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Query: Annual Doppler effect

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Tom Roberts

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Feb 24, 2012, 5:09:40 PM2/24/12
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The annual Doppler effect is the variation in frequency and wavelength of light
from a distant star that lies near the ecliptic, due to earth's varying motion
over a year. There is also a sidereal Doppler effect due to earth's rotation,
and a related effect for a satellite telescope due to its orbit.

Google and Google Scholar give very few useful hits on these terms, so I suspect
that these are so well established that they are discussed only in textbooks,
not in recent research papers accessible to Google. I am not an astronomer, and
am not familiar with the literature or the textbooks. Pannekoek's
_A_History_of_Astronomy_ is commonly cited, but it gives no details, references,
or actual measurements.

I am interested in this, because good measurements of these effects would
constitute tests of Special Relativity in which the observer is moving. There
are very few moving-observer tests of SR.

Can anybody point me to references about any of these Doppler measurements? I am
particularly interested in measurements from satellites, because they would
avoid complications in interpretation due to the atmosphere. I would especially
like measurements of both wavelength and frequency, so the invariance of the
speed of light could be directly tested.

Are telescope spectra routinely corrected for annual Doppler shift? If so, a
reference to how that is done would be most welcome.


Tom Roberts

Phillip Helbig---undress to reply

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Feb 25, 2012, 1:18:02 PM2/25/12
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In article <mt2.0-18907...@hydra.herts.ac.uk>, Tom Roberts
<tjrobe...@sbcglobal.netwrites:

> The annual Doppler effect is the variation in frequency and wavelength
> of light from a distant star that lies near the ecliptic, due to earth's
> varying motion over a year. There is also a sidereal

I think you mean "daily". "Sidereal" means "in relation to the stars".
There are siderial days (as opposed to solar days), siderial years (as
opposed to tropical years) etc.

> Doppler effect due
> to earth's rotation, and a related effect for a satellite telescope due
> to its orbit.

> I am interested in this, because good measurements of these effects
> would constitute tests of Special Relativity in which the observer is
> moving. There are very few moving-observer tests of SR.

Moving relative to what? The whole point of SR is that there is no
absolute standard of rest, so any motion could be taken to be motion of
the observer. Of course, if one is questioning SR, then you can't
assume it is true, but you need to state your standard of rest.

> Can anybody point me to references about any of these Doppler
> measurements? I am particularly interested in measurements from
> satellites, because they would avoid complications in interpretation due
> to the atmosphere. I would especially like measurements of both
> wavelength and frequency, so the invariance of the speed of light could
> be directly tested.

I doubt any astronomical instrument measures optical frequencies
directly.

> Are telescope spectra routinely corrected for annual Doppler shift? If
> so, a reference to how that is done would be most welcome.

I'm pretty sure this is stuff which is just so obvious it is usually not
even mentioned. There was a case where someone forgot to correct for
the annual motion of the Earth and actually announced a pulsar planet
with a period of exactly one Earth year, based on Doppler shift. Rather
embarrassing.

[Mod. note: 6 months; see
http://adsabs.harvard.edu/abs/1991Natur.352..311B . Still embarrassing
though -- mjh]

It might be more useful to state a specific question so that people can
point you to specific answers.

Tom Roberts

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Mar 1, 2012, 1:28:43 PM3/1/12
to
On 2/25/12 2/25/12 - 12:18 PM, Phillip Helbig---undress to reply wrote:
> In article<mt2.0-18907...@hydra.herts.ac.uk>, Tom Roberts
> <tjrobe...@sbcglobal.netwrites:
>> The annual Doppler effect is the variation in frequency and wavelength
>> of light from a distant star that lies near the ecliptic, due to earth's
>> varying motion over a year. There is also a sidereal
>
> I think you mean "daily". "Sidereal" means "in relation to the stars".
> There are siderial days (as opposed to solar days), siderial years (as
> opposed to tropical years) etc.

The period of the variation due to the earth's rotation has a period of one
sidereal day, not one solar day. That's what I was trying to say.


>> I am interested in this, because good measurements of these effects
>> would constitute tests of Special Relativity in which the observer is
>> moving. There are very few moving-observer tests of SR.
>
> Moving relative to what?

Moving relative to the source, relative to the sun, relative to a locally
inertial frame -- any of those will do, and it's clear that the earth's orbit
has all of them. Moreover, the known period of the earth's orbit permits one to
distinguish it from the proper motion of the source.


>> Can anybody point me to references about any of these Doppler
>> measurements? I am particularly interested in measurements from
>> satellites, because they would avoid complications in interpretation due
>> to the atmosphere. I would especially like measurements of both
>> wavelength and frequency, so the invariance of the speed of light could
>> be directly tested.
>
> I doubt any astronomical instrument measures optical frequencies
> directly.

Sure, but radio and microwave instruments could do so. I used "light" in the
physicist's meaning of "any electromagnetic radiation", not just visible light.
As I said, I am not an astronomer, and am not familiar with the literature or
nomenclature.


>> Are telescope spectra routinely corrected for annual Doppler shift? If
>> so, a reference to how that is done would be most welcome.
>
> I'm pretty sure this is stuff which is just so obvious it is usually not
> even mentioned.

I'm glad to see confirmation of my guess. But somewhere there must be a
description of how to correct observations for this. Perhaps a textbook or
reference book.


> There was a case where someone forgot to correct for
> the annual motion of the Earth and actually announced a pulsar planet
> with a period of exactly one Earth year, based on Doppler shift. Rather
> embarrassing.
>
> [Mod. note: 6 months; see
> http://adsabs.harvard.edu/abs/1991Natur.352..311B . Still embarrassing
> though -- mjh]

Thanks. I'm looking through the papers that cited it....


> It might be more useful to state a specific question so that people can
> point you to specific answers.

Specific questions:

* What is a reference to the standard technique of correcting data for
annual Doppler shift and/or the related shifts due to earth's rotation
or satellite orbit?

* What is a reference to some measurements of annual Doppler shift, and/or
those related shifts?


Tom Roberts

carlip...@physics.ucdavis.edu

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Mar 3, 2012, 2:34:54 AM3/3/12
to
Tom Roberts <tjrobe...@sbcglobal.net> wrote:
> The annual Doppler effect is the variation in frequency and wavelength of light
> from a distant star that lies near the ecliptic, due to earth's varying motion
> over a year. There is also a sidereal Doppler effect due to earth's rotation,
> and a related effect for a satellite telescope due to its orbit.

This might not be quite what you're looking for, but an early COBE paper,
Kogut et al., Ap. J. 419 (1993) , extracts the Earth's orbital motion around
the Sun from a modulation of the CMB temperature (see just before
section 3).

Steve Carlip

Richard D. Saam

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Mar 9, 2012, 2:09:40 AM3/9/12
to
On 2/24/12 4:09 PM, Tom Roberts wrote:
> Are telescope spectra routinely corrected for annual Doppler shift? If so, a
> reference to how that is done would be most welcome.


http://lanl.arxiv.org/abs/gr-qc/0104064
The Pioneer acceleration studies used a Orbit Determination Program
(ODP) to quantify annual observer oscillatory contributions


[86] J. A. Estefan, L. R. Stavert, F. M. Stienon, A. H. Taylor,
T. M. Wang, and P. J. Wolff, Sigma User’s Guide.
Navigation Filtering/Mapping Program, JPL document
699-FSOUG/NAV-601 (Revised: 14 Dec. 1998).

Google ODP JPL and search lanl.arxiv.org point to some references.

Richard D Saam

[mod. note: quoted text trimmed -- mjh]

Steve Willner

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Mar 10, 2012, 2:43:20 AM3/10/12
to
In article <mt2.0-18907...@hydra.herts.ac.uk>,
Tom Roberts <tjrobe...@sbcglobal.net> writes:
> The annual Doppler effect is the variation in frequency and
> wavelength of light from a distant star that lies near the
> ecliptic, due to earth's varying motion over a year.

Yes, this is completely standard. Virtually all spectroscopy
reduction pipelines correct their derived velocities to heliocentric
(or solar system barycentric) velocities to take out this effect.
The radial velocity exoplanet searches have to make corrections to
better than 1 m/s.

I'm not sure where you'd find actual code to do the calculations
yourself, but you could look at the JPL "Horizons" server and see
whether they have explanatory material. Or you could look at the
IRAF routines (available through noao.edu), which must incorporate
the relevant corrections.

> There is also a sidereal Doppler effect due to earth's rotation,

"Diurnal" is the word, and this too is a standard correction.

> and a related effect for a satellite telescope due to its orbit.

And this one, if the observatory is in orbit. As I wrote above, it's
entirely standard for the data reduction process to remove all the
observer motions.

> I would especially
> like measurements of both wavelength and frequency,

This is done, in effect, when galaxy radial velocities are measured
both in visible light (wavelength) and with radio telescopes
(frequency). The results agree very well so far, though there are
some claims of disagreement in the literature. You could use ADS to
search for relevant papers.

--
Help keep our newsgroup healthy; please don't feed the trolls.
Steve Willner Phone 617-495-7123 swil...@cfa.harvard.edu
Cambridge, MA 02138 USA
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