A Study of Some Early Type Close Binary Stars.

Abhyankar, K. D.

doi:10.1086/190047

Cited by 21 publications

(13 citation statements)

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“…SB: spectroscopic binaries from Batten et al (1989) catalogue; SB1 and SB2: single and double spectrum spectroscopic binary, respectively (for none of the three SB2 binaries the companion is expected to significally affect the spectral appearance of the primary over the λλ 8500 − 8750Å range here investigated. Details on the three SB2 are given by Abhyankar 1958;Morrison & Conti 1978;Wright 1970). Column 13.…”

Section: Observationsmentioning

confidence: 99%

High resolution spectroscopy over $\lambda\lambda$ 8500-8750 Å for GAIA

Munari

Tomasella

1999

Astron. Astrophys. Suppl. Ser.

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Abstract. We present an Echelle+CCD high resolution spectroscopic atlas (0.25Å/pix dispersion, 0.43Å FWHM resolution and 20 000 resolving power) mapping the MKK classification system over the interval λλ 8500 − 8750Å. The wavelength interval is remarkably free from telluric lines and it is centered on the near-IR triplet of Ca II, the head of hydrogen Paschen series and several strong metallic lines. The spectra of 131 stars of types between O4 and M8 and luminosity classes I through V are included in the atlas. Special care was put in maintaining the highest instrumental homogeneity over the whole set of data. The capability to derive accurate MKK spectral types from high resolution observations over the interval λλ 8500−8750Å is discussed. The observations have been performed as part of an evaluation study of possible spectroscopic performances for the astrometric mission GAIA planned by ESA.

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Section: Observationsmentioning

confidence: 99%

High resolution spectroscopy over $\lambda\lambda$ 8500-8750 Å for GAIA

Munari

Tomasella

1999

Astron. Astrophys. Suppl. Ser.

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“…Binnendijk 1960). The columns, respectively, show the orbital elements obtained by Duncan (1912), Daniel and Schlesinger (1912), Luyten, Struve, and Morgan (1940), Abhyankar (1959), and (in part) from the present data. The last column gives the results for the overall minimization.…”

Section: A the Primarymentioning

confidence: 63%

“…A weak secondary spectrum is present allowing a mass ratio to be determined. In addition, a sizable rotation of the line of apsides has been found, although the uncertainties in the rate of rotation remain large (Abhyankar 1959).…”

Section: Introductionmentioning

confidence: 99%

“…In the process of reducing these new data it became clear that substantial changes in the orbital parameters as last determined by Abhyankar (1959) were in order. Thus, we undertook reexamination of essentially all the spectroscopic data published to date with the intent of establishing a new definitive set of elements and their uncertainties for this system.…”

Section: Introductionmentioning

confidence: 99%

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The spectroscopic orbit of Beta Scorpii A

Peterson

Elliot

Mink

1979

PASP

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We reconsider the spectroscopic orbit of the ß Seo A pair. With the addition of 33 additional spectrograms over 1975-77, we are able to perform a least-squares minimization for the orbital parameters using data from 1908 to the present, covering 3689 cycles. Although the elements and their errors are converging, the residuals for both the primary and secondary remain larger than expected. The line of apsides has rotated through a full 30° since the initial determinations by Duncan and by Daniel and Schlesinger in 1912, and its rate of rotation is now known to 10%.

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“…Component A is HD 144217 (HR 5984), a B0.5 V star with V = 2.62 (Nicolet 1978). It was found by Abhyankar (1959) to be a spectroscopic binary (Aa + Ab) with Δm = 1.26 (Elliot et al 1976) and an orbital period of 6.828245 ± 0.000009 days (Holmgren at al. 1997).…”

Section: Introductionmentioning

confidence: 99%

First spectroscopic analysis of β Scorpii C and β Scorpii E

Catanzaro¹

2010

A&A

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Context. The multiple system β Scorpii consists of five components and two suspected members forming a total of seven stars. In the past, this system acquired much interest because of a series of occultation by the planet Jupiter and one of its satellites (Io). The study of this phenomena allowed us to ascertain the principal components of the system and the possible nature of each component. Aims. By using optical spectroscopy, we derive radial velocities, T eff , log g, abundances L/L , M/M , and R/R for β Sco C and E. We also refine previously published values of L/L , M/M , and R/R of β Sco Aa + Ab to obtain a clear understanding of the evolutionary state of the β Sco system. Methods. We convert Doppler shifts in wavelength into radial velocities. Atmospheric parameters and abundances are computed by assuming the local thermodynamic equilibrium using model atmospheres and the spectral synthesis codes ATLAS and SYNTHE. Results. We solve the orbit of β Sco E and provide information about the motion of β Sco C. By fitting four Balmer lines, we determine that: T C eff = 24 000 ± 500 K, log g C = 3.8 ± 0.2, and T Ea eff = 13 000 ± 800 K, log g Ea = 4.2 ± 0.2. Rotational velocities are derived by modeling the profiles of metallic lines: v sin i C = 55 ± 3 km s −1 and v sin i Ea = 5 ± 1 km s −1 . As for the abundances, we find that β Sco C is more or less of solar abundance, while β Sco Ea has a significant overabundance of manganese, followed by those of strontium, phosphorous, and titanium. The most underabundant element is magnesium, followed by silicon, aluminum, sulfur, iron, and nickel. Other light elements, such as carbon, nitrogen, oxygen, and neon, are found to be normal. From the derived values of luminosities and temperatures, we infer that these stars have an age of ≈6.3 ± 3.0 Myr. Conclusions. We explain the observed variability in velocity of β Sco E in terms of a close companion. Thus, we observe a triple system composed by β Sco C and β Sco Ea + Eb. While β Sco C is a normal star, β Sco Ea is probably a mercury-manganese (HgMn) star. The line-profile variability observed for β Sco C could be explained by assuming its membership to the class of slow pulsating B stars. According to the position of β Sco Ab in the HR diagram, we exclude the possibility that this star could be a β Cephei class pulsator.

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A Study of Some Early Type Close Binary Stars.

Cited by 21 publications

References 0 publications

High resolution spectroscopy over $\lambda\lambda$ 8500-8750 Å for GAIA

High resolution spectroscopy over $\lambda\lambda$ 8500-8750 Å for GAIA

The spectroscopic orbit of Beta Scorpii A

First spectroscopic analysis of β Scorpii C and β Scorpii E

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