Hideyuki Izumiura

Detached shells as tracers of asymptotic giant branch-interstellar medium bow shocks

New Spitzer imaging observations have revealed the structure around the Mira variable star R Hya to be a one-sided parabolic arc 100 arcsec to the West stretching from North to South. We successfully model R Hya and its surroundings in terms of an interaction of the stellar wind from an asymptotic giant branch (AGB) star with the interstellar medium (ISM) the star moves through. Our three-dimensional hydrodynamic simulation reproduces the structure as a bow shock into the oncoming ISM. We propose this as another explanation of detached shells around such stars which should be considered alongside current theories of internal origin. The simulation predicts the existence of a tail of ram-pressure-stripped AGB material stretching downstream. Indications for such a tail behind R Hya are seen in IRAS maps.

OPTICAL AND NEAR-INFRARED POLARIMETRY OF HIGHLY REDDENED Type Ia SUPERNOVA 2014J: PECULIAR PROPERTIES OF DUST IN M82

We presented optical and near-infrared multi-band linear polarimetry of the highly reddened Type Ia SN~2014J appeared in M82. SN~2014J exhibits large polarization at shorter wavelengths, e.g.,

Molecular envelope of the planetary nebula NGC 7027

4.8

Herschel Planetary Nebula Survey (HerPlaNS) First detection of OH+ in planetary nebulae

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High spatial resolution observations of HCO(+) in the NGC 7027 molecular envelope

B

THE NEW DETECTIONS OF 7Li/6Li ISOTOPIC RATIO IN THE INTERSTELLAR MEDIA*

band, and the polarization decreases rapidly at longer wavelengths, with the position angle of the polarization remaining at approximately

V Hydrae: a carbon star in transformation to a bipolar nebula

40^{\circ}

Extended dust shell of the carbon star U Hydrae observed with AKARI

over the observed wavelength range. These polarimetric properties suggest that the observed polarization is likely to be caused predominantly by the interstellar dust within M82. Further analysis shows that the polarization peaks at a wavelengths much shorter than those obtained for the Galactic dust. The wavelength dependence of the polarization can be better described by an inverse power law rather than by Serkowski law for Galactic interstellar polarization. These suggests that the nature of the dust in M82 may be different from that in our Galaxy, with polarizing dust grains having a mean radius of

Detection of planet candidates around K giants. HD 40956, HD 111591, and HD 113996

<0.1\ \mu

Spitzer/MIPS Imaging of the Extremely Extended Dust Shell(s) around R Hya

m.