On Thursday, January 23, 2020 at 5:32:50 AM UTC-6, John Clark wrote: > > > > On Thu, Jan 23, 2020 at 6:01 AM Lawrence Crowell <[email protected] > <javascript:>> wrote: > > > > *> There have been a couple of these unnova events. Some stars have just >> winked out almost instantly. I would imagine this would ;produce a fair >> amount of gravitational radiation, even if the whole star is gulped by a >> black hole before EM radiation escapes. * >> > > That's what some are saying, but wouldn't the collapse have to be pretty > unsymmetrical for a significant amount of Gravitational Waves to be > produced? >
The implosion has to have a quadrupole moment. That could generate a gravitational wave. How the astrophysics of this works is not my bailiwick so I have to punt on any statement about the astrophysics, > > > >> *> I would hazard to propose this gravitational wave blip might be due to >> a small mass, maybe a planet, falling into a black hole.* >> > > A stellar mass Black Hole couldn't swallow a planet in one gulp, tidal > forces would tear it apart into dust long before it reached the Event > Horizon. The tidal force is weaker for a supermassive Black Hole so a small > strong nickel-iron asteroid might reach the Event Horizon more or less > intact, but the mass would be so low I don't think the Gravitational Waves > would amount to much, and the nearest supermassive is a long way away. > A planet entering stellar mass black hole would be tidally disrupted and it would be pulled into a streamer. The 1994 cometary impact on Jupiter is a plausible model. A lump of matter crossing the event horizon will be physics of moving a holographic screen and there will be a gravitational wave. The details of this again I am not that privy to. Maybe the BH has to be an intermediate mass BH. LC > > > John K Clark > -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/e9c71344-b386-4ad4-a924-31f192417916%40googlegroups.com.
