Pith. sign in

REVIEW 4 cited by

Quantitative spectral classification of Galactic O stars

Not yet reviewed by Pith; the record is open.

This paper has not been read by Pith yet. Machine review is queued; the pith claim, tier, and objections will appear here once it completes.

SPECIMEN: schema-true, not a live event

T0 review · schema-true

One-sentence machine reading of the paper's core claim.

pith:XXXXXXXX · record.json · timestamp

arxiv 1805.08267 v1 pith:QD6FLHEO submitted 2018-05-21 astro-ph.SR

classification astro-ph.SR
keywords starsspectralclassificationcriterialuminosityclassclassesheii
verification ladder T0 review T1 audit T2 compute T3 formal

Signed reviews

No signed human review yet.

0 comments
read the original abstract

Our goal is to provide a quantification of several spectral classification criteria for O stars. We collected high-spectral resolution spectra of 105 Galactic O-type stars from various archives. We measured equivalent widths of classification lines. We defined average values of classification criteria for given spectral types and luminosity classes. We find that the ratio HeI 4471 to HeII 4542 well matches the published ratios for spectral types. We have quantified equivalent width ratios of helium and silicon lines among O8-O9.7 stars to refine spectral class typing in this spectral range. We present quantitative criteria to separate between luminosity class V, IV-III-II (grouped), and I among O3-O8.5 stars, mainly based on the strength of HeII 4686. We find that these criteria also define very well the f, (f), and ((f)) classes for O3-O7.5 stars. Among O9-O9.7 stars we quantify the ratios of HeII 4686 to HeI 4713 and SiIV 4089 to HeI 4026 for all luminosity classes. The tabulated values of the classification criteria should help classify any new O-type stars. The final step of the classification process should rely on a direct comparison to standard stars of the assigned spectral type and luminosity class.

Discussion (0). Continue with ORCID to comment.

Forward citations

Cited by 4 Pith papers

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score. Full citation record

  1. Southern Massive Stars at High Angular Resolution (SMaSH+): Properties of hierarchical massive triples

    astro-ph.SR 2026-06 unverdicted novelty 7.0 of 10

    SMaSH+ survey data yields the first observationally grounded distributions of key parameters for 26 hierarchical massive triples, dominated by tight inner binaries and wider tertiaries with no strong mass-separation c...

  2. Gravity modes and potential evidence for Rossby Waves in late O-type supergiants

    astro-ph.SR 2026-08 conditional novelty 6.0 of 10

    TESS photometry of three late O-type supergiants reveals evenly spaced frequencies interpreted as rotationally split gravity modes, with a few residual frequencies plausibly matching Rossby wave predictions.

  3. Astro+ database. I. Description and first results

    astro-ph.SR 2026-08 conditional novelty 6.0 of 10

    An automated pipeline and public database for massive star spectra recovers literature stellar parameters for OB stars and red supergiants, with the red-supergiant temperature check relying on the same code used to pr...

  4. MUSE Imaging Spectroscopy of the Fullerene Planetary Nebula Tc 1

    astro-ph.SR 2026-06 unverdicted novelty 6.0 of 10

    MUSE observations of Tc 1 map structured extinction, Te, and Ne, revealing a low-extinction annulus outside the main fullerene zone that is interpreted as evidence for locally altered dust properties in the core-halo ...

Pith tools