A news release last week reported what may seem self-evident to most planet hunters: white dwarf stars are lousy places to go looking for inhabited worlds. However, we've learned that exoplanets are so eclectic, that we should never say never.
A white dwarf is the burned-out dense core of a sunlike star that has collapsed under gravity. It's conceivable that planets could wind up orbiting close enough to the dwarf to be warmed by its feeble radiation.
But the odds of them being habitable are very unlikely, concludes Rory Barnes of the University of Washington and René Heller of Germany’s Leibniz Institute for Astrophysics Potsdam in a report in the November edition of Astrobiology. The researchers looked at two planets know to orbit a white dwarf in or near its habitable zone. They predict that tidal heating from their close passage to the white dwarf will desiccate the planets and leave them sterile.
But I'd say not so fast. If there's one thing we've learned from exoplanet discoveries is that we live in a compulsive universe where anything is possible so long as it doesn't violate the laws of physics and chemistry.
One reason not to write off white dwarfs is that, as slowing cooling embers, they release energy for billions of years. Over that vast time-span almost anything can happen.
In the first billion years of its existence the white dwarf cools rapidly and the habitable zone shrinks like a tightening noose. But the cooling rate slows between 4 and 7 billion years, leaving plenty of time for interesting things to happen on a planet.
A super-civilization that has reach a level of social and technological maturity that makes them virtually immortal, could have a long-term plan for surviving through the star's late stages of evolution. They would have to shuffle planet orbits to set up worlds that are livable as the star’s habitable zone shifts outward and then inward as stellar brightness rises and fall.
The final stage might be to target asteroid flybys to exchange momentum with a large icy moon and cause it to fall toward the white dwarf. Alternatively, aliens might fashion a compact Dyson Sphere to encase the dwarf. Such astroengineering would buy the civilization billion of years more to remain in their home star system.
Assuming a habitability niche could be created, living conditions around a simmering white dwarf would be more placid than around a petulant star with its seething electromagnetic storms.
Now if your argument was that doesn't seem very easy to do, I'd agree, but it seems like they did address the concern you raised.
Originally posted by mcx1942
They would have to shuffle planet orbits to set up worlds that are livable as the star’s habitable zone shifts outward and then inward as stellar brightness rises and fall.
Originally posted by iforget
reply to post by wmd_2008
true but then a white dwarf would provide a stable energy source after all those good times we could guess that a race that is able to survive so long might be handy at finding and exploiting the advantages of any given situation
maybe you could pull back to any icy moon around a favorably positioned gas giant and then use the same moon or comets to effuse your toasted little cinder of a planet with more water
In this talk, I would like to speculate a little, on the development of life in the universe, and in particular, the development of intelligent life. I shall take this to include the human race, even though much of its behaviour through out history, has been pretty stupid, and not calculated to aid the survival of the species. Two questions I shall discuss are, 'What is the probability of life existing else where in the universe?' and, 'How may life develop in the future?'
This mechanical life could also be self-designing. Thus it seems that the external transmission period of evolution, will have been just a very short interlude, between the Darwinian phase, and a biological, or mechanical, self design phase. This is shown on this next diagram, which is not to scale, because there's no way one can show a period of ten thousand years, on the same scale as billions of years. How long the self-design phase will last is open to question. It may be unstable, and life may destroy itself, or get into a dead end. If it does not, it should be able to survive the death of the Sun, in about 5 billion years, by moving to planets around other stars. Most stars will have burnt out in another 15 billion years or so, and the universe will be approaching a state of complete disorder, according to the Second Law of Thermodynamics. But Freeman Dyson has shown that, despite this, life could adapt to the ever-decreasing supply of ordered energy, and therefore could, in principle, continue forever.
Dubbed 55 Cancri e, the rocky world is only twice the size of Earth but has eight times its mass—classifying it as a "super Earth," a new study says. First detected crossing in front of its parent star in 2011, the close-in planet orbits its star in only 18 hours. As a result, surface temperatures reach an uninhabitable 3,900 degrees Fahrenheit (2,150 degrees Celsius)—which, along with carbon, make perfect conditions for creating diamonds.
A newly discovered alien planet that formed from a dead star is a real diamond in the rough.
The super-high pressure of the planet, which orbits a rapidly pulsing neutron star, has likely caused the carbon within it to crystallize into an actual diamond, a new study suggests.
The composition of the planet, which is about five times the size of Earth, is not its only outstanding feature.
Orbiting only about three million miles out from its star, the Jupiter-size gas giant planet, dubbed TrES-2b, is heated to 1,800 degrees Fahrenheit (980 degrees Celsius). Yet the apparently inky world appears to reflect almost none of the starlight that shines on it, according to a new study.
About 153 light-years from Earth, planet HD 209458b hugs its star so tightly that the planet's atmosphere is likely a scorching 2,000 degrees Fahrenheit (1,093 degrees Celsius) an a year passes in just 3.5 days—making Mercury's 88-day orbit seem downright leisurely.
That tight orbit also means this gas giant—meaning it's made primarily of gas—is subjected to blistering forces from its host star, which scientists say are the cause of HD 209458b's comet-like tail.
Ultimately this scenario would be plausible, but not exactly a good personal investment since you’d be dead long before you’d be able to reap the benefits. A long term strategy for the survival of a space faring species perhaps, but not a quick fix to toss down colonies and outposts.
Aliens could conceivably live on planets illuminated by the swirling mass of photons orbiting the singularity of a special type of black hole, according to a new theory.
Certain black holes are charged and rotate, and they possess a region past the event horizon — the point of no return — in which the fabric of spacetime appears normal again. This is called the inner Cauchy horizon.
Against a background of such all-encompassing finitude, today's apocalyptic visions start to pale. But they remain the more frightening for their proximity: Destruction by asteroid could come tomorrow, but the cosmological Dark Era won't arrive for about 10,000 trillion trillion trillion trillion trillion trillion trillion trillion years.
The one we're living in now, full of stars with planets and moons, asteroids and comets, galaxies and clusters. Most stars existing now will burn themselves out over the next 20 or 30 billion years. New stars will cease to form after about 100 trillion years, and the Stelliferous Era will end.
In the wake of stellar burnout, the cosmos is a dimly lit shadow of today's--so dim that, to the human eye (if there were any to see), it would seem black. All that remains are the corpses of former stars and the dead hulks that never became stars: black holes, brown dwarfs, white dwarfs, neutron stars. As the ages roll on, protons decay. Atoms evaporate. After 100 trillion trillion trillion years or so, the universe is nearly unrecognizable--devoid of matter as we know it, and utterly dark.
Defined by one familiar feature, black holes, which continue to devour nearby particles and grow larger. Slowly--very, very slowly--black holes radiate their energy away, until they disappear. At that point, some 100 trillion trillion trillion trillion trillion trillion trillion trillion years from now, there's nothing left but a diffuse sea of electrons, positrons, neutrinos, and radiation.
Possibly the end of it all. Without significant physical processes generating movement or change, the cosmos may exist in that flat, lifeless, lightless state for eternity. Or something totally unforeseen could take place. That far in the future, even the astrophysicist's speculative tools break down. All we know is it won't be a place for Homo sapiens or their descendants if they resemble, however remotely, the life forms of today.
These wandering planets are so dark and distant they are currently essentially impossible to detect using regular techniques, so we don’t know if any are in our galactic neighborhood or not. The only way to get a grip on how close one might be is to look at it in a statistical sense: on average in the galaxy, how many of these planets are there per cubic light year of space? Then we can fiddle with the number a bit to see how far away one of these planets could be.