Gravitational Waves Detected

Since gravity waves travel at the theoretical speed of light in a perfect vacuum and even deep space is not a perfect vacuum, maybe we will see a very bright Betelgeuse for a few weeks.

I think we would probably know by now...

https://www.forbes.com/sites/startswithabang/2017/03/22/what-will-happen-when-betelgeuse-explodes/#118166bc13ac

That's all?

I don't disagree but I was hoping for a more entertaining and enlightening discussion than that! Something like comparing the time between now and the January 14 gravity wave detection (just 8 days) would then necessitate just over a 0.003% reduction in the velocity of visible light in the media of interstellar space. That is if we saw the 600 lightyear distant Betelgeuse going supernova today. I'll grant you the abrupt annihilation of mass from a supernova will be many orders of magnitude smaller in comparison to neutron stars or black holes colliding. Then again 600 lightyears is much closer than those other collisions presumably were.

On the other hand, AFAIK we have never time correlated a LIGO gravity wave detection with a visible, radio or even X-ray telescope observation. That would be interesting to analyze and discuss.

I just went out and checked. Orion is almost directly overhead, and Betelgeuse looks just fine now (or 642.5 years ago), maybe a little dim. You are right, a week is pretty small compared to 642 years, and it would be interesting if gravity got here first. But there shouldn't be much in interstellar space to slow light down.

I'm wondering what you would expect to see before it exploded. It has dimmed in the last few months, but it's known for being kind of variable.

https://interestingengineering.com/is-the-star-betelgeuse-about-to-experience-a-supernova

Seeing a supernova would be far more awesome than even a solar eclipse, but maybe sad too. No more Betelgeuse and Orion would look kind of funny.

Phil Plait (Bad Astronomy) tells it pretty straight, and he thinks Betelgeuse probably has another 1000 centuries to go.

https://www.syfy.com/syfywire/dont-panic-betelgeuse-is-almost-certainly-not-about-to-explode

I looked at the Mollweide projection map of this LIGO event. Betelgeuse coordinates are not all that far away from one of the probability localizations. I am assuming the projection is of the celestial coordinates.

While I was trying to steer the discussion back to LIGO and gravity waves by proposing a possible link to Betelgeuse dimming, I have to refute the idea that Orion would look funny or sad. The crab nebula is 6500 lightyears away and it still attracts astronomers. The crab nebula exploded in 1054 and was recorded by multiple ancient "naked eye" astronomers.

The Orion nebula is 1344 light years away and on a clear winter's night this can be seen as a fuzzy patch with the naked eye. Having two naked eye nebula in the same constellation would not be sad. It would be GREAT!

This looks like a pretty dramatic change in brightness over the last 55 years:

And the last five years

From AAVSO

Does anyone know of a site that adds observations from the southern hemisphere so we don't get the gaps in the data?

Was Kepler's star, SN1604 a visible star before it went super? Did any ancient astronomers observe its brightness dimming before it did?

The southern hemisphere does not get a good view of Orion in the summertime.

I'm thinking the gaps are not a north/south hemisphere thing but that Betelgeuse is above the horizon in the daytime part of the year. As can be seen from the diagram below, Betelgeuse is fairly close to the plane of the ecliptic, the yearly path of the sun in the sky.

I do remember gravitational waves travel at the speed of light in a vacuum regardless of media characteristics. Thus a gravitational wave produced within the core of a dying star will leave the star long before anything else does. This is one of the ways they hope to look into what happens inside a star.

I fully accept I am discussing an idea far outside of my expertise. It's still fun to speculate.

According to this, our first indication should be a flood of high energy neutrinos. When it runs out of elements to fuse (silicon is the last), there's no more energy produced and the entire weight of the star comes crashing down. All that excess energy will fuse elements for the rest of the periodic table and a lot of energy will be released as neutrinos, for which matter is almost perfectly transparent.

"In 1987, a supernova from 168,000 light-years away wound up creating a signal of a little over 20 neutrinos across three small neutrino detectors that were operating at the time. There are many different neutrino observatories in operation today, much larger and more sensitive than the ones we had at our disposal 33 years ago, and Betelgeuse, just 640 light-years away only, would send a signal some 70,000 times stronger on Earth due to its close proximity.

In 2020, if Betelgeuse were to go supernova, our first surefire signature would come in the form of high-energy neutrinos flooding our neutrino detectors all over the world in a burst spanning some 10-15 seconds. There would literally be millions, perhaps even tens of millions, of neutrinos picked up all at once by these observatories. A few hours later, when the first energetic ripples created by this cataclysm reached the star's outer layers, a "breakout" of photons would reach us: a swift spike that increased Betelgeuse's optical brightness tremendously."

https://www.forbes.com/sites/startswithabang/2020/01/23/this-is-what-well-see-when-betelgeuse-really-does-go-supernova/#274b6b8a43a2

So when Betelgeuse goes into supernova we will be getting a neutrino flood as a precursor. (I still don't understand how 20 detected neutrinos can be attributed to a supernova 168,000 lightyears away when we are constantly flooded by neutrinos from our sun. I don't dispute that they can, I just don't understand it. But neutrino detection and energy resolution is another interesting tangent worthy of a new thread. I'll get back to this tangent.)

Still, since neutrinos do have a very tiny amount of mass they must travel slower than the speed of light in a vacuum. Thus the event producing this neutrino burst must have happened at some point even earlier than that graph indicates. Depending on how much kinetic energy those 20 neutrinos have the timeline may not move much but then again that was still a race lasting 168,000 years and the resolution of that timeline is individual days. That's at least seven orders of magnitude in time alone.

Aha! The plot is apparently from supernova 1987A which means the 20 neutrinos were between 7.5 and 35 MeV putting the relative difference of neutrino velocity and the absolute speed of light at ≤10^-14. So timelines should be consistent.

This was definitely an entertaining tangent from the sudden gravitational wave detected, and I thank you. I think we lost my point that started this tangent. A supernova has a similar abrupt change in gravity this gravitational waveform detected. Immense objects (neutron stars, black holes) spiraling into each other do not produce what seems like the step function that LIGO just detected. A supernova does have such a change. While it may not be Betelgeuse finally going into this expected cataclysmic change I still wonder if we may see a supernova related to this gravitational wave.

Could be another supernova, I suppose, but my guess is that neutrinos should be easier to detect from a supernova than gravitational waves are. Neither is very easy, and optical is far easier unless it is in the direction of the sun.

It's a puzzle. I wonder if we'll ever know.

Maybe these waves were from a FTL alien spaceship whizzing by....?

Maybe Boob Lazar could shed some light on that idea.

Perhaps it was a dark matter mass collapse?

Or a star ship going into warp drive?

So if it is not from Betelgeuse going boom might it be this big boom?