Greetings,
I’m quite skeptical of the claims made in these ATels. A significant issue I see with these works is that they are treating the data in isolation, without considering past behavior of the system.
Photometrically, we know that T CrB is highly variable. Looking at the light curve (below), we can see a long-term sinusoidal pattern that has a ~227 day period. This is attributed to orbital motion.
One can also see that the light curve have considerable spread within each band. While this could be attributed calibration issues between observers (which certainly does exist) or noise, once you zoom in, you can see that much of the behavior appears to be short-term changes in brightness. This is most often attributed to accretion or flickering.
With such a high degree of photometric variability, it should come at no surprise that T CrB is also highly spectroscopically variable.
Since I started reviewing AVSpec data about two years ago, I’ve seen T CrB do some really interesting things. While most behavior is beyond the scope of the present discussion, one item I wish to highlight is that the system lights up with copious emission lines a few times a year.
Most of the time, the system looks similar to this spectrum taken on 2024-07-15. It shows the sawtooth-like TiO molecular bands indicative of M-type stars along with emission lines in H-alpha and sometimes in H-beta.
However, the system does light up from time to time with additional emission lines. For example, a spectrum taken on 2025-02-06, just a few days before the ATels, show H-alpha through H-gamma in emission along with potentially two He I lines as well:
This is not an isolated event. Going back about 244 days to a spectrum from 2024-07-07 we again see all the same lines in emission (albeit at a lower resolution):
While I’d be tempted to suggest this may be a function of orbital phase, it probably isn’t. Here is a spectrum from 2024-10-12 (117 days) which also shows the same features in emission:
I suspect if the ATel authors were to investigate the high resolution spectroscopy around the events I mentioned above, they would find that H-alpha was at a significantly greater intensity and greater width than normal. Yet in all of these situations, the eruption didn’t happen. Thus, I think we need to treat these papers with a high degree of skepticism.
As Brad mentioned in the post above, simply because there are signs of enhanced accretion does not mean the conditions on the white dwarf are right for the eruption to occur.
While on this face may seem discouraging, please note that I would not have been able to critique the ATels if it weren’t for the data you have been providing. This is science in action and you are making it happen!
Kind regards,
Brian
P.S. Now that I’ve gone on the record stating that the eruption is not immediately forthcoming, T CrB is surely going to make a fool of me 
.