S2 orbit deviates from Keplerian ellipse

[David Levy]

The orbital period is ~15 years. A single year's worth of data is not the basis for the fit.

 

The 2002 data is THE MOST important data!!!

 

Please look again in the diagram:

 

http://www.universetoday.com/wp-content/uploads/2010/08/nature01121-f2.22.jpg

 

If I understand it correctly, by 2002,33 S2 and Sgr A* were nearly coincident.

How can we ignore 2002 data?

[swansont]

 

The 2002 data is THE MOST important data!!!

 

 

 

It's not used to the exclusion of the rest of the data, and even if it were more important, it's still not the extent of the data.

 

You have not shown that anybody is ignoring the 2002 data. Only that the errors associated with the data are somewhat larger than originally thought.

[David Levy]

One more issue

 

I do not argue with the scientists if their error bar level was O.K. or not.

I have full trust in what they say.

 

However - they say clearly that in order to set the fit they had to use an increased bar level.

What shall we understand from that?

What is the real meaning of "increased bar level"?

[Strange]

 

Why is it so important for the scientists to prove that S2 center of mass is Sgr A*?

 

 

Please provide a reference that says it is important to prove this.

 

The 2002 data is THE MOST important data!!!

 

Please provide a reference that says this is the most important data?

 

How can one sample be more important than the others?

I have full trust in what they say.

 

And yet you insist they are wrong. Odd.

 

What is the real meaning of "increased bar level"?

 

It means the value is not as accurate as thought.

[David Levy]

You have not shown that anybody is ignoring the 2002 data. Only that the errors associated with the data are somewhat larger than originally thought.

 

Perfect!

So the error associated with the data is somewhat larger than original thought.

 

If I understand you correctly - the meaning of original thought is the expected accuracy.

 

Therefore, they have used an error bar which is higher than the expected accuracy.

[swansont]

There is an argument that the 2002 data are more important than another year's (two, actually): there are more data points, and as S2 is near periapsis, it is traveling faster, so it covers a larger arc than at other times. But that's not the argument David Levy is making.

 

Perfect!

So the error associated with the data is somewhat larger than original thought.

 

If I understand you correctly - the meaning of original thought is the expected accuracy.

 

Therefore, they have used an error bar which is higher than the expected accuracy.

 

Yes. This is not a revelation of any great magnitude to those familiar with experimental results in difficult experiments

[David Levy]

There is an argument that the 2002 data are more important than another year's (two, actually): there are more data points, and as S2 is near periapsis, it is traveling faster, so it covers a larger arc than at other times. But that's not the argument David Levy is making.

 

Yes, all of those points are important.

However - the most important one is that S2 is near periapsis

Therefore - 2002 data is absolutely important.

 

Yes. This is not a revelation of any great magnitude to those familiar with experimental results in difficult experiments

 

Thanks

So, you agree that without increasing the error bar above the expected accuracy there is no fit.

it is traveling faster, so it covers a larger arc than at other times.

 

Let's focus on that;

Please look again in the following diagram:

http://www.universetoday.com/wp-content/uploads/2010/08/nature01121-f2.22.jpg

 

It looks to me that the arc between 2001.50 to 2002.25 (31 weeks) is larger than 2002.25 to 2002.66 (41 weeks).

Do you agree?

 

However, in 2002.33 it was at the nearest point to its periapsis.

If so, the meaning is that S2 speed between 2001.50 to 2002.25 arc (when it was far from its periapsis) was faster than its speed at 2002.25 to 2002.6 arc (when it was at the nearset point to its periapsis).

 

 

How that fits with Keplerian ellipse?

Edited April 7, 2017 by David Levy

[swansont]

 

So, you agree that without increasing the error bar above the expected accuracy there is no fit.

 

 

No, I never said that.

 

It looks to me that the arc between 2001.50 to 2002.25 (31 weeks) is larger than 2002.25 to 2002.66 (41 weeks).

Do you agree?

 

 

 

The arc is longer, but so is the time

 

(.66 - .25)*52 is 21 weeks, not 41 (.66 - .25 = .41)

(1.25 - .5)*52 is 39 weeks, not 31 (1.25 - .5 = .75)

[David Levy]

No, I never said that.

 

The arc is longer, but so is the time

 

(.66 - .25)*52 is 21 weeks, not 41 (.66 - .25 = .41)

(1.25 - .5)*52 is 39 weeks, not 31 (1.25 - .5 = .75)

 

 

Thanks for the explanation.

 

It seems to me that the arc between 1999.47 to 2000.47 (52 weeks) is longer than 200.47 to 2001.50 (53.5 weeks).

Therefore, S2 moves faster at the first arc which is further from the periapsis than the second one.

Same issue with 1996.43 to 1997.54 arc with relative to 1997.54 to 1998.36.

So it seems that S2 slow down and up in some sort of cycles as it comes closer to the periapsis

How can we explain those different speed cycles?

[swansont]

 

 

Thanks for the explanation.

 

It seems to me that the arc between 1999.47 to 2000.47 (52 weeks) is longer than 200.47 to 2001.50 (53.5 weeks).

Therefore, S2 moves faster at the first arc which is further from the periapsis than the second one.

Same issue with 1996.43 to 1997.54 arc with relative to 1997.54 to 1998.36.

So it seems that S2 slow down and up in some sort of cycles as it comes closer to the periapsis

How can we explain those different speed cycles?

 

 

There are error bars on the measurements, which you are ignoring. To say with any confidence one is longer or shorter, you have to include these uncertainties.

[David Levy]

There are error bars on the measurements, which you are ignoring. To say with any confidence one is longer or shorter, you have to include these uncertainties.

 

Accuracy and Error Bar ---

 

It seems to me that the science is using this argument to fix any evidence which doesn't meet its expectation.

 

This is really beyond my understanding.

 

The scientists set the Error bar and the accuracy level.

 

It is stated clearly:

 

"This work refines our previous analysis mainly by greatly improving the definition of the coordinate system, which reaches a longterm astrometric accuracy of ≈ 300 µas, and by investigating in detail the individual systematic error contributions."

 

Hence, the accuracy had been set by our scientists to 300 µas. I didn't set this level.

 

If they think that this accuracy level is too challenging, then please go ahead and select different accuracy level.

 

However, any new selected level should apply to all points.

 

I really can't understand why they state (with high proud) up front in the article that their accuracy level is 300 µas, while in the article they are using completely different value for those points whish doesn't obey to their expectation.

 

Sorry - They can't just play with the accuracy level as they wish.

 

As they have stated - 300 µas, then they must evaluate the whole picture according to this value not even one error bar more than that!

 

If they want to decrease the accuracy - then off course they are more than welcome to change it and let us know the updated value.

 

However, it is really unacceptable to highlight their high accuracy, while they are using totally different value whenever they wish.

 

This action can't represent a valuable science article.

 

[David Levy]

Please see the following video - Mass of Sagittarius A* from SO-2 (S2) Star's Orbital Parameters

https://www.youtube.com/watch?v=mT1_vol_F_0&t=4s

It gives a simple explanation how to extract the Sagittarius A* mass out of the S2 orbit.

It is stated that the Preiapsis range is 120 AU while the Apoapsis range is 1800AU.

However, we already know that In 2002 S2 was nearly coincident with. Sgr A*.

https://arxiv.org/abs/0810.4674

"In 2002, S2 was positionally nearly coincident with Sgr A* and thus confused with the NIR counterpart of the MBH."

So, how could it be that a nearly coincident had been translated to 120 AU?

This is a severe violation of the accuracy of 300 µas."

 

which reaches a longterm astrometric accuracy of ≈ 300 µas,"

In the following video - Orbital Velocity of Star SO-2 (S2) Around Sagittarius A*

It is stated that the calculated S2 velocity at its nearest location to the periapsis is 2.4% the speed of light. Is it correlated with 2002 S2 data?

Edited April 8, 2017 by David Levy

[swansont]

Accuracy and Error Bar ---

 

It seems to me that the science is using this argument to fix any evidence which doesn't meet its expectation.

 

This is really beyond my understanding.

 

Clearly.

 

The scientists set the Error bar and the accuracy level.

 

The error bars are dictated by the experiment. They mention statistical error — that's from the variation in data points. If you measure something multiple times, you will get some scatter in the results. You have an average and a standard deviation.

 

Some errors can be determined by looking at the instrumentation. e.g. a digital camera's resolution, which depends on the pixel size, and the quality and nature of the optics.

 

It is stated clearly:

 

"This work refines our previous analysis mainly by greatly improving the definition of the coordinate system, which reaches a longterm astrometric accuracy of ≈ 300 µas, and by investigating in detail the individual systematic error contributions."

 

Hence, the accuracy had been set by our scientists to 300 µas. I didn't set this level.

 

They did not "set" the error, like it was a dial on an instrument. They did more and better measurements, and better calibrations, in order to reduce the error. They did not make an arbitrary choice of the value.

 

If they think that this accuracy level is too challenging, then please go ahead and select different accuracy level.

 

Again, that's not how this works. The uncertainties, much like the data, are being measured by the scientists.

 

It gives a simple explanation how to extract the Sagittarius A* mass out of the S2 orbit.

It is stated that the Preiapsis range is 120 AU while the Apoapsis range is 1800AU.

However, we already know that In 2002 S2 was nearly coincident with. Sgr A*.

https://arxiv.org/abs/0810.4674

"In 2002, S2 was positionally nearly coincident with Sgr A* and thus confused with the NIR counterpart of the MBH."

So, how could it be that a nearly coincident had been translated to 120 AU?

This is a severe violation of the accuracy of 300 µas."

 

 

 

How severe? Show the math — I want a number to compare it to. And explain why that's the relevant comparison to make.

 

(IOW, Imagine, for a moment, that we were looking at the orbit edge-on. What would periapsis and having the observations being nearly coincident have to do with each other?)

[David Levy]

Thanks

 

We see S2 Orbit in 2D.

 

This also ignores the fact that we are viewing a 3-D system, but observations are in 2D.

 

Therefore, it is clear that the real shape and size of S2 orbit might be totally different from what we see. Technically it could be much longer orbit ellipse and in different shape.

 

Hence;

1. How can we set any sort of calculation on an orbit shape and size which isn't fully clear to us.

2. How did we get in a conclusion that the Preiapsis range is 120 AU while the Apoapsis range is 1800AU?

 

Edited April 9, 2017 by David Levy

[swansont]

 

Therefore, it is clear that the real shape and size of S2 orbit might be totally different from what we see. Technically it could be much longer orbit ellipse and in different shape.

 

Hence;

1. How can we set any sort of calculation on an orbit shape and size which isn't fully clear to us.

2. How did we get in a conclusion that the Preiapsis range is 120 AU while the Apoapsis range is 1800AU?

 

 

 

Viewing angle will change these lengths according to well-known geometry. If the orbit was appreciably rotated so that the semi-major axis were directed toward or away from us, we couldn't determine these parameters by simple observation. But rotation along the semi-major axis doesn't change the periapsis or apoapsis.

[David Levy]

Thanks

Sorry if I ask too many questions, however, I really appreciate all your excellent support.

With regards To S2 Orbit Cycle -

http://www.universetoday.com/wp-content/uploads/2010/08/nature01121-f2.22.jpg

So far that is the only real valid data about S2 locations on the ellipse per time table.

 

Now we are already 15 years after 2002.

How could it be that there is no updated data on S2 orbit?

What about similar orbit data for other S0 star?

In the article it is stated that they are tracing many S0 stars and even have evaluated Srg A8* based on those other stars orbits.

So, somehow the data should be available.

 

Any Idea how to find it?

Edited April 10, 2017 by David Levy

[swansont]

 

Thanks

Sorry if I ask too many questions, however, I really appreciate all your excellent support.

With regards To S2 Orbit Cycle -

http://www.universetoday.com/wp-content/uploads/2010/08/nature01121-f2.22.jpg

So far that is the only real valid data about S2 locations on the ellipse per time table.

 

Now we are already 15 years after 2002.

How could it be that there is no updated data on S2 orbit?

What about similar orbit data for other S0 star?

In the article it is stated that they are tracing many S0 stars and even have evaluated Srg A8* based on those other stars orbits.

So, somehow the data should be available.

 

Any Idea how to find it?

 

 

 

Look for other articles published by this group of scientists, or at least by the principle author(s). Look in the references of the article for any other data they might cite, and look for articles by those authors.

 

Several reasons there might not be updated data. Groups need funding and telescope time (and for terrestrial telescopes, you need the good fortune of clear weather). If any of these are lacking, you won't have data.

[Strange]

I guess you could email them and ask what the latest status is?

[David Levy]

Look for other articles published by this group of scientists, or at least by the principle author(s). Look in the references of the article for any other data they might cite, and look for articles by those authors.

 

Several reasons there might not be updated data. Groups need funding and telescope time (and for terrestrial telescopes, you need the good fortune of clear weather). If any of these are lacking, you won't have data.

 

Thanks

It is quite frustrated that our scientists do not take the extra efforts to verify if their assumption about S2 center of mass location is correct or incorrect.

 

Therefore, let's look again at the following:

https://arxiv.org/pdf/0810.4674.pdf

 

It is stated that starting 2002 our scientists have started to use NACO telescope which has higher resolution than the Sharp Telescope. Its statistical error had been reduced dramatically comparing the Sharp and therefore its accuracy had been improved.

 

"The first AO imaging data available to us of the GC region was obtained in 2002 with the Naos-Conica (NACO) system mounted at the fourth unit telescope Yepun of the VLT (Lenzen et al. 1998; Rousset et al. 1998). Compared to the SHARP data the NACO data are superior due to the larger telescope aperture (8.0 m versus 3.5 m) and the higher Strehl ratios (typically 40% for NACO) of the AO which is equipped with an IR wavefront sensor, allowing the use of the nearby K=6.5 mag star IRS7 as AO guide star. Furthermore, the sampling is increased compared to the Speckle data. For NACO we have typically ten epochs per year, compared to one per year for SHARP. We obtained images both in the 27 mas/pix and the 13 mas/pix image scales.'

 

"The statistical errors of the pixel positions for the NACO K-band data as a function of arbitrary detector units of flux. The thin lines show the respective error model for each epoch; the thick dashed line is the mean for the data. The mean has a floor at 99 µas, the median (not shown) at 84 µas."

 

"For the SHARP data we obtained a broad distribution of the statistical pixel position errors with no clear maximum and a tail to 2 mas. The median error is 360 µas, the mean error 760 µas in the SHARP data."

 

"Since the NACO camera when operated in the 27 mas/pix mode exhibits notable geometric image distortions we constructed de-distorted mosaics from the individual images by applying a distortion correction, involving rebinning of the measured flux distribution to a new pixel grid."

 

Hence, the NACO 2002 S2 data is much more accurate than ever before.

 

However, It was found that in 2002, S2 was nearly coincident with Sgr A* and it was very bright:

 

" In 2002, S2 was positionally nearly coincident with Sgr A* and thus confused with the NIR counterpart of the MBH."

 

"It is clear that S2 was brighter in 2002 than in the following years."

 

"There are several reasons why a star could change its apparent brightness.":

 

In the article they have offer several options and tried to evaluate how the interaction with other star or with Srg A* might affect S2 brightness.

 

If I understand it correctly, the only option which they didn't eliminate was:

 

"6. The brightness of S2 could be affected by dust in the accretion flow onto the MBH. The dust would be heated by S2 and account for the excess brightness, a proposal that was used by Genzel et al. (2003b) to explain the MIR excess of S2/Sgr A*."

 

Hence, that proves that by 2002, S2 was absolutely nearly coincident with Sgr A. The Accuracy of MACO gives higher confidence for that observation.

 

However, instead of focusing on this most updated and accurate data from NACO dated 2002, our scientists have preferred to ignore it and based their calculation on a lower accurate data from Sharp Telescope and from previous years.

So they have ignored the most valid data for the most critical time when S2 and Sgr A* were nearly coincident.

 

They did it in order to prove that Sgr A* is the center of mass for S2.

I would consider it as a severe mistake!

 

Unfortunately, I have no further data on S2 orbit or on all other S0 stars orbits. Therefore I have no further valid data to set full confidence for this significant mistake of our scientists.

 

Some people might wonder why it is so important issue.

What is the big difference if S2 center of mass is Srg A* or some virtual point in space?

The answer is as follow:

If S2 center of mass isn't Srg A*, than the calculated S2 center of mass can't represent Srg A* total mass. It just gives an indication about the estimated mass at S2 orbit center of mass.

 

Therefore, in order to evaluate the real Srg A* mass, we must monitor that virtual S2 Center of mass location in space and see how long it takes it to orbit Srg A*.

Once we know the orbit shape and size of this virtual center of mass, we can set a real calculation for Srg A* mass.

I would assume that it could show that Srg A* mass is significantly heavier that the 4 Million solar mass which we have calculated as S2 center of mass.

In any case, as I have already stated - it is quite frustrated that our scientists do not take the extra effort to verify if their assumption about S2 center of mass location is correct or incorrect.

Edited April 11, 2017 by David Levy

[imatfaal]

 

Thanks

It is quite frustrated that our scientists do not take the extra efforts to verify if their assumption about S2 center of mass location is correct or incorrect.

...

 

Bullshit.

 

This entire thread (in common with almost all your other threads) has been one misunderstanding from YOU followed by another. Yet you assume, in an act of monumental arrogance, that your failure to understand is someone else's fault. You clearly have only a passing understanding on this topic; you do not comprehend the papers you quote; your posts are a nasty amalgam of chop logic, bare assertions, and quote-mining; and yet it is the lack of effort of scientists which you focus upon. I find this thread more offensive than any of the mad pipe-dreams in Speculations - your lack of humility and inability to conceive that the weakness may be yours is truly astonishing.

 

I realise these are comments directed at you as a person rather than at the argument and for that I apologize - but I believe it needed to be said.

[Strange]

 

Thanks

It is quite frustrated that our scientists do not take the extra efforts to verify if their assumption about S2 center of mass location is correct or incorrect.

 

 

That is exactly what they are doing with all the observations.

 

If they weren't interested in testing their hypotheses (NOT assumptions) then they wouldn't keep making observations.

 

 

 

However, instead of focusing on this most updated and accurate data from NACO dated 2002, our scientists have preferred to ignore it

 

You have just quoted from articles discussing the work. How is that "ignoring" it?

 

 

 

Therefore I have no further valid data to set full confidence for this significant mistake of our scientists.

 

Seeing as you are unable to do basic arithmetic and do not understand any pot the physics involved, I don't think anyone is going to lose sleep over your delusional thinking.

 

Either go and study the relevant science, or stop posting your daft misapprehensions.

I realise these are comments directed at you as a person rather than at the argument and for that I apologize - but I believe it needed to be said.

 

I think this is one of those rare occasions where this is entirely justified. David has shown himself, repeatedly, to be unable to learn even the most basic aspects of science and yet continues to be convinced that he is right and the rest of the world has made a terrible mistake.

[David Levy]

Bullshit.

This entire thread (in common with almost all your other threads) has been one misunderstanding from YOU followed by another.

 

I have set several key arguments without getting real valid answers. (Assuming that "I don't know" wouldn't be considered as valid answer)

Therefore, it seems to me that instead of dealing with the message, it is much easier to deal with the messenger.

I do learn and I do appreciate the excellent support from all of you. Therefore, I have no intention to argue or upset anyone of you.

In any case, what would you consider as a bullshit in the following description?

 

 

Hence, the NACO 2002 S2 data is much more accurate than ever before.

However, It was found that in 2002, S2 was nearly coincident with Sgr A* and it was very bright:

" In 2002, S2 was positionally nearly coincident with Sgr A* and thus confused with the NIR counterpart of the MBH."

"It is clear that S2 was brighter in 2002 than in the following years."

"There are several reasons why a star could change its apparent brightness.":

In the article they have offer several options and tried to evaluate how the interaction with other star or with Srg A* might affect S2 brightness.

If I understand it correctly, the only option which they didn't eliminate was:

"6. The brightness of S2 could be affected by dust in the accretion flow onto the MBH. The dust would be heated by S2 and account for the excess brightness, a proposal that was used by Genzel et al. (2003b) to explain the MIR excess of S2/Sgr A*."

Hence, that proves that by 2002, S2 was absolutely nearly coincident with Sgr A. The Accuracy of MACO gives higher confidence for that observation.

 

 

If you woun't consider it as a bulshit, than the question is:

"So, how could it be that a nearly coincident had been translated to 120 AU?"

 

 

It is stated that the Preiapsis range is 120 AU while the Apoapsis range is 1800AU.

So, how could it be that a nearly coincident had been translated to 120 AU?

 

If I understand correctly the answers, than, this 120AU had been set by an increased error bar.

What does it mean?

What is the real maximal error bar value which the science had been used in order to get this 120AU?

However, Normally, errors bars works with ±

For example, in the article it is stated:

 

https://arxiv.org/pdf/0810.4674.pdf

 

"Our main results are: all stellar orbits are fit extremely well by a single point mass potential to within the astrometric uncertainties, which are now ≈ 6× better than in previous studies. The central object mass is (4.31 ± 0.06|stat ± 0.36|R0 ) × 106M⊙ where the fractional statistical error of 1.5% is nearly independent from R0 and the main uncertainty is due to the uncertainty in R0."

Hence, why technically it couldn't be set to 110 AU, 50AU, 0AU or even a negative direction -120AU?

Each amplitude and direction of error bar should set a different result of center of mass value and location.

So, how could it be that the rest of the world has so high confidence in S2 Center of mass - value and location - if it is based on an error bar???

Edited April 12, 2017 by David Levy

[swansont]

the question is:

"So, how could it be that a nearly coincident had been translated to 120 AU?"

 

 

I have yet to see an argument from you that indicates that these are inconsistent with each other.

[David Levy]

I have yet to see an argument from you that indicates that these are inconsistent with each other.

 

With regards to the orbital fitting process:

 

"The aim of the orbital fitting is to infer the orbits of the individual stars as well as information on the gravitational potential. A Keplerian orbit can be described by the six parameters semi major axis a, eccentricity e, inclination i, angle of the line of nodes Ω, angle from ascending node to pericenter ω and the time of the pericenter passage tP."

 

In the article there is long explanation how they set the fit.

 

I assume that by this process they have concluded that the distance between S2 at its closest place with the center of mass should be 120AU.

 

So far so good!

 

However at the end of that explanation it was stated:

 

"From the numbers it seems that the fit excluding the 2002 data agrees better with the expectations for the coordinate system (equation 4) than the fit including it. The latter is marginally consistent with the priors, while the former is fully consistent. This means that the 2002 data not only affects R0 (which we want to measure and thus cannot use to judge the result) but also the position and velocity of the mass for which we have an independent measurement via the coordinate system definition. This argument points towards rejecting the 2002 data".

 

What shall we understand from the following statement:

 

"fit excluding the 2002 data agrees better with the expectations for the coordinate system (equation 4) than the fit including it."

 

Could it be that the meaning is:

 

"This argument points towards rejecting the 2002 data".

 

Or:

 

2002 data "indicates that these are inconsistent with each other."

 

Hence, it is clear that 2002 data have set a severe problem to the rest of the world.

 

Technically, they could say - well there is no fit with 2002 NACO data, therefore it proves that Srg A* isn't S2 center of mass.

 

However, this was totally unaccepted approach.

 

How could it be that 2002 data does not obey to the rest of the world hypotheses???

 

Therefore, in order to set those problematic data from 2002, a "small" shift by error bar set it on track.

 

Please see Fig 10

 

"Fig. 10.— The 2002 data of S2. The grey symbols show the measured positions, the errors are as obtained from the standard analysis and are not yet enlarged by the procedure described in section 3.5. The black dots are the positions predicted for the observation dates using an orbit fit obtained from all data other than 2002. The blue shaded areas indicate the uncertainties in the predicted positions resulting from the uncertainties of the orbital elements and of the potential, taking into account parameter correlations. The little ellipse close to the origin denotes the position of the fitted mass and the uncertainty in it. This plot shows that the S2 positions are dragged for most of the data by ≈ 10 mas to the NE; they are not biased towards Sgr A*."

 

So,

 

The grey symbols are based on 2002 data. Those naughty symbols contradict the fit process as expected by the rest of the world hypotheses.

 

Therefore those symbols had been dragged by 10 mas to the NE and placed at the new black dot positions.

 

Hence, the error bar is represented by ≈ 10 mas.

 

As I have stated - error bar usually works in all direction.

 

Hence, I would expect that the rest of the world should state the following:

 

This plot shows that the S2 positions are dragged for most of the data by ≈ 10 mas to the NE.

 

The chance for this error (amplitude and direction) in 2002 data is X%.

 

Therefore, the chance that Srg A* is the S2 center of mass is X%.

 

Now it is up to the rest of the world to calculate the value of X%.

 

[swansont]

Could it be that the meaning is:

 

"This argument points towards rejecting the 2002 data".

 

Or:

 

2002 data "indicates that these are inconsistent with each other."

 

Or neither? You seem to have glossed over their lengthy section on their efforts to reconcile using different instruments for different measurements.

 

 

Hence, it is clear that 2002 data have set a severe problem to the rest of the world.

 

Technically, they could say - well there is no fit with 2002 NACO data, therefore it proves that Srg A* isn't S2 center of mass.

 

 

Could they say that? Where's your analysis?

 

I have asked you a number of questions along they way here (as has Strange), and I notice that you have routinely ignored them. Answering them might actually aid in your understanding of this matter.