Hi All

Here's some links about red-dwarfs...

http://www.newscientist.com/hottopics/astrobiology/redwilling.jsp

...and here on red-dwarf UV...

http://www.astrobiology.com/asc2002/abstract.html?ascid=352

...which suggests that flare stars will have decent amounts of UV, but intermittently. How well their planetary biospheres will survive the luminosity spikes is a different issue again. But I can imagine that the different thermal reservoirs will buffer the planet fairly well. If planets in elliptical orbits can survive...

piece snipped from here... http://www.solstation.com/habitable.htm

As many extra-Solar planets have been found to have more eccentric ("elliptical") orbits (e> 0.3), astronomers have been wondering how high the orbital eccentricity of an Earth-type planet with a similar habitable zone could be before it would become unsuitable for support life. For example, a mildly eccentric orbit would keep Earth in its so-called habitable zone all year long so that there is little significant change in climate. After undertaking many computer simulations lasting 30 theoretical years of 365 days (with the GENESIS2 model), however, astronomer Darren Williams, paleoclimatologist David Pollard, and their colleagues at Pennsylvania State University at Erie have come to believe that Earth could support life even in highly elliptical orbits (0.3> e >0.7).

At an eccentricity of 0.3, Earth's orbital motion would take it between the orbit paths of Venus and Mars, as its orbital distance from the Sun ranged between 0.7 and 1.3 AUs. Because the abundant water in Earth's oceans has a very high capacity to absorb heat, however, the planet would be slow to heat up when it was flying inside Venus' orbital path at its closest but brief approach to the Sun, when it would be traveling fastest. At the farthest point of its orbit from Sol, moreover, the planet has absorbed so much heat during its closer travel around the Sun that its coldest months out by Mars' orbital path are still warmer than winter months on a circular orbit. Although the current average global temperature from Earth's current circular orbit is 58° F (14.4° C), it would rise to 73° F (22.8 °C) with an orbital eccentricity of 0.3. At an orbital eccentricity of 0.4, however, some of the larger continents would become "insufferably hot" so that some local migration would be desirable during the summer months.

At an eccentricity of 0.7 and a range of orbital distance from 0.3 and 1.7 AUs, Earth would remain still habitable if the Sun's luminosity were reduced by 29 percent or Earth's orbit was widened so that the planet received the same amount of light from Sol as it does now. Even then, however, summer temperatures in a mid-latitude location like Erie, Pennsylvania, in the United States would peak around 140° F (60° C) under a Sun that looks twice as large, as Earth moves within even Mercury's orbital path. The Arctic Ocean would melt, and central Africa would have be near boiling so that higher lifeforms would have to migrate although microbes have been known to survive temperatures of 230° F (110° C) with water. Half a year later beyond the orbital distance of Mars, the Sun would look only half its current size, but oceanic heat would still keep temperatures mostly above freezing.

Even at higher eccentricities (e> 0.7), life may be still be possible if planetary parameters are different. For example, more oceanic surface at the expense of land mass or a thicker atmosphere like Venus' for insulation would be better at moderating smoothing temperature extremes for planets in extremely elliptical orbits. On the other hand, planetary systems around stars in highly elliptical orbits tend to be less stable than those with highly circular orbits because their planets are more likely to cross orbit paths and so could eventually sling each other out of their star systems, into their star, or into collisions. (For further discussion, see: William Weed, Discover, November 2002; and Williams and Pollard, 2000.)

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Darren Williams' web-site has PDF versions of the article...

http://shahrazad.bd.psu.edu/Williams/faculty_williams.html

Many of the "hot" to "mild" Jupiters might be in the right orbit for their moons to be viable sites for life. Here's a Sky and Telescope link on Habitable Moons...

http://skyandtelescope.com/printable/resources/seti/article_258.asp

happy reading all. Back to study for me so I won't be posting for a while. See you all.

Adam