RE: Atypical variable stars...

["Robert J. Bradbury" <bradbury@aeiveos.com>]

On Tue, 24 Aug 2004, Thomas Droege wrote:

> This brings up an interesting problem with the TASS data.  The present
> software requires simultaneous hits in V and I to keep an measurement.
> This throws out about 80% of the data.  OK, I have set the cut low because
> of this, but still we probably only put half the possible data in the data
> base.

In particular it would seem to remove the type of trend that MBrain
development would represent.  In that case V would diminish quite
a bit faster than I.  (This is because as MBrain development takes
place the star still radiates the energy but it gets shifted further
and further from the visible into the infrared region (even far
beyond I into J, K, L, etc.).

So one would want to identify cases where V is going down at some
rate where I is decreasing at a slower rate.

As mentioned -- these trends may vary from rates that involve days
to years (ultimately millions of years -- but this involves very
old/cold MBrains that are probably invisible in both the V/I regions).

> Long period stars tend to be red.  This means the V component is typically
> 2-4 mags less than the I component.  As the star dims, when the V component
> drops below 13 or so we begin to have losses, and most data is lost by V of
> 15.   But the I component is still quite bright for a typical red long
> period star.  Too bad, it is lost by our present analysis.

Understood.  But the question is whether the *rate* of decline in V
is significantly different from the rate of decline in I.

If one is shifting the blackbody radiation curve of a star you
can have a decline in V but it has to be compensated for by
a maintenance or increase in I.  So those stars that TASS
"drops" because they decrease in V should be sub-selected for
those that "never" come back.  If these still have a detectable
I component they may be significant.  Ultimately one would like
to match this with the Hipparcos, 2MASS or IRAS data to determine
if the star is excessively bright (or brighter) in with respect to
IR wavelengths.

> ...but I don't think there are any stars where V is many mags
> brighter than I???

Not normally as far as I know *but* there are scenarios I can
imagine where one would attempt to heat up a star for various
energy production purposes (if you can surround a star with
solar collectors you can obviously reflect all the energy
back onto the star with some interesting effects most likely).
There are MBrain applications where one might want to produce
the greatest amount of energy in the shortest period of time
in which case stellar super-heating may be a reasonable engineering
strategy.  There are also strategies along this line that I
could envision might be used for shifting the nucleosynthesis
reactions in the surface of the star to produce heavier elements
(which get blown off into space and subsequently collected).

So I would suggest that there is merit in noticing any data
that varies from the "norm" to any significant degree.

Robert