The curious case of II Lup: a complex morphology revealed with SAM/NACO and ALMA

摘要: We present the first-ever images of circumstellar environment carbon-rich AGB star II Lup in infrared and sub-mm wavelengths, discovery envelope's non-spherical morphology with use high-angular resolution imaging techniques sparse aperture masking mode on NACO/VLT (that enables diffraction limited from a single telescope) ALMA. have successfully recovered $Ks$ (2.18$\mu$m), $L'$ (3.80$\mu$m) $M'$ (4.78$\mu$m), that revealed envelope around Lup. The stellar surface is unresolved (i.e. $\leq30$ mas $Ks$) however detected structure extends up to 110 all filters. Clumps been found maps, while at lower emission levels hook-like appears extend counter-clockwise south. At larger spatial scales, approximately 23 arcsec, its shape suggests spiral four different molecules, namely CO, SiO, CS HC$_3$N, an average arm spacing 1.7 arcsec which would imply orbital period 128 years for distance 590pc.