Serendipity and the Sloan Digital Sky Survey: Discovery of the Largest Known Planetary Nebula on the Sky
Bibliographic record
Abstract
Investigation of spectra from the Sloan Digital Sky Survey reveals the presence of a region of ionized gas of greater than 2° diameter centered approximately at α = 10 h 37 m , δ = -00 ° 18' (J2000.0) (Galactic coordinates l = 248 ° , b = +48 ° ). [O III] λλ4959, 5007 emission is particularly strong, and emission from Hα and [N II] λλ6548, 6583 is also detectable over a substantial area on the sky. The combination of emission-line ratios, the close to zero heliocentric radial velocity, and the morphology of the structure is consistent with an identification as a very nearby planetary nebula. The proximity of the hot, DO white dwarf PG 1034+001 further strengthens this interpretation. The object is (1) the largest planetary nebula on the sky, (2) certainly closer than any planetary nebula other than Sh 2-216, and (3) the first to be unambiguously associated with a DO white dwarf. A parallax distance for PG 1034+001 would establish whether the structure is in fact the closest, and one of the physically largest, planetary nebulae known.
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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 | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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 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".