[TML] Noncanonical TU 3D.

[Thad Coons]

On 1/2/08, Jerry W Barrington <jursamaj at yahoo.com> wrote:
>
> On 1/2/08 5:36 AM, "shadow at shadowgard.com" <shadow at shadowgard.com> wrote:
>
> > On 1 Jan 2008 at 21:10, Jerry W Barrington wrote:
> >
> >> With reference to the lack of dim stars, I made a graph of the 32000
> dimmest
> >> stars in my list of 77,000 stars mentioned above.  Link is below (PNG
> >> format).  The horizontal scale is in Absolute Solar Luminosities.  The
> >> vertical scale is in Squared LY from Sol (the 1,000,000 at top is
> actual
> >> 1,000 LY).  The 3 dots at the bottom of the chart include Alpha
> Centauri &
> >> Proxima Centauri, and something else I haven't identified.
> >>
> >> Note the complete lack of stars left of the pink line, and how few are
> just
> >> right of it.  Stars should be there, but are too dim to be seem at that
> >> distance by the Hipparcos telescope.  This is a major shortcoming of
> all
> >> star catalogs.  :(
> >>
> >> <http://briefcase.yahoo.com/jursamaj>
> >> Folder: Star Stuff
> >> File: HipparcosLimits
> >
> > The folder isn't public.
>
> Odd.  It was when I created it about 2 years ago.  And it still was before
> I
> put that file in it.  I guess since Yahoo dumped Yahoo Photos in favor of
> Flikr & "premium Storage", they don't like me sharing any more.
>
> Fortunately, I still have a Geocities page from waaaay back.  :)
>
> <http://www.geocities.com/jursamaj/HipparcosLimits.png>
>
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It looks like our current charts pick up most stars brighter than about .001
Solar luminosity out to about 30 LY. For me, that looks like a reasonable
cutoff.  The very dark and cold planets that might be found around
stars that dim or dimmer seem to be excellent places to stay away from
unless it's absolutely necessary.