Differential Proper-Motion Measurements of The Cygnus Egg Nebula; The Presence of Fast Equatorial Outflows

ORAL

Abstract

We present the results of differential proper-motion analyses of the dust shell structure in the Egg Nebula (RAFGL 2688, V1610 Cyg), based on the archived two-epoch imaging-polarimetric data in the optical taken with the Hubble Space Telescope. We measured the amount of motion of local structures and the signature concentric arcs in the nebula by determining their relative shifts over an interval of 7.25 yr. We discovered that the optical polarization characteristics of the Egg Nebula was influenced by the marginal optical thickness of the circumstellar shell and the illumination of the nebula was done in two-step mechanism - most of the nebula is illuminated by the secondary/dust-scattered starlight emanating from the bipolar lobes themselves due to the central concentration of dust grains of more than 10$^3$ AU diameter that regulates the seepage of the starlight from the central region. Nevertheless, based on two types of differential proper-motion analyses we revealed interesting dynamics of the lobes and concentric arcs, which should provide solid constraints on the subsequent theoretical/numerical investigations.

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Authors

  • Rachael Tomasino

    University of Denver

  • Toshiya Ueta

    University of Denver

  • Norm Buchanan

    Brigham Young University, Stanford University, University of Central Florida, NCAR/High Altitude Observatory, Arizona Vitro-retinal consultants, University of Michigan, Arizona State University, University of Denver, Arizona State University Dept of Physics, Arizona State University Dept of Chemistry and Biochemistry, LASP, University of Colorado Boulder, Center for Atmospheric and Space Science, Utah State University, Dixie State College, Utah, USU Materials Physics Group, UVU Physics Department, Box Elder Innovations, Space Telescope Science Institute, Northern Kentucky University, Retired, Utah Valley University, Univ. of California, Los Angelos, Colorado State University, St. Petersburg Electro-technical University, Universidad Nacional Aut\'onoma de M\'exico, New Mexico State University, University of New Mexico, University of Wurtzberg, Theoretical Division, Los Alamos National Laboratory, National High Magnetic Field Laboratory, LANL, UCLA, Max-planck-Institut f\"{u}r Astronomie, W. M. Keck Observatory, University of Arizona, Nuclear Physics Group, Brigham Young University, GLOBALFOUNDRIES, IBM Systems and Technology Group, IBM Research Division, T.J. Watson Research Center, Sandia National Laboratory, NMSU, Military University of Technology, Warsaw, Poland, James Franck Institute and Department of Physics, University of Chicago, Department of Atmospheric Sciences, University of Washington, JISAO, University of Washington, New Mexico Institute of Mining and Technology, NorthWest Research Associates, University of Alaska, Fairbanks, Utah State University, New Mexico Tech, University of Cambridge, Los Alamos National Laboratory, RAPTOR Science, Institute of Space and Astronomical Science, Japanese Aerospace Exploration Agency, Weber State University, Department of Physics, New Mexico State University, BYU Physics, Physics Department, University of Arizona, ABQMR, University of Colorado at Boulder, SNL and CINT, Los Alamos National Lab, Center for Quantum Information and Control, University of Arizona, Center for Quantum Information and Control, University of New Mexico, University of Calgary, Colorado School of Mines