PTF1 J085713+331843, a new post-common-envelope binary in the orbital period gap of cataclysmic variables
Bibliographic record
Abstract
We report the discovery and analysis of PTF1 J085713+331843, a new eclipsing post-common-envelope detached white-dwarf–red-dwarf binary with a 2.5 h orbital period discovered by the Palomar Transient Factory. ULTRACAM multicolour photometry over multiple orbital periods reveals a light curve with a deep flat-bottomed primary eclipse and a strong reflection effect. Phase-resolved spectroscopy shows broad Balmer absorption lines from the DA white dwarf and phase-dependent Balmer emission lines originating on the irradiated side of the red dwarf. The temperature of the DA white dwarf is TWD = 25 700 ± 400 K and the spectral type of the red dwarf is M3–M5. A combined modelling of the light curve and the radial velocity variations results in a white dwarf mass of |$M_\mathrm{WD} = 0.61^{+0.18}_{-0.17}\, \mathrm{M_{{\odot }}}$| and radius of |$R_\mathrm{WD} = 0.0175^{+0.0012}_{-0.0011}\, \mathrm{R_{{\odot }}}$|, and a red dwarf mass and radius of |$M_\mathrm{RD} = 0.19^{+0.10}_{-0.08}\, \mathrm{M_{{\odot }}}$| and |$R_\mathrm{RD} = 0.24^{+0.04}_{-0.04}\, \mathrm{R_{{\odot }}}$|. The system is either a detached cataclysmic variable or has emerged like from the common-envelope phase at nearly its current orbital period. In |${\sim }70$| Myr, this system will become a cataclysmic variable in the period gap.
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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 | 0.000 |
| 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 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.001 |
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".