In our observing campaign at the Thuringian State Observatory on the recurrent nova T Coronae Borealis (T CrB), we have noticed significant changes in the spectrum of T Coronae Borealis over the last two weeks. The emission lines in the spectrum have risen sharply, indicating a greatly increased accretion rate. Furthermore, emission lines can now be seen that can only occur at a temperature of at least 40000 K. These could be the first signs that the nova is about to erupt. The brightness of the system shows no change yet. We are continuing our observation campaign to catch the outburst of the nova.
The coloured lines show the spectra taken at the indicated dates and time. In February, the intensity of the lines increased dramatically. T shows Universal Time.
Evolution of the hydrogen emission lines around Hα 6560 and Hβ 4860 in the spectrum of T Coronae Borealis in the past two weeks
Evolution of the emission line of the neutral Helium He I 5876 and ionized He II 4686, which became visible in the last two weeks
Brightness variability of T CrB in the last 2.5 years (data taken from the AAVSO database): There is no change in the brightness during the increase in the emission lines
More details can be found at Astronomers Telegram.
Contact:
Dr. Veronika Schaffenroth