Spectral and photometric observations of the B[e] stars MWC 314 and OY Gem

Kurchakov, A. V.; Rspaev, F. K.

doi:10.1080/10556790500483618

Cited by 4 publications

(3 citation statements)

References 7 publications

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“…In Fig. 2, we plot the degree of linear polarization P Q as a function of phase angle α in comet 46P/Wirtanen versus what was measured with the broadband V filter in other comets; C/1975 V1 (West) as reported by Kiselev and Chernova (1978), 21P/Giacobini-Zinner measured in the 1985 apparition by Kurchakov et al (1986) and in the 2018 apparition by Chornaya et al (2020a), and C/2018 V1 (Machholz-Fujikawa-Iwamoto) adapted from Zubko et al (2020). Clearly, polarization of dust in comet 46P/Wirtanen is considerably lower as compared to 21P/Giacobini-Zinner and it better corresponds with the case of C/2018 V1 (Machholz-Fujikawa-Iwamoto).…”

Section: Aperture-averaged Degree Of Linear Polarization In Comet 46p/wirtanenmentioning

confidence: 92%

Monitoring polarization in comet 46P/Wirtanen

Zheltobryukhov

Zubko

Chornaya

et al. 2020

Monthly Notices of the Royal Astronomical Society

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We measure the degree of linear polarization of comet 46P/Wirtanen during two months, embracing the perihelion passage in December, 2018 with phase angles ranging from α = 18.1° to 46.4°. The polarimetric response PQ obtained resembles what was previously found in comet C/1975 V1 (West). This suggests 46P/Wirtanen belongs to a group of comets with high maximum positive polarization. In the first half of February of 2019, we conducted BVRI photometry of 46P/Wirtanen and found either neutral or blue colour of its dust, which is in good accordance with measurements of C/1975 V1 (West). While aperture-averaged polarimetry of 46P/Wirtanen reveals a nearly zero polarization PQ at the lowest phase angle α = 18.1°, simultaneous imaging polarimetry suggests that the negative polarization (PQ < 0) arises in a region of within 5,000 km of the nucleus, where the negative polarization could be as strong as PQ = –(1.44 ± 0.15) per cent. This observation suggests the existence of the circumnucleus halo and that the coma is populated by at least two types of dust particles. One of those reveals a low positive polarization at side scattering and high negative polarization near backscattering. Both polarimetric features are simultaneously produced by weakly absorbing Mg-rich silicate particles. Another type of dust produces solely positive polarization that could be attributed to carbonaceous particles. This composition of 46P/Wirtanen coma appears to be similar with what was previously found in comet C/1975 V1 (West).

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Section: Aperture-averaged Degree Of Linear Polarization In Comet 46p/wirtanenmentioning

confidence: 92%

Monitoring polarization in comet 46P/Wirtanen

Zheltobryukhov

Zubko

Chornaya

et al. 2020

Monthly Notices of the Royal Astronomical Society

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“…18 (Lobel et al 2013). We searched for other forbidden emission lines in the spectrum but failed to detect the [O i] λ5577 and λ6300 lines reported by Kurchakov & Rspaev (2005). There is no indication of stellar emission at these line rest wavelengths.…”

Section: Orbital Modulation Of Permitted and Forbidden Emission Linesmentioning

confidence: 99%

Modelling the asymmetric wind of the luminous blue variable binary MWC 314

Lobel

Groh

Martayan

et al. 2013

A&A

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Aims. We present a spectroscopic analysis of MWC 314, a luminous blue variable (LBV) candidate with an extended bipolar nebula. The detailed spectroscopic variability is investigated to determine if MWC 314 is a massive binary system with a supersonically accelerating wind or a low-mass B[e] star. We compare the spectrum and spectral energy distribution to other LBVs (such as P Cyg) and find very similar physical wind properties, indicating strong kinship. Methods. We combined long-term high-resolution optical spectroscopic monitoring and V-band photometric observations to determine the orbital elements and stellar parameters and to investigate the spectral variability with the orbital phases. We developed an advanced model of the large-scale wind-velocity and wind-density structure with 3-D radiative transfer calculations that fit the orbitally modulated P Cyg profile of He i λ5876, showing outflow velocities above 1000 km s −1 . Results. We find that MWC 314 is a massive semi-detached binary system of 1.22 AU, observed at an inclination angle of i = 72.8• with an orbital period of 60.8 d and e = 0.23. The primary star is a low-vsini LBV candidate of m 1 = 39.6 M and R 1 = 86.8 R . The detailed radiative transfer fits show that the geometry of wind density is asymmetric around the primary star with increased wind density by a factor of 3.3, which leads the orbit of the primary. The variable orientation causes the orbital modulation that is observed in absorption portions of P Cyg wind lines. Wind accretion in the system produces a circumbinary disc. Conclusions. MWC 314 is in a crucial evolutionary phase of close binary systems, when the massive primary star has its H envelope being stripped and is losing mass to a circumbinary disc. MWC 314 is a key system for studying the evolutionary consequences of these effects.

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“…The apparatus, procedures for initial analysis of the data, and the first results of the research program have been published by Kurchakov and Rspaev [10,11]. Table 1 is a complete list of the dates on which spectra were obtained in the regions of the Hα and Hβ lines and Table 2 lists the results of the BVR photometry.…”

Section: Observationsmentioning

confidence: 99%

Large-scale variability in the profiles of Hα and Hβ in the spectrum of the Herbig B8e star MWC 419 and a model interpretation of it

2007

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Spectroscopic data taken with a moderate resolution spectrograph in the region of the Hα and Hβ lines are presented for the Herbig B8e star MWC 419. The spectroscopic observations were accompanied by broad band BVR photometric measurements. The observations reveal a variability in the line profiles that is typical of Herbig Ae/Be stars with signs of a strong stellar wind. The greatest changes are observed in the region of the absorption components of the line profiles, which convert the profile from a type P CygII to P CygIII, as well as in the intensities of the central emission components. A model technique is used for quantitative interpretation of this variability and it shows that the P Cyg profile conversion of the absorption component can be explained in terms of a stellar wind model in which its distribution over latitude varies on a time scale of a few days.

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Spectral and photometric observations of the B[e] stars MWC 314 and OY Gem

Cited by 4 publications

References 7 publications

Monitoring polarization in comet 46P/Wirtanen

Monitoring polarization in comet 46P/Wirtanen

Modelling the asymmetric wind of the luminous blue variable binary MWC 314

Large-scale variability in the profiles of Hα and Hβ in the spectrum of the Herbig B8e star MWC 419 and a model interpretation of it

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