The x-ray source 1rxs J180431.1-273932: The importance of being pinpointed

We report on the optical follow-up observation of the X-ray source 1RXS J180431.1-273932 which was previously recognized as a Symbiotic X-ray Binary. With the new analysis, we found that the brightest optical source inside the 90% X-ray positional error circle is spectroscopically identified as a magnetic cataclysmic variable (CV), most likely of Intermediate Polar type, hosting an accreting white dwarf with mass ≃ 0.8 M⊙