B2 0954+25A , detected by the Fermi satellite , is a blazar with interesting observational properties : it has been observed to transit from a jet dominated to a disk dominated state ; its radio spectrum appears flat at all observing frequencies ( down to 74 MHz ) ; optically , the H \beta line profile is asymmetric .
The flatness of radio spectrum suggests that the isotropic emission from radio lobes is very weak , despite the large size of its jet ( \gtrsim 500 kpc ) .
Its broad–band spectral energy distribution is surprisingly similar to that of the prototypical \gamma –ray , radio loud , Narrow Line Seyfert 1 ( \gamma –NLS1 ) galaxy PMN J0948+0022 .
In this work we revisit the mass estimates of B2 0954+25A considering only the symmetric component of the H \beta line and find ( 1–3 ) \times 10 ^ { 8 } M _ { \sun } .
In light of our composite analysis , we propose to classify the source as a transition object between the class of Flat Spectrum Radio Quasar and \gamma –ray , radio loud NLS1 .
A comparison with two members of each class ( 3C 273 and PMN J0948+0022 ) is discussed .