Why are the 'Fixed Stars' so FIXED?

On Fri, 16 Feb 2007 14:24:01 +0000 (UTC), bz
wrote:

"George Dishman" wrote in
roups.com:

You should get the same as the conventional theory
if you enter a distance of zero, a simple check to
start. Then as you increase the distance the
acceleration term will introduce a quadrature
element which will change both the phase and
amplitude. To keep the match to the amplitude, you
can change the orbital inclination or the masses.


NOTE: at zero distance, the photons would arrive from greatly different
directions at all times.

I think zero distance would actually put you (in Henri's model, using his
program) at the center of gravity of the system.

Yes the barycentre is OK to use. The travel time across the orbit is generally
negligible for the purposes of determining bunching and brighness curves.

I suspect the program would yield garbage out (or even crash).

No it doesn't crash, It merely indicates no brightness variation. (actually it
indicates a very variation because I had to add a small corection to avoid a
log(0) situation.

Of course, some would say that there are strong indications that it already
does yield garbage out, for all distances.

You can't laugh at the curves it produces bob. They match perfectly.

On 16 Feb 2007 00:38:58 -0800, "George Dishman"
wrote:

On 15 Feb, 23:15, HW@....(Henri Wilson) wrote:
On 15 Feb 2007 05:33:24 -0800, "George Dishman"
wrote:
On 15 Feb, 12:48, bz wrote:
"George Dishman" wrote oups.com:
On 14 Feb, 23:29, bz wrote:
HW@....(Henri Wilson) wrote

... My point is that I doubt the technique
has been tried because the velocity due to the
variable diameter would hide any overall motion
due to a planet.

That is probably true in most cases, although you can't be sure that the
observed velocity figures are really due to huff puffing and not to orbital
movement.

That's what I just said Henry, it would be hard
to tell the difference so I doubt the technique
has been applied.

And why don't those nearby systems with planets show Wilson Variability
in brightness along with the doppler shift and wobble that they
display?

Similarly, why don't all spectroscopic binaries
show extreme variability?

That is a very good question. I think it has been asked of Henri before.

answered.

In that case which non-variable spectroscopic
binaries have you analysed and what wa the
predicted light curve?

George, like I said, the biggest problem for me is to find both velocity and
brightness curves for the same star.
Brightness curves for near circular orbits are pretty well the same so all I
need is the magnitude change and maximum velocity.

If you can find some examples for me I will try to match them.

Yes, that's why I said "the value". Basically, he
can chose k in the earlier equation as any arbitrary
function of the local density but then has to stick
with it, and probably the form of that equation would
be dictated by the physics any way, probably
proportional to the density on the assumption that
each encounter with a particle was independent, leaving
only a simple constant to be determined empirically.

There appears to be another factor contributing to light speed unification
other than plain space density of matter.
Maybe this is related to the gravity field of the stars involved. I have no
explanation as yet.

Gravity would slightly couteract the speed unification
effect but it is a second order effect so increases the
unification distance by about one part in ten thousand
typically, completely irrelevant as you don't know the
distance to within an order of magnitude yet.

I'm not trying to explain it at this stage. I just want to find a consistent
pattern. Unification distance appears to be definitely related to orbit period.

If the speeds unify so fast on nearby stars (including Cepheids) that we do
not see differences in aberation and stellar position for slow vs fast
photons, then the speeds would unify too fast for brightness variation to
be significant.

I think aberation and stellar position effects are
going to be too small to be noticeable even with
significant brightness variations, but the apparent
Doppler variations would then imply non-Keplerian
orbits. After all, once the fast photons catch the
slow ones, the Doppler goes to infinity as would
the inferred orbital speed ;-) Very rapid extinction
is the only way round that.

...not necessarily so 'rapid'.

Well 'rapid' is subjective. What I mean is very
much less than the parallax distance to the system.

for small period orbits, yes...but not so much for orbits over about a year.

However the brightness is predicted to go to
infinity at the critical distance when the first double image would occur.
Since this doesn't seem to happen and multiple images are not commonly
observed, I am prepared to accept that exinction rates are normally fairly
high.

That's all I meant. Typically it must be no more
than a fraction of a light year.

No. It doesn't work like that. Something makes it period dependent. After all,
you cannot unify light with other light that hasn't yet been emitted.

George

On 16 Feb 2007 00:56:32 -0800, "George Dishman"
wrote:

On 15 Feb, 22:55, HW@....(Henri Wilson) wrote:
On 15 Feb 2007 00:41:00 -0800, "George Dishman"
wrote:
On 14 Feb, 23:29, bz wrote:
HW@....(Henri Wilson) wrote :
On Wed, 14 Feb 2007 11:25:05 +0000 (UTC), bz
wrote:
HW@....(Henri Wilson) wrote in
m:

If they travel far enough to bunch up and show variation in brightness,
they will travel far enough (at different speeds) to be coming from
different directions by the time the arrive here.

After all, they start out from different places in the sky. The slow ones
come from the side of the orbit where the star is going away from us. The
fast ones come from the side of the orbit whewre the star is approaching
us.

My guess is that the process would essentially
unify the speeds within a few tens of hours so
the displacement might not be detectable directly.
Last year Henry was tallking of tens or hundreds
of light years but now he is saying the effect
of bunching is too fast if anything, so I'm not
sure what his view is now.

I have to explain why the extinction rates for contact binaries with very short
periods and high speeds appear to be a lot faster than those required for slow
moving stars in long period orbits.

The gas stripped from one by the other may be
higher in those cases.

I don't believe that light speed unification is dependent solely on the amount
of matter present. I think the gravity fields of the source pair might have a
lot to do with the initial extinction.

No, gravity acts to oppose unification but it's
a very small effect.

Similarly, why don't all spectroscopic binaries
show extreme variability?

Because the distance/velocity combination is in the wrong range.

Which ones have you analysed?

You might say that the light has not traveled far enough yet for it to
bunch up, but then you are contradicting the idea that the velocities unify
rapidly.

More likely he will say the speeds unify so fast
there is no time for the bunching to cause
significant brightness variation. Again that comes
down to the value he chooses for extinction distance
as a function of density.

It's complicated George. For one thing, the effect appears to depend on orbit
period. ...which stands to reason because obviously the light emitted by a star
traveling towards us right now cannot unify with light that WILL BE emitted in
say 8 months time when the star is moving away.

Of course it should, the ISM hasn't changed in
that time. The distance should be independent
of the orbital parameters but probably dependent
on the type of star which will influence the
density of the stellar wind.

'Unification' is not like conventional 'extinction' even though I often call it
'extinction' for convenience.
..

On the other hand, the extinction rate for short period contact binaries is
very high. The required unification distance can be less than 1 LY.

Let's see what you get for J1909-3744.

If I know the details of the dwarf I might be able to tell you something.


George

On Fri, 16 Feb 2007 12:18:29 +0100, YBM wrote:

Henri Wilson a écrit :
On Thu, 15 Feb 2007 23:43:23 +0100, YBM wrote:

Henri Wilson a écrit :
The method I use is to reduce the difference between actual speed and c by a
fixed factor per unit distance.
speed relatively to what ? Ether ?

If you didn't snip MORON, you would see that I plainly stated the reference for
speed....the binary barycentre..

I'm not talking about emission speed in your so-called 'model'... but final
speed.

The final speed is c wrt the barycentre. It is c+u wrt Earth where u is the
speed of the barycentre wrt earth.
Actually it wont be exactly that for other reasons.

Henri Wilson wrote:

The method I use is to reduce the difference between actual
speed and c by a fixed factor per unit distance.

If the initial speed relative to the barycentre of the binary
is say, 1.00015c, then I multiply the 0.00015 by the extinction
rate each light day of travel.

speed relatively to what ? Ether ?

I plainly stated the reference for speed....the binary barycentre..

How does the light know that it should adjust its speed
relative to the barycentre rather than something else?

How does the light determine its speed relative to the
barycentre of the system it has left?

Would light leaving the Moon toward a distant viewer unify
its speed to c relative to the Earth-Moon barycentre or to
the Moon-Sun barycentre?

Leonard

On Fri, 16 Feb 2007 14:43:52 +0000 (UTC), bz
wrote:

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

I think you mean asymtotic(with most of the unification very early)
rather than exponential.

Yes I have often described it as asymptotic...similar really.

Inverse exponential is asymtotic, exponential, on the other hand, grows
without limit.

Yes everyone should know what I meant by 'exponential'.
..
The method I use is to reduce the difference between actual speed and c
by a fixed factor per unit distance.

If the initial speed relative to the barycentre of the binary is say,
1.00015c, then I multiply the 0.00015 by the extinction rate each light
day of travel.

So, your fast and slow photons have a 'half life'. But you are changing
the speed, not the number of photons at that speed?

correct.

My extinction rates are like '0.9999', '0.999995', etc.
My intention is to determine required extinction rates for various stars
to see if there is a pattern.

I finally devised a neat way to include extinction in my program...so I
can now make some real progress.

However that produces the problem of how can the velocities unify very
close to the stars in question, when they have not traveled very far
yet.

If they travel far enough to bunch up and show variation in brightness,
they will travel far enough (at different speeds) to be coming from
different directions by the time the arrive here.

Very little though.

That depends on the geometry. Currently, all your action occurs along a
single, one dimensional line, and you 'scale' things, using trig, to
'emulate' an orbit with tilts in three space, but you make no allowance for
different 'line of sight' paths that the photons would need to travel.

I know what you are saying and have considered it myself. particularly in the
case of long period orbits where the conditions along the LOS could be quite
different for light emitted, say, one year apart.

I have thought about this myself...if it happens at all it should affect
stars with a large orbit diameter and long period more than say 'contact
binaries'.

Yes, and it would effect those close to us more than those very distant.

Thus it would effect those with high parallax more than those with low
parallax.

Finally, it would effect systems with high proper motion more than those
with low proper motion.

Yes..but I still don't think it's worth worrying about. Mind you, it could
explain some of the erratic behavior often seen in recorded brightness curves.


I also believe that the extinction rate itself decreases with distance
from the source star. That is, most takes place in the vicinity of the
source....maybe in the first couple of LYs of travel.

Use a half life model. Most will be gone within 10 half lives.

I do use a 'half distance' model.

After all, they start out from different places in the sky. The slow
ones come from the side of the orbit where the star is going away from
us. The fast ones come from the side of the orbit whewre the star is
approaching us.

Astronomers have been able to see the wobble of 'nearby' stars that have
large planets, why wouldn't they see the wobble of nearby cephieds?

And why don't those nearby systems with planets show Wilson Variability
in brightness along with the doppler shift and wobble that they display?

The light from these stars still travels throgh similar quality space,
even if it emitted months later.

That does NOT answer the question.

I'm not going to worry about it.

You might say that the light has not traveled far enough yet for it to
bunch up, but then you are contradicting the idea that the velocities
unify rapidly.

It all depends on the star's orbit velocity.

If so, then all doppler binaries, with orbital velocities similar to those
which give the Wilson Curves that match the cephieds, should show similar
variations in brightness.

I dont have enough data to make any definite claims about unification as
yet....except that is appears to happen according to the BaTh.

Of course there are many stars that DO vary intrinsically and maybe I'm trying
to match those with a theory that doesn't apply.

If it is a large orbit with velocities below 0.00001 c, very little
bunching or brightness change will be expected over quite large
distances.

For instance a star in a 1 year orbit moving at 0.00001 c should vary by
only about 0.04 magnitudes at 300 LYs distance without taking into
account any extinction.
At 500 LYs the figure is about 0.065 mag variation.

So all double stars (with the right orbital plane) at great distances
should show large brightness variations.

Without unification they would, yes...but they don't...
That is what I'm trying to explain. There could be other reasons for it.
.....face-on orbits for instance.

bz

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

"Henri Wilson" HW@.... wrote in message
...
On 16 Feb 2007 00:30:15 -0800, "George Dishman"
wrote:

On 16 Feb, 03:17, HW@....(Henri Wilson) wrote:
On Thu, 15 Feb 2007 23:53:52 -0000, "George Dishman"

wrote:
"Henri Wilson" HW@.... wrote in message
.. .
On 15 Feb 2007 01:58:58 -0800, "George Dishman"

wrote:
....
There is a cyclic doppler shift.
That means pulses come closer together then move apart again every
orbit.
If that isn't 'bunching' (of the pulses) what is?

Ah, true. However that is a function of speed
alone, I was talking of the bunching due to
your variable speed which is in additional to
the conventional effect. Here's the bit snipped
from above:

-:-

Not quite, there is an interesting difference. The
bunching effect depends on the acceleration and if
you think of a circular orbit seen edge on, clearly
the acceleration will vary 90 degrees out of phase
with the velocity. For high speed and a short
extinction distance the velocity will predominate
while for low speed and long distance the
acceleration will produce the larger contribution.

George, you are refering to conventional doppler shift using constant
c.
This is not the same as bunching due to c+v changes.

No, I'm describing ballistic theory, there is
no acceleration term in conventional Doppler.

-:-

Yes...well I don't use equations anyway. I let the computer do the
simulation...and there is no acceleration term .. although it might be
present
indirectly.

Whatever, we both know qualitatively how the curves should
look so we can check if your code gives a credible answer.

Bottom line though is that previously I was not talking
about conventional theory, please take more care as I
understand very well what the consequences of your theory
will be.

The apparent maximum radial velocity using the
conventional formula (invariant c) is 27983 m/s
by my reckoning.

I will get the same answer for the maximum....but it will occur at a
slightly
different phase.

You should get the same as the conventional theory
if you enter a distance of zero, a simple check to
start. Then as you increase the distance the
acceleration term will introduce a quadrature
element which will change both the phase and
amplitude. To keep the match to the amplitude, you
can change the orbital inclination or the masses.

The orbital inclination is already included in the radial velocity
reading.

Yes, as we said before, your velocity figure is actually
v*sin(i). We both understand that.

I have tried to explain this to Androcles but he cannot get it.

There's lots he doesn't get but you and I understand it.

No matter how an orbit is tilted, you can always rotate your telescope
(and
head) so that there exists an axis in the orbit plane that is
perpendicular to
your LOS. From that viewpoint, the radial velocities around the whole
orbit are
The 'edge on ones' simply multiplied by the same (unknown) cos factor.

The measured radial velocities ARE those of the edge on orbit multiplied
by
cos(tilt)....so you cannot include it again.

For circular orbits like this, that's true.

For the purposes of predicting brightness curves, I only have to consider
edge
on orbits. My 'yaw angle' is that for an edge on orbit. It is not the
conventional definition....but it works and it makes the programming much
easier.

For elliptical orbits in general you have to consider
the angle between the major axis and the line of sight
which I guess is your yaw, but for J1909-3744 we can
ignore it.

It doesn't matter what it is.
If a circular orbit is tilted around an axis perpendicular to the LOS,
the
radial velocities around the whole orbit are multiplied by the same
factor
cos(tilt). That is already included in the observed velocity readings.

Yes, what your program really tells you is v*sin(i)
(using the standard convention for inclination)
rather than v itself.

It doesn't tell me anything about v.

I FEED IN the measured value of maximum observed velocity (If I can get
it).

I don't think you quite understand the principle involved George.

Trial and error Henry, you feed what you think is the
true value of v*sin(i) and see whether the curves match
the observations. If not you alter the value until you
get a match and then you have found the value of v*sin(i).
At that point the predicted velocity curve should match
the published curve and you have found the true velocity
which takes into account the effect of ballistic theory
on the Doppler. Isn't that how you use it?

However, consider the difference
between a low speed orbit seen edge on and a high
speed orbit at high inclination. Given that we know
the period is 1.5 days, the high speed orbit requires
either a higher mass companion or a smaller orbit.

However, we know from spectroscopic analysis that
the companion is a white dwarf with a surface
temperature around 8500 degrees and a magnitude
of about 21. That gives an indication of the mass
so you can combine that with your result to work
out limits for the inclination.

Like I said, if you redefine YAW you don't have to worry about
inclination.

Yaw angle is the angle the major axis of an edge on orbit makes with the
LOS.

Ah, I guessed correctly :-)

Anyway, put the numbers into your program and tell
me what you get and then we can discuss their
interpretation. Check the results for zero distance
first and make sure you get the right speed and
phase.

Naturally for zero distance I get no brightness variation. The observed
velocity is in phase with the true velocity.

You should still get a very small variation due to
the conventional bunching you reminded me of at the
top.

Then increase the distance to 3 light years
but keep everything else the same and tell me how
the amplitude and phase change. Those two checks
should just confirm your software is working, after
that we can try the more interesting questions of
mass etc. and see if we can put some limits on the
extinction distance.

My software works.

We'll see.

It predicts brightness curves. Orbit inclination does not affect curve
shape.

I can predict the brightness curve of the dwarf companion. Where can I
find the
observed one?

There is no observed brightness variation reported
but that can probably only be taken to say any
variation is less than 1 mag, the existing single
measurements are no more accurate than that.

I'm not sure what it is you are asking me to do.

OK, let's do it in small steps so that I can
give you clear questions.

Common to all: set the eccentricity to zero, yaw
becomes irrelevant. Set the orbital period to
1.5334494503 days.

Step 1. Set the distance to zero (your sim should
reproduce the conventional theory) and set the
actual velocity to 27983 m/s.

Check that the observed velocity curve you get
matches that and that the maximum velocity is
90 degrees after conjunction.

Step 2. Increase the distance until you just get
the velocity curves going to infinity and tell me
what distance you get.

I am guessing that the critical distance should be
around 4 light years but let's see what your program
says before we get on to the more interesting stuff.

George

On Feb 16, 5:00 pm, bz wrote:
"PD" wrote groups.com:



On Feb 16, 2:12 pm, HW@....(Henri Wilson) wrote:
...
Tell me what is wrong with my derivation...

Nothing is wrong with your derivation. Your conclusion that it implies
circularity is what's wrong.

The rule for combining velocities is not, nor was it ever, used to
assert that the speed of light is constant regardless of reference
frame. The only claim that is made is that the frame independence of
the speed of light is *consistent with* the rule for combining
velocities. Moreover, the experimental evidence in support of the rule
for combining velocities has nothing to do with measuring the speed of
light, but in fact measuring the speed of other particles in different
reference frames -- and it is there that measurements are completely
consistent with the velocity combination rule.

The frame-independence of the speed of light is taken as an unproven
*postulate* in special relativity. It is not necessary in science to
experimentally prove a postulate. One determines the implications of a
postulate (and just as you derived it, the velocity addition rule is
an example of an implication of this postulate) and then tests those
implications against experiment. If the implications match experiment,
and if the postulate is able to generate more successful implications
that match up to experiment than competing postulates, then this is
taken in science to be sufficient grounds for belief in the truth of
that postulate.

In this particular case, the postulate is the frame-independence of
the speed of light. One implication (of numerous implications) is the
rule for combining velocities. The rule for combining velocities has
been tested experimentally in a wide variety of circumstances (without
needing a direct test of the frame-independence of the speed of
light). And because this, and so many other implications, match
experiment so well, we take stock in the truth of the frame-
independence of the speed of light.

....

Well said.


Well, thanks, but Henri will ignore it, since it doesn't feed his
fantasy.

PD

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

On Fri, 16 Feb 2007 14:43:52 +0000 (UTC), bz
wrote:

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

.....
That depends on the geometry. Currently, all your action occurs along a
single, one dimensional line, and you 'scale' things, using trig, to
'emulate' an orbit with tilts in three space, but you make no allowance
for different 'line of sight' paths that the photons would need to
travel.

I know what you are saying and have considered it myself. particularly
in the case of long period orbits where the conditions along the LOS
could be quite different for light emitted, say, one year apart.

give it due consideration.

I have thought about this myself...if it happens at all it should
affect stars with a large orbit diameter and long period more than say
'contact binaries'.

Yes, and it would effect those close to us more than those very distant.

Thus it would effect those with high parallax more than those with low
parallax.

Finally, it would effect systems with high proper motion more than those
with low proper motion.

Yes..but I still don't think it's worth worrying about. Mind you, it
could explain some of the erratic behavior often seen in recorded
brightness curves.

I doubt it, I am not talking about brightness curves here, I am talking
about the image of the star jumping back and forth.

The faster photons arrive from the direction 'more close to current actual
location in the sky of the star' (which we can't see because the light from
there has not arrived here yet.)

The slower photons come from where the star was when those photons were
emitted.

A star with a high proper motion should look like an airplane at night with
{blinking} red and green lights on the wing tips. The lights being seen as
streaks of different colored light from different locations in the sky.

The photons would NOT merge into a single image any more than the red and
green lights merge into a single white light.

I also believe that the extinction rate itself decreases with distance
from the source star. That is, most takes place in the vicinity of the
source....maybe in the first couple of LYs of travel.

Use a half life model. Most will be gone within 10 half lives.

I do use a 'half distance' model.

Which is 'equivalent' to a half life model IF the velocity is constant.

So, what is the 'half distance' or 'half life' of c+v and c-v photons?

And are they the same?

Why should photons traveling at .8 c speed up at exactly the same rate that
photons traveling at 1.2 c slow down?

But if they don't 'unify at the same rate' then one or the other would
predominate (and speed up or slow down the 'c' photons). This should cause
some strange effects.

If the orbit is eccentric, there will be more photons emitted that are in
one or the other of the sub/super luminal states. This will produce an
unbalance. Even if you can invent a method of taking energy from the c+v
photons and giving it to the c-v photons, there will be problems because
there will be less of one kind than of the other.

This, in itself is a severe problem for the Ritz model.

After all, they start out from different places in the sky. The slow
ones come from the side of the orbit where the star is going away from
us. The fast ones come from the side of the orbit whewre the star is
approaching us.

Astronomers have been able to see the wobble of 'nearby' stars that
have large planets, why wouldn't they see the wobble of nearby
cephieds?

And why don't those nearby systems with planets show Wilson
Variability in brightness along with the doppler shift and wobble that
they display?

The light from these stars still travels throgh similar quality
space, even if it emitted months later.

That does NOT answer the question.

I'm not going to worry about it.

You must IF your theory is ever going to be acceptable.


You might say that the light has not traveled far enough yet for it to
bunch up, but then you are contradicting the idea that the velocities
unify rapidly.

It all depends on the star's orbit velocity.

If so, then all doppler binaries, with orbital velocities similar to
those which give the Wilson Curves that match the cephieds, should show
similar variations in brightness.

I dont have enough data to make any definite claims about unification as
yet....except that is appears to happen according to the BaTh.

More like: without adding the magic of unification, BaT fails.
'Magic' because it is difficult to justify speeding up slow photons while
slowing down fast one and still maintain coherent images of the source.

Of course there are many stars that DO vary intrinsically and maybe I'm
trying to match those with a theory that doesn't apply.

Well said!

If it is a large orbit with velocities below 0.00001 c, very little
bunching or brightness change will be expected over quite large
distances.

For instance a star in a 1 year orbit moving at 0.00001 c should vary
by only about 0.04 magnitudes at 300 LYs distance without taking into
account any extinction.
At 500 LYs the figure is about 0.065 mag variation.

So all double stars (with the right orbital plane) at great distances
should show large brightness variations.

Without unification they would, yes...but they don't...

Exactly.

That is what I'm trying to explain.

There is a simple explaination: the Ritzian model is wrong. Light always
moves at c wrt all observers, even those in the interial FoR of the source.

There could be other reasons for it.
....face-on orbits for instance.

I did say 'with the right orbital plane'.

Face on orbits would show no doppler shift in either model. We probably do
not even know they are double stars unless they are optically separable.


bz

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









--
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 Sat, 17 Feb 2007 14:22:20 -0000, "George Dishman"
wrote:


"Henri Wilson" HW@.... wrote in message
.. .
On 16 Feb 2007 00:30:15 -0800, "George Dishman"
wrote:



You should get the same as the conventional theory
if you enter a distance of zero, a simple check to
start. Then as you increase the distance the
acceleration term will introduce a quadrature
element which will change both the phase and
amplitude. To keep the match to the amplitude, you
can change the orbital inclination or the masses.

The orbital inclination is already included in the radial velocity
reading.

Yes, as we said before, your velocity figure is actually
v*sin(i). We both understand that.

I have tried to explain this to Androcles but he cannot get it.

There's lots he doesn't get but you and I understand it.

No matter how an orbit is tilted, you can always rotate your telescope
(and
head) so that there exists an axis in the orbit plane that is
perpendicular to
your LOS. From that viewpoint, the radial velocities around the whole
orbit are
The 'edge on ones' simply multiplied by the same (unknown) cos factor.

The measured radial velocities ARE those of the edge on orbit multiplied
by
cos(tilt)....so you cannot include it again.

For circular orbits like this, that's true.

For the purposes of predicting brightness curves, I only have to consider
edge
on orbits. My 'yaw angle' is that for an edge on orbit. It is not the
conventional definition....but it works and it makes the programming much
easier.

For elliptical orbits in general you have to consider
the angle between the major axis and the line of sight
which I guess is your yaw, but for J1909-3744 we can
ignore it.

If the orbit is near circular we can.

It doesn't matter what it is.
If a circular orbit is tilted around an axis perpendicular to the LOS,
the
radial velocities around the whole orbit are multiplied by the same
factor
cos(tilt). That is already included in the observed velocity readings.

Yes, what your program really tells you is v*sin(i)
(using the standard convention for inclination)
rather than v itself.

It doesn't tell me anything about v.

I FEED IN the measured value of maximum observed velocity (If I can get
it).

I don't think you quite understand the principle involved George.

Trial and error Henry, you feed what you think is the
true value of v*sin(i) and see whether the curves match
the observations. If not you alter the value until you
get a match and then you have found the value of v*sin(i).
At that point the predicted velocity curve should match
the published curve and you have found the true velocity
which takes into account the effect of ballistic theory
on the Doppler. Isn't that how you use it?

Not exactly.
Unless I have access to a reliable figure for the maximum radial velocity I
cannot really come to a firm conclusion about distance or unification rate.

I really need three quantities, Vmax, distance and magnitude change. I can
determine yaw angle and orbit eccentricity when matching the basic SHAPE of a
brightness curve ....if I have such a curve.

However, consider the difference
between a low speed orbit seen edge on and a high
speed orbit at high inclination. Given that we know
the period is 1.5 days, the high speed orbit requires
either a higher mass companion or a smaller orbit.

However, we know from spectroscopic analysis that
the companion is a white dwarf with a surface
temperature around 8500 degrees and a magnitude
of about 21. That gives an indication of the mass
so you can combine that with your result to work
out limits for the inclination.

Like I said, if you redefine YAW you don't have to worry about
inclination.

Yaw angle is the angle the major axis of an edge on orbit makes with the
LOS.

Ah, I guessed correctly :-)

Note MY definition of 'yaw angle' makes it independent of orbit pitch.

Anyway, put the numbers into your program and tell
me what you get and then we can discuss their
interpretation. Check the results for zero distance
first and make sure you get the right speed and
phase.

Naturally for zero distance I get no brightness variation. The observed
velocity is in phase with the true velocity.

You should still get a very small variation due to
the conventional bunching you reminded me of at the
top.

Not if the observer is at the orbit centre.

George, I think you are refering to the pulses emitted by the pulsar itself.
These will be observed to have a cyclic doppler shift.

The 'bunching of pulses' I refer to is not the same.

I will explain for the case of an orbiting star.

The program assumes the star emits identical pulses of light towards the
observer at regular intervals as it moves around its orbit...I can use 20000,
33000 or 60000 points per orbit. 30000 is usually enough to produce a smooth
curve.

The pulses are assumed to move at (c+v)cos(a) towards a distant observer, where
a is the angle between the orbit tangent and the LOS. The program then
calculates the arrival times of all the pulses emitted over a number of orbits
at the observer distance.
At any instant the pulse positions form a regular spatial pattern. As this
pattern moves past the observer, it gives the impression of brightness
variation. (dn/dt = dn/dx.dx/dt)

Thus, a bunching of pulses shows up as a brightness increase.

Brightness variations are converted to the conventional log output before being
displayed on the screen.

Then increase the distance to 3 light years
but keep everything else the same and tell me how
the amplitude and phase change. Those two checks
should just confirm your software is working, after
that we can try the more interesting questions of
mass etc. and see if we can put some limits on the
extinction distance.

My software works.

We'll see.

It has been checked thoroughly. Many of the values have been watched through
the program to see if they are correct.

It predicts brightness curves. Orbit inclination does not affect curve
shape.

I can predict the brightness curve of the dwarf companion. Where can I
find the
observed one?

There is no observed brightness variation reported
but that can probably only be taken to say any
variation is less than 1 mag, the existing single
measurements are no more accurate than that.

Most variations are around 1.5 mag or less.
....and yes, I don't have much faith in the accuracies of many published
figures.

I'm not sure what it is you are asking me to do.

OK, let's do it in small steps so that I can
give you clear questions.

Common to all: set the eccentricity to zero, yaw
becomes irrelevant. Set the orbital period to
1.5334494503 days.

Step 1. Set the distance to zero (your sim should
reproduce the conventional theory) and set the
actual velocity to 27983 m/s.

Check that the observed velocity curve you get
matches that and that the maximum velocity is
90 degrees after conjunction.

That wont work.
'Zero distance' means 'at the orbit centre'. Radial velocity is zero...so is
brightness variation.

.....So I'm not with you at all, here.

Step 2. Increase the distance until you just get
the velocity curves going to infinity and tell me
what distance you get.

I assume you mean the 'brightness curves'.

I am guessing that the critical distance should be
around 4 light years but let's see what your program
says before we get on to the more interesting stuff.

Period = 0.0042 years
Velocity = 0.0000933c

Critical distance = ~ 8 LYs.

See: http://www.users.bigpond.com/hewn/J1909-3744.jpg

Note that the observed velocity curve (red) is very different from the real
curve (blue) at that distance.

(I'm having some trouble producing the right colours with Vbasic on windowsXP).

George