Optical Observations with Milliarcsecond Resolution of Stars, Their Environments and Companions

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  • ABSTRACT

    Observations with milliarsecond resolution using the Navy Optical Interferometer have been obtained for a number of stellar systems which include high-mass binaries, eclipsing binaries, and radio stars. These observations also reveal the previously unseen companions in single-lined spectroscopic binaries via directly measured flux ratios. We will present examples of published and ongoing research efforts of these systems to illustrate how an optical interferometer contrib-utes to our knowledge of stars, their environment, and companions. These studies include a conclusive revealing of the previously unseen companion in the single-lined binary Φ Herculis, the direct determination of orbital parameters in the wide and close orbits of Algol, and revealing the orbit of β Lyrae with spatially resolved images of the Hα emission.


  • KEYWORD

    optical interferometry , binaries , astrometry , Navy Optical Interferometer

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  • [Fig. 1.] The calibrated squared visibilities of Φ Her for Navy Optical Interferometer observations made on 1998 May 16. This data shows the characteristic cosine wave signature of a binary.
    The calibrated squared visibilities of Φ Her for Navy Optical Interferometer observations made on 1998 May 16. This data shows the characteristic cosine wave signature of a binary.
  • [Fig. 2.] The left panel shows the observed spectra overlaid on normalized synthetic spectra for Φ Her A (solid blue line) and Φ Her B (red dashed line). In these images we can see the primary and secondary components of Mg I (2) 5183.6042. In the right panel is the same data but now is overlaid with a line representing the summed synthetic spectra for Φ Her A and B.
    The left panel shows the observed spectra overlaid on normalized synthetic spectra for Φ Her A (solid blue line) and Φ Her B (red dashed line). In these images we can see the primary and secondary components of Mg I (2) 5183.6042. In the right panel is the same data but now is overlaid with a line representing the summed synthetic spectra for Φ Her A and B.
  • [Fig. 3.] Separation of the two binary components (left panel blue data points with larger errors) with each point showing the uncertainty in the position of the separation of the two sources. Besides each point an indication of the orbital phase and the date is given along with a dotted line representing a least squares fit to the data. The dotted line gives the orbit in the plane of the sky. The position of the peak of Hα emission relative to the continuum photo-center is also displayed within the left panel (red square data points). The series of panels on the right show the Hα images of β Lyrae. Each panel corre-sponds to a different night and is organized, in a clockwise fashion, of increasing orbital phase. The white star points to the photo-center of the system. The lowest contour in each figure corresponds to the 3σ level. The reconstructing beam size and orientation is shown in the bottom left corner of each panel.
    Separation of the two binary components (left panel blue data points with larger errors) with each point showing the uncertainty in the position of the separation of the two sources. Besides each point an indication of the orbital phase and the date is given along with a dotted line representing a least squares fit to the data. The dotted line gives the orbit in the plane of the sky. The position of the peak of Hα emission relative to the continuum photo-center is also displayed within the left panel (red square data points). The series of panels on the right show the Hα images of β Lyrae. Each panel corre-sponds to a different night and is organized, in a clockwise fashion, of increasing orbital phase. The white star points to the photo-center of the system. The lowest contour in each figure corresponds to the 3σ level. The reconstructing beam size and orientation is shown in the bottom left corner of each panel.
  • [Fig. 4.] Images of the Algol triple system made from Navy Optical Interferometer data on 2006 Oct 29 are seen in the left panel. In the right panel observations from 2006 Oct 30 are shown to emphasize the motion of Algol B between the two epochs. The Algol C component can be found in the upper right hand of each panel. To help guide the eye, the approximate positions of Algol B are indicated at each epoch by a filled in red circle.
    Images of the Algol triple system made from Navy Optical Interferometer data on 2006 Oct 29 are seen in the left panel. In the right panel observations from 2006 Oct 30 are shown to emphasize the motion of Algol B between the two epochs. The Algol C component can be found in the upper right hand of each panel. To help guide the eye, the approximate positions of Algol B are indicated at each epoch by a filled in red circle.
  • [Fig. 5.] The left panel is an illustration showing the Navy Optical Interferometer (NOI) astrometric results for the AB-C orbit superposed on top of previously determined orbits from Mark III and CHARA observations. In the right panel an illustration of NOI astrometric results are plotted with the astrometry of Pan et al. (1993) and rotated by 180°. A vector from the origin indicates the periastron point.
    The left panel is an illustration showing the Navy Optical Interferometer (NOI) astrometric results for the AB-C orbit superposed on top of previously determined orbits from Mark III and CHARA observations. In the right panel an illustration of NOI astrometric results are plotted with the astrometry of Pan et al. (1993) and rotated by 180°. A vector from the origin indicates the periastron point.