EXOSAT observations of the ring nebula NGC 6888 and HD 192163 |
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| Authors: | H Kähler T Ule H J Wendker |
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| Institution: | (1) Hamburger Sternwarte, Hamburg, FRG |
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| Abstract: | A 25 hr exposure of the ring nebula NGC 6888 was obtained with the EXOSAT X-ray Observatory. X-ray emission of the nebula was not found. Taking all instrumental effects and the large nebular area into account, a conservative upper limit of 1×10–12 erg s–1 cm–2 (0.05–2 keV) is derived. This is about an order of magnitude less than predicted from braking the stellar wind of the central star HD 192163. Two point sources were serendipitously found in the field, HD 192163 and HD 192020. |
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