Here is a comparison of 3 days fo T CrB
Red 04-05-2026
Blue 13-05-2026
Green 20-05-2026
I read somewhere that when the blue end starts to brighten it means the star is about to Flare or Explode or whatever it is called ¿?
I was curios and wanted to know what the raising brightness of the blue end could mean in my spectrum and asked ChatGPT and got the information below
Hmmm could be… I suspect that when, if an outburst in T CrB happens… when that candle gets lit… things will happen so fast that any blue precursor rise will be small potatoes in the grande scheme of evolution of the spectra and outburst timeline.
I noticed that ChatGPT scraped the phrase “hydrogen burning” from the web-cloud database. I over the decades have had several very smart astronomers tell me not to use that phrasing as it is wrong. No H burning involved… but H fusion is…!
Keep “Watching and waiting”… --The Moody Blues 
Jim (DEY)
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Thanks for drawing my attention to the Hydrogen fusion.
Rainer
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No it is just a poor response correction. Other spectra by experienced observers for these dates from the ARAS database for example
do not show this.
Cheers
Robin
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Any increase in the blue end though is associated with an increase in accretion rate but this in itself (or indeed anything as far as we know) cannot be used to predict when the nova outburst will happen.
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I never used this what I found in my spectra to make a prediction. This is far beyond of my knowledge.
I was just curios why two later taken spectra, May 13 and May 20, showed an elevated blue end and that is why I asked AI what this could mean.
If my spectra have a bad processing I need to verify that.
Not more and not less. That was all.
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I do not know if this is helpful. These are only estimates. It needs some corrections, tweaking and improvements. Not even sure if I should put this in the forum because of size. I can delete it if needed….
Of some of the things I noticed in this animation is the possible effect that resolution has on emission peaks. Note some of the days in 2025. You can also notice the other Hydrogen lines making appearances during the earlier years. I need to look into equivalent width for comparing(?). Also, I assume the emission lines are indicators of the accretion disk, it’s activity and revolution with the red star….
It would be valuable to know of indicators to follow, in the spectrum, that might indicate changes, e.g., something like He lines???
I’m still working on this but if any questions…
