Why are the 'Fixed Stars' so FIXED?

"Henri Wilson" HW@.... wrote in message
...
On Wed, 22 Aug 2007 18:39:17 +0100, "George Dishman"
wrote:
"Henri Wilson" HW@.... wrote in message
. ..
On Mon, 20 Aug 2007 03:39:59 +0000 (UTC), bz
wrote:
HW@....(Henri Wilson) wrote in
m:
On Sun, 19 Aug 2007 14:44:51 +0000 (UTC), bz
wrote:
HW@....(Henri Wilson) wrote in
news:q7sec355kreu68a8jpo9qtadisje8qur8t@4ax. com:
...
You haven't a clue either.

the ADoppler shift is slightly different for the layers where the two
bands
dominate (on average)

Maybe somebody needs to give Henry a clue. The layer
is few hundred km thick. The figure for the Sun is
400km and the temperatures are comparable so I'll
use that as an example. The light we see contains
contributions from all depths through that but there
is little light emitted from the top and most of what
is emitted at the bottom is absorbed as the higher
material is opaque. Somewhere in the middle, the
contribution per metre of depth peaks. Now suppose
the location of that surface of peak contribution
varies with frequency by 10% of the depth between
two widely separated filter bands, that's just 40km
difference between the surfaces. Of course as the
layer rises and falls, if those surfaces stay 40km
apart, there is no difference in their motion, but
suppose it varied from 30km to 50km due to some phase
lag between them. You now have a difference in motion
of 10km.

For L Car the radius of the layer varies by about
1.6 million km over the cycle so that's a difference
in motion of 6 parts per million.

According to Henry, this is supposed to explain why
the K band surface brightness varies by 5.3% while in
the V band it is over 50%.

The K band varies by about 35% and the V band by nearly 90%.

Well done Henry, you are actually doing physics now.

the most interesting feature is that the K max lags the V max by about 90.
Can you expain that George?

Easily, brightness is luminosity per unit area. Why do
you think I have been correcting you on that for weeks?

The radius varies by about 12% giving an area variation
of 26%. We would expect the K band brightness variation
of 33% to be mostly due to the change of area and if
you compare the K curve with figure 2 you will see the
maxima are around phase 0.4 with the minimum at 0.9
and the minimum is a sharper turn-round than the max.
In fact the curves are very similar.

For the V band the situation is reversed, the 26% area
change is less than the 90% luminosity change so the V
band curve should be dominated by the temperature curve.
Unfortunately that isn't shown in this paper but if you
look at typical temperature curves you will see they are
similar to luminosity in general.

That corresponds to what we expect from the Planck curve
as the peak of the radiation curve is much higher than
the K band (and of course filter widths matter too).

To check the match you need to combine both radius and
temperature effects. Turning it round, divide the
luminosity by the brightness curve derived from the
temperature curve for the band and you get the area.
The square root of that gives the photometric radius
shown in figures 2 and 3 and as you can see it matches
the integrated velocity and ESO's interferometric angular
radius extremely well.

Your modelling using ballistic theory should be trying
to match the _difference_ between the curves (in terms
of brightness of course), but there is no difference
above the noise.

George

HW@....(Henri Wilson) wrote in news:677sc3hiao99eof0o9iip8bo5enqihkdak@
4ax.com:

There is a time diffrence in average emission of light in the two bands.
K maximum is about 90 behind the V max. What does that suggest?

it certainly throws out YOUR theory.

Henri, When does the max temperature occur in a gasoline engine? NOT when
the pistons are moving at max velocity.

In an oscillating star, the max brightness of different emission lines
occurs at different times because the temperature is different at those
times. [and one must also take into account the diameter, as George has
been pointing out]

If the max brightness of the different emission lines did NOT occur at
different times in the cycle, THAT would be an indication that the
temperature was constant and something else what causing the brightness to
vary.




--
bz

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.

remove ch100-5 to avoid spam trap

On Fri, 24 Aug 2007 09:32:17 +0100, "George Dishman"
wrote:


"Henri Wilson" HW@.... wrote in message
.. .
On Thu, 23 Aug 2007 09:54:29 +0100, "George Dishman"

For L Car, the K band variation in brightness is
of the order of 5%. If K 0.1 then the VDoppler
is an order of magnitude larger than the ADoppler
even if that brightness variation were purely
ADoppler and not actually due to the temperature
change.

I really like your maths George.

The K band brightness varies by about 0.3 mags.

That's a linear increase in luminosity of about 35%

Yep 33%, and the radius varies by 12% giving
a 26% change in disc area so the brightness
(luminosity per unit area) varies by about 5%,
get it?

However, there are two deliberate mistakes here
that you missed, The first is simple and you
should have got it, the VDoppler is only 0.01%
so 5% variation means K=0.002 will give equal
contributions.

Now the question is, can you find the second?

George, as far as I'm concerned, everything you say is riddled with mistakes.
For a start, I certainly DON'T accept that the radius varies by 12%

I said to Bob that I didn't want to give the
game away but since you didn't get the simple
one, I've decided to let you know where it is.

They weren't deliberate. You realised your mistake after you posted. Tell the
truth George.

Do the maths Henry, don't guess, you are regularly
wrong by several orders of magnitude.

I love your maths George.

I love the way your layman's use of 'brightness'
when you meant 'luminosity' has come back to bite
you even after I tried to help by correcting it
in every post for the last several months. You
should now appreciate the second reason why all
your curves where you get a match to the
"brightness" are useless, you actually matched
the _luminosity_, not the brightness.

George, does our sun noticeably vary in size?
To a distant observer, our sun will appear to vary in both BRIGHTNESS and
LUMINOSITY by the same fractional amount every 12 years due to its orbit around
its barycentre with Jupiter.

I understand that in the case of genuine huff puffs (if such exist), a
correction should be made to accommodate any change in luminosity due to any
radius change. However I doubt if that would significantly affect the shapes of
the curves I am producing.

So here's the bottom line, take the temperature
measured using (V-K), convert to brightness
using the Planck Law and divide that into the
luminosity. That gives you a measure of the disc
area. Then find the square root and you get the
radius. That's what you see in figure 2 of
astro-ph/0402244 as the points and as you can
see it is an excellent match to the integrated
velocity curve. What you should be matching
with your program is the additional ADoppler
contribution, which is the difference between
those radius curves expressed as the brightness
residual.

George, you and I have totally different approaches to this. From my point of
view, all you and Kervella et al. have done is match one ste of willusory
observations with another. I would not make any of the above assumptions.

Figure 3 shows the same photometric points as
red crosses and the angular radius measurement
by interferometery and again there is a good
fit.

I don't accept the interferometry.

If you take either of those and plot the
difference between the radii versus the phase,
then square that and convert to the magnitude
scale, you get the residual in terms of
brightness. If you match the velocity curve with
your program as I suggested, you get a template
for the ADoppler from your brightness curve, and
you could then calculate a correlation with the
actual residual to find the magnitude of the
ballistic effect. However, it is obvious from the
plots that the error is so small the ADoppler
will be in the noise.

The ADoppler is responsible for most - if not all - of the luminosity
variation.

As I said before, there is NO evidence of any
ADoppler contribution in Cepheids. L Car is
unusual in having the angular diameter
measurement from interferometry, it is a very
recent technique, but photometric radii match
the integrated velocity curves for other
Cepheids so this isn't a unique conclusion, it
is typical.

All wrongly based on Einsteiniana.
No current astronomical principle is immune to the 'constant c' curse.

George




www.users.bigpond.com/hewn/index.htm

The difference between a preacher and a used car salesman is that the latter at least has a product to sell.

On Fri, 24 Aug 2007 09:40:25 +0000 (UTC), bz
wrote:

HW@....(Henri Wilson) wrote in news:677sc3hiao99eof0o9iip8bo5enqihkdak@
4ax.com:

There is a time diffrence in average emission of light in the two bands.
K maximum is about 90 behind the V max. What does that suggest?

it certainly throws out YOUR theory.

Henri, When does the max temperature occur in a gasoline engine? NOT when
the pistons are moving at max velocity.

In an oscillating star, the max brightness of different emission lines
occurs at different times because the temperature is different at those
times. [and one must also take into account the diameter, as George has
been pointing out]

If the max brightness of the different emission lines did NOT occur at
different times in the cycle, THAT would be an indication that the
temperature was constant and something else what causing the brightness to
vary.

OK. I tend to agree that the two bands were emitted (on average) at different
times. But there are other possible explanations and implications according to
BaTh.

Much of the 'apparent' ~80 phase difference between the two bands can be
explained by substituting different 'yaw' and 'eccentricity' values to produce
the two luminosity curves.
This actually becomes somewhat complicated in BaTh and I haven't thought about
the possibilities yet.... so give me some time..




www.users.bigpond.com/hewn/index.htm

The difference between a preacher and a used car salesman is that the latter at least has a product to sell.

HW@....(Henri Wilson) wrote in
:

On Fri, 24 Aug 2007 09:40:25 +0000 (UTC), bz
wrote:

HW@....(Henri Wilson) wrote in news:677sc3hiao99eof0o9iip8bo5enqihkdak@
4ax.com:

There is a time diffrence in average emission of light in the two
bands. K maximum is about 90 behind the V max. What does that suggest?

it certainly throws out YOUR theory.

Henri, When does the max temperature occur in a gasoline engine? NOT
when the pistons are moving at max velocity.

In an oscillating star, the max brightness of different emission lines
occurs at different times because the temperature is different at those
times. [and one must also take into account the diameter, as George has
been pointing out]

If the max brightness of the different emission lines did NOT occur at
different times in the cycle, THAT would be an indication that the
temperature was constant and something else what causing the brightness
to vary.

OK. I tend to agree that the two bands were emitted (on average) at
different times. But there are other possible explanations and
implications according to BaTh.

Much of the 'apparent' ~80 phase difference between the two bands can be
explained by substituting different 'yaw' and 'eccentricity' values to
produce the two luminosity curves.
This actually becomes somewhat complicated in BaTh and I haven't thought
about the possibilities yet.... so give me some time..

Take all the time you need.

But don't try 'two dark heavy bodies in a stable 3 bodied orbit', that boat
won't float.



--
bz

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.

On Fri, 24 Aug 2007 08:53:31 +0100, "George Dishman"
wrote:


"Henri Wilson" HW@.... wrote in message
.. .
On Thu, 23 Aug 2007 10:19:55 +0100, "George Dishman"


they arrive
seemingly IN phase.
So what I'm suggesting is that the light is emitted from the fairly thin
surface layer at slightly different times rather than from different
layers (at
the same instant)

Do the sums Henry, for toy numbers suppose the
separation varies by +/- 10km peak over 35 days
and the layer as a whole moves by 1,600,000 km
in that time. What is the peak difference in
speed? What is the difference between time of
emission? What is the speed difference between
the layers?

Tell me George, why does the K brightness lag the V brightness by 90
degrees?

It doesn't, the shapes differ and the minima are
nearly in phase.

Now that is one of the siliest things you have said here. Have another look..

The difference in shapes is
because the temperature changes which affects
the V band more than the K. If the temperature
was stable, the two would both follow a curve
given by the square of the radius curve.

I don't think so. I think the temperature of the star's exterior layer would
FALL as the star expanded. ..plain adiabatic stuff....

I think all your theory is complete bulldust.



Incidentally, that should illustrate why using
the terms "luminosity" and "brightness" correctly
matters.

Of course...

So we do you insist on getting it wrong? It
didn't matter when we were discussing your
suggestion that Cepheids were ordinary stars
in binary systems, the radius and temperature
were assumed constant but it is significant
here.

Only if one accepts assumptions based on Willusions.

So at most ADoppler accounts for 5.3% while the
change in diameter alone accounts for 26% and
then you still have the temperature variation to
consider so ADoppler certainly doesn't dominate
and all the evidence is that it doesn't exist.

see.... you still don't have a clue about ADoppler.

:-)

I know exactly what ADoppler does.

What are you trying to tell me?

Even 5.3% is far greater than VDoppler can produce.

BUT because individual photons are also ADOPPLER 'compressed',

Oh whoopeee - yet another ad hoc bodge, what the
heck is 'ADOPPLER compression'?

If you don't know by now I might as well not bother to explain again.

It's a new term you have introduced, you cannot
be talking about the "bunching" you discussed
before because your "K" factor eliminates that
so what do you mean?

George, consider what happens to a rubber ball a it sinks in the ocean.
....that's something like what happens to a photon as the 'photon density'
increases. It's volume change is not LINEARLY related to the pressure increase.

....incidentally, does the ball speed up or slow down as it sinks? There's a
temperature effect if not a pressure one. I might let geesey provide the
equation for that one as a good exercise.

The two bands are emited at slightly different instants... when the
radial
velocities and accelerations are also slightly different. We see them
arriving
in phase.

Do the maths Henry, the differences are utterly
negligible.

Do your own back-of-envelope estimates Henry,
then you will understand why your comments are
nonsensical or you will be able to express
yourself in a way that others can follow.

In light of the fact that the OUTER surface of a star should COOL as it is
forced to expand, I think I should give you some time to reconsider your whole
theory.

George




www.users.bigpond.com/hewn/index.htm

The difference between a preacher and a used car salesman is that the latter at least has a product to sell.

On Aug 23, 7:10 am, "George Dishman" wrote:

Never heard of it, and to be honest I'm not the
slightest bit interested.

Good attitude.

On the other hand, I know a _lot_ more about Cepheids
than I did when this started (far more than the snippets
I have posted) and that is my reason for doing this.
Henry is an amusement but learning real astrophysics
is my motivation, and perhaps sharing some of it with
some lurkers too.

Count me as one of the lurkers who has learned a LOT
from your posts. Thank you!

Classes start Monday, so I have to curtail most of my
newsgroup activities, except for maybe a very occasional post. I've
been spending the last few weeks tapering off
so as to avoid withdrawal symptoms and possible relapse.
Don't want to risk getting another "B" and a nasty
lecture from mein lieber Bruder...

But I'll still be following your posts.

BTW, have you spotted the deliberate mistake in my
recent postings? It will be interesting to see if
Henry can spot it (even with this hint) but don't
give it away if you have ;-)

Yeah, I thought at first it was a typo.

Jerry

HW@....(Henri Wilson) wrote in
:

I don't think so. I think the temperature of the star's exterior layer
would FALL as the star expanded. ..plain adiabatic stuff....

Is the 'expanded water' immediately above a pot about to boil cooler or
warmer than the water in the pot?
Is the solar corona cooler or warmer than the layer immediately under it?

The expansion allows more energy to radiate into space and EVENTUALLY the
exterior layer temperature falls and the layer itself falls back but the
magnitude of the star increases as the star expands.





--
bz

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.

remove ch100-5 to avoid spam trap

"Henri Wilson" HW@.... wrote in message
...
On Thu, 23 Aug 2007 09:59:10 +0100, "George Dishman"

wrote:


"Henri Wilson" HW@.... wrote in message
. ..

George, we have already established that light from pulsars experiences
very
fast extinction, probably due to te fact that the 'EM control sphere'
around
the pulsar is steady, even if the pulsar moves around a small orbit.

No, what we have established is that there is no
evidence for the existence of ADoppler from pulsars
and that the Shapiro effect on pulse times falsifies
ballistic theory.

We have only looked at a couple of pusars...so you can hardly generalise.

There are only a couple in binary systems where
the Shapiro delay can be measured to give an
orbital phase reference. There is no reason to
doubt that they are typical.

That however, doesn't tell me whether you are capable
of the simple piece of algebra required for (a) or not.
Part (b) is more complex and I don't expect you to be
able to do it, but I am curious to know if you can do
(a) because it will determine how much maths I can use
in replies. If you can't do (a), there is little point
in using any at all.

You can use all the maths you can copy from a web page George.

I haven't copied any henry, and I don't think
you will find it anywhere either, it is a test
to see if you can work it out for yourself.

But don't fall
into the Paul Andersen trap of not understanding it yourself.

You are the only one who is struggling with it
Henry, and before you understand it, you have
to be able to produce it. My impression is that
you cannot do it and you are making excuses to
cover it up.

George

"Henri Wilson" HW@.... wrote in message
...
On Wed, 22 Aug 2007 00:31:34 -0700, George Dishman
wrote:
Henri Wilson wrote:
On Mon, 20 Aug 2007 05:03:04 -0700, George Dishman
wrote:
Henri Wilson wrote:
On Sun, 19 Aug 2007 12:11:49 +0100, "George Dishman"
wrote:
"Henri Wilson" HW@.... wrote in message
.. .

Still trying to avoid the question Henry, of course
you have to fit the OBSERVED velocity curve as I have
told you every time you tried this ruse, but still you
repeat it thinking nobody will remember the last time.
The (few) people who follow these posts aren't that
absent-minded Henry, don't waste your time (and mine).

i have given you the approximate OBSERVED velocity curve.

No you haven't, you have provided only a fit of
luminosity which is worthless because it ignores
the dominant temperature variation. Stop stalling
and produce the fit Henry.

It isn't important.

Of course it is Henry, the temperature change
dominates the luminosity variation so fitting gives
a false result. It doesn't affect the measurement
of the shift of spectral lines so that is a valid thing
for you to model.

George, the temerature is not measured directly. It is calculated from a
willusion,using Eiunsteiniana. It might be way out.

No, it is calculated from the _ratio_ of intensities
in different bands and since ballistic theory would
apply the same 'bunching' in each band, the effect
cancels out when you take a ratio. he resulting
temperature is therefore accurate.

As with all cepheids,
it is similar to the brightness curve.

There are two quite different luminosity curves,

The parameters that are needed to simulate the two curves aren't as
different
as you might think.

They remain meaningless, the relate to temperature
not motion.

George, even if there IS an additional intrinsic temperate variation,
the fact
that my 'yaw angles' and 'eccentricities' have to be slightly different
to
produce a match for the two layers is still very informative.

No Henry, Kirchoff's Law tells us there is only one
band. Your model is constructed on the wrong basis,
it is fine for binary systems but meaningless for this
situation.

Explain the 90 deg phase lag then George.

We have covered that elsewhere, the K band matches
the radius curve because the area varies by ~26%
while the brightness only varies by ~5%.

oh and when are ytou going to learn the difference
between luminosity and surface brightness? It is
quite important when the diameter is varying by
more than 10%.

yes I realise that luminosity is the correct term. Brightness is used
widely
but incorrectly.

So why not be correct, it matters in this case.

relative changes are the same for a particular star..... so it really
matters
not.

That would be true for normal stars where the diameter
is constant but not for Cepheids. Regardless of whether
they are the same or not, I am curious to know why you
prefer to make yourself look ignorant when using the
correct term would indicate at least a passing knowledge
of astronomy.

I am quite aware of the fact that luminosity is the correct term. I
checked on
that years ago.
However the word 'brightness' is used very widely...and since I'm not
convinced
that cepheids DO actually change diameter significantly, it is good enough
for
my purposes.

See above, the reason you didn't identify the cause
of the K band shape is because you glossed over that
key difference.

The velocity curve of the layer tells spectral
lines are only shift by 0.01%, it is negligible
compared to the luminosity filter widths. Don't
keep repeating this crap Henry, I have pointed
that out several times now so deal with it.

...the lines shift only 0.01% according to YOUR willusory velocity
curve.
Don't you have any actual data?

You are forgetting what is observed - the actual data
is the shift of 0.01% and the "velocity" is what is
inferred from it. According to your interpretation, it
is the velocity that is "willusory" as you say, the shift
is merely the measured value so remains the same
regardless of the theory.

The problem lies in the interpretation of that shift.

No, there is no interpretation needed, the shift
itself determines which filter band the light
passes hence the deduced temperature is valid.

Why does the K band lag the V band by 90?

See above. The shift is small in comparison to
the flter widths so the temperature determination
is valid.

You said a highly tuned system off resonance. Try 5Hz.

for instance magnetically or by moving one end....the wire's
amplitude will lag the applied force by more than the usual 90
deg.

And 90 degrees is what I said before.

....but it wont be 90 degrees if it is driven off resonance George.

Right, that's why I said zero or 180 when far from resonance.

That's not the point.
The lead or lag varies as the driving frequency moves away from the
resonant
one.

Only close to resonance but you asked about a
_highly_tuned_ circuit driven off-resonance implying
a signal well outside that region.

No I didn't. I'm saying the 'overtone' involves slightly different
material
that has a resonant frequency slightly different from twice the
fundamental...hence the quite significant phase differences.

OK, the oscillations are driven by a thin layer
at about 95% of the radius of the star, however
that drives the fundamental resonance which
causes oscillation of the atmosphere down to
about 60% of the radius. The material throughout
the region is a mix of hydrogen and helium.

Don't you
know anything about this? I thought you were an expert. I shouldn't
have to
teach you.

You haven't said anything I hadn't said a post
or two before.

You still don't know what I'm talking about.

I always have, you are just rediscovering conventional
theory.

You've obviously been looking it up since we started...

Of course! I'm posting in sci.astro to learn some
astrophysics and the conversation is just a light
hearted vehicle for that. I know far more about
Cepheids now than when I started which is all I am
looking to do. Ritz's theory was proven wrong by
Sagnac and that was the end of it. The suggestion
that Cepheids were binary systems was made when
they first appeared but almost immediately discarded
because some had periods that meant the companion
would have an orbital radius smaller tan the radius
of the star.

Yes, and if you are far from resonance the wire
follows the drive with a lag that tends towards a
constant time rather than a fixed phase. You said
you couldn't draw the response (understandable
given ASCII limitations) but we can express it
easily as a time delay.

If you are far from resonance the wire wont vibrate at all.

If you are far below then the motion is that caused
by the drive itself.

well I suppose that depends on how it is driven....let's not go into that.

Sure, I think the key point is that a fundamental
with harmonics is the conventional theory anyway
but there is no scope for separate layers, about
the outer 40% of the radius of the star takes
part in that oscillation.

They are working hopelessly in the dark because of Einsteiniana.

What a remarkable coincidence then that the
theory correctly predicts the relationship between
pulsation period and the phase of the bump.

but the phase of the various bumps varies considerably between stars.

Yes, and conventional theory predicts both the variation
and the value of the period when the bump matches the
peak.

BaTh explains that very simply.

Show your calculation that leads to a 10 day period using
c+v. Forget about resonances, that is acoustic theory and
nothing to do with light.

The star probably has a WCH orbiting it, causing a large tidal bulge or
similar.
The dead constancy of most cepheid periods strongly suggests that they are
connected to an orbit of some description.

Sorry Hanery, you know that isn't true. Cepheids
do not have particulary good stability and change
too much to be explained by an orbiting body.

The paper describe the general class of stars
to which your example belongs.

I don't care what the paper states. It is based entirely on
willusory
facts.

Whatever, for a 10 day period the bump is
coincident with maximum velocity so it isn't
an eclipse, and don't say that is 'willusory',
the time delay due to c+v applies to both
curves.

George, the dip is coincident with hte point of maximum luminosity,

Typically that is true when the period is around
10 days but it leads for longer periods and lags
for shorter periods.

who said?

That is what is observed.

BaTh gets something like that but I gather that's not what you are
refering to.

I think we are both discussing the same thing, the
position of the harmonic bump in your "curve 7"
relative to the background peak caused by the
fundamental.

It is far too large in curve 7 to be a harmonic bump.
It has to be an eclipse.

See the paper I cited, the model reproduces
not only the size of the bump but the phase
dependence and the period of 10 days when it
is in phase.

which is
also the point of maximum ACCELERATION for cepheids and most other
variables.

No, the point of maximum luminosity is mainly
driven by the temperature variation but as you
said before the luminosity curve is generally in
phase with the velocity curve so the bump also
occurs at the peak of the velocity curve which
means it cannot be an eclipse, it is a resonance
in the acoustics of the star.

That's not my interpretation.

I know but ...

The luminosity variation is due mainly to c+v bunching. Tempertaure
variation
isn't enough to account for it.

It remains a fact that the measured temperature
variation (which is valid for ballistic theory), and
to a lesser extent the radius variation, are exactly
the right amount to fully account for the luminosity
change.

You a re assuming the measured temperature variations are accurate...when
in
fact they are 100% willusory..

Ballistic theory says the measured temperature
is accurate, any 'photon bunching' applies by
the same factor in each band so the ratio is
unaffected. Only the time of arrival is altered
by the varying emission speed to distort the
temperature curve.

Even if there was a small discrepancy,
the temperature effect still accounts for the majority
so simply fitting your luminosity without taking that
into account means you results are worthless. What
you need to do is get your fit from the velocity curve,
then see what that predicts for luminosity, not the
other way round.

The true velocity curve is not known.
The observed one is willusory.

Why do you keep repeating things we both know
already, I keep telling you that what you need
to do is fit your _prediction_ of the OBSERVED
velocity to the actual OBSERVED velocity.

Most things do Henry but you just need to bear
in mind that your view is that it is the velocity
which is inferred from the shift and hence would
be 'willusory' while the spectral shift is what is
actually measured, not the other way round. I'm
not telling you anything that you should find
surprising or objectionable at all.

The spectral shift might be measured directly....but how should that
shift be
interpreted George. That is the question...

No, the question doesn't arise, the measured shift
immediately determines which measurement band
the light contributes to, hence we know the temperature
accurately. You only need to worry about interpretation
when you try to work out velocity but we aren't doing
that here.

George, the theory is that measuring the intensity of two bands can give
an
accurate assessment of the shift of the peak of the Planckian radiation
curve.

No it isn't the theory is that measuring the ratio
of the two bands indicates the temperature

That is not acceptable according to BaTh.

Wrong, ballistic theory says the temperature is
correct because 'photon bunching' applies equally
to both bands so the ratio is unaffected. Where
ballistic theory says there is an error is in
the time of arrival. The temperature measured
from light arriving while the radius is increasing
is correct but it will arrive earlier in the phase
than would be seen close to the star.

George