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Table · dataset · 2010

Blue-H{alpha} objects in M33

Listed in IVOA Registry (Virtual Observatory)

For the purposes of a search for SS433 type objects, LBV stars and hypergiants in M33, we have carried out a photometry of blue stars in H{alpha} images of this galaxy.

Description

From 2332 listed OB stars, we have isolated 549 objects, which have H{alpha} excess over stars of the same V magnitude. Among them 81 emission stars (s) have been selected.

About 60% of isolated objects found to be extended in H{alpha}, among them 154 diffuse (d) and 180 bubble-type (b) nebulae. 117 objects are compact (c) and faint H{alpha} sources. These groups are different in colour indices, H{alpha} fluxes, surface brightness and sizes. The most probable size of the H{alpha} nebulae is FWHM=10-14pc.

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There is evidence that their properties and location in the galaxy are defined by interstellar gas pressure and related to spiral arms. The d objects are HII regions with an embedded star. The b objects are probably envelopes around WR stars or SN remnants.

Among s-type objects we isolated a group of 20 brightest stars, which in their average properties fit well to the parameters of blue hypergiants or LBV-type stars. The stars of intermediate brightness follow very well to blue Ia supergiants. The interstellar absorption derived from brightest H{alpha} stars is A_V_=0.93+/-0.05mag.

We classify the faintest stars as blue Ib supergiants, their average absorption is A_V_~0.6mag. They are restricted in number by the limiting stellar magnitude in the original sample.

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Stated by source
Optical
Inferred from text
Image 65%
Provenance · 1 source records, 9 field assertions
SourceKeyLast seenRaw
IVOA Registry (Virtual Observatory)ivo://cds.vizier/j/a+as/140/30912 d agoJSON v1
FieldAssertionExtractorEvidence
access_levelsource · IVOA Registryconnector:ivoa_registry@1.0.0
concepts[field].local:field:astronomymapping · IVOA Registryconnector:ivoa_registry@1.0.0
concepts[modality].ivoa_waveband:opticalsource · IVOA Registryconnector:ivoa_registry@1.0.0
concepts[modality].local:modality:imageenrichment · IVOA Registrykeyword-concept-rules@1.0.0title+description (65%)
descriptionsource · IVOA Registryconnector:ivoa_registry@1.0.0rr.resource.res_description
license_textsource · IVOA Registryconnector:ivoa_registry@1.0.0
publication_datesource · IVOA Registryconnector:ivoa_registry@1.0.0
titlesource · IVOA Registryconnector:ivoa_registry@1.0.0rr.resource.res_title
updated_datesource · IVOA Registryconnector:ivoa_registry@1.0.0