Studying the population of faint hard X-ray sources along the plane of the Galaxy is challenging because of high-extinction and crowding , which make the identification of individual sources more difficult .
IGR J18293–1213 is part of the population of persistent sources which have been discovered by the INTEGRAL satellite .
We report on NuSTAR and Swift /XRT observations of this source , performed on 2015 September 11 .
We detected three eclipsing intervals in the NuSTAR light curve , allowing us to constrain the duration of these eclipses , \Delta t = 30.8 ^ { +6.3 } _ { -0.0 } min , and the orbital period of the system , T = 6.92 \pm 0.01 hr .
Even though we only report an upper limit on the amplitude of a putative spin modulation , the orbital period and the hard thermal Bremsstrahlung spectrum of IGR J18293–1213 provide strong evidence that this source is a magnetic Cataclysmic Variable ( CV ) .
Our NuSTAR and Swift /XRT joint spectral analysis places strong constraints on the white dwarf mass M _ { wd } = 0.78 ^ { +0.10 } _ { -0.09 } M _ { \odot } .
Assuming that the mass to radius ratio of the companion star M _ { \star } / R _ { \star } = 1 ( solar units ) and using T , \Delta t and M _ { wd } , we derived the mass of the companion star M _ { \star } = 0.82 \pm 0.01 M _ { \odot } , the orbital separation of the binary system a = 2.14 \pm 0.04 R _ { \odot } , and its orbital inclination compared to the line of sight i = ( 72.2 ^ { +2.4 } _ { -0.0 } ) \pm 1.0 ° .