John E. Gaustad

A Robotic Wide‐Angle Hα Survey of the Southern Sky

ABSTRACT We have completed a robotic wide‐angle imaging survey of the southern sky ( \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape

The 5° Diameter Ionized Halo of the Planetary Nebula Abell 36

\delta =+15^{\circ }

A Wide-Angle Hα Image of the LMC

\end{document} to −90°) at 656.3 nm wavelength, the Hα emission line of hydrogen. Each image of the resulting Southern Hα Sky Survey Atlas (SHASSA) covers an area of the sky 13° square at an angular resolution of approximately 0 \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepa...

V482 Cygni: an R Coronae Borealis star in a quadruple system

We have observed an ionized halo surrounding the planetary nebula Abell 36. It is barrel-shaped, with dimensions 4° × 5°, which is 17 pc × 21 pc at a distance of 240 pc. With an average Hα surface brightness of 0.8 ± 0.2 rayleighs, the halos total Hα flux, 8.3 × 10-10 ergs cm-2 s-1, exceeds that of the previously known inner part of the nebula by a factor of 30. The ionized mass of the halo is 48 M⊙, where is the filling factor of the ionized gas. Velocity-resolved Hα spectra indicate that the halo is ambient interstellar matter and not matter ejected from the planetary nebula. The edges of the halo are evident in both 100 μm emission and red optical continuum.

Temperature And Brightness Variations On Betelgeuse

We are conducting a wide-angle Hα survey of the southern sky at CTIO using a robotic CCD camera. The survey consists of 283 fields covering the sky from δ = −90° to δ = +10°, with the same centers as those in the IRAS Sky Survey Atlas. As of July 1, 1998, it was about 45% complete. When all the images are obtained and fully processed, the survey will be made available to the scientific community on the web and on CD-ROM.

A Robotic Wide-Angle H α Survey of the Southern Sky

Observations of the R CrB variable star V482 Cyg, obtained with the University of Rochester 32 x 32 InSb array camera at the NASA IR Telescope Facility on Mauna Kea on August 20, 1984, are reported. The data-reduction and analysis procedures are described in detail, and the results are presented in tables and maps. V482 Cyg is shown to be a member of a quadruple system or perhaps a small obscured cluster. Parameters determined include distance 1.7 kpc, circumstellar-shell temperature 800 K, and absolute magnitude MV = -2.8.

The Distribution Of Interstellar Dust In The Solar Neighborhood

Changes in TiO band strengths correlate well with the brightness changes of α Orionis, thus supporting the hypothesis of Schwarzschild that the irregular luminosity variations of red giants are due to temperature changes in a few extremely large convective elements on their surface.

The 3 Dimensional Distribution of Cirrus

We have completed a robotic wide-angle imaging survey of the southern sky (δ = +15 to −90) at 656.3 nm wavelength, the Hα emission line of hydrogen. Each image of the resulting Southern H-Alpha Sky Survey Atlas (SHASSA) covers an area of the sky 13 square at an angular resolution of approximately 0.8 arcminute, and reaches a sensitivity level of 2 rayleigh (1.2 × 10 erg cm s arcsec) per pixel, corresponding to an emission measure of 4 cm pc, and to a brightness temperature for microwave free-free emission of 12 μK at 30 GHz. Smoothing over several pixels allows features as faint as 0.5 rayleigh to be detected. Subject headings: surveys—instrumentation: miscellaneous—techniques: image processing—ISM: structure—H II regions—cosmic microwave background Cottrell Scholar of Research Corporation Wide-Angle Hα Survey of the Southern Sky 2