{"id":"a7b59bc3-d17e-4a47-8f99-502abad8afea","arxiv_id":"2507.20206","paper_version":1,"verdict":"CONDITIONAL","confidence":"MODERATE","novelty_score":6.0,"correctness_risk":"medium","formal_verification":"none","parameter_count":3,"one_line_summary":"A Gaia-based HRD preselection plus LAMOST emission-line diagnostics yields five new symbiotic stars and twenty-six new symbiotic star candidates.","lead":"Using 13 million LAMOST spectra and Gaia distances, the authors searched for symbiotic binaries, pairs in which a cool giant orbits a hot compact star. They report five newly identified symbiotic stars and twenty-six additional candidates that still need confirmation.","discovery_kind":"new_application","skeptic_critique":{"model":"deepseek-v4-flash","headline":"HRD preselection admits pre-main-sequence stars; one new symbiotic (ATO J094...) has a prior YSO classification dismissed only by HRD position, so the strongest claim is not yet secure.","rationale":"The reader correctly identifies the HRD box as the weak link, and I partially agree. My stress-test sharpens this into a concrete failure mode: PMS stars occupy the same HRD region, and the candidate list already contains known members of a young cluster (NGC 2244). Because the paper's emission-line criteria are formal (0.5 sigma threshold, no equivalent widths, no control sample), the method cannot distinguish symbiotic stars from PMS stars or H II region contamination. Among the five new symbiotics, ATO J094.1375+07.5304 is the most vulnerable: the paper explicitly cites a prior YSO classification but dismisses it solely on HRD location, which is not a discriminating argument. The two systems independently confirmed by Chen et al. (2025) stand, and ZTF J005917.52+315605.4 and LAMOST J200310.90+360822.6 show strong He II and molecular absorption, so I would not reject the paper. However, the summary claim should be conditional on confirming ATO's nature and on testing for nebular [O III] contamination in the candidate tier. This matches the CONDITIONAL verdict, so the reader's verdict remains unchanged.","tokens_in":18839,"tokens_out":14998,"duration_ms":167074,"concrete_test":"Obtain a high-resolution spectrum (e.g., X-shooter or UVES) of ATO J094.1375+07.5304 and measure the Li I 6708 resonance line and the WISE/2MASS infrared excess: strong Li and a disk-like K-W2 excess would confirm the prior YSO classification and remove it from the new-symbiotic list, while no Li and S-type symbiotic IR colors would support the paper's claim.","verdict_should_be":"UNCHANGED","load_bearing_attack":"The most load-bearing weakness is the assumption in Section 3.1 that the Gaia-HRD box selects late-type giants. The box (G_BP-G_RP 0.95-4.05, M_G -10 to 3.05) overlaps the locus of pre-main-sequence (PMS) stars, whose H I, He I, and [O III] emission can mimic symbiotic diagnostics. This is not hypothetical: Table 4 lists Cl* NGC 2244 PS 47 (J063134.09+050418.4), a member of the young cluster NGC 2244, plus several other candidates in the same Rosette star-forming region, where [O III] may be nebular H II region emission rather than evidence of a hot companion. More directly, ATO J094.1375+07.5304, one of the five claimed new symbiotic stars, was previously classified as a young stellar object by Zhang et al. (2023); the paper rejects that classification only because the object sits in the HRD giant region, yet PMS stars occupy the same HRD area. Consequently, the abstract's central claim that five systems 'have been found as new symbiotic stars' is not yet secure: if ATO is a YSO, the new-detection claim drops to four, and if the H II region interpretation applies, the 26-candidate tier is substantially contaminated.","agreement_with_reader":"partial"},"referee_report":{"model":"deepseek-v4-flash","summary":"The paper reports a systematic search for symbiotic stars in LAMOST low-resolution spectra from DR12 v1.0 and DR13 v0. The method first selects candidate late-type giants using a Gaia color-absolute-magnitude box defined from the overlap of known symbiotics and a giant catalog, then inspects the LAMOST spectra of the resulting ~1.06 million objects for strong H I and He I emission together with at least one high-ionization line ([O III], He II, [Ne III], O VI, or [Fe VII]). The output is 36 systems: five known symbiotics recovered from the literature, five systems claimed as new symbiotics (three here, and two independently also reported by Chen et al. 2025), and 26 candidates selected primarily by [O III] emission in the absence of He II. Two of the new objects are also validated by an adjacent-fiber contamination check in an appendix.","tokens_in":18952,"tokens_out":10394,"duration_ms":97220,"significance":"If correct, the discovery adds up to five objects to the small Galactic symbiotic sample, of which three are not yet independently confirmed. The paper's strengths are its honest recovery of five known symbiotics as a validation set, the independent confirmation of two of its new detections, and the careful check of LAMOST fiber-mask contamination in Appendix A. However, the result rests on an HRD selection box that is not demonstrated to exclude pre-main-sequence stars, and on a very permissive emission-line threshold. The two objects confirmed by Chen et al. (2025) are the most secure; the three remaining new symbiotics and the entire 26-object candidate tier need additional validation before they can be considered established. If the contamination concerns are resolved, the candidate list would still be a useful resource for follow-up.","major_comments":[{"comment":"The HRD selection box is defined from the known symbiotics and the giant catalog, and the argument that ATO J094.1375+07.5304 is a giant rather than a pre-main-sequence star (previously classified as a YSO by Zhang et al. 2023) is based solely on this same HRD box; this is circular. In addition, the LAMOST giant sample is selected with only a ϖ>0 cut, not the ϖ/σϖ>100 quality cut used to build the background HRD, so absolute magnitudes of distant sources have large errors and the box can admit main-sequence or PMS stars. Please add a parallax-quality criterion and test the PMS hypothesis for ATO J094... using lithium λ6708, WISE W1-W2 colors, and matches of the LAMOST spectrum against giant and YSO templates.","section":"Section 3.1 / Section 4.1.2"},{"comment":"The 26 candidates are selected solely on the basis of H I, He I, and [O III] emission without He II. Several of these objects are spatially concentrated in the Rosette Nebula / NGC 2244 star-forming region (e.g., Cl* NGC 2244 PS 47 = J063134.09+050418.4, and also J063148.01+051037.6, J063257.79+051427.2, J063133.88+050024.3). In this environment [O III] can be produced by the H II region or by young-star activity rather than by a hot companion ionizing the wind of a late-type giant. The paper does not check the angular offset from known nebulosity, the radial-velocity coincidence of the [O III] line with the nebula, or the presence of other nebular diagnostics. These checks should be performed before the candidate tier is presented as a symbiotic-star sample.","section":"Section 4.3 / Table 4"},{"comment":"The detection rule 'flux exceeds 0.5σ above the pseudo-continuum' is very permissive, and the paper provides no minimum S/N, equivalent-width threshold, or line-width criterion. With ~1.06 million spectra processed, spurious 0.5σ features will certainly be flagged; Tables 2-5 give only presence/absence of lines, so the reader cannot assess the significance of any individual detection. I ask that the authors report measured equivalent widths and S/N for the key lines (Hα, Hβ, He I 5876, He II 4686, [O III] 5007) for all 36 objects and estimate how many chance detections are expected under this threshold.","section":"Section 3.2"}],"minor_comments":[{"comment":"The heading 'Twenty-six new symbiont star candidates' and the Table 4 caption should say 'symbiotic star candidates'; 'symbiont' appears to be a typo.","section":"Section 4.3 / Table 4"},{"comment":"Section 2 reports 13,290,865 low-resolution spectra, while Section 5 cites 13,302,574 spectra including machine-learning candidates from Y. Jia et al. (2023); the source and processing of the additional 11,709 spectra are not described in the Data section.","section":"Section 2 vs Section 5"},{"comment":"The Figure 3 caption says the light green points denote the 355 known symbiotic stars from the Merc catalog, but Section 3.1 states that the cross-match with Gaia DR3 yielded only 318 counterparts; please reconcile the numbers.","section":"Figure 3"},{"comment":"The note to Table 2 describes R_V, T_eff, and logg as coming from both Gaia and LAMOST, but the table shows a single value per column; please clarify which values are Gaia and which are LAMOST for each star.","section":"Table 2"},{"comment":"Table 4 lists two candidates with Gaia effective temperatures of 15005 K and 9912 K (J063257.79+051427.2 and J063133.88+050024.3) that are nonetheless claimed to be late-type giants; this is inconsistent with the method and should be explained (e.g., unreliable GSP-Phot temperatures for emission-line stars).","section":"Table 4"},{"comment":"The reference to 'J.-C. Nussbaumer et al. 1989' cites 'British journal of pharmacology, 98, 373', which is clearly a misattribution; please replace it with the correct astronomical reference for the λ6830 Raman-scattered O VI feature.","section":"References"}],"recommendation":"major_revision","confidential_remarks":"The paper is within the scope of the journal and the analysis is straightforward. The main concern is that the headline claim of 'five new symbiotic stars' overlaps substantially with Chen et al. (2025); the truly new secure objects are three. The candidate list could be genuinely useful, but only after the contamination issues are addressed. I recommend major revision."},"author_rebuttal":null,"desk_editor":{"model":"deepseek-v4-flash","letter":"Dear [Name], quickly: this paper is a systematic search for symbiotic stars in 13.3 million LAMOST spectra. The headline claim of five new symbiotics is plausible for three of the objects, but not yet secure because the HRD preselection admits pre-main-sequence stars, and one of the claimed symbiotics (ATO J094137.5+075304) has a prior YSO classification. The 26 candidates, in particular, look vulnerable to contamination from young stars and H II regions; many are in the direction of the Rosette Nebula.\n\nWhat is genuinely new: three objects are newly claimed as symbiotics (ZTF J005917.52+315605.4, ATO J094137.5+075304, LAMOST J200310.90+360822.6), and two more (LAMOST J072528.18+342530.4, V* V758 Cyg) were independently confirmed by Chen et al. (2025) during the same period. The independent confirmation of the last two lends credibility to the method. The paper also checks for adjacent-fiber contamination in the two fiber-mask-flagged sources, which is a thoughtful step. The references are appropriate and include the relevant recent work.\n\nWhere the soft spots are: the HRD box (G_BP-G_RP 0.95-4.05, M_G -10 to 3.05) is defined from 318 nearby, high-confidence symbiotics and 3,675 giants, but it is then applied to over a million LAMOST sources with only parallax > 0, no precision cut. That box overlaps the PMS locus. ATO J094... was classified as a YSO by Zhang et al. (2023); the paper rejects that only because the object sits in the giant region of the HRD, which is not a discriminating argument. For the 26 candidates, the only high-ionization line is [O III] (no He II), and several are in the Rosette Nebula region, where [O III] can be nebular H II emission. A control sample would have helped; none is presented. The emission-line detection threshold is 0.5 sigma above a pseudo-continuum, with no equivalent widths or S/N reported; at that threshold, noise can easily be flagged as emission. The 'noise exclusion' step is not described quantitatively.\n\nNet: the paper is worth taking seriously. The two objects confirmed by Chen et al. (2025) are probably real symbiotics, and the spectra of the other three show strong He II and giant absorption, so the core detections are not implausible. But the strongest claim — five new symbiotics — needs revision, and the candidate tier needs a proper false-positive estimate and a discussion of star-forming regions. I would send it to peer review, with major revision required: add a control sample, report equivalent widths, and re-examine ATO and the Rosette sources. It is a useful contribution to the symbiotic-star catalog, but it is not a finished piece in its current form.","headline":"A systematic but undercooked search: the five new symbiotics are plausible for two, doubtful for one (ATO is a known YSO), and the 26 candidates may be contaminated by star-forming regions.","tokens_in":19670,"tokens_out":6589,"would_cite":false,"duration_ms":60159,"reading_group":"maybe","serious_thinker":"yes","would_accept_peer_review":true},"rs_alignment":null,"lean_confirmation":null,"pith_extraction":{"msc":[],"pacs":[],"model":"deepseek-v4-flash","headline":"This paper reports five new symbiotic stars and 26 candidates selected from more than a million late-type giants in LAMOST low-resolution spectra.","keywords":["symbiotic stars","LAMOST","low-resolution spectroscopy","emission-line stars","late-type giants","Hertzsprung-Russell diagram","Gaia astrometry","Type Ia supernova progenitors"],"falsifier":"For any of the three singly reported new symbiotics—for example, LAMOST J200310.90+360822.6—take repeated high-resolution spectra: if the giant absorption lines show no orbital velocity shift and the He II/[O III] emission turns out to come from a foreground or unrelated nebula rather than from a hot companion irradiating the giant, the symbiotic classification collapses. The same test applied to the 26 candidates would separate true symbiotics from other emission-line stars.","tokens_in":18494,"feed_emoji":"🔭","tokens_out":8707,"duration_ms":78491,"temperature":0.7,"pith_summary":"This paper searches for undiscovered symbiotic stars—binaries in which a cool giant star orbits a hot white dwarf or other compact companion—using more than 13 million low-resolution spectra from LAMOST. It claims that restricting the sample to 1,061,427 late-type giants via a Gaia color–magnitude box, then requiring strong H I and He I emission plus at least one high-ionization line, recovers all tested known symbiotics and yields five new symbiotic stars and 26 candidates. The result matters because fewer than 400 symbiotic stars are known while population estimates range into the thousands; every new system is a testbed for wind accretion, nova eruptions, and Type Ia supernova progenitor scenarios. The five new systems are ZTF J005917.52+315605.4, ATO J094137.5+075304, LAMOST J200310.90+360822.6, LAMOST J072528.18+342530.4, and V* V758 Cyg, with the last two also confirmed by an independent recent study.","feed_headline":"Five new symbiotic stars found in LAMOST spectra","feed_subtitle":"26 more candidates join the hunt for binaries that may explode as Type Ia supernovae.","key_machinery":"The load-bearing machinery is a two-stage selection funnel. Stage one is a Hertzsprung-Russell diagram box—$G_{BP}-G_{RP}$ between 0.95 and 4.05 with absolute magnitude $M_G$ between $-10$ and 3.05—drawn from the overlap of 318 known symbiotic stars and 3,675 catalog giants; it reduces 13,290,865 LAMOST spectra to 1,061,427 late-type giant spectra. Stage two is a normalized-spectrum emission-line screen that requires strong H I and He I emission plus at least one of [O III], O VI, He II, [Fe VII], or [Ne III], lines whose ionization potentials exceed 35 eV. The pipeline also inspects LAMOST fiber-mask flags to exclude spectra contaminated by light from adjacent fibers, which matters for two of the new detections.","core_discovery":"The central claim is that five previously unlisted binaries are symbiotic stars and that another 26 systems are strong candidates. The five—ZTF J005917.52+315605.4, ATO J094137.5+075304, LAMOST J200310.90+360822.6, LAMOST J072528.18+342530.4, and V* V758 Cyg—show late-type giant absorption features together with strong H I and He I emission and high-ionization lines such as He II or [O III], signatures of a hot companion ionizing material around a cool giant. Two of them, LAMOST J072528.18+342530.4 and V* V758 Cyg, were simultaneously reported as symbiotic stars in another study, which the paper reads as independent confirmation of the method. The 26 candidates show H I, He I, and [O III] emission and giant absorption but lack the He II $\\lambda4686$ line, so the paper stops short of calling them confirmed symbiotics and calls for follow-up observations.","pith_inferences":["The paper does not test how the HRD box transfers from the nearby, high-precision calibration sample to the much larger LAMOST set, which was filtered only by positive parallax; distant giants could be lost and non-giants admitted, so the yield is best read as a lower bound until that transfer is checked.","Because the 26 candidates are separated from the confirmed stars by a single missing line (He II), some may simply be lower-excitation symbiotics rather than a distinct population; a UV or X-ray detection of the hot component, or time-resolved radial velocities, would decide.","A natural extension is to rerun the same emission-line screen without the HRD cut, or with widened boundaries, to measure how candidate counts respond; that would quantify completeness and could be done with existing LAMOST and Gaia catalogs."],"forward_implications":["The confirmed Galactic symbiotic population grows by five, a small but concrete step toward the thousands predicted from stellar-population arguments.","The 26 candidates, if follow-up spectroscopy confirms them, would roughly double the yield of this search.","Two of the new systems were found independently by another group, so the selection criteria have an external check.","Previously cataloged interpretations of some objects—such as a young stellar object classification for ATO J094137.5+075304—are challenged by the giant-star evidence assembled here.","Widening the HRD box, as the paper suggests, would likely reveal more systems outside the current selection region."],"supporting_citations":[{"why":"Provides the 355-object symbiotic catalog used to build the HRD selection box and to check recovery of known systems.","marker":"J. Merc et al. (2020)"},{"why":"Supplies the observational definition of symbiotic stars whose line criteria the selection implements.","marker":"K. Belczyński et al. (2000)"},{"why":"Establishes the LAMOST low-resolution spectral method for identifying symbiotic stars, which this work extends with additional diagnostic lines.","marker":"J. Li et al. (2015)"},{"why":"Provides the 3,675 late-type giant catalog whose Gaia colors and magnitudes define the HRD overlap region.","marker":"S. Li et al. (2022)"},{"why":"Independently confirms LAMOST J072528.17+342530.4 and V* V758 Cyg as symbiotic stars, corroborating two of the five detections.","marker":"J. Chen et al. (2025)"}],"fun_headline_variants":["5 new symbiotic stars plus 26 candidates found in LAMOST survey","Symbiotic star discovery: 5 new, 26 candidates from LAMOST","31 new symbiotic star systems: 5 confirmed, 26 candidates","LAMOST yields 5 new symbiotic stars, 26 more candidates"],"cache_read_input_tokens":3200,"weakest_assumption_plain":"The paper assumes that the color–brightness box drawn around a few hundred nearby known symbiotics and several thousand catalog giants will still pick out genuine giant stars when applied to more than a million LAMOST sources that were included merely because their Gaia parallax is positive.","fun_headline_variants_meta":{"raw":{"variants":["5 new symbiotic stars plus 26 candidates found in LAMOST survey","Symbiotic star discovery: 5 new, 26 candidates from LAMOST","31 new symbiotic star systems: 5 confirmed, 26 candidates","LAMOST yields 5 new symbiotic stars, 26 more candidates"]},"model":"deepseek-v4-flash","effort":"low","cost_usd":0.000831,"raw_usage":{"total_tokens":3660,"prompt_tokens":1008,"completion_tokens":2652,"prompt_tokens_details":{"cached_tokens":384},"prompt_cache_hit_tokens":384,"prompt_cache_miss_tokens":624,"completion_tokens_details":{"reasoning_tokens":2580}},"tokens_in":624,"tokens_out":2652,"duration_ms":19377,"temperature":1.0,"reasoning_tokens":2580,"cache_read_input_tokens":384,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-08-15T17:47:31.956592+00:00","model_set":{"reader":"deepseek-v4-flash"},"falsifier":"For any of the three singly reported new symbiotics—for example, LAMOST J200310.90+360822.6—take repeated high-resolution spectra: if the giant absorption lines show no orbital velocity shift and the He II/[O III] emission turns out to come from a foreground or unrelated nebula rather than from a hot companion irradiating the giant, the symbiotic classification collapses. The same test applied to the 26 candidates would separate true symbiotics from other emission-line stars.","supporting_citations":[{"cited_title":"2020, title Galactic members in the New Online Database of Symbiotic Variables, Contrib","cited_arxiv_id":null,"evidence_quote":"Provides the 355-object symbiotic catalog used to build the HRD selection box and to check recovery of known systems."}],"review_version":2}