Inhabited worlds around red zwergsterne?
Harald fence 20.02.2006
SETI researchers and astrobiologists reorient one’s opinion and believe that on planets, which circle m-m-Zwergsterne so mentioned intelligent life could exist
After the recent discovery of a Exoplaneten around one of the m-m-Zwergsterne, which also generally call astronomers red dwarves (down load The “second earth” on the trace), the question at topicality wins whether stellar bodies of this design could be the suns of inhabited planets at the same time. Since m-dwarves are much light and mass-poor, SETI researchers and astrobiologists gave in the past however only little attention to such objects. In the meantime they believe however that there could be a large number of habitable planets around red dwarves, on which to even highly developed civilizations to exist could. Computer simulations speak for it. SETI wants to modify therefore its old search strategy immediately, particularly since red dwarves are very long-lived and place 70 per cent of the stars in the Milky Way.
[ extern]
In the cosmic “ether” the control room prevails the terrestrial from [ extern] SETI researcher out seen, which look for look out for 45 years handstruggling for an extraterrestrial message in the form of radio signals and hold recently even for light signals, the large silence. To date with them from the depths of the universe neither a Kosmogramm with extraterrestial sender still another artificially generated light signal were received, let alone an intelligent beep. But regardless of all problems and the relatively small probability on success the SETI Protagonisten operating world-wide looks further persistently for light and radio signals of intelligent extraterrestial provenance.
Search for the correct search
All SETI astronomers proceed from a maxim, which leads the moment of the eventuality of its Observationen drastically before eyes: Who does not wait at the correct coast region at the right time, in order to gather the unknown stranded goods, goes out empty, since radio signals do not wait, but to constantly further-pull and with increasing distance over a ever larger radius in the universe distribute themselves. Which formerly the antenna as bundled, intensive jet leaves, arrives with the unknown addressee as extremely weak impulse, as the jet of a flashlight. The further this from its source is distant, he becomes the weaker. Also that [ extern] SETI Optical Program, which holds after strongly bundled laser lightnings of artificial origin look out, is faced with the same problem. Finally also light waves (like radiowellen) zerstreuen themselves over very large distances.
ESO 269-57 – so the catalog number of the 155 million light-years removed convenient spiral galaxy in the constellation bull (Centarus). With a diameter of 200,000 light-years it is approximately twice as large like our galaxy, in which at least an intelligent civilization is resident. How can many have lived or live in this world island? (picture: ESO)
The classical search method via radiowellen saves still further problems. Thus many SETI projects focused themselves so far on those [ extern] 21-Zentimeter-Wasserstofflinie, which is regarded also today still as cosmic standard frequency, on which extraterrestial Intelligenzen could send. For a search for artificial radio signals the long-wave range of the hydrogen line (1.42 gigahertz) is suitable, because on this frequency the element most frequently occurring in the universe, that [ extern] neutral interstellar hydrogen, radiates. But it is still completely open whether “frequent extraterrestial at all this frequency range”. What would be, if they operated on and with wavelengths beyond our imaginative power? And which would be, if intelligent ways of life on other planets operate at all no radio astronomy or directly no interest in the stars have, since they live no entrance to the starlit sky deeply in the ground or as sea inhabitants naturally have?
part 2
With all that an extraterrestial Kosmogramm could have reached our planet before millions years – or have arrived with us only in the distant future. Just as well the specially-solar bottle post office drifting in the wave sea could have been washed ashore, without we would have ever noticed this will respectively ever register. And which would be, if all only send, but none listens – or turned around everything only listens, however none sends? Not least the short life-span of intelligent civilizations could give the excursion. “based on the age of our universe intelligent cultures are only eintagsfliegen”, fear the well-known Astronomin and current directress of the SETI institute in Mountain View (California), [ extern] Jill Tarter.
Apart from the choice of the “correct” frequencies above all choice of the search strategy must correspond with that of the anvisierten target area and goal star to good the latter. All pieces of puzzle must engage, so that at all an overall view can consolidate itself. Likewise an important Steinchen in the mosaic is the question, which admitted type of star to that so far [ extern] sieve spectral types O, B, A, F, G, K, M just the necessary characteristics exhibits, which are essential for the training of planets with biological life. What for a category of suns favours the emergence of earthsimilar planets? “the classical SETI programs were limited traditionally to stars, which are very similar to our sun”, confess Jill Tarter. “the earth is the only planet, from which we know exactly that on its surface life developed and trained a technology, which is provable over interstellar distances.”
Dr. Jill Tarter (geb. 1944) of SETI SETI-Institut in Moutain View/Kalifornien.
No miracle thus that the SETI municipality a special Faible for sun-sunning something similar [ extern] Stars of the type G , sometimes also f-stars anvisiert, which are somewhat hotter than the sun, and even an eye on k-stars threw, which are a little colder certainly. Thus the catalog of the stars observierten by SETI grew [ extern] however in the Milky Way rising to believe it or not more than 250,000 – at tendency.
A class of stars, which did not become fair the set I-beam section so far and ergo in the models for further discussion of the Exobiologen and SETI researchers at all no role played, are brown dwarves. They originate in like all stars as consequence of the gravitativen collapse of interstellar clouds, do not reach however not the mass and the pressure to set in order to reach the core temperature from at least three million Kelvin to, which is necessary, in order a classical solar nuclear fusion in course.
In addition, the others [ extern] eleven subspecies from zwergsternen like – their “colleagues” from the brown dwarf parliamentary group directly – too little light and warmth, around habitable worlds around itself to crowds, donate on which biological evolution processes take place. At least the bulk of the researchers proceeded so far from these assumptions.
Too much infrared light
In particular with at the most frequent occurring type of star in the universe, the m-m-Zwergsternen and/or red dwarves, which place roughly 70 per cent of all stars in the Milky Way, bio astronomers and SETI scientists know to begin not yet all too much. This is connected primarily with the fact that this stellar type sends and thus as potential Muttergestirn of a habitable world separates almost exclusively infrared light. On a planet, which circles a red dwarf, a photosynthesis would be as possible on earth not, since its Muttergestirn within this range of the spectrum emits most meagerly.
So far are “only” 170 Exoplaneten discovered and confirmed.
Even with a Exoplaneten, which would lie in the habitablen zone, thus within that range of a m-Zwergsternsystems, which favoured a developing and the preservation of liquid water, two problems would take over hand. Since the oekosphaere amounts to usually straight around a red dwarf once between 0,04 and 0,2 astronomical units, a planet would have to go to sufficient light on close contact to its nut/mother star, in order to receive and warmth.
Too much heat and radiation
But even this scenario is utopian, there in direct proximity to its sun no matter to each – planet whether this is massive or mass-poor – high heat and above all most life-hostile solar radiation would be suspended. Besides the planet would rotate due to the stellar strong gravitation synchronously and ergo its Muttergestirn the same side would always show. While it would work on ball half in the wahrsten sense of the word hot and there extremely high temperatures would have a saying, the other side would be strongly cooled down – on the half prevailed eternal day, on the other eternal darkness.
In addition, on a planet, which circled its sun in large distance, the training of biological life would not have the breath of a chance. Here each milliliter water would freeze immediately to ice, which would be to the training of life everything else as helpful. “liquid water is necessarily for lives absolutely, at least for lives, like we it knows”, stresses Jill Tarter.
Announcement
Due to their high radioactivity m-dwarves are not considered last as extremely “life hostile”. It would give a Ranking for in producing [ extern] Sonnenflares most effective stars, undoubtedly the point place was entitled to this stellar class. UV-B- and x-ray reached in particular emitted a peak value of such things. The fact that in the proximity of such sources of light biological life has hardly a chance of survival is obvious. The jet bombardment would prevent the development of complex DNA molecules smoothly. Only earthsimilar planets, which have a well working atmosphere and thus over an effective shield, could hold solar eruptions of such extent.
Planet around m-dwarves – of strongholds of the life
For some years however with the astrobiologists and SETI scientists a reorientation began. Meanwhile assumes ever more bio astronomer planets, which float around brown dwarves of the category M could be quite strongholds of the life. At this conclusion at least an interdisciplinary group of researchers in an end last yearly in SETI SETI-Institut held Workshop arrived.
After their opinion m-m-Zwergsterne could supply planets despite all astralen deficits with sufficiently light and warmth and in this way promote the development of biological life such that on their planetary companions even highly developed civilizations with radio technology could have trained themselves.
Diameter: 305 meters: The Arecibo dish in Puerto Rico (the USA) is still the world-wide largest immovable radio telescope, with which SETI researchers temporarily look for extraterrestial radio messages. (picture: NAIC – Arecibo Observatory)
Cosmic long-lasting phenomena
Another important aspect, which became to always survey so far, is connected with the life span and the “best years” from m-dwarves. Fact is: Red dwarves become old, very old. Because of their low energy consumption these cosmic long-lasting phenomena shine nearly an eternity. Cosmologists certify an age, which could – lie depending upon – mass between 50 billion and 50 trillion years to them. If that once the star populations and galaxies their light ausgehaucht, a high number of red dwarves could still populate the universe.
Still more importantly for Exobiologen is however the fact that m-dwarves through-live their most productive and/or most active time in the first billions years of their existence. If the wild years are once past and if the radiate-rich fireworks are terminated, the star sits down to the peace and donates for the first time thereby warmth and energy in an intensity, which makes the development possible of organic – life on – infrared basis.
With ATA after m-dwarves hunt
Over the question whether m-dwarves are to come on the “goal list” (target cunning) or not, have SETI researcher, astronomer, planet hunter as well as in the context of interdisciplinary conferences already the more frequent discusses astrobiologists and geologists. Now they made specializedspreading nails with heads for the first time and decided that with the all Telescope array ([ extern] ATA such m-dwarves to be shortly anvisiert are. "in the next decade we want to start the most modern and fastest search with the greatest possible number of stars. I want an enormous catalog of goal stars. I want millions of stars ", wish myself Jill Tarter. With the ATA operate one, thus Tarter, conventional astronomical observations and at the same time classical SETI Observationen. It is the first telescope, which was built, in order to interconnect and optimize both strategies.
So the ATA area of a daily could look
The ATA consists of small radio telescopes, which are in each case six meters large only. 350 of it is used in form of a lattice and the principle that articles print Interferometrie following in the group hooked up. Interestingly enough the attention of the SETI researchers is directed not generally toward stars, but completely purposefully at planets, how Tarter clarifies:
It is not the star, which interests me. There is the signatures, which come from highly developed technologies, whose planet circles around stars. As long as I know that we anvisieren the correct direction, I do not need to see the star. Yes, I do not even need to see the planet. I make however a radio signal from – (no meaning)! –, then I found an inhabited world!
the full Germann Story can be found here
That’s an interesting article which deserves a wider audience. Thanks, Ulli. German television recently broadcast a translated program including simulations of life on various alien worlds in less conventional regions. One was the large moon of a gas giant orbiting a hot star at some distance (a warmer Triton.) Another was a tidally-locked planet orbiting a red dwarf, as described in your article. Some climate simulations have shown a large, stable, temperate equatorial belt on such a planet.
There would perhaps be room for a DC project running CPDN (or whatever) simulations for plausible other-planet configurations.
That’s enough serious for a moment. I just love the automatic translators. How about this:
their “colleagues” from the brown dwarf parliamentary group
Phew, Made it, and an interesting read it was thanks Ulli. Seems there are many conflicting theories about the most probable places floating around at the moment
Thanks for the read Ulli.
Its really difficult to grasp the possiblities of what “intelligent” life could actually be. We are in reallity still early in scientific advancement. We barely understand ourselves and the world we live on, which limits our understanding of the possibilities that are out there. :Orbit:
Given that Red Dwarfs are small and not so intense along with long lived, and given that some simulations show rocky planets more commomly form closer to stars…it seems they could possibly harbor more habital planets than suns like our own …
