Spectropolarimetric Evidence of Asymmetric Outburst in the Fast Nova V1494 Aquilae
| Autor: | S. Nakayama, H. Akitaya, T. Karube, Masahiro Kondoh, M. Seki, Akira Okazaki, Ryuko Hirata, Y. Ikeda, Koji S. Kawabata, Mizuki Isogai, Masafumi Matsumura, Nobuyuki Hirakata |
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| Rok vydání: | 2001 |
| Předmět: | |
| Zdroj: | The Astrophysical Journal. 552:782-786 |
| ISSN: | 1538-4357 0004-637X |
| DOI: | 10.1086/320585 |
| Popis: | We present our extended polarimetric observations of a fast nova from the premaximum to transition stages. The observations were made for V1494 Aquilae (=Nova Aql 1999 No. 2) at the Dodaira Observatory of the National Astronomical Observatory of Japan between 1999 December 2 and 2000 March 29. We discovered that the light from the nova had already been intrinsically polarized in the premaximum stage and that the intrinsic polarization took a local maximum at visual maximum light. For the next 6 days a nearly orthogonal polarization component gradually increased. This component was later accompanied and finally replaced by rapidly oscillating components. These observations provide direct evidence that an asymmetric geometry was present even prior to maximum brightness. The principal geometry of the wind projected onto the sky appears nearly constant, at least from shortly after visual maximum to transition stages, but clumping of the ejecta appears to become significant in the later stages. |
| Databáze: | OpenAIRE |
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