"Henri Wilson" H@.. wrote in message
...
| On Wed, 21 Sep 2005 00:02:20 GMT, "Androcles" Androcles@ MyPlace.org
wrote:
|
|
| "Henri Wilson" H@.. wrote in message
| .. .
| | On Tue, 20 Sep 2005 04:51:46 GMT, "Androcles" Androcles@
MyPlace.org
| wrote:
|
| | | speeds.
| |
| | No, no, NO! Any particular spectral emission line will be
broadened
| due
| | to molecular speeds.
| |
| | The hotter the source, the more the broadening....a pure doppler
| | | effect.
| |
| | No H! The hotter the source, the more the broadening....a pure
| doppler
| | effect. Right up until the lines meet and overlap, producing a
| | continuous spectrum,
| | but forget about the continuous spectra, it doesn't exist.
| | Androcles.
| |
| | OK you are talking about thermal radiation in general, with lots of
| different
| | atoms and energy levels involved.
|
| That's what happens in a star shrug.
|
|
| | In the case of a reasonably cool star, there is usually enough H to
| create a
| | number of distinguishable emission lines.
|
| http://www.astro.umd.edu/~ssm/ASTR220/OBAFGKM.html
| Temperature is on the right.
| Hot star is O.
| Cool star is M.
| I can't see any distinguishable emissions lines in M, but I'm sure
you
| can,
| you have a good imagination.
|
| They are faint and diffuse but a sensitive photo detector would pick
them up.

Yes, I have two of those. I call it my "eye". The problem is my eye
doesn't
detect any distinguishable emissions lines in M. Your imagination does.
You
are confusing your imagination with a sensitive photo detector.



|
|
| I can't ignore empirical data. You can, I know.
|
| Never.

You do, because you confuse your imagination with a sensitive
photo detector, your eye.

Hmm... I could be wrong. This opens up a new line of research.
Are Henri Wilson's sensitive photo detectors more sensitive than
Androcles' sensitive photo detectors?
We are disqualified from judging that, of course. Let's ask someone else
if they can see any distinguishable emissions lines in M, shall we?
Perhaps Andersen can see them, or Uncle Al. Neither one would be
prejudiced in favour of you or I.




| | Their broadening is dependent on
| | temperature. That's the point I was trying to make. A cool gas
| discharge tube
| | at 40C will produce much finer lines than an arc discharge at
4000C.
|
| I haven't seen you make a point beyond what I already know, but keep
| trying.
|
|
| | I gather that doppler shifts are measured principally with the aid
of
| | absorption lines.
|
| Correct.
|
| | The same broadening applies to them. The hotter the star, the
| | broader the lines.
|
| Sure. So how fast are the stars O, B, A, F,G, K moving?
| What about M?
|
| A has a broader H-alpha line than K. (H_alpha is the dark line in the
| red)
| What doppler shift would you give to A?
| I'd give it zero.
|
| | So it is not surprising that there is a great deal of difficulty in
| | establishing radial velocities of distant stars.
|
| Well.... This is the principle:
|
http://instruct1.cit.cornell.edu/cou...y/binary.htmAs I
look at this page tonight, I'm not seeing the spectrum.It is gray,with
black lines, but I have seen it in full colour and athin blackline where
the red and blue dots are moving, so there is bug somewhere.I've now
closed the window and reloaded and its fine.Hopefully it works for
you.What I will say is this. I have seen the spectrum of Algol, years
ago.I did not see the kind of spread that this simulation
demonstrates,and my own program (of which you have a copy)
deliberatelyexaggerates the shift to make it apparent, but the
exaggeration is user selectable.So let us write a simple program that
will simulate the shiftand the velocity. I'll use a spreadsheet.f' =
f(c+v)/clambda' = c/f'The range of the visible spectrum is 740 nm red to
380 nm violet.740-380 = 360 so you can easily afford 1 pixel per
nanometer.H-alpha is at 656 nanometersThat corresponds to a frequency of
4.57317E+14 Hz.Now.... let v = 450
| km/secand you should get a 1 pixel shift.Check it out, that's a lot
of velocity, 0.0015c, I'm tired tonightand hate ****ing about with lots
of zeros.Androcles.
|
| Mind the ankle....

I'm more worred about my eyes than my ankle. I can't see any faint and
diffuse distinguishable emissions lines in M but a sensitive photo
detector would pick them up.

Androcles.

On Fri, 23 Sep 2005 11:34:40 GMT, "Androcles" Androcles@ MyPlace.org wrote:


"Henri Wilson" H@.. wrote in message
.. .
| On Wed, 21 Sep 2005 00:02:20 GMT, "Androcles" Androcles@ MyPlace.org
wrote:

|
| | In the case of a reasonably cool star, there is usually enough H to
| create a
| | number of distinguishable emission lines.
|
| http://www.astro.umd.edu/~ssm/ASTR220/OBAFGKM.html
| Temperature is on the right.
| Hot star is O.
| Cool star is M.
| I can't see any distinguishable emissions lines in M, but I'm sure
you
| can,
| you have a good imagination.
|
| They are faint and diffuse but a sensitive photo detector would pick
them up.

Yes, I have two of those. I call it my "eye". The problem is my eye
doesn't
detect any distinguishable emissions lines in M. Your imagination does.
You
are confusing your imagination with a sensitive photo detector.



|
|
| I can't ignore empirical data. You can, I know.
|
| Never.

You do, because you confuse your imagination with a sensitive
photo detector, your eye.

Hmm... I could be wrong. This opens up a new line of research.
Are Henri Wilson's sensitive photo detectors more sensitive than
Androcles' sensitive photo detectors?
We are disqualified from judging that, of course. Let's ask someone else
if they can see any distinguishable emissions lines in M, shall we?
Perhaps Andersen can see them, or Uncle Al. Neither one would be
prejudiced in favour of you or I.

I once helped make and operate a pretty good solar telescope. We photographed
the surface through a narrow red filter (H). This brought out the granulation
of the surface beneath the outer gases.

Have you ever seen the color of the sun's corona...with a disk covering the
main sphere? It is predominantly red.

| | So it is not surprising that there is a great deal of difficulty in
| | establishing radial velocities of distant stars.
|
| Well.... This is the principle:
|
http://instruct1.cit.cornell.edu/cou...y/binary.htmAs I
look at this page tonight, I'm not seeing the spectrum.It is gray,with
black lines, but I have seen it in full colour and athin blackline where
the red and blue dots are moving, so there is bug somewhere.I've now
closed the window and reloaded and its fine.Hopefully it works for
you.What I will say is this. I have seen the spectrum of Algol, years
ago.I did not see the kind of spread that this simulation
demonstrates,and my own program (of which you have a copy)
deliberatelyexaggerates the shift to make it apparent, but the
exaggeration is user selectable.

What I want to know is whether absorption lines or the main spectrum is used in
the measurement of doppler shift. Either way, there are problems.

If the peak of the thermal distribution curve is used, it could be confused
with varying day/night tempertaure if the pair was in tidal lock...do you see
what I mean.


So let us write a simple program that
will simulate the shiftand the velocity. I'll use a spreadsheet.f' =
f(c+v)/clambda' = c/f'The range of the visible spectrum is 740 nm red to
380 nm violet.740-380 = 360 so you can easily afford 1 pixel per
nanometer.H-alpha is at 656 nanometersThat corresponds to a frequency of
4.57317E+14 Hz.Now.... let v = 450
| km/secand you should get a 1 pixel shift.Check it out, that's a lot
of velocity, 0.0015c, I'm tired tonightand hate ****ing about with lots
of zeros.Androcles.
|
| Mind the ankle....

I'm more worred about my eyes than my ankle. I can't see any faint and
diffuse distinguishable emissions lines in M but a sensitive photo
detector would pick them up.

Androcles.


HW.
www.users.bigpond.com/hewn/index.htm
see: www.users.bigpond.com/hewn/variablestars.exe

"Sometimes I feel like a complete failure.
The most useful thing I have ever done is prove Einstein wrong".

"Henri Wilson" H@.. wrote in message
...
| On Fri, 23 Sep 2005 11:34:40 GMT, "Androcles" Androcles@ MyPlace.org
wrote:
|
|
| "Henri Wilson" H@.. wrote in message
| .. .
| | On Wed, 21 Sep 2005 00:02:20 GMT, "Androcles" Androcles@
MyPlace.org
| wrote:
|
| |
| | | In the case of a reasonably cool star, there is usually enough H
to
| | create a
| | | number of distinguishable emission lines.
| |
| | http://www.astro.umd.edu/~ssm/ASTR220/OBAFGKM.html
| | Temperature is on the right.
| | Hot star is O.
| | Cool star is M.
| | I can't see any distinguishable emissions lines in M, but I'm sure
| you
| | can,
| | you have a good imagination.
| |
| | They are faint and diffuse but a sensitive photo detector would
pick
| them up.
|
| Yes, I have two of those. I call it my "eye". The problem is my eye
| doesn't
| detect any distinguishable emissions lines in M. Your imagination
does.
| You
| are confusing your imagination with a sensitive photo detector.
|
|
|
| |
| |
| | I can't ignore empirical data. You can, I know.
| |
| | Never.
|
| You do, because you confuse your imagination with a sensitive
| photo detector, your eye.
|
| Hmm... I could be wrong. This opens up a new line of research.
| Are Henri Wilson's sensitive photo detectors more sensitive than
| Androcles' sensitive photo detectors?
| We are disqualified from judging that, of course. Let's ask someone
else
| if they can see any distinguishable emissions lines in M, shall we?
| Perhaps Andersen can see them, or Uncle Al. Neither one would be
| prejudiced in favour of you or I.
|
| I once helped make and operate a pretty good solar telescope. We
photographed
| the surface through a narrow red filter (H). This brought out the
granulation
| of the surface beneath the outer gases.
|
| Have you ever seen the color of the sun's corona...with a disk
covering the
| main sphere? It is predominantly red.
|
| | | So it is not surprising that there is a great deal of difficulty
in
| | | establishing radial velocities of distant stars.
| |
| | Well.... This is the principle:
| |
|
http://instruct1.cit.cornell.edu/cou...y/binary.htmAs
I
| look at this page tonight, I'm not seeing the spectrum.It is
gray,with
| black lines, but I have seen it in full colour and athin blackline
where
| the red and blue dots are moving, so there is bug somewhere.I've now
| closed the window and reloaded and its fine.Hopefully it works for
| you.What I will say is this. I have seen the spectrum of Algol, years
| ago.I did not see the kind of spread that this simulation
| demonstrates,and my own program (of which you have a copy)
| deliberatelyexaggerates the shift to make it apparent, but the
| exaggeration is user selectable.
|
| What I want to know is whether absorption lines or the main spectrum
is used in
| the measurement of doppler shift. Either way, there are problems.
|
| If the peak of the thermal distribution curve is used, it could be
confused
| with varying day/night tempertaure if the pair was in tidal lock...do
you see
| what I mean.

NO, I do not see what you mean.
What "PAIR" are you going on about? What tidal lock are you on about?
Pittsburgh Observatory operates all day and all night in the infrared,
so what day/night are talking about? (How would I know that?)
If you want to know what IR looks like, use a web cam in the dark, aimed
at
something hot.

Androcles


|
|
| So let us write a simple program that
| will simulate the shiftand the velocity. I'll use a spreadsheet.f' =
| f(c+v)/clambda' = c/f'The range of the visible spectrum is 740 nm red
to
| 380 nm violet.740-380 = 360 so you can easily afford 1 pixel per
| nanometer.H-alpha is at 656 nanometersThat corresponds to a frequency
of
| 4.57317E+14 Hz.Now.... let v = 450
| | km/secand you should get a 1 pixel shift.Check it out, that's a
lot
| of velocity, 0.0015c, I'm tired tonightand hate ****ing about with
lots
| of zeros.Androcles.
| |
| | Mind the ankle....
|
| I'm more worred about my eyes than my ankle. I can't see any faint
and
| diffuse distinguishable emissions lines in M but a sensitive photo
| detector would pick them up.
|
| Androcles.
|
|
| HW.
| www.users.bigpond.com/hewn/index.htm
| see: www.users.bigpond.com/hewn/variablestars.exe
|
| "Sometimes I feel like a complete failure.
| The most useful thing I have ever done is prove Einstein wrong".

On Fri, 23 Sep 2005 23:18:52 GMT, "Androcles" Androcles@ MyPlace.org wrote:


"Henri Wilson" H@.. wrote in message

|
| What I want to know is whether absorption lines or the main spectrum
is used in
| the measurement of doppler shift. Either way, there are problems.
|
| If the peak of the thermal distribution curve is used, it could be
confused
| with varying day/night tempertaure if the pair was in tidal lock...do
you see
| what I mean.

NO, I do not see what you mean.
What "PAIR" are you going on about? What tidal lock are you on about?
Pittsburgh Observatory operates all day and all night in the infrared,
so what day/night are talking about? (How would I know that?)
If you want to know what IR looks like, use a web cam in the dark, aimed
at
something hot.

Androcles


I didn't think you would. I dindn't explain myself well.
I was referring to the 'day/night' of the stars, not ours.

If binary star pairs DO exist then the sides facing each other are the
'daytime' ones. The rear sides are in darkness. If they are reasonably close
and in or near tidal lock, then one side will be considerably hotter than the
other....somewhat like our moon.

c(S)hot------|----h(S)cooler O

Now, consider what happens if the two stars are very different in size and/or
temperature. For a near edge-on orbit, a distant observer will see a varying
brightness as the hot face of one star and the cold face of the other
periodically swap positions.

The effect might be fairly small... or it could be quite large, depending on
the separation and individual luminosities.

....but you don't think binaries exixst so I know what you will say.


HW.
www.users.bigpond.com/hewn/index.htm
see: www.users.bigpond.com/hewn/variablestars.exe

"Sometimes I feel like a complete failure.
The most useful thing I have ever done is prove Einstein wrong".