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An all-sky catalogue of Be transition stars from WISE and Gaia

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Qi Jia, Mingjie Jian, Gang Li, Qian Cui, Chengyuan Li

Solar and Stellar Astrophysics · Submitted 2 Nov 2026 · 300 references

Pith's verdict: Useful, honest catalogue paper: the method is inherited from Jian et al. (2024) but the all-sky sample is new; the one real gap is that purity of the 2,743 new objects is only indirectly validated.

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arXiv ID2611.02450 (version 1)
Pith ID7NZ2K2CJ, Pith's permanent record of this paper and its review
CitationChengyuan Li, Gang Li, Mingjie Jian, Qian Cui, Qi Jia. "An all-sky catalogue of Be transition stars from WISE and Gaia." arXiv:2611.02450 (2026). https://pith.science/paper/7NZ2K2CJ
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The paper

The paper claims

Correlated WISE brightness and colour changes identify 3,300 Be stars in the act of building or shedding their circumstellar disks.

The reading

This paper sets out to prove that a single diagnostic — a tight anti-correlation between a star's brightness at 3.4 μm and its 3.4–4.6 μm colour over years of monitoring — can pick out classical Be stars in the act of building or shedding the gas disk that defines them. Classical Be stars are rapidly rotating B-type stars that episodically eject material into a disk, and the transition between the diskless and disk states is the least understood phase of the phenomenon. Applying this diagnostic to 4.2 million candidate O, B, and A stars selected from Gaia DR3, the authors construct an all-sky catalogue of 3,300 Be transition stars, of which 2,743 are new identifications. Because earlier samples were assembled from heterogeneous spectroscopic databases with uneven sky coverage, this uniformly selected catalogue can support statistical statements about how long disk-building episodes last and how often they recur. The authors report median outburst and decay durations of 459 and 478 days, consistent with the slow timescales of the viscous decretion disk picture in which ejected gas spreads outward through viscosity, and they use TESS and LAMOST data to connect the sample to binarity and spectroscopic variability.

What carries the argument

The load-bearing mechanism is the anti-correlation between the WISE $W_1$ (3.4 μm) magnitude and the $W_1-W_2$ (3.4–4.6 μm) colour across the 13-year WISE/NEOWISE time baseline. A forming circumstellar disk adds an infrared excess that makes the star brighter (smaller $W_1$) and redder (larger $W_1-W_2$); a dissipating disk reverses both, so the two time series move in opposite directions and their Pearson correlation coefficient $r$ falls below $-0.70$. That single threshold, applied to light curves binned per WISE visit after quality, saturation, and magnitude cuts, is what turns 959,512 usable light curves into the 3,300-star catalogue. A secondary piece of machinery is B-spline smoothing of the $W_1$ light curves followed by monotonic-segment detection, which converts each light curve into a sequence of outburst (brightening) and decay (fading) phases whose durations can be measured.

Extended reading notes

Core claim

On the paper's own terms, the central discovery is that correlated mid-infrared variability is a reliable all-sky tracer of disk phase transitions in classical Be stars. During disk formation a star brightens in $W_1$ and reddens in $W_1-W_2$; during dissipation both trends reverse, so requiring a Pearson correlation $r<-0.70$ between the two time series selects stars that are demonstrably changing disk state. From 959,512 stars with usable WISE/NEOWISE light curves, the selection yields 3,300 candidates after visual inspection, recovering 557 objects from the earlier work of Jian et al. (2024) and adding 2,743 new ones that extend the sample to larger heliocentric distances. The authors quantify the trade-off openly: the method captures 210 of the 2,456 BeSS-confirmed Be stars (8.5 per cent overall, 24.6 per cent of those with usable WISE light curves), because it is deliberately a selection for currently transitioning systems rather than a census of Be stars. Ancillary results follow from the catalogue: 63 of 3,017 TESS targets show eclipsing-binary signatures, and two multi-epoch LAMOST sources show candidate radial-velocity shifts above 20 km s$^{-1}$ that the authors argue trace outburst-related line-profile variability rather than unambiguous orbital motion.

Load-bearing premise

The load-bearing premise is that the correlation threshold $r < -0.70$, empirically calibrated by Jian et al. (2024) on spectroscopically confirmed Be stars, keeps its meaning when transferred unchanged to a purely photometric Gaia-selected sample, so the 3,090 newly identified stars are presumed to be genuine Be stars on the strength of the infrared pattern alone.

Editorial extensions

If this is right

  • If the catalogue is as pure as claimed, it is the first all-sky, uniformly selected sample of Be stars observed while their disks are actually changing, enabling statistical studies of outburst frequency, duty cycle, and duration distributions that were not possible from heterogeneous spectroscopic samples.
  • The median outburst and decay durations of 459 and 478 days, with events spanning roughly 200 to 1,800 days, give the viscous decretion disk framework a large empirical anchor: disk build-up and dispersal typically take about 15 to 16 months at the median, and the duration distributions are statistically indistinguishable from those of Jian et al. (2024) (KS p-values of 0.31 and 0.27).
  • The 63 eclipsing binaries found in TESS data (33 Algol-type, 17 Beta Lyrae-type, 13 W Ursae Majoris-type) provide a starting sample for studying whether binarity drives or modulates Be outburst activity; the authors are explicit that this is not a measurement of the binary fraction.
  • The radial-velocity result implies that RV monitoring of actively outbursting Be stars cannot be read as a clean binary diagnostic: two sources show epoch-to-epoch shifts above 20 km s$^{-1}$ with line-dependent behaviour pointing to outburst-related line-profile changes rather than orbital motion.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • A direct purity measurement is already latent in the catalogue: with roughly 15 per cent of the 3,090 new candidates having LAMOST spectra, counting the Hα-emission rate in that subsample would give the first statistical check of how well the $r<-0.70$ calibration transfers to unconfirmed stars, without any new observations.
  • Because the method selects only currently transitioning systems — it recovers just 8.5 per cent of BeSS stars — the catalogue is best paired with a complementary sample of stable-disk and diskless B stars; together they would allow the first all-sky measurement of the Be outburst duty cycle, which this paper does not attempt.
  • The same $W_1$ versus $W_1-W_2$ anti-correlation criterion could be applied to future denser time-domain surveys, such as the Tianyu and Roman programmes the authors mention; if faster cadence resolves shorter outbursts, the median 459/478-day durations may come down, which would be a testable prediction of this paper's completeness model.
  • The threshold itself is a tunable survey knob: relaxing $r<-0.70$ would admit partially sampled, low-amplitude outbursts at the cost of contamination from variable A stars and other mid-infrared variables, so the published boundary is as much a design choice as a physical dividing line.
Original abstract

We present an all-sky catalogue of classical Be stars undergoing transitions between quiescent B-type and active Be-star phases, based on Gaia DR3 astrometry and multi-epoch mid-infrared photometry from WISE and NEOWISE-R. From a Gaia-selected parent sample of 4.2 million candidate OBA stars, we identify Be transition stars through correlated variability in $W_1$ magnitude and $W_1-W_2$ colour, which traces circumstellar disk formation and dissipation. The final catalogue contains 3,300 Be transition stars, including 2,743 newly identified objects, and provides a large, homogeneous sample for studying Be outburst activity across the sky. The median durations of the measured outburst and decay phases are 459 and 478 days, respectively, consistent with previous WISE-based measurements and compatible with the long disk-evolution timescales expected in the viscous decretion disk framework. As an initial application, we use TESS photometry for 3,017 targets to identify 63 eclipsing binary systems hosting Be transition stars, including 33 Algol-type, 17 Beta Lyrae-type, and 13 W Ursae Majoris-type systems. Among the multi-epoch LAMOST spectra, two sources show candidate radial-velocity shifts exceeding 20 km s $^{-1}$; their line-profile behaviour suggests that RV variability in active Be transition stars may be influenced by outburst-related line-profile changes rather than being an unambiguous indicator of binary motion. This catalogue provides a basis for future statistical studies of Be outbursts, disk evolution, and their connection with binarity and spectroscopic variability.

The compiled record

The paper's own sentences, arranged, kept beside the review and separate from it. Each label is drawn from a closed vocabulary; the number beside it is the probability the classifier gave that label. Numbers in the tables are the authors', checked by code. No sentence in this record was written by a model.

Compiled by classifier-1.13.0 via TypeSafe API, question bank abstract-p1-20260923, 2026-11-03: 1 request, 6,070 input tokens.

What the abstract itself states, as probabilities: claims first 0.06 · states limitation 0.85 · human participants 0.01 · controlled comparison 0.05 · randomized assignment 0.01 · states quantitative result 0.99 · compares with prior results 0.92 · mentions code or data availability 0.10.

The abstract, sentence by sentence

arXiv listing abstract v1. Results and the main claim are underlined; .

We present an all-sky catalogue of classical Be stars undergoing transitions between quiescent B-type and active Be-star phases, based on Gaia DR3 astrometry and multi-epoch mid-infrared photometry from WISE and NEOWISE-R. From a Gaia-selected parent sample of 4.2 million candidate OBA stars, we identify Be transition stars through correlated variability in $W_1$ magnitude and $W_1-W_2$ colour, which traces circumstellar disk formation and dissipation. The final catalogue contains 3,300 Be transition stars, including 2,743 newly identified objects, and provides a large, homogeneous sample for studying Be outburst activity across the sky. The median durations of the measured outburst and decay phases are 459 and 478 days, respectively, consistent with previous WISE-based measurements and compatible with the long disk-evolution timescales expected in the viscous decretion disk framework. As an initial application, we use TESS photometry for 3,017 targets to identify 63 eclipsing binary systems hosting Be transition stars, including 33 Algol-type, 17 Beta Lyrae-type, and 13 W Ursae Majoris-type systems. Among the multi-epoch LAMOST spectra, two sources show candidate radial-velocity shifts exceeding 20 km s $^{-1}$; their line-profile behaviour suggests that RV variability in active Be transition stars may be influenced by outburst-related line-profile changes rather than being an unambiguous indicator of binary motion. This catalogue provides a basis for future statistical studies of Be outbursts, disk evolution, and their connection with binarity and spectroscopic variability.

background contribution method result interpretation main claim

What the classifier reports for each sentence. The number is the probability it gave the label.
#sentencerolethe authors' own workstates the main conclusionstrength
s0 We present an all-sky catalogue of classical Be stars undergoing transitions between quiescent B-type and active Be-star phases, based on Gaia DR3 astrometry and multi-epoch mid-infrared photometry from WISE and NEOWISE-R. contribution 1.00 0.96 0.21 asserted 1.00
s1 From a Gaia-selected parent sample of 4.2 million candidate OBA stars, we identify Be transition stars through correlated variability in $W_1$ magnitude and $W_1-W_2$ colour, which traces circumstellar disk formation and dissipation. method 0.99 0.96 0.07 asserted 1.00
s2 The final catalogue contains 3,300 Be transition stars, including 2,743 newly identified objects, and provides a large, homogeneous sample for studying Be outburst activity across the sky. result 0.74 0.97 0.34 asserted 1.00
s3 The median durations of the measured outburst and decay phases are 459 and 478 days, respectively, consistent with previous WISE-based measurements and compatible with the long disk-evolution timescales expected in the viscous decretion disk framework. result 0.92 0.90 0.13 asserted 0.76
s4 As an initial application, we use TESS photometry for 3,017 targets to identify 63 eclipsing binary systems hosting Be transition stars, including 33 Algol-type, 17 Beta Lyrae-type, and 13 W Ursae Majoris-type systems. result 0.72 0.96 0.07 asserted 1.00
s5 Among the multi-epoch LAMOST spectra, two sources show candidate radial-velocity shifts exceeding 20 km s $^{-1}$; their line-profile behaviour suggests that RV variability in active Be transition stars may be influenced by outburst-related line-profile changes rather than being an unambiguous indicator of binary motion. interpretation 0.75 0.93 0.06 hedged possibility 1.00
s6 This catalogue provides a basis for future statistical studies of Be outbursts, disk evolution, and their connection with binarity and spectroscopic variability. future work 0.99 0.23 0.25 asserted 0.91

What kind of paper the classifier reports this is: dataset or benchmark 1.00 · evidence from analysis of existing data 0.98.

What was examined, and what was not

sources read
  • arXiv listing abstract v1
not examined
  • full text
  • figures and tables
  • references and citing sentences
  • relations to other papers
levels run
  • P abstract
not run
  • S sections
  • T body sentences
  • C citations
  • R cross-paper relations

Every quoted sentence on this record is the authors'. Every label is from Pith's closed vocabulary, with the probability shown beside it. Every number in the measurements table is the authors', checked by code. Record as JSON

Figures
Figure 2. WISE light curve of the BeT star Gaia DR3 190242350860127360. Same as
Figure 4. WISE light curve of the BeT star Gaia DR3 4308210849168038400. Same as
Figure 5. Normalised distance distributions of the BeT stars in this work (red) and of Jian et al. (2024) (blue). Distances for both samples are the Gaia geometric distances of Bailer-Jones et al. (2021). 0.0 0.5 1.0 1.5 2.0 W1, ptp (This work) 0.00 0.25 0.50 0.75 1.00 1.25 1.50 1.75 2.00 W 1, p tp ( Jia n + 2 0 2 4 ) 0.0 0.1 0.2 0.3 0.4 0.5 (W1 W2)ptp (This work) 0.0 0.1 0.2 0.3 0.4 0.5 ( W 1 W 2 ) p tp ( Jia n + 2 0 2 4 )
Figure 6. Comparison of 𝑊1 and 𝑊1 − 𝑊2 peak-to-peak amplitudes between this work and Jian et al. (2024). MNRAS 000, 1–15 (2026)
Figure 7. Combined WISE, TESS, and LAMOST view of Gaia DR3 37694252194590976 (TIC 435336653). (a) WISE and TESS light curves; vertical lines indicate LAMOST spectroscopic observation dates. (b) Temporal evolution of the WISE 𝑊1 − 𝑊2 colour. (c) CMD from WISE epoch photometry. (d) Time-varying H𝛼 line profiles from LAMOST spectra of the same target. 0 500 1000 1500 2000 2500 3000 3500 Duration (days) 0 200 400 600 800 1000 1200 1400 Number of phases Outburst Decay O median: 459 days D median: 478 days
Figure 8. Distribution of all measured O and D phase durations. The blue and orange histograms represent the O and D events, respectively. The vertical lines mark the median durations of the measured events (O: 459 days; D: 478 days). distribution and can be readily distinguished from the bulk of the BeT sample. We then cross-matched the remaining 3,036 sources with the TESS variable-star catalogue of Gao et al. (2025), yielding 54 matches, all classified as GCAS (𝛾 Cassiopeiae variables). Because GCAS variables are rapidly rotating B-type stars with mass outflow, physically the same phenomeno
Figure 9. Example TESS light curve of an EB-type eclipsing binary system hosting a BeT star. Top: Lomb-Scargle periodogram (power spectral density, PSD) of the TESS light curve; the red filled circle marks the orbital frequency. Bottom: phased light curve folded on the adopted orbital period; the gray dots show the original data and the red line shows the best-fitting Fourier model. Together with the substantial subset carrying independent Be-related classifications and the spectroscopic and variability-based checks described below, this provides no evidence for a dominant contami￾nating…
Figure 10. 𝑊1 − 𝑊2 colour versus H𝛼 equivalent width for the BeT stars in this work with LAMOST spectra (blue points). The orange shaded region marks the locus occupied by the 916 spectroscopically confirmed BeT stars of Jian et al. (2024), and the vertical dashed line indicates the intrinsic colour (𝑊1 − 𝑊2 )0 ≈ −0.05 mag. interpretation that the bulk of our photometrically selected candidates are classical Be stars. Possible contamination from other variable-star classes is considered further below. MNRAS 000, 1–15 (2026)
Figure 11. Normalized flux as a function of RV for multiple spectral lines of LAMOST J030246.39+523958.8 (Gaia DR3 441009960673526656). The panels show H lines (4861.35, 4101.73, 4340.47 Å) and several He I lines (4026.19, 4387.92, 4921.93, 6678.15, 7065.25 Å). Each panel corresponds to one spectral line, labelled with its rest wavelength. Vertical dashed lines indicate the zero RV. For each line, we report the RV difference between the two epochs and the RV measured at each epoch with its 1𝜎 uncertainty. All flux profiles have been normalized to the local continuum. 1500 1000 500 0 500 1000…
Figure 13. WISE mid-infrared light curves for one RV variable source and one comparison source: LAMOST J030246.39+523958.8 (top panel, Gaia DR3 441009960673526656) and LAMOST J030551.37+522900.5 (bottom panel, Gaia DR3 440215769680339456). Vertical dashed lines mark the epochs of LAMOST LRS observations. 1000 500 0 500 1000 0.7 0.8 0.9 1.0 Normalized Flux H (4861.35Å) RV: 2 km/s 2018-10-31: -33±1 km/s 2014-10-14: -35±2 km/s 500 0 500 He I (4387.92Å) RV: 1 km/s 2018-10-31: -34±3 km/s 2014-10-14: -33±4 km/s 500 0 500 He I (4921.93Å) RV: 1 km/s 2018-10-31: -35±2 km/s 2014-10-14: -34±4 km/s 500 0…

Showing 10 of the paper's 14 figures. See all figures in the PDF ↗ Figures reproduced from arXiv:2611.02450 by the authors.

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