[TML] The Sky at Night?

[Patrik Holmstrom]

On Dec 3, 2007 2:50 PM, John Kwon <jtkwon at jtkgroup.com> wrote:
>
> On 12/3/07, Patrik Holmstrom <patrik.holmstrom at gmail.com> wrote:
> >
> > On Dec 3, 2007 1:07 PM, Timothy Little <tim at little-possums.net> wrote:
> > > On Mon, Dec 03, 2007 at 11:18:44AM +0000, Ewan Quibell wrote:
> > > > Would the F7 V just look like a bright star or would it produce
> > > > something like moon light?
> > >
> > > It would illuminate about the same as a bright full moon, yes.  It
> > > would be a very dazzling star, apparent magnitude probably about -13.
> > > I don't think it would actually be dangerous to look at: despite the
> > > pointlike focus on the retina, the light passing through the pupil
> > > would be less than a microwatt.
> >
> > That looks like it is in the ballpark. Assuming a luminosity of 2.1
> > sol I get an apparant magnitude of -14.5 or 6 times brighter than mean
> > full moon luminosity (-12.6).
> >
> >
> So we wouldn't need night vision devices, and we could read our comp-pads
> without using the backlight.

I have skied a couple of kilometers under a full moon (lights went off
one hour ahead of the posted time) and that was interesting but
doable. If the second star is above the horizon on a clear night you'd
probably be just fine if you're taking a walk but if you suspect that
a Vargr with an Gauss rifle might interrupt that walk you'd definitely
want the NV goggles.

Also the frequency of those clear nights are another matter. Bitter?
Me? Got myself a new telescope a while back and the only clear night
in the last 4 weeks had hurricane strength wind gusts...

/Patrik