The Discovery of Two LISA Sources within 0.5 kpc
Bibliographic record
Abstract
Abstract We report the discovery of the brightest detached binary white dwarfs with periods less than an hour, which provide two new gravitational-wave verification binaries for the Laser Interferometer Space Antenna (LISA). The first one, SMSS J033816.16−813929.9 (hereafter J0338), is a 30.6 minute orbital period, g = 17.2 mag detached double white dwarf binary with a Gaia parallax measurement that places it at a distance of 533 pc. The observed radial velocity and photometric variability provide precise constraints on the system parameters. J0338 contains a 0.230 ± 0.015 M ⊙ white dwarf with a 0.38 − 0.03 + 0.05 M ⊙ companion at an inclination of 69° ± 9°. The second system, SDSS J063449.92+380352.2 (hereafter J0634), is a 26.5 minute orbital period, g = 17.0 mag detached double white dwarf binary at a distance of 435 pc. J0634 contains a 0.452 − 0.062 + 0.070 M ⊙ white dwarf with a 0.209 − 0.021 + 0.034 M ⊙ companion at an inclination of 37° ± 7°. The more massive white dwarf in J0634 is hotter than its companion, even though tidal dissipation is predicted to be relatively inefficient at such periods. This suggests that the more massive white dwarf formed last. J0338 and J0634 will be detected by LISA with a signal-to-noise ratio of 5 and 19, respectively, after four years. We identified these two systems based on their overluminosity and u-band photometry. Follow-up of u-band selected Gaia targets will likely yield additional LISA verification binaries.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.002 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 0.002 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".