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Flux variations of QSO 0957 + 561 A, B and image splitting by stars near the light path


If the double QSO 0957 + 561 A, B is the result of gravitational lens actions by a massive galaxy, stars in its outer parts and close to the light paths may cause significant flux changes in one year. One star can split a QSO image into two to four images with angular separations of 10−5 arc s.

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Chang, K., Refsdal, S. Flux variations of QSO 0957 + 561 A, B and image splitting by stars near the light path. Nature 282, 561–564 (1979).

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