12 million light years is 0.013% of the size of the observable universe (93 billion light years diameter). That's quite close on a scale relative to the size of space.
> the size of the observable universe 93 billion light years diameter
While observable Universe will always be 93 billion light years in diameter, it is worth noting that everything is moving away from everything faster than gravity can counteract. That is, the Causally Disconnected (un-observable) Universe is inflating faster, the bigger it gets.
I suppose You could also measure such things in respect to time, considering the apparent distance of this event it also occurred long long ago in a galaxy far far away!
> a person that understands the topic should immediately understand we are talking about relatively close galaxy.
Sure, but a person who doesn't would receive the message more clearly if it were stated as "Supermassive black hole eruption near milky way". Otherwise I could write "Supermassive black hole eruption near New York" and be equally correct.
I suspect the potential for misunderstanding was the reason the headline was chosen in this form, however ...
Wow! This has a size of about 1.7 million lightyears, which is nine times the size of the milky way, and nearing the distance to Andromeda which is about 2.5 million light years.
Spanning 8 degrees, 12 million light years away? That's insane. A feature that's 1.67 million light years across? That's insane. That's a sixth of the size of the entire local cluster.
As noted, 0.5° across... but this misconception is in part because 360° or even 180° is really big when you're sitting at the center of it.
I believe part of this misconception comes from that when we look at something, we're only paying attain to +/- 15° while the bifocal range is 120° and the full field of view with both eyes is about 200°. Additionally, the field of view of the photographs that involve the sun or moon are often in the 5° to 15° range.
Another aspect of the moon and its size and the sky sphere - it moves at a fairly good clip. The sun is easier to think of though, it moves through 360° is 24h. That gives 15°/h or 0.25°/m. Every two minutes, the sun moves a solar diameter across the sky the moon has a similar amount of motion over a short period of time. This makes it difficult to take long exposures of the moon without a tracking mount.
> Is that a coincidence, or did this SMBH eat one of those enormous stars that's the diameter of Venus' orbit?
au contraire, enormous (in terms of mass not volume) but dying Neutron stars are so compressed under their own gravity, some are barely 12 to 25 kilometers in diameter of highly condensed Iron and other stable atomic arrangements, and may be spinning 40,000 times per minute on their own axis. Sometimes, there are two of those in a binary system, orbiting each other, on a collision course for a Kilonova, spraying out bazillion tonnes of star and planet making substances across a Galaxy.
A blackhole gulping Neutron Stars down would make for an interesting event!
More probably it ate thousands if not millions of stars.
It would be tricky to get it to swallow a star so big before that went supernova, while on the way in, on its own initiative. Whether the resulting black hole would then be swallowed up, or also be flung out at near light-speed with the rest of the ejecta, is an interesting question.
> The emission is powered by a central black hole in the galaxy Centaurus A, about 12 million light years away.
> As the black hole feeds on in-falling gas, it ejects material at near light-speed, causing ‘radio bubbles’ to grow over hundreds of millions of years.
I wonder what the radiation environment in the galaxy is. How bright a galactic center black hole can be before the whole galaxy becomes uninhabitable by something like us.
Galaxies are hazardous places to be. E.g., a minor hiccup on a magnetar 500 ly from Earth would sterilize it. Earth, that is. One might drift into range any time; Sol has probably been that near to one for a million years at least several times, as it orbits inside the Milky Way every 200 million years.
Any civilization interested in longevity would get the hell away from any galaxy as soon as it could manage.
Are the stars orbiting the Milky way all orbiting at very different speeds then? If not, I would think the stellar environment of any star would remain relatively constant over time.
I wonder if this is an example of an amazing event in the universe or an example of the amazing improvements in observational technologies. Will this be a much more common observation in six months or so when the James Webb telescope comes online?
the relative sizes of things you have trouble seeing due to dimness or can't see due to wavelength is very wild to me, for example the andromeda galaxy (you can only, at best, see its nucleus even with a proper telescope or binoculars):
Readit News
While observable Universe will always be 93 billion light years in diameter, it is worth noting that everything is moving away from everything faster than gravity can counteract. That is, the Causally Disconnected (un-observable) Universe is inflating faster, the bigger it gets.
So a person that understands the topic should immediately understand we are talking about relatively close galaxy.
Sure, but a person who doesn't would receive the message more clearly if it were stated as "Supermassive black hole eruption near milky way". Otherwise I could write "Supermassive black hole eruption near New York" and be equally correct.
I suspect the potential for misunderstanding was the reason the headline was chosen in this form, however ...
That explains a lot of clickbait!
But yes, farther out than Andromeda.
I believe part of this misconception comes from that when we look at something, we're only paying attain to +/- 15° while the bifocal range is 120° and the full field of view with both eyes is about 200°. Additionally, the field of view of the photographs that involve the sun or moon are often in the 5° to 15° range.
That narrow range photograph - https://www.deviantart.com/shagie/art/Crescent-Moonset-70823... and that has a 3.4° field of view on the short axis.
This is closer to the regular field of view - https://www.deviantart.com/shagie/art/Moon-and-sunset-318111... though I shot it portrait rather than landscape. That has a 27° field of view on the short axis and a 40° field of view on the long axis.
Another aspect of the moon and its size and the sky sphere - it moves at a fairly good clip. The sun is easier to think of though, it moves through 360° is 24h. That gives 15°/h or 0.25°/m. Every two minutes, the sun moves a solar diameter across the sky the moon has a similar amount of motion over a short period of time. This makes it difficult to take long exposures of the moon without a tracking mount.
Sun, likewise, of course.
So these radio lobes reach out another moon-width from both sides of your thumb.
No blackhole, no jets. Seems a bit pedantic to mention that the observed jets aren't crossing the event horizon.
Is that a coincidence, or did this SMBH eat one of those enormous stars that's the diameter of Venus' orbit?
au contraire, enormous (in terms of mass not volume) but dying Neutron stars are so compressed under their own gravity, some are barely 12 to 25 kilometers in diameter of highly condensed Iron and other stable atomic arrangements, and may be spinning 40,000 times per minute on their own axis. Sometimes, there are two of those in a binary system, orbiting each other, on a collision course for a Kilonova, spraying out bazillion tonnes of star and planet making substances across a Galaxy.
A blackhole gulping Neutron Stars down would make for an interesting event!
It would be tricky to get it to swallow a star so big before that went supernova, while on the way in, on its own initiative. Whether the resulting black hole would then be swallowed up, or also be flung out at near light-speed with the rest of the ejecta, is an interesting question.
> As the black hole feeds on in-falling gas, it ejects material at near light-speed, causing ‘radio bubbles’ to grow over hundreds of millions of years.
Any civilization interested in longevity would get the hell away from any galaxy as soon as it could manage.
https://slate.com/technology/2014/01/moon-and-andromeda-rela...