Direct Imaging of Multiple Planets Orbiting the Star HR 8799
Science, 2008 · paper · Astronomy
Reports direct images, from Keck and Gemini telescopes, of three planets orbiting the star HR 8799 at 24, 38 and 68 astronomical units. All move counter-clockwise, and their brightness and the system's age imply masses of 5 to 13 Jupiters.
Checked: PDF from arxiv.org, fetched 4 Oct 2026. Page numbers are those of that PDF.
6 findings
Substance SOM text dates the 2004 Keck data as "non-ADI NIRC2 data obtained on July 10 2004", while Table 1, Table S1, Table S2 and the Figure 1 and Figure 2 labels all give 2004 July 14.
- p. 22 SOM, ADI Observations and Data Reduction, first paragraph
non-ADI NIRC2 data obtained on July 10 2004
- p. 28 Table S1, first row
2004 July 14
- p. 16 Table 1, astrometry rows
2004 July 14 (±0.005′′)
- p. 17 Figure 1, upper-left panel label
Keck H−band July 14, 2004UT
Judge's note: Viewed the SOM text (page 22), Table 1 (page 16), the Figure 1 panel label "Keck H-band July 14, 2004UT" (page 17), the Figure 2 legend "July 14, 2004UT" (page 18), Table S1 (page 28) and Table S2 (page 29). The Table S1 observing log lists a single 2004 NIRC2 data set, in H band on July 14, so the SOM sentence cannot refer to a second observation. A UT versus local date difference would explain one day, not four. Five places agree on July 14, so the SOM text is the outlier.
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Substance The SOM text (p.22) says the archival Keck data were "obtained on July 10 2004", but Table 1 (p.16), Table S1 (p.28) and Table S2 (p.29) all list the epoch as "2004 July 14".
- p. 22
obtained on July 10 2004 at the Keck Observatory
Only the authors can say what is right here.
Judge's note: Checked the p.22 crop, the Table 1 image (p.16) and the Table S1 image (p.28). All three tables give 2004 July 14, and no other date for the 2004 Keck data appears anywhere in the paper. The date matters for the proper-motion time baseline. The tables agree with each other, so the text's 'July 10' is probably the error, but only the authors can confirm the true date.
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Reference or label Reference "[11] D. Lafrenière et al., Astrophys J. 660, 770 (2007)." is identical to [29] and S6; [11] is cited for "A statistical Bayesian analysis of a dedicated AO survey of nearby young F-, G- and K-type stars", while [29] and S6 are cited for the ADI technique and "The improved ADI LOCI data reduction scheme".
- p. 12 Reference list, entry [11]
[11] D. Lafreni`ere et al., Astrophys J. 660, 770 (2007).
- p. 14 Reference list, entry [29]
[29] D. Lafreni`ere et al., Astrophys J. 660, 770 (2007).
- p. 3 Introduction, end of first paragraph on page
separations > 20 AU around stars with masses similar to the Sun [11]
- p. 30 SOM References, S6
S6 D. Lafreni`ere et al., Astrophys J. 660, 770 (2007).
Only the authors can say what is right here.
Judge's note: Rests on outside knowledge: that ApJ 660, 770 is the LOCI algorithm paper and the survey analysis is a different Lafrenière et al. 2007 article. Verified in the files: entries [11] (page 12), [29] (page 14) and S6 (page 30) are character-for-character the same, and the three citation contexts (page 3 survey statistics; page 6 ADI; SOM LOCI reduction) describe two different kinds of work. The duplicated entry is certain; which volume and page [11] should carry is for the authors.
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Reference or label Reference "[32] D. A. Golimowski et al., Astrophys J. 127, 3516 (2004)." gives volume 127 for a 2004 Astrophys J. article, whereas the list's other 2004 Astrophys J. entries are volumes 603 and 616; the volume fits the Astronomical Journal.
- p. 14 Reference list, entry [32]
[32] D. A. Golimowski et al., Astrophys J. 127, 3516 (2004).
- p. 14 Reference [32]
D. A. Golimowski et al., Astrophys J. 127, 3516 (2004).
Only the authors can say what is right here.
Judge's note: Rests on outside knowledge: that Golimowski et al. 2004 appeared in the Astronomical Journal, vol. 127, p. 3516. Internal evidence from the page 14 image supports it: [36] is Astrophys J. 616 (2004), and the list's Astron. J. entries are 118 (1999) and 124 (2002), so volume 127 in 2004 is consistent with Astron. J., not Astrophys J. Whether the journal name or the volume is the wrong element cannot be settled from the files.
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Reference or label Table 1 row label "Luminosity (LSun)" for the planets lists "−5.1 ± 0.1", "−4.7 ± 0.1", "−4.7 ± 0.1"; these are log10(L/LSun), and the label omits the logarithm.
- p. 16 Table 1, Luminosity row for the planets
Luminosity (LSun)
- p. 16 Table 1, Luminosity row, column b
−5.1 ± 0.1
- p. 20 Figure 4 y-axis
log L/L
Judge's note: Table 1 image (page 16) shows the label with no 'log' and negative values; Figure 4 (page 20) plots the same three points at about -5.1 and -4.7 on an axis labelled log L/L⊙. The same table uses 'Luminosity' with a linear 4.92 ± 0.41 LSun for the star. The data are fine; the label is wrong.
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Wording SOM says "The derived photometry (absolute magnitudes) at all epochs and wavelengths can be found in Table 1", but Table 1 gives one magnitude per band (J, H, CH4S, CH4L, Ks, L'), with no per-epoch values and no K' magnitude.
- p. 24 SOM, photometry paragraph
at all epochs and wavelengths can be found in Table 1
- p. 16 Table 1, photometry rows
MKs (2.146µm)
Judge's note: Viewed the SOM text (page 24), Table 1 (page 16) and Table S1 (page 28). Table S1 shows H observed at three epochs, J and L' at two, CH4S at three including Gemini, and K' on 2008 Aug. 12. Table 1 has six photometry rows with one value per companion and no K' row. The SOM says on page 24 that coronagraphic data were preferred for J, Ks and L', which explains one adopted value per band, but the sentence as written promises more than the table contains. No other table in the PDF gives per-epoch photometry.
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17 minor (typos and the like; most checked by the judge only)
Wording Introduction gives "three faint objects at 0.63′′, 0.95′′ and 1.73′′ (24, 38 and 68 AU projected separation", but Table 1 offsets give 0.62′′, 0.96′′ and 1.72′′ at every epoch, and the AU values in the same sentence match the table, not the quoted arcseconds (0.63′′ and 0.95′′ at 39.4 pc are 24.8 and 37.4 AU).
- p. 4 Introduction, last paragraph
0.63′′, 0.95′′ and 1.73′′
- p. 16 Table 1, 2008 Sept. 18 astrometry
[−0.657, 0.706]
- p. 4 Introduction, last paragraph
three faint objects at 0.63′′, 0.95′′ and 1.73′′ (24, 38
- p. 16 Table 1, astrometry row 2008 Sept. 18, column d
[−0.216, −0.582]
Only the authors can say what is right here.
Judge's note: Read page 4, Table 1 (page 16) and Table S2 (page 29) images. Separations from the 2008 Sept. 18 offsets: d sqrt(0.38538)=0.621′′, c sqrt(0.93009)=0.964′′, b sqrt(2.97159)=1.724′′; no tabulated epoch rounds to 0.63, 0.95 or 1.73. The differences are 0.01′′ and the text may use a different measurement (e.g. Gemini data), which the paper does not state, so this is an author query. The second point in the cluster (Table S2 Sept. 18 average for c N printed 0.706 while the three rounded entries average 0.7053) is not confirmed: a 0.001 difference is within what averaging unrounded values could give; all other averages reproduce.
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Wording "With the large proper motion of HR 8799 (0.13′′/year)": Table 1 proper motion "[107.88 ± 0.76,−50.08 ± 0.63] mas/year" gives a total of 118.9 mas/year, i.e. 0.12′′/year.
- p. 7 Astrometric Analysis, first paragraph
(0.13′′/year)
- p. 16 Table 1, Proper motion [E,N]
[107.88 ± 0.76,−50.08 ± 0.63] mas/year
- p. 7 Astrometric Analysis, first paragraph
With the large proper motion of HR 8799 (0.13′′/year)
Judge's note: Page 7 and Table 1 images read. 107.88^2 + 50.08^2 = 14146.1, square root 118.9 mas/yr; 0.13 squared corresponds to 16900. No statement in the text that the 0.13 includes parallactic motion or comes from another source. Small parenthetical discrepancy.
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Wording The same reference [40] is cited for two different mass thresholds for planets formed by disk instability: "massive planets (> 6 MJup)" (p.10) and "objects with masses above 5 MJup [40]" (p.11, Conclusions).
- p. 10 Third paragraph on page
of massive planets (> 6 MJup)
- p. 11 Conclusions
with masses above 5 MJup [40]
- p. 10 Discussion, formation paragraph
Some models [40] of such instabilities do favor the creation of massive planets (> 6 MJup).
- p. 11 Conclusions
which may form objects with masses above 5 MJup [40]
Only the authors can say what is right here.
Judge's note: Rests on outside knowledge: which threshold Rafikov (2005, ApJ 621, 69; ref [40]) actually gives. Both sentences appear as quoted on the p.10 and p.11 crops, and both cite [40] for the same claim with different numbers. The paper does not explain the difference. It matters because the lower mass bound for b in Table 1 is 5 MJup. Only the authors can say which number they intended.
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Typo "LIR/Lbol = 2.3X10−4": an italic letter X is printed in place of the multiplication sign ×.
- p. 4 HR 8799 Stellar Properties
LIR/Lbol = 2.3X10−4
Judge's note: Page 4 image shows an italic capital X between 2.3 and 10^-4. Cosmetic.
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Typo Star name printed without a space, "HR8799" (page 5: "Our age estimate for HR8799", "lie near HR8799", "similar to that of HR8799"; page 23: "HR8799’s space motion"), against "HR 8799" elsewhere.
- p. 5 Age estimate
Our age estimate for HR8799
- p. 23 SOM
HR8799’s space motion
Judge's note: Page 5 image and page 23 crop both show HR8799 with no space; the same page 5 also prints "HR 8799" several times. Cosmetic inconsistency.
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Typo Missing possessive apostrophe: "details of the stars accretion and atmospheric physics" should read "the star's accretion".
- p. 10 Second paragraph on page
details of the stars accretion
- p. 10 Discussion, second paragraph on page
details of the stars accretion and atmospheric physics
Judge's note: Page 10 image shows no apostrophe; the preceding sentence prints "The star’s metallicity" correctly, so it is not an extraction loss.
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Typo Reference "[16] E. van Leeuwen, Astron. Astrophys 474, 653 (2007).": author initial printed as E., reported to be F. van Leeuwen.
- p. 13 Reference list, entry [16]
[16] E. van Leeuwen, Astron. Astrophys 474, 653 (2007).
Only the authors can say what is right here.
Judge's note: Rests on outside knowledge: that the author of the Hipparcos new reduction paper at A&A 474, 653 is F. van Leeuwen. The page 13 image confirms the entry prints "E. van Leeuwen"; the correct initial cannot be verified from the files.
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Typo Stray commas between initials and surnames in the reference list: "[14] V. Bujarrabal, K., Young, D., Fong"; "[21] J. P. Williams, S. M., Andrews Astrophys J." (also no comma before the journal); "[41] D. Saumon, M. S., Marley"; "[42] C., Ducourant et al."
- p. 13 Reference list, entry [14]
V. Bujarrabal, K., Young, D., Fong
Judge's note: All four entries confirmed on the page 13 and page 14 images. Cosmetic punctuation errors.
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Typo Reference-list formatting slips: S11 "A. S. Ackerman, M. S. Marley, Astrophys J. 556 (2001)." has no page number; stray commas inside author names in [14] "V. Bujarrabal, K., Young, D., Fong", [21] "J. P. Williams, S. M., Andrews Astrophys J." (also missing the comma before the journal), [41] "D. Saumon, M. S., Marley" and [42] "C., Ducourant et al."
- p. 30 SOM References, S11
S11 A. S. Ackerman, M. S. Marley, Astrophys J. 556 (2001).
- p. 13 Ref. [14]
V. Bujarrabal, K., Young, D., Fong, Astron. Astrophys
- p. 13 Ref. [21]
J. P. Williams, S. M., Andrews Astrophys J.
- p. 14 Ref. [41]
D. Saumon, M. S., Marley, Astrophys J.
Judge's note: Viewed the reference lists on pages 13, 14 and 30. Every item is as quoted. Every other journal entry in the SOM list gives volume and first page (for example S10, volume 556, page 357); S11 gives the volume only. The missing page number can be supplied only by the authors or from the cited journal; the punctuation slips are cosmetic.
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Typo Figure 1 caption has a stray article: "to compensate for the orbital motion of the d between July and September" (should be "of d").
- p. 17 Figure 1 caption
motion of the d between July and September
Judge's note: Read the Figure 1 caption on the page 17 image; the text is as quoted. Elsewhere the caption refers to the planet simply as "d".
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Typo Figure 2 caption: "the expected motion of a unbound background objects relative to the star" (wrong article and singular/plural mismatch; should be "an unbound background object" or "unbound background objects").
- p. 18 Figure 2 caption
the expected motion of a unbound
- p. 18
expected motion of a unbound background objects relative to the star
- p. 18 Figure 2 caption
expected motion of a unbound background objects
Judge's note: Read the Figure 2 caption on the page 18 image; the text is as quoted.
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Typo Figure 3 caption says "Old, field (grey dots)", but the figure legend plots field L dwarfs as grey triangles and only field T dwarfs as grey dots.
- p. 19 Figure 3 caption
Old, field (grey dots)
- p. 19 Figure 3 legend
(field)
Judge's note: Viewed Figure 3 on page 19. The legend shows a triangle for L and a filled circle for T, both bracketed as "(field)", and the plot has grey triangles at MH 9.5-12.5. The caption names only grey dots. The legend makes the meaning recoverable, so this is a loose caption rather than a data error.
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Typo Plot symbols for b and c are swapped between figures: Figures 3 and 4 use "HR 8799b (square), c (diamond), and d (circle)", while Figure 5 plots b with open diamonds and c with open squares.
- p. 21 Figure 5, panels b and c
b (820K, 1.3 RJup )
- p. 19 Figure 3 caption
Open symbols are HR 8799b (square), c (diamond)
- p. 20 Figure 4 caption
HR 8799b (square), c (diamond), and d (circle)
- p. 21 Fig. 5 data symbols
Figure 5: Synthetic spectra from model atmospheres
Judge's note: Viewed Figures 3, 4 and 5. The Figure 3 legend and the Figure 3 and 4 captions give b as a square and c as a diamond. In Figure 5 the panel labelled b has open and filled diamonds and the panel labelled c has squares; d is a circle in all three figures. The Figure 5 caption does not define symbols and each panel is labelled with its planet letter, so no data are misattributed.
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Typo Misspelling in the SOM: "d is detected at almost all wavelenghs" (should be "wavelengths").
- p. 24 SOM, photometry paragraph
d is detected at almost all wavelenghs
- p. 24
fact that d is detected at almost all wavelenghs, the Keck data
Judge's note: Read on the page 24 image; the word is printed "wavelenghs".
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Typo Duplicated word in the SOM: "The relative star-to-planet relative intensity is obtained by taking the ratio of the peak fluxes".
- p. 24 SOM, photometry paragraph
The relative star-to-planet rela-
- p. 24
The relative star-to-planet relative intensity is obtained
- p. 24 SOM, photometry paragraph
The relative star-to-planet relative intensity
Judge's note: Read on the page 24 image; "relative" appears twice, the second split across a line break as "rela-tive".
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Typo Number disagreement in the SOM: "estimated from image statistics at the separation of each companions" (should be "each companion").
- p. 25 SOM, top of page
at the separation of each companions
Judge's note: Read on the page 25 image, first line; the text is as quoted.
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Typo SOM: "This later situation is very unlikely since edge-on disks are rare" ("later" should be "latter").
- p. 26 SOM, Planet Atmosphere Modeling, third paragraph on page
later situation is very unlikely
- p. 26
This later situation is very unlikely since edge-on disks
- p. 26 SOM, Planet Atmosphere Modeling
This later situation is very unlikely
Judge's note: Read on the page 26 image. The sentence refers to the second of two alternatives given in the preceding sentence (small radii, or an edge-on disk), so "latter" is meant.
Second check: another model agreed