very popular astrophysical objects as the physics is pretty straight forward. Just Google or hit the ADS or the ArXiv.