Analysis of photometric and spectroscopic observations of classical nova V615 Vul

We present an investigation of the classical nova V615 Vul that erupted on July 29, 2024. The results obtained are based on our multicolor observations at AI SAS, the M. R. Stefánik Observatory in Hlohovec and MAO NASU, as well as photometry from the AAVSO and ASAS-SN database. We also present spectral observations obtained with the 1.3-meter telescope at Skalnaté Pleso Observatory , when the very broad asymmetric H α emission line dominated during the nova’s decline. From the constructed light curves, we determined the brightness decay rates at 2 and 3 magnitudes, obtaining t 2,V = 5 d.2, t 3,V = 8 d.9 and t 3,B = 11 d.6, which corresponds to fast novae. We analyzed short-term brightness variations detected in the light curve around day 35 from the onset of the outburst. Using our V RcIc data, we found a period of 0 d .2238 ± 0.005, which we interpret as the orbital period of V615 Vul. We calculated color indices and estimated the color temperature of the system. The tracks in the the V −Rc and Rc −Ic diagrams exhibit loop-like variations caused by changes in the intensity and profile of the broad H α emission line, while the tracks in U − B/B − V diagram reflect changes in color temperature during the outburst-behavior typical of many cataclysmic variables and novae. We also estimated the main parameters of the system, such as the absolute magnitude, its distance, and the mass of the white dwarf.