An in-depth reanalysis of the alleged type Ia supernova progenitor Henize 2-428
Bibliographic record
Abstract
<div>Context. The nucleus of the planetary nebula Hen 2-428 is a short orbital-period (4.2 h), double-lined spectroscopic binary, whose</div><div>status as a potential supernova type Ia progenitor has raised some controversy in the literature.</div><div>Aims. With the aim of resolving this debate, we carried out an in-depth reanalysis of the system.</div><div>Methods. Our approach combines a refined wavelength calibration, thorough line-identifications, improved radial-velocity measurements, non-LTE spectral modeling, as well as multi-band light-curve fitting. Our results are then discussed in view of state-of-the-art</div><div>stellar evolutionary models.</div><div>Results. Besides systematic zero-point shifts in the wavelength calibration of the OSIRIS spectra which were also used in the previous analysis of the system, we found that the spectra are contaminated with diffuse interstellar bands. Our Voigt-profile radial</div><div>velocity fitting method, which considers the additional absorption of these diffuse interstellar bands, reveals significantly lower masses</div><div>(M1 = 0.66 ± 0.11 M? and M2 = 0.42 ± 0.07 M?) than previously reported and a mass ratio that is clearly below unity. Our spectral</div><div>and light curve analyses lead to consistent results, however, we find higher effective temperatures and smaller radii than previously</div><div>reported. Moreover, we find that the red-excess that was reported before to prove to be a mere artifact of an outdated reddening law</div><div>that was applied.</div><div>Conclusions. Our work shows that blends of He ii λ 5412 Å with diffuse interstellar bands have led to an overestimation of the</div><div>previously reported dynamical masses of Hen 2−428. The merging event of Hen 2−428 will not be recognised as a supernova type</div><div>Ia, but most likely leads to the formation of a H-deficient star. We suggest that the system was formed via a first stable mass transfer</div><div>episode, followed by common envelope evolution, and it is now composed of a post-early asymptotic giant branch star and a reheated</div><div>He-core white dwarf.</div>
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
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 teacher head, 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".