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Mayer, P.; Hanna, Magdy A.; Wolf, M.; Chochol, D.

doi:10.1023/a:1001840718226

Cited by 4 publications

(3 citation statements)

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“…Stankov & Handler (2005) rather proposed it to be a slowly pulsating B star (SPB). Our RVs do not significantly vary, but when combined with literature values (Mayer et al 1998), evidence for variability is found. Period searches on the full RV set yield peaks near 1.5 or 3 d, with numerous close aliases.…”

Section: C10 Hd 28446asupporting

confidence: 77%

Chemical abundances of fast-rotating massive stars

Cazorla

Morel

Nazé

et al. 2017

A&A

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Aims. Recent observations have challenged our understanding of rotational mixing in massive stars by revealing a population of fastrotating objects with apparently normal surface nitrogen abundances. However, several questions have arisen because of a number of issues, which have rendered a reinvestigation necessary; these issues include the presence of numerous upper limits for the nitrogen abundance, unknown multiplicity status, and a mix of stars with different physical properties, such as their mass and evolutionary state, which are known to control the amount of rotational mixing. Methods. We have carefully selected a large sample of bright, fast-rotating early-type stars of our Galaxy (40 objects with spectral types between B0.5 and O4). Their high-quality, high-resolution optical spectra were then analysed with the stellar atmosphere modelling codes DETAIL/SURFACE or CMFGEN, depending on the temperature of the target. Several internal and external checks were performed to validate our methods; notably, we compared our results with literature data for some well-known objects, studied the effect of gravity darkening, or confronted the results provided by the two codes for stars amenable to both analyses. Furthermore, we studied the radial velocities of the stars to assess their binarity.Results. This first part of our study presents our methods and provides the derived stellar parameters, He, CNO abundances, and the multiplicity status of every star of the sample. It is the first time that He and CNO abundances of such a large number of Galactic massive fast rotators are determined in a homogeneous way.

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Section: C10 Hd 28446asupporting

confidence: 77%

Chemical abundances of fast-rotating massive stars

Cazorla

Morel

Nazé

et al. 2017

A&A

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“…It should be stressed that in many cases low-dispersion spectra of OB stars yield imaginary radial velocity variations, which cannot be confirmed by modern measurements using high dispersion spectra (see e.g. Mayer et al 1994). …”

Section: Spectroscopymentioning

confidence: 93%

Photometry and spectroscopy of the central star of the Trifid nebula

Kohoutek

Mayer

Lorenz³

1999

Astron. Astrophys. Suppl. Ser.

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Abstract. UBV photometry of the central star of the Trifid nebula -HD 164492, which has so far been suspected of photometric as well as of radial velocity variability -is presented. The results of our photometry do not confirm any variability. Moreover, based on new high resolution CCD spectra any radial velocity variability can be discarded. Photometry of several other members of the multiple stellar system is included; according to this photometry, the system is a physical one. Equivalent widths for the main component of HD 164492 are given. Positions measured on CCD exposures are presented too.

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“…HD 42087 : this star does not exhibit significant radial velocity variations (Mayer et al 1998). The highest peak in the 2D PS is found at ν 1 = 0.040 d −1 , and appears both in the emission component and in the absorption trough of the Hα P Cygni profile (Fig.…”

Section: Period Searchmentioning

confidence: 99%

Large-scale wind structures in OB supergiants: a search for rotationally modulated Hα variability

Morel¹,

Марченко²,

Pati³

et al. 2004

Monthly Notices of the Royal Astronomical Society

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We present the results of a long-term monitoring campaign of the Hα line in a sample of bright OB supergiants (O7.5-B9) which aims at detecting rotationally modulated changes potentially related to the existence of large-scale wind structures. A total of 22 objects were monitored during 36 nights spread over six months in 2001-2002. Coordinated broad-band photometric observations were also obtained for some targets. Conspicuous evidence for variability in Hα is found for the stars displaying a feature contaminated by wind emission. Most changes take place on a daily time-scale, although hourly variations are also occasionally detected. Convincing evidence for a cyclical pattern of variability in Hα has been found in two stars: HD 14134 and HD 42087. Periodic signals are also detected in other stars, but independent confirmation is required. Rotational modulation is suggested from the similarity between the observed recurrence time-scales (in the range 13-25 d) and estimated periods of stellar rotation. We call attention to the atypical case of HD 14134, which exhibits a clear 12.8-d periodicity, both in the photometric and in the spectroscopic data sets. This places this object among a handful of early-type stars where one may observe a clear link between extended wind structures and photospheric disturbances. Further modelling may test the hypothesis that azimuthallyextended wind streams are responsible for the patterns of spectral variability in our target stars.

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Cited by 4 publications

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Chemical abundances of fast-rotating massive stars

Chemical abundances of fast-rotating massive stars

Photometry and spectroscopy of the central star of the Trifid nebula

Large-scale wind structures in OB supergiants: a search for rotationally modulated Hα variability

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