On several occasions, I too have seen the afterglow of Orionids and other fast meteors suddenly swell in brightness after the main event, taking but a second or two to dim back down. To me, this pulse of afterglow mimics the meteor’s flash, as if the two were one unit but out of sync — something like a distant lightning strike and its delayed peal of thunder (if one could see thunder).
Denning thought it “unfair” to rate a meteor as 4th magnitude “when it leaves a short [train] that intensifies and then becomes as conspicuous as a second mag[nitude star.]”
Meteor expert Peter Jenniskens of the SETI Institute says that this phenomenon is a known effect in bright, fast meteors. “After the afterglow fades in a few seconds — mostly due to light from oxygen atoms — a persistent emission emerges that increases in brightness,” he explains. “It is due to ambient ozone molecules diffusing into the train of oxygen atoms. Iron atoms from the meteor recombine this ozone and the oxygen atoms and create the iron-oxide radical [a molecule that contains at least one unpaired electron] in an excited state in the process. When that electron returns to its normal state, it emits an orange glow, called a persistent train. These trains linger for a while and are great binocular targets.”
Persistent trains are themselves a separate and dynamic phenomenon that can last for tens of minutes. Generally, brighter and faster meteors produce brighter and more persistent trains. These sights may steal your attention away from the brief two-second pulse in the afterglows that precede them. So keep your eyes peeled, and let me know what you see at
sjomeara31@gmail.com.