On Wed, 21 Feb 2007 10:59:41 -0000, "George Dishman"
wrote:


"Henri Wilson" HW@.... wrote in message
.. .
On 20 Feb 2007 02:18:17 -0800, "George Dishman"
wrote:

Henry, I have already done that several times. In
round figures the PRF is 339 Hz and that is varied
by +/- 30.5 mHz. The exact numbers are in my previous
posts.

The velocity curve that would be published is just
a sine wave (near zero eccentricity) with an
amplitude of c * 0.0305 / 339 = 27983 m/s.

That should be the same
as my 'brightness curve'. I can't make sense of the curve published by
Jacoby
et al
...
OK
The frequency variation correspondes to a magnitude change of about 0.2.
(CMIIW)

I think you used Hz instead of mHz, it is a brightness
ratio of 1.00018 which corresponds to a magnitude change
of about 0.0001955. Your approach is right though.

Yes i did use hz onstead of mhz. Sory about that.

and: http://www.users.bigpond.com/hewn/J1909-3744b.jpg
mag change ~0.2
Period = 0.0042 years
max velocity=0.0000933c.

To obtain curve b, I have to plug in a distance of less than 1 LY....more
like
0.7 LYs.
This order of 'extinction length' is quite consistent with those I have
derived
from short period contact binaries.

In curve b, the magnitude change is smaller and a sine-like red velocity
curve
corresponds with an e ~ 0.06, yaw -90.
A circular orbit results in a clearly skewed red curve.
So my theory says the orbit is NOT circular at all.

OK, that's exactly the sort of difference in prediction I have
been interested in. Pop in the right brightness and let's see
what you get now. My guess is your 'extinction length' will
need to go down by a factor of 1000 to 0.0007 light years or
about 6 light hours !!!!

I cannot give you an exact figure because of way magnitude is calculated...but
it is less than 1 lightday.

.....Not imposible since it is a neutron star.

I think other factors are operating here.




George