Speckle interferometric measurements of binary stars. VII

McAlister, H. A.; Hendry, E. M.

doi:10.1086/190798

Cited by 24 publications

(8 citation statements)

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“…The other at 33A (BD[00 983B) has V \ 14. Two bright components of d Ori A were identiÐed by Heintz (1980) and later conÐrmed by speckle interferometry observations (McAlister & Hendry 1982). Recent determinations of their separation yield a value (Lindegren et al 1997 ;Mason et al 0A .267 1998), which is much smaller than the equivalent of our wavelength resolution projected onto the sky (about 10A).…”

Section: T Arget Starsmentioning

confidence: 87%

The Properties of Molecular Hydrogen toward the Orion Belt Stars from Observations by the Interstellar Medium Absorption Profile Spectrograph

Jenkins

Woźniak

Sofia

et al. 2000

ApJ

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Section: T Arget Starsmentioning

confidence: 87%

The Properties of Molecular Hydrogen toward the Orion Belt Stars from Observations by the Interstellar Medium Absorption Profile Spectrograph

Jenkins

Woźniak

Sofia

et al. 2000

ApJ

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“…The two stars are classified as O9.5 II and B1 III/IV (Galkina 1976; Koch & Hrivnak 1981), with somewhat uncertain V magnitudes of 2.90 and 4.4 respectively; both stars are significantly evolved from the main sequence. In addition, a third star, δ Ori D, was detected by Heintz (1980) and McAlister & Hendry (1982); the Hipparcos survey (ESA 1997) found δ Ori D to be 1.35 magnitudes fainter, and 0.27 arcsec away from, δ Ori A. The small separations of these three stars leads to the observations being a composite of flux from all three.…”

Section: Discussionmentioning

confidence: 99%

Detection of a variable interstellar absorption component towards Orionis A

Price

Crawford

Barlow

2000

Monthly Notices of the Royal Astronomical Society

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Observations of d Ori A made with the UHRF in its highest resolution mode R < 900 000 have revealed the presence of a cool T k < 350 K variable absorption component at a heliocentric velocity of 121.3 km s 21 . The component is detected in Na i D 1 , where clear hyperfine splitting is seen, and Ca ii K. Comparison of our data with existing spectra suggests that the component has consistently increased in strength from 1966 to 1994, and subsequently reduced in intensity by 1999. Following a discussion of the possible origins of this component it is concluded that an interstellar, rather than circumstellar, origin is most likely. This is one of very few detections of variable interstellar absorption reported in the literature, and we suggest an origin within filamentary material associated with the expanding H i shell surrounding the Orion±Eridanus superbubble.

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“…The velocity amplitude of the binary is 98 km s~1, and it has a period of 5.7 days (Harvey et al 1987). It is also a partially eclipsing binary (Koch & Hrivnak 1981), and it has a visual companion of comparable brightness at a separation of (Heintz 1980 ;McAlister & Hendry 1982). The D0A .2 spectroscopic binary nature of the star system presents an opportunity to investigate systematic errors in the determination of the interstellar N(H I) : the H I Lya proÐle is extremely broad, and if there are unrecognized stellar lines in the principal part of the Lorentz wings of the Lya feature, then their additional optical depth could lead to an overestimate of N(H I).…”

Section: Determination Of N(d I) and Its Uncertaintymentioning

confidence: 99%

Spatial Variability in the Ratio of Interstellar Atomic Deuterium to Hydrogen. I. Observations toward δ Orionis by the Interstellar Medium Absorption Profile Spectrograph

Jenkins

Tripp

Woźniak

et al. 1999

ApJ

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Studies of the abundances of deuterium in di †erent astrophysical sites are of fundamental importance to answering the question about how much deuterium was produced during big bang nucleosynthesis and what fraction of it was destroyed later. With this in mind, we used the Interstellar Medium Absorption ProÐle Spectrograph (IMAPS) on the ORFEUS-SPAS II mission to observe at a wavelength resolution of 4 km s~1 (FWHM) the Lyd and Lyv absorption features produced by interstellar atomic deuterium in the spectrum of d Ori A. A s2 analysis indicated that 0.96 \ N(D I) \ 1.45 ] 1015 cm~2 at a 90% level of conÐdence, and the gas is at a temperature of about 6000 K. In deriving these results, we created a template for the velocity proÐle deÐned by seven di †erent N I transitions recorded at a high signal-to-noise ratio. Extra free parameters in the analysis allowed for the additional uncertainties that could arise from various sources of systematic error. To derive a value for D/H, we measured the Lya absorption features in 57 spectra of d Ori in the IUE archive, with the objective of arriving at an H I column density more accurate than those reported by other investigators.

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Speckle interferometric measurements of binary stars. VII

Cited by 24 publications

References 0 publications

The Properties of Molecular Hydrogen toward the Orion Belt Stars from Observations by the Interstellar Medium Absorption Profile Spectrograph

The Properties of Molecular Hydrogen toward the Orion Belt Stars from Observations by the Interstellar Medium Absorption Profile Spectrograph

Detection of a variable interstellar absorption component towards Orionis A

Spatial Variability in the Ratio of Interstellar Atomic Deuterium to Hydrogen. I. Observations toward δ Orionis by the Interstellar Medium Absorption Profile Spectrograph

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