15 research outputs found

    Observations of Mira stars with the IOTA/FLUOR interferometer and comparison with Mira star models

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    We present K'-band observations of five Mira stars with the IOTA interferometer. The interferograms were obtained with the FLUOR fiber optics beam combiner, which provides high-accuracy visibility measurements in spite of time-variable atmospheric conditions. For the M-type Miras X Oph, R Aql, RU Her, R Ser, and the C-type Mira V CrB we derived the uniform-disk diameters 11.7mas, 10.9mas, 8.4mas, 8.1mas, and 7.9mas (+/- 0.3mas), respectively. Simultaneous photometric observations yielded the bolometric fluxes. The derived angular Rosseland radii and the bolometric fluxes allowed the determination of effective temperatures. For instance, the effective temperature of R Aql was determined to be 2970 +/- 110 K. A linear Rosseland radius for R Aql of (250 +100/-60) Rsun was derived from the angular Rosseland radius of 5.5mas +/- 0.2mas and the HIPPARCOS parallax of 4.73mas +/- 1.19mas. The observations were compared with theoretical Mira star models of Bessel et al. (1996) and Hofmann et al. (1998). The effective temperatures of the M-type Miras and the linear radius of R Aql indicate fundamental mode pulsation.Comment: 12 pages, 4 postscript figure

    Observations of MIRA stars with the IOTA/FLUOR interferometer and comparison with MIRA star models

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    We present K-band observations of five Mira stars with the IOTA interferometer. The interferograms were obtained with the FLUOR fiber optics beam combiner which provides high- accuracy visibility measurements in spite of time-variable atmospheric conditions. For the Mira stars X Oph, R Aql, RU Her, R Ser, and V CrB we derived the uniform-disk diameters 11.7 mas, 10.9 mas, 8.4 mas, 8.1 mas, and 7.9 mas (+/- 0.3 mas), respectively. Simultaneous photometric observations yielded the bolometric fluxes. The derived angular Rosseland radii and the bolometric fluxes allowed the determination of effective temperatures. For instance, the effective temperature of R Aql was determined to be 3072 K +/- 161 K. A Rosseland radius for R Aql of 250 R⊙ +/- 63 R⊙ was derived from the angular Rosseland radius of 5.5 mas +/- 0.2 mas and the HIPPARCOS parallax of 4.73 mas +/- 1.19 mas. The observations were compared with theoretical Mira star models (D/P model Rosseland radius equals 255 R⊙ measured R Aql Rosseland radius equals 250 R⊙ +/- 63 R.)

    Autonomous Pose Estimations for In-Orbit Self-Assembly of Intelligent Self-Powered Modules

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    The ability to autonomously determine the position and attitude of a swarm of satellites is a promising way of assembling Intelligent Self-powered Modules (ISMs) in orbit. This self assembly is guided through simple actuators and sensors and requires fewer resources. A vision based system is used to determine the pose of ISMs attempting docking, through two strategies: Spheroid modeling and feature detection methods. The former technique takes an image of the ISM to reconstruct its position. An additional set of reflectors are placed on each facet to then determine the attitude of the ISM. The attitude algorithms developed are validated for distances up to 30m, with the position determination tested for distances up to 50m. These methods are combined to autonomously estimate the pose of an ISM attempting to dock with a coupled structure of previously launched and connected ISMs

    Pose Estimation for In-Orbit Self-Assembly of Intelligent Self-Powered Modules

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