Re: Old colony obiting type F star?

In article <48335ef6$0$15880$edfadb0f@xxxxxxxxxxxxxxxxxxxx>,
peter@xxxxxxxxxxxxxxxx (Peter Knutsen) says...
Larry Caldwell wrote:
In article <27a45878-1ab6-4dbd-bc34-
7f94bfffc99e@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>, lwcamp@xxxxxxxxx (Luke
Campbell) says...
A contact binary between a main sequence star and a white dwarf or
other stellar remnant? When a blob of gas gets sucked off the
photosphere and spirals down onto the dead sun, you get a burst of
radiation. The x-rays and such are absorbed by the air, but the peak
level of UV would increase drastically.

That leaves you with the problem of how a habitable planet survived the
death of a star. Either the red giant phase of a white dwarf, or the
supernova phase of a neutron star is unlikely to leave much in the way
of habitable real estate.

However, an F class star could have some whopping huge solar flares and
CMEs. Put the habitable planet in orbit around a gas giant and let the

What does CME stand for?

Coronal Mass Ejection. Up to a few gigatons of plasma and magnetic
fields. http://en.wikipedia.org/wiki/Coronal_mass_ejection

gas giant's magnetic field shield the habitable planet from radiation
except when a big CME deforms the giant's magnetic field. If the

Having the colony planet orbit a gas giant would make for an interesting
day cycle.

habitable planet is in day side transit during a big solar storm, it
might be wise to take cover. That would also give the habitable planet

What advance warning occurs before a solar storm? And can it be used by
low-techs during the interregnum(s)? If they're taught by rote via some
sort of invented religion?

Auroras. Not so much in advance, but solar storms last 2-3 days, so you
could duck early in the event. If you were orbiting a gas giant, maybe
you would see polar auroras on the other planet before you saw them in
your own. The sun would have a much smaller apparent disc, so the rest
of the sky might be dark enough for a little daylight astronomy.

a reason to be very geologically active. Earthquakes and volcanoes
could be a good plot element.

One thing I've thought about, to justify the efforts to colonise the
planet, is that due to its slightly low gravity, it is the ideal place
to set up a ground-to-orbit tower, for hauling materials (alloys) up
into space, even if the planet itself isn't particularly mineral-rich.

But would that work if the planet orbits a gas giant? I know that
Jupiter exerts quite a harmful pull on Io's insides, but would a gas
giant also pull on a space elevator tower?

Everything pulls on a space elevator. If the planet is tidally locked
to its primary, or rotates slowly, a space elevator would be out of the
question. If you want an easy space elevator, make your planet rotate
faster. If the earth had a 6 hour rotation period, getting into space
would be substantially easier.

Also, the space elevator might well have been hit by a meteorite or
asteroid during the first interregnum after the colonisation, or it
might have managed to avoid all such collisions due to automated
maintenance-free systems, but if it does get hit, seriously, what would
the result be?

One of the Mars books (Red Mars?) by Kim Stanley Robinson has a neat
description of a collapsing space elevator. Think meteor strike that
wraps all the way around the planet.

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Relevant Pages

  • Re: Old colony obiting type F star?
    ... Why would the planet have to be habitable through the red giant phase? ... Put the habitable planet in orbit around a gas giant and let the ... Everything pulls on a space elevator. ...
    (rec.arts.sf.science)
  • Re: Old colony obiting type F star?
    ... That leaves you with the problem of how a habitable planet survived the death of a star. ... Put the habitable planet in orbit around a gas giant and let the ... Having the colony planet orbit a gas giant would make for an interesting day cycle. ...
    (rec.arts.sf.science)
  • Re: Old colony obiting type F star?
    ... Why would the planet have to be habitable through the red giant phase? ... The planet would not survive the red giant phase. ... Put the habitable planet in orbit around a gas giant and let the ... Everything pulls on a space elevator. ...
    (rec.arts.sf.science)
  • Re: OT: Even they see it
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  • Re: Gliese 581 c
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