A Star in a 15.2-Year Orbit around the Supermassive Black Hole at the Centre of the Milky Way
2002 · paper · Astronomy
Reports ten years of imaging tracing a star's orbit around the Milky Way's central radio source Sgr A*. The 15.2-year orbit implies an enclosed mass of about 3.7 million Suns, excluding a cluster of objects or degenerate fermions as the central mass.
Checked: PDF from arxiv.org, fetched 4 Oct 2026. Page numbers are those of that PDF.
1 finding
Reference or label Figure 3 caption: "An open rectangle denotes the Bahcall-Tremaine mass estimate obtained from Keck proper motions", and later "Open rectangles denote mass estimates from a non-parametric, maximum likelihood model"; the plot shows one open triangle (near 0.015 pc) that the caption never describes, and three open squares, so the Keck point is evidently the open triangle.
- p. 10 Figure 3 caption
An open rectangle denotes the Bahcall-Tremaine mass
- p. 10 Figure 3 caption
Open rectangles
- p. 13 Figure 3, open symbols between 0.004 and 0.05 pc
radius from SgrA* (pc)
- p. 10 Figure 3 caption
An open rectangle denotes the Bahcall-Tremaine mass estimate obtained from Keck proper motions
Judge's note: Read the caption on page 10 and an enlarged crop of the plot on page 13. The plot has three open squares (near 0.0045 pc and two near 0.045-0.05 pc) and a single open upward triangle near 0.015 pc at about 2.6e6 solar masses with a small error bar. The caption describes filled circle, filled triangles, light filled rectangles, open circles, and "open rectangle" twice for two different data sets (reference 3, singular, and reference 22, plural); it has no entry for the open triangle. The caption text contains no other explanation. The singular Keck estimate matches the single open triangle, so the symbol name in the caption is wrong for that entry. The data are unaffected; this is a symbol label.
Second check: another model agreed
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17 minor (typos and the like; most checked by the judge only)
Wording Text says the peri-centre velocity was "about 8 times greater than 6 years ago1,2 when S2 was at apo-centre", but Table 1 (peri-centre 2002.30, period 15.2 years, eccentricity 0.87) puts apo-centre at about 1994.7, 7.6 years earlier, and gives a peri- to apo-centre speed ratio of about 14.
- p. 3 second paragraph
about 8 times greater than 6 years
- p. 8 Table 1
2002.30
- p. 8 Table 1, Period
15.2
- p. 3 main text, paragraph 2
about 8 times greater than 6 years ago1,2 when S2 was at apo-centre
Only the authors can say what is right here.
Judge's note: Read the sentence on the page 3 image and Table 1 on the page 8 image. Half a period before 2002.30 is 1994.70, not 1996; for a Kepler orbit the peri/apo speed ratio is (1+e)/(1-e) = 14.4. No statement elsewhere in the paper reconciles this. The wording is probably loose: "6 years ago" may point to the dates of references 1 and 2 (1996, 1997), "at apo-centre" may mean near apo-centre, and the factor 8 may compare sky-projected velocities measured at those times. So this is a wording ambiguity and not a definite numerical error; only the authors can say what was meant.
Second check: another model agreed
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Typo Title footnote a reads "based on observations at the Very Large Telescope (VLT) of the European Observatory in Chile"; "Southern" is missing (the same page gives the affiliation "European Southern Observatory").
- p. 1 footnote a
of the European Observatory
- p. 1 footnote a
European Observatory
- p. 1 footnote a
of the European Observatory in Chile
- p. 1 affiliation of Brandner et al.
European Southern Observatory
Judge's note: Checked on the page 1 image. The footnote prints "European Observatory", while the affiliation of Brandner et al. on the same page prints "European Southern Observatory" and page 2 refers to the "ESO VLT". The paper itself supplies the correct name, so no outside knowledge is needed.
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Typo Affiliation note reads "* also Dept. Dept.of Physics, University of California, Berkeley": "Dept." is duplicated and the space before "of" is missing.
- p. 1 affiliation footnote for R. Genzel
also Dept. Dept.of Physics
- p. 1
∗also Dept. Dept.of Physics, University of California, Berkeley
Judge's note: Visible in the page 1 image; not an extraction artefact.
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Typo Misspelling: "theoretical simluations of very dense, core collapsed clusters" should read "simulations".
- p. 4 third paragraph
theoretical simluations
- p. 4 main text, paragraph 3
theoretical simluations of very dense, core collapsed clusters
- p. 4 p.4
theoretical simluations of very dense
- p. 5 p.5
increased resolution and sensibility
Judge's note: Visible in the page 4 image. The other items some reviewers bundled here ("Dept. Dept.", "European Observatory", "sensibility") are covered by C002, C001 and C013; this verdict covers only "simluations".
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Typo "increased resolution and sensibility of the CONICA/NAOS camera" should read "sensitivity" (as on page 2: "To further improve the sensitivity"); and "over 3 orders in magnitude in spatial scale" should read "orders of magnitude".
- p. 5 second paragraph
increased resolution and sensibility
- p. 5 first paragraph
3 orders in magnitude
- p. 5 main text, final paragraph
increased resolution and sensibility of the CON-
- p. 2 main text, paragraph 1
To further improve the sensitivity (by ∼20)
Judge's note: Both are printed on the page 5 image. The paper itself uses "sensitivity" on page 2 and "orders of magnitude" on page 4.
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Typo "The peri-centre distance radius of S2 is 70 times greater": "distance radius" is redundant; one of the two words should have been deleted.
- p. 3 last lines
distance radius of S2 is 70 times greater
- p. 3 main text, last lines of page
The peri-centre distance radius of S2 is 70 times greater
- p. 3 p3, last paragraph
The peri-centre distance radius of S2
Judge's note: Both words are printed on the page 3 image (last lines).
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Typo The fitting software is named "Binary Star Combined Solution Package15" in the text (page 3) and Figure 2 caption, "Binary-Star Combined Solution Program" in the acknowledgments, and reference 15 is titled "A Multiple-Star Combined Solution Program".
- p. 3 second paragraph
Binary Star Combined
- p. 7 Reference [15]
A Multiple-Star Combined Solution Program
- p. 7 Acknowledgments
Binary-Star Combined Solution Program
- p. 3 p3
Binary Star Combined Solution Package15
Judge's note: Confirmed on the page 3 and page 7 images. The Package/Program and hyphenation variation is the paper's own inconsistency. The difference from the reference title may reflect the actual title of the cited abstract, so it is a minor consistency point and not a clear error.
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Typo "over 3 order of magnitude in radius4), its central density": "order" should be plural, and the closing parenthesis after the reference mark has no opening partner.
- p. 4 third paragraph
over 3 order of magnitude in radius
- p. 4 main text, paragraph 3
over 3 order of magnitude in radius4), its
Judge's note: Checked on the page 4 image. The earlier parenthesis "(with a power-law index of α =5)" is already closed, so the ")" after "radius4" is unmatched. The singular "order" is printed.
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Typo "Schwarzschild radius of a black hole16,19 However, it would be very hard": the full stop is missing before "However"; two lines later "accretion16,19.The data" lacks a space after the full stop.
- p. 5 first paragraph
However, it would be very hard
- p. 5 first paragraph
.The data on the Galactic centre
- p. 5 main text, paragraph 1
black hole16,19 However, it would be very hard
- p. 5 p5, paragraph 1
black hole16,19 However, it would be
Judge's note: Checked on the page 5 image: no full stop is printed after the superscript 16,19 before "However", and ".The data" has no space.
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Typo Reference [2] prints the first author as "Genzel, T., Eckart, A., Ott, T. & Eisenhauer, F."; the initial should be R. ("Genzel, R." in references 1, 4, 6 and 14 and in the author list).
- p. 5 Reference [2]
Genzel, T., Eckart, A., Ott, T. & Eisenhauer, F.
- p. 5 reference list, entry [2]
[2] Genzel, T., Eckart, A., Ott, T. & Eisenhauer, F., On the nature of the
- p. 6 reference list, entry [4]
[4] Genzel, R., Pichon, C., Eckart, A., Gerhard, O. & Ott, T.
- p. 6 reference [4]
Genzel, R., Pichon, C.
Only the authors can say what is right here.
Judge's note: Rests on outside knowledge: that the first author of the cited MNRAS 291, 219 (1997) paper is R. Genzel. The page 5 image shows "Genzel, T." as quoted. Support inside the paper is strong: the text cites reference 2 among the group's own earlier work ("SgrA*1−2,4,6"), every other entry gives "Genzel, R.", and "T." matches the initial of "Ott, T." in the same entry.
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Typo Wrong word: "observable with the increased resolution and sensibility of the CONICA/NAOS camera/AO system"; "sensitivity" is meant.
- p. 5 p5, paragraph 2
increased resolution and sensibility of the CON-
Judge's note: Read the crop of page 5: the printed word is "sensibility". The context (faint stars becoming observable with an instrument) calls for "sensitivity". Word-choice slip, meaning recoverable.
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Typo References 2, 4 and 6 give the journal as "Mon.Not.R.Soc.", which omits the "Astron." of Monthly Notices of the Royal Astronomical Society.
- p. 6 Reference [2]
Mon.Not.R.Soc., 291
- p. 6 Reference [4]
Mon.Not.R.Soc., 317
- p. 6 Reference [6]
Mon.Not.R.Soc., 331
Only the authors can say what is right here.
Judge's note: Rests on outside knowledge: the journal's name is Monthly Notices of the Royal Astronomical Society, usually abbreviated Mon. Not. R. Astron. Soc. The page image of page 6 shows "Mon.Not.R.Soc." in references 2 (291, 219-234), 4 (317, 348-374) and 6 (331, 917-934). It is used consistently, so it is a non-standard abbreviation, not a one-off slip; the cited works remain identifiable. Cosmetic.
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Typo Reference 14 has a stray italic initial before the journal name: "Frames at the Galactic Center. R. Astrophys.J., 475, L111–115 (1997)."
- p. 7 Reference [14]
R. Astrophys.J., 475
- p. 7 ref 14
R. Astrophys.J., 475, L111–115 (1997)
- p. 7 ref 18
Viollier, The Motion of Stars near the Galactic Center
Judge's note: Page 7 image: reference 14 lists the last author as "Genzel, R.," and then prints an extra italic "R." between the title and "Astrophys.J.". The stray initial belongs to nothing. The matching problem in reference 18 is judged under C019.
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Typo Reference 18 displaces the second author's initials: "Munyaneza, F. & Viollier, The Motion of Stars near the Galactic Center: ... Fermion Ball Scenarios. R.D. Astrophys. J., 564, 274–283 (2002)"; "R.D." belongs after "Viollier" (as in reference 17), and the entry has no closing full stop.
- p. 7 Reference [18]
Munyaneza, F. & Viollier, The Motion of Stars
- p. 7 Reference [18]
R.D.
- p. 7 reference [18]
Munyaneza, F. & Viollier, The Motion of Stars near the Galactic Center: A Comparison of the Black Hole and Fermion Ball Scenarios. R.D. Astrophys. J.
- p. 7 reference [14]
Galactic Center. R. Astrophys.J., 475
Judge's note: Page 7 image: "Viollier," is followed directly by the title, and an italic "R.D." stands before "Astrophys. J.". Reference 17 on the same page prints "Viollier, R.D.", so the intended form is evident from the paper itself. The entry also ends without a full stop. One reviewer's remark that Munyaneza's initial is missing is wrong: "Munyaneza, F." is printed. The stray "R." in reference 14 is a separate entry, judged under C018.
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Typo Reference 19 prints the third author as "Liambase, G." ("Torres, D. F., Capozziello, S. & Liambase, G., Supermassive boson star at the galactic centre?. Phys.Rev.D., 62, id.104012 (2000)"); the author's name is believed to be Lambiase.
- p. 7 Reference [19]
Liambase, G.
Only the authors can say what is right here.
Judge's note: Rests on outside knowledge: that the third author of Phys. Rev. D 62, 104012 (2000) is G. Lambiase. The page 7 image does print "Liambase, G.". Nothing in the files gives the name a second time, so the spelling cannot be checked here; the authors or the cited paper would settle it.
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Typo Table 1 caption ends with a doubled full stop: "See the caption of Figure 2 for a description of the angles and of the errors.."
- p. 8 Table 1 caption
of the errors..
- p. 8 Table 1 caption
for a description of the angles and of the errors..
- p. 8 Table 1 caption
errors..
- p. 8 Table 1 caption
See the caption of Figure 2 for a description of the angles and of the errors..
Judge's note: The crop of page 8 shows two full stops after "errors". Cosmetic.
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Typo Figure 1 caption: "Right: The central ∼ 2′′ region (rectangle in left inset)"; the left image is the main wide-field panel, not an inset, and the rectangle is drawn in it.
- p. 9 Figure 1 caption
(rectangle
Judge's note: Read the caption crop on page 9 and Figure 1 on page 11. The left panel is the wide-field image and contains a small rectangle at the centre marking the area shown at right; there is no inset in it. "Inset" is used loosely for "panel". The meaning is clear from the figure, so this is a loose word choice and not an ambiguity that misleads.
Second check: none (judge only)