David Levy

Why? O.K. Let look at B. Do you agree that the relative speed between B and A is 0.6 the speed of light? Do you agree that the relative speed between B and C is also 0.6 the speed of light? Hence, do you agree that with regards to B, the relative speed between A and C is 1.2 the speed of light? If the relative speed between A and C is only 1.0 the speed of light, than how could B see A and C moving at 0.6 the speed of light? Yes, that is correct between B to A and B to C. However, that is not relevant to the speed between A to C. One more example - If we look left we can see galaxy D which is moving away from us at almost the speed of light. If we look rightwe can see galaxy F which is moving away from us at almost the speed of light. So, what is the relative speed between D to F?

Yes - At any given aria nothing can go faster than a speed of light. However, Based on relativity - objects can go faster than a speed of light. Hence, even if an object is not moving at a speed of light, there is a possibility that with regards to other object, it could go faster than a speed of light. Explanation: Let assume that A represents an object which is not moving in space. B will represent an object which moves away from A at 0.6 the speed of light. C will represent an object which moves away from B at 0.6 the speed of light (at the same vector as AB). Therefore, the relative speed between A and C is 1.2 the speed of light. Do you agree with that?

Hello Mordred Why is it so important to verify the cause for that outwards orbit migration? Do we have any real evidence about even one moon or planet in the whole universe which has an inwards orbit migration? (unless it is a broken moon or Asteroid)

What do you mean by dormant BH cores? Do we have any evidence for a dormant BH core in spiral galaxy? (Please focus only on spiral galaxy). Do you see any dormant BH core in the following galaxies? M33, Triangulum Galaxy M31, Andromeda Milky Way There is so big difference in their size but somehow there is a fix correlation between the Galaxies and their BH size. How could it be? If the BH will continue to eat some mass from those spiral galaxies, while they won't get new mass – than at some point there must be a significant change in that correlation. How could it be that there are billions of spiral galaxies with a fix BH/Bulge Galaxy correlation, while none of them has a dormant BH??? If the BH increase its mass (even by "some mass"), the galaxy must also increase its mass in order to keep on with this magic correlation. The correlation is one to 700 between the BH and the bulge: "This 1 to 700 relationship supports the notion that the evolution and structure of a galaxy is closely tied to the scale of its black hole". Therefore, if the BH eats one kilogram, than the galaxy bulge must increase its size by 701 kilograms in order to keep on with that correlation. So how they do it? How does the bulge increase its mass by 701 Kilo for every kilo which the BH eats from his mass? It can't be based on a random process. There must be a simple system which could keep that kind of correlation forever and ever.

It is stated that relationship is as follow: "This 1 to 700 relationship supports the notion that the evolution and structure of a galaxy is closely tied to the scale of its black hole". Hence, after one billion, 10 Billion or even 1000 Billion years even "some mass" would become 'significant mass". That could change the requested relationship. So, how could it be that a constant eating of "some mass" by the SMBH, won't set a severe effect in the relationship at very long run?

It is stated: http://www.cosmotography.com/images/supermassive_blackholes_drive_galaxy_evolution_2.html "The size of a supermassive black hole appears to have a direct correlation to the galaxy where it exists. Almost a decade ago, researchers calculated that the mass of a supermassive black hole appeared to have a constant relation to the mass of the central part of its galaxy, known as its bulge (think of the yolk in a fried egg). This 1 to 700 relationship supports the notion that the evolution and structure of a galaxy is closely tied to the scale of its black hole". Hence, the SMBH and its galaxy is similar to one body. However, the rest of the word believes that the SMBH eats stars and mass from its galaxy. This activity would increase the SMBH mass but simultaneously decrease the galaxy mass. Therefore; How could it be that the SMBH eats its galaxy mass, while the size of a suppermassive black hole appears to have a direct correlation to the galaxy where it exists?

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%.

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? 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?" 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???

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.

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?

Thanks We see S2 Orbit 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?

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?

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.

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?

Yes, all of those points are important. However - the most important one is that S2 is near periapsis Therefore - 2002 data is absolutely important. Thanks So, you agree that without increasing the error bar above the expected accuracy there is no fit. 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?

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.

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"?

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?

Not at all! It is not stated anywhere in the article that the measurement accuracy in 2002 was poorer than the average. They claim clearly that In order to set the fit, they had to disregard 2002 data of S2 or to increase the error bar level. Therefore, it is clear that based on 2002 measurement + the maximal permitted accuracy they didn't get any fit. Just after increasing the error bar above the maximal permitted level they have got some sort of fit. However, even this fit includes offset and non zero velocity of the central point of mass. This by itself is a key violation for Keplerian ellipse. One more question - Why is it so important for the scientists to prove that S2 center of mass is Sgr A*?

Well, if you don't know, than technically you can't reject my conclusion. However, I assume that we all have some sort of basic common sense. So, please try to answer the following simple questions: 1. Assuming that 2002 data of S2 meets perfectly the fit between S2 center of mass and Sgr A*; Do you think that our scientists would consider to: completely disregard the 2002 data of S2 or to include the 2002 data with the increased error bar? Please - only Yes or No ("I don't know" - is not a valid answer) 2. What is the meaning of: "increased error bar" message? The meaning of "Error bar" is quite clear by google: "a line through a point on a graph, parallel to one of the axes, which represents the uncertainty or error of the corresponding coordinate of the point." So I assume that this is based on our accuracy. Hence, each accuracy level associates with some sort of error bar level. However, when we say "Increased error bar" - what does it mean? The meaning by cambridge dictionary. http://dictionary.cambridge.org/dictionary/english/increase?q=Increased+ Increased - to (make something)become larger in amount or size: The cost of the project has increased dramatically/significantly since it began. So could it be that increased error bar" means higher/larger error bar? In other words - could it be that our scientists are using higher error bar level than the permited accuracy?

So can you please send your reply with regards to all the above points 1-8 ? In any case, based on your understanding, why our scientists had to consider the following two options?: "a) we include the 2002 data with the increased error bars; b) we completely disregard the 2002 data of S2." Why they couldn't use 2002 data as is?

O.K. I assume that by now it's clear for all of us that based on 2002 data there is no fit. It means that S2 center of mass is not Sgr A*. Few questions: 1. a. Why our scientists refused to accept 2002 Data as is (although they were very proud with their accuracy)? b. Why it was so important for them to prove a fit against the evidences? c. Why they do not introduce new updated data on S2 orbit? d. Why they do not set other S0 stars calculations for center of mass? 2. What could be the impact of that non fit discovery?

Thanks Janus In the article it is stated that S2 and Sgr A* were - "nearly coincident". This isn't the case in your fig. However, the 2002 data dilemma with regards to S2 center of mass had been introduced deeply by our scientists. Please see the following: https://arxiv.org/pdf/0810.4674.pdf 1. Disregard the 2002 data of S2 - "Thus, it is clear that using the 2002 data will affect the results, but we cannot decide whether it biases towards the correct solution or away from it. Therefore we use in the following two options: a) we include the 2002 data with the increased error bars; b) we completely disregard the 2002 data of S2." So, if the 2002 data was correlated with the scientists expectations of fitting S2 central mass into the Sgr A*, they wouldn't consider those two options, especially not to disregards that data. Hence, it is clear that based on the pure 2002 - There is no fit!!! That is my understanding from that indirectly statement. 2. Increased error bars - So, in order to set the fit, our scientists select the option to increase the error bars on 2002 data to its maximal positions. We see the impact o that "increased error bars" in 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." So they have shift S2 location with the maximal error bar in order to set the fit. However, error bars works in all directions. Hence, technically, if we would shift S2 location just to the other side at the same error bar value we could find that Sgr A* is already outside the S2 orbit plane. Therefore, let me ask the following: Please look again on fig 10. Let's set a circle around the real location of S2 (based on 2002 data) with a radius of the maximal error resolution. Now, what is the chance that S2 should be moved to those selected new points out of all the other possibilities (based on the maximal error resolution)? I would assume that from statistical point of view it is very low! Therefore, I wonder why our scientists decided to set the error bar just in the amplitude and direction which fits their expectation. 3. Why they only consider those two options? Why they do not consider that there is a possibility that 2002 data is correct? Why they couldn't ask themselves - could it be that there is no fit? Why always our scientists try to fit the evidences to their expectations? 4. Offset and non zero velocity- Even after fixing the 2002, they have found that there is an offset and non zero velocity between S2 center of mass and Sgr A*. This is a clear violation of the basic requirements from any sort of Keplerian ellips. How can we accept it? 5. Hiding 2002 data dilemma from the Abstract - In the abstract of that article it is stated: "We present the results of 16 years of monitoring stellar orbits around the massive black hole in center of the Milky Way using high resolution near-infrared techniques. 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. The combination of a long time baseline and the excellent astrometric accuracy of adaptive optics data allow us to determine orbits of 28 stars, including the star S2, which has completed a full revolution since our monitoring began." Not even one word about the huge dilemma of 2002 data. They are proud of their accuracy, but they have forgotten to mention that directly based on the 2002 Data there is no fit! Actually just based on the very poor resolution, they could set some sort of a fit!!! In other words, in the article they use their poor accuracy to set the fit, while in the abstract they highlight their excellent accuracy. So, why they are so proud with this accuracy if in the article it is stated clearly that they have to shift S2 position to the maximal error bar in order to set a fit (and even with that fit they still have a relative offset and non zero velocity)? 6. New S2 data – We are already 15 years after 2002. Soon, S2 should complete one more cycle and come close to Sgr A*. In those 15 years we have improved our accuracy. So where is the updated data??? 7. Other S0 stars: Why we just set the calculation on S2? what about all the others? Did we try to evaluate Sgr A* mass by one of the other S0 star orbit? 8. Why our scientists are in panic to prove that Sgr A* is the only valid option for S2 center of mass? What could be the disaster if we will discover that it isn't? Why it was so difficult for them to say clearly that based on pure 2002 data there is no fit?

Well it is even more complicate In a kepler orbit the center of mass must be located at the same plate as the orbit itself. https://en.wikipedia.org/wiki/Kepler_orbit#/media/File:Kepler_orbits.svg Therefore, we are looking on a 2D orbit system which is located in a 3D space by a 2D observation. So, you claim that we can see one in the front while the other one is located behind the other. However, if I understand it correctly, in order to achieve it, Sgr A* can't be located at S2 orbit cycle plate Well, I have tried all the possibilities for a 2D ellips, while the center is located at the same plate of the orbit. Unfortunately, I couldn't get a result which is similar to S2 orbit shape with a similar asymmetric location of center of mass. However, once the Sgr A* is moved outside the orbit plate than you get it immediately. So, can we understand that Sgr A* is not located on S2 orbit plate?

With regards to the distance between S2 and Sgr A* in 2002 In 2002 S2 was at the closest position to Sgr A*. (nearly coincident). ". In 2002, S2 was positionally nearly coincident with Sgr A* and thus confused with the NIR counterpart of the MBH. Typically, Sgr A* is fainter than mK = 17 and thus the extra-light from Sgr A* in quiescence is not sufficient to explain the observed increase in brightness of S2. However, Sgr A* is known to exhibit flares that can reach a brightness level that could account for the observed increase in brightness" So, when S2 was nearly coincident with Sgr A* its brightness increased significantly. One of the explanation for that was that the extra brightness came from Sgr A*: " 4. Loeb (2004) proposed that the stellar winds of early-type stars passing their pericenters close to the MBH could alter the accretion flow onto Sgr A*. Such an event would produce a change in the brightness of Sgr A* on the timescale of months, compatible with Figure 8. However, Martins et al. (2008) showed that the mass loss rate of S2 is too low for this mechanism to work." So, does it mean that S2 and Sgr A* were exactly at the same spot? Otherwise, Loeb would not even consider an option that the extra light came out of Sgr A* which was at the same spot as S2. If so, why they claim nearly coincident? why not Fully coincident? And if it was so close, why they didn't collide? How could it be that the Sgr A*with its all of its Huge mass and gravity power didn't eat S2? In any case, in fig 10 it is stated that the scientists fixed that position of S2. "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." However, Sgr A* was exactly at the same position as S2. So, why our scientists decided to fix the data only for S2? If there is an error as it is stated by our scientists, than this error should also apply to Sgr A* position. Hence, why they only adjust S2 with the maximal error threshold while they didn't move Sgr A* accordingly to the selected maximal error margin?.