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During the classical nova outburst, the radiation generated by the nuclear burning of hydrogen in the surface layer of a white dwarf (WD) is reprocessed by the outer material into different forms at softer energies, which distribution in the spectrum depends on the nova age. Using the method of multiwavelength modeling the SED we determined physical parameters of the stellar, nebular and dust component of radiation isolated from the spectrum of the classical nova V339 Del from day 35 to day 636 after its explosion. The transition from the iron-curtain phase to the super-soft source phase (days 35 - 72), when the optical brightness dropped by 3-4 mag, the absorbing column density fell by its circumstellar component from $sim 1times 10^{23}$ to $sim 1times 10^{21}$ cm$^{-2}$, and the emission measure decreased from $sim 2times 10^{62}$ to $sim 8.5times 10^{60}$ cm$^{-3}$, was caused by stopping-down the mass-loss from the WD. The day 35 model SED indicated an oblate shape of the WD pseudophotosphere and the presence of the dust located in a slow equatorially concentrated outflow. The dust emission peaked around day 59. Its co-existence with the strong super-soft X-ray source in the day 100 model SED constrained the presence of the disk-like outflow, where the dust can spend a long time. Both the models SED revealed a super-Eddington luminosity of the burning WD at a level of $1-2times 10^{39},(d/4.5{rm kpc})^2$ erg s$^{-1}$, lasting from $sim$day 2 to at least day 100.
We determine the temporal evolution of the luminosity L(WD), radius R(WD) and effective temperature Teff of the white dwarf (WD) pseudophotosphere of V339 Del from its discovery to around day 40. Another main objective was studying the ionization str
The origin of lithium (Li) and its production process have long been an unsettled question in cosmology and astrophysics. Candidates environments of Li production events or sites suggested by previous studies include big bang nucleosynthesis, interac
We present infrared spectroscopy of the classical nova V339 Delphini, obtained over a $sim2$ year period. The infrared emission lines were initially symmetrical, with HWHM velocities of 525 km s$^{-1}$. In later ($tgtrsim77$days, where $t$ is the tim
Here we report that the most rapidly recurring nova, M31N 2008-12a, which erupts annually, is surrounded by a nova super-remnant which demonstrates that M31N 2008-12a has erupted with high frequency for millions of years.
V745 Sco is a recurrent nova, with the most recent eruption occurring in February 2014. V745 Sco was first observed by Swift a mere 3.7 hr after the announcement of the optical discovery, with the super-soft X-ray emission being detected around four