Former astronomer here! A lot of the comments here are about how this event occurred 26,000 years ago. I thought it would be useful to describe how we think about these things in astronomy.<p>Firstly, yes it is true that this happened 26,000 years ago! More specifically, the event happened 26,000 years ago in our reference frame. There are other reference frames in which this event occurred two minutes ago or 5 million years ago. But generally these are not useful reference frames since the Earth's reference frame is not too different from the reference frame with respect to the center of mass of the Galaxy (we are not moving all that fast compared to the speed of light).<p>That said, as astronomers we are not particularly interested in dating precisely when the event happened. 26,000 years is a very long time in human history, but it's not very long on astronomical timescales. Not very much has changed in the Galaxy over the past 26,000 years, so we don't gain much by dating it at the time the event occurred (with respect to the Earth's reference frame, of course). Furthermore, we wouldn't even know exactly when it happened even if we wanted to! Our clocks are very precise here on Earth, but our distance measurements to most celestial objects are very fuzzy, particularly the further away you get. Because of this, these sorts of events are always referred to with respect to the year they were observed on Earth. (Thus, the most recent nearby supernova is known as 1987A because it was the first supernova observed in 1987.)<p>This all changes when you are studying more distant objects though! For very distant galaxies, we are now seeing things when the universe was considerably younger and things were much different. Then it becomes important to keep the event's age in mind. For these objects we will actually refer to their <i>redshift</i>. The redshift can be measured relatively well, and is related to the distance and age of the event via the Hubble constant and the acceleration parameter. Measuring these parameters is tricky and is a whole subfield of their own, so we usually stick with redshift as it is more related to things we can easily measure.<p>A final note on the paper itself. These observations were taken at Keck on Mauna Kea. There has been a lot of controversy around the construction of the Thirty Meter Telescope, so the authors actually acknowledge indigenous Hawaiians specifically in their paper:<p>> The authors wish to recognize that the summit of Maunakea has always held a very significant cultural role for the indigenous Hawaiian community. We are most fortunate to have the opportunity to observe from this mountain.
I didn’t realize until recently that supermassives and classic black holes are formed differently.<p><a href="https://en.wikipedia.org/wiki/Supermassive_black_hole" rel="nofollow">https://en.wikipedia.org/wiki/Supermassive_black_hole</a><p>It’s also fun to remember that this event happened 26,000 years ago.
It seemed that the pulse jumped for about an hour. Obviously this happened thousands of years ago, but would that be a literal hour? How much time is lost/bent in transit?
Here is the researcher's visualization of the near-infrared flaring activity:
<a href="https://twitter.com/i/status/1160368687590727680" rel="nofollow">https://twitter.com/i/status/1160368687590727680</a>
It's amazing given the lifespan of celestial entities that we can witness such significant change in such seemingly human time scales (2 hours).<p>The milky way galaxy is estimated to be ~13.7B years old. The black hole was brighter for a 2 hours. That event, as a percentage of the milky way's age represents: 0.00000000000001666500016665%.<p>As a comparison of what that represents as a unit of time in an average human lifespan (79 years) it equals:<p>0.00000069197080291971 seconds.
0.00069197080291971 milliseconds.
0.69197080291971 microseconds.
It's awesome when a natural phenomenon matches a timescale that a human being can witness, rather than taking centuries or more.<p>We get to see the whole show.
I think this video does a great job at describing what happened, how, and the theories of why.<p><a href="https://youtu.be/Or8O_b7F640" rel="nofollow">https://youtu.be/Or8O_b7F640</a><p>Is there an object massive enough to make the black hole emit that amount of light, but which is not bright enough to be detected by our equipment?
Out of curiosity, is it possible that some cataclysmic event in the universe happened thousands of years ago that has yet to reach and potentially affect Earth?
What software are these people using for the fantastic animations?<p>Is there an established framework for astrophysics that allows to work on a high level to produce these nice visuals?
So if the light from this event took 26 kyear to reach us, how long until the "om nom nom" sound reaches at least a Voyager probe in the interstellar medium?<p>Well, supernova shockwaves can travel at up to 0.1c, so at best another 234 kyear. Keep your microphones ready.
Why link to ad blogs instead of the actual study <a href="https://arxiv.org/abs/1908.01777" rel="nofollow">https://arxiv.org/abs/1908.01777</a>?
I'm always amazed at the amount of information and details astronomers can get from such a blurry little picture. It puts our galaxy's size in better perspective.
Remember when Beowulf Shaeffer took the Long Shot to the galactic core and discovered that it was exploding and would wipe out life in Known Space, so the Puppeteers moved their planets to parts unknown?<p>Could this flare be a foreshock of that? It'd be nice to have some time to settle my affairs.
I like to play Bingo with comments on science stories:<p>- "it was actually X thousand years ago"<p>- "it's actually false color, why can't we see what it really looks like"<p>- "surely this means quantum FTL communication works"<p>- something casually eugenic<p>and recently, with the Mauna Kea stories, there's a guaranteed "who do these bozos think they are, science is more important than anything"
[Removed poor joke, no one thinks it's funny and it's attracting downvotes.. Please stop hurting my karma. I can't delete this post anymore either. Sorry.]
Doesn't look like I can comment on this article or contact the author, but there is a typo.<p>> SO-2 made it’s closest approach about a year before the flaring observed in May 2019.<p>Should be its not it's
Um, shouldn't the headline say 25 Ky ago? It didn't "just" flare, unless "just" means "happened to for no known reason" which I suppose is a legit interpretation.
If a black hole is of brightness 0 (by definition), then 75 times that is still 0. They are probably referring to something happening just outside the event horizon and thus something that is not actually the black hole and just a phenomenon caused by the black hole.