The German Astrophysical Virtual Observatory ( GAVO ) developed the registered service TheoSSA ( theoretical stellar spectra access ) and the supporting registered VO tool TMAW ( Tübingen Model-Atmosphere WWW interface ) .
These allow individual spectral analyses of hot , compact stars with state-of-the-art non-local thermodynamical equilibrium ( NLTE ) stellar-atmosphere models that presently consider opacities of the elements H , He , C , N , O , Ne , Na , and Mg , without requiring detailed knowledge about the involved background codes and procedures .
Presently , TheoSSA provides easy access to about 150 000 pre-calculated stellar SEDs and is intended to ingest SEDs calculated by any model-atmosphere code .
In the case of the exciting star of PN PRTM 1 , we demonstrate the easy way to calculate individual NLTE stellar model-atmospheres to reproduce an observed optical spectrum .
We measured \mbox { $T _ { \mathrm { eff } } $ } \hskip { -1.422638 pt } = \hskip { -1.422638 pt } 98 000 \pm 5 % 000 \mathrm { K } , \log ( g / \mathrm { cm / s ^ { 2 } } ) = 5.0 ^ { +0.3 } _ { -0.2 } , and photospheric mass fractions of H = 7.5 \times 10 ^ { -1 } ( 1.02 times solar ) , He = 2.4 \times 10 ^ { -1 } ( 0.96 ) , C = 2.0 \times 10 ^ { -3 } ( 0.84 ) , N = 3.2 \times 10 ^ { -4 } ( 0.46 ) , O = 8.5 \times 10 ^ { -3 } ( 1.48 ) with uncertainties of \pm 0.2 dex .
We determined the stellar mass and luminosity of 0.73 ^ { +0.16 } _ { -0.15 } M _ { \odot } and \log ( L / L _ { \odot } ) = 4.2 \pm 0.4 , respectively .