We present the light curve of the old nova V603 Aql (Nova Aql 1918) from 1898-1918 and 1934-2013 using 22,722 archival magnitudes. All of our magnitudes are either in, or accurately transformed into, the Johnson B and V magnitude systems. This is vital because offsets in old sequences and the visual-to-V transformation make for errors from 0.1-1.0 magnitude if not corrected. Our V603 Aql light curve is the first time that this has been done for any nova. Our goal was to see the evolution of the mass accretion rate on the century time scale, and to test the long-standing prediction of the Hibernation model that old novae should be fading significantly in the century after their eruption is long over. The 1918 nova eruption was completely finished by 1938 when the nova decline stopped, and when the star had faded to fainter than its pre-nova brightness of B=11.43±0.03 mag. We find that the nova light from 1938-2013 was significantly fading, with this being seen consistently in three independent data sets (the Sonneberg plates in B, the AAVSO V light curve, and the non-AAVSO V light curve). We find that V603 Aql is declining in brightness at an average rate of 0.44±0.04 mag per century since 1938. This work provides remarkable confirmation of an important prediction of the Hibernation model. However, our result does not uniquely point to the Hibernation model because other models of novae evolution are now making similar predictions.
Authors: Christopher B. Johnson (LSU), Bradley E. Schaefer (LSU), Peter Kroll (Sonneberg Observatory), Arne Henden (AAVSO)
Read the pre-print on arXiv