# What would it be called if a galaxy exploded **URL:** \ **Category:** In My Humble Opinion\ **Created:** [October 8, 2007, 10:16pm UTC](https://boards.straightdope.com/t/what-would-it-be-called-if-a-galaxy-exploded/422001 "2007-10-08T22:16:25Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![bonitahi](https://avatars.discourse-cdn.com/v4/letter/b/7993a0/32.png) [@bonitahi](https://boards.straightdope.com/u/bonitahi)\ **Post date:** [October 8, 2007, 10:16pm UTC](https://boards.straightdope.com/t/what-would-it-be-called-if-a-galaxy-exploded/422001/1 "2007-10-08T22:16:25Z")
What would it be called if a galaxy exploded (like star from a nova or super nova)? ---
**Author:** ![The\_Hamster\_King](https://avatars.discourse-cdn.com/v4/letter/t/8edcca/32.png) [@The\_Hamster\_King](https://boards.straightdope.com/u/The_Hamster_King)\ **Post date:** [October 8, 2007, 10:36pm UTC](https://boards.straightdope.com/t/what-would-it-be-called-if-a-galaxy-exploded/422001/2 "2007-10-08T22:36:26Z")
[QUOTE=bonitahi] What would it be called if a galaxy exploded (like star from a nova or super nova)? [/QUOTE] There’s not a mechanism by which a galaxy COULD explode. If you somehow managed to compress a galaxy together to create supernova-like conditions on a large scale, it would just collapse into a black hole. (In fact, astronomers think many galaxies already have massive black holes at their centers.) ---
**Author:** ![bonitahi](https://avatars.discourse-cdn.com/v4/letter/b/7993a0/32.png) [@bonitahi](https://boards.straightdope.com/u/bonitahi)\ **Post date:** [October 8, 2007, 10:40pm UTC](https://boards.straightdope.com/t/what-would-it-be-called-if-a-galaxy-exploded/422001/3 "2007-10-08T22:40:05Z")
And the name they call that is…? ---
**Author:** ![danceswithcats](https://avatars.discourse-cdn.com/v4/letter/d/9e8a1a/32.png) [@danceswithcats](https://boards.straightdope.com/u/danceswithcats)\ **Post date:** [October 8, 2007, 10:53pm UTC](https://boards.straightdope.com/t/what-would-it-be-called-if-a-galaxy-exploded/422001/4 "2007-10-08T22:53:58Z")
[QUOTE=bonitahi] What would it be called if a galaxy exploded ? [/QUOTE] A Ford with greatly diminished trade-in value. ---
**Author:** ![The\_Hamster\_King](https://avatars.discourse-cdn.com/v4/letter/t/8edcca/32.png) [@The\_Hamster\_King](https://boards.straightdope.com/u/The_Hamster_King)\ **Post date:** [October 8, 2007, 10:54pm UTC](https://boards.straightdope.com/t/what-would-it-be-called-if-a-galaxy-exploded/422001/5 "2007-10-08T22:54:32Z")
There’s no name for it. What’s the name for an exploding cloud? It’s possible for a galaxy to experience a “starburst” where large numbers of new stars form in a short period of time. This can cause an outflow of gas that resembles an explosion, but the galaxy itself isn’t “exploding”. ---
**Author:** ![Lemur866](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lemur866/32/434_2.png) [@Lemur866](https://boards.straightdope.com/u/Lemur866)\ **Post date:** [October 8, 2007, 11:03pm UTC](https://boards.straightdope.com/t/what-would-it-be-called-if-a-galaxy-exploded/422001/6 "2007-10-08T23:03:24Z")
This might be close to what you’re looking for. Galaxies don’t “explode”, but there are lots of galaxies that put out tremendous amounts of radiation. > **[Active galactic nucleus](https://en.wikipedia.org/wiki/Active_galactic_nuclei)** > > An active galactic nucleus (AGN) is a compact region at the center of a galaxy that emits a significant amount of energy across the electromagnetic spectrum, with characteristics indicating that the luminosity is not produced by stars. Such excess, non-stellar emissions have been observed in the radio, microwave, infrared, optical, ultra-violet, X-ray and gamma ray wavebands. A galaxy hosting an AGN is called an active galaxy. The non-stellar radiation from an AGN is theorized to result from the ... ---
**Author:** ![bonitahi](https://avatars.discourse-cdn.com/v4/letter/b/7993a0/32.png) [@bonitahi](https://boards.straightdope.com/u/bonitahi)\ **Post date:** [October 8, 2007, 11:11pm UTC](https://boards.straightdope.com/t/what-would-it-be-called-if-a-galaxy-exploded/422001/7 "2007-10-08T23:11:21Z")
So, there is no such chance for a super black hole embracing or sucking in via its gravitational force, a galaxy, even a small galaxy. ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [October 8, 2007, 11:18pm UTC](https://boards.straightdope.com/t/what-would-it-be-called-if-a-galaxy-exploded/422001/8 "2007-10-08T23:18:24Z")
[QUOTE=bonitahi] So, there is no such chance for a super black hole embracing or sucking in via its gravitational force, a galaxy, even a small galaxy. [/QUOTE] Pretty much not. Our own galaxy, the Milky Way, has at its core a supermassive black hole of approximately 3 million solar masses and yet we’re in absolutely no danger of being sucked in. The gravity from black hole is intense very near the hole itself, but the gravitational field gradient is just the same as it would be for a normal object of the same mass. If our Sun where compressed into a black hole, we’d all die from lack of energy, but the Earth would continue in the exact same orbit as before. ---
**Author:** ![bonitahi](https://avatars.discourse-cdn.com/v4/letter/b/7993a0/32.png) [@bonitahi](https://boards.straightdope.com/u/bonitahi)\ **Post date:** [October 8, 2007, 11:21pm UTC](https://boards.straightdope.com/t/what-would-it-be-called-if-a-galaxy-exploded/422001/9 "2007-10-08T23:21:29Z")
“If our Sun where compressed into a black hole, we’d all die from lack of energy…” or boredom. ---
**Author:** ![The\_Hamster\_King](https://avatars.discourse-cdn.com/v4/letter/t/8edcca/32.png) [@The\_Hamster\_King](https://boards.straightdope.com/u/The_Hamster_King)\ **Post date:** [October 8, 2007, 11:23pm UTC](https://boards.straightdope.com/t/what-would-it-be-called-if-a-galaxy-exploded/422001/10 "2007-10-08T23:23:23Z")
[QUOTE=bonitahi] So, there is no such chance for a super black hole embracing or sucking in via its gravitational force, a galaxy, even a small galaxy. [/QUOTE] Sure, but that wouldn’t be an explosion. Once it gets sucked in, it’s not coming out again. [Quasars](http://en.wikipedia.org/wiki/Quasar) seem to be the result of huge amounts of gas spiraling into a galaxy-sized black hole. It’s a very violent and energetic process … but it’s not an “explosion”. ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [October 8, 2007, 11:50pm UTC](https://boards.straightdope.com/t/what-would-it-be-called-if-a-galaxy-exploded/422001/11 "2007-10-08T23:50:55Z")
[QUOTE=bonitahi] What would it be called if a galaxy exploded (like star from a nova or super nova)? [/QUOTE] Fiction. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [October 9, 2007, 12:12am UTC](https://boards.straightdope.com/t/what-would-it-be-called-if-a-galaxy-exploded/422001/12 "2007-10-09T00:12:55Z")
> [@](#): > > Quasars seem to be the result of huge amounts of gas spiraling into a galaxy-sized black hole. It’s a very violent and energetic process … but it’s not an “explosion”. I think that quasars are the closest thing to an answer to the OP’s question, and the only reason one might not call them “explosions” is that they last for billions of years, but even there, the total amount of matter consumed is only a tiny fraction of the mass of the host galaxy. ---
**Author:** ![Earl\_Snake-Hips\_Tucker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/earl_snake-hips_tucker/32/3269_2.png) [@Earl\_Snake-Hips\_Tucker](https://boards.straightdope.com/u/Earl_Snake-Hips_Tucker)\ **Post date:** [October 9, 2007, 12:47am UTC](https://boards.straightdope.com/t/what-would-it-be-called-if-a-galaxy-exploded/422001/13 "2007-10-09T00:47:44Z")
A non-localized phenomenon. ---
**Author:** ![flurb](https://avatars.discourse-cdn.com/v4/letter/f/51bf81/32.png) [@flurb](https://boards.straightdope.com/u/flurb)\ **Post date:** [October 9, 2007, 12:50am UTC](https://boards.straightdope.com/t/what-would-it-be-called-if-a-galaxy-exploded/422001/14 "2007-10-09T00:50:00Z")
The apocalypse? ---
**Author:** ![SlickRoenick](https://avatars.discourse-cdn.com/v4/letter/s/e68b1a/32.png) [@SlickRoenick](https://boards.straightdope.com/u/SlickRoenick)\ **Post date:** [October 9, 2007, 2:14am UTC](https://boards.straightdope.com/t/what-would-it-be-called-if-a-galaxy-exploded/422001/15 "2007-10-09T02:14:36Z")
[QUOTE=Q.E.D.] Pretty much not. Our own galaxy, the Milky Way, has at its core a supermassive black hole of approximately 3 million solar masses and yet we’re in absolutely no danger of being sucked in. The gravity from black hole is intense very near the hole itself, but the gravitational field gradient is just the same as it would be for a normal object of the same mass. If our Sun where compressed into a black hole, we’d all die from lack of energy, but the Earth would continue in the exact same orbit as before. [/QUOTE] But what if the black hole was the _size_ of our sun, not compressed, with mass equal to whatever a black hole of that size would be? ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [October 9, 2007, 2:32am UTC](https://boards.straightdope.com/t/what-would-it-be-called-if-a-galaxy-exploded/422001/16 "2007-10-09T02:32:03Z")
[QUOTE=SlickRoenick] But what if the black hole was the _size_ of our sun, not compressed, with mass equal to whatever a black hole of that size would be? [/QUOTE] We would be dead before our brains could comprehend the transition. ---
**Author:** ![bonitahi](https://avatars.discourse-cdn.com/v4/letter/b/7993a0/32.png) [@bonitahi](https://boards.straightdope.com/u/bonitahi)\ **Post date:** [October 9, 2007, 4:03am UTC](https://boards.straightdope.com/t/what-would-it-be-called-if-a-galaxy-exploded/422001/17 "2007-10-09T04:03:31Z")
That’s just negative thought. ---
**Author:** ![Ravenman](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ravenman/32/2929_2.png) [@Ravenman](https://boards.straightdope.com/u/Ravenman)\ **Post date:** [October 9, 2007, 4:15am UTC](https://boards.straightdope.com/t/what-would-it-be-called-if-a-galaxy-exploded/422001/18 "2007-10-09T04:15:03Z")
[QUOTE=Q.E.D.] If our Sun where compressed into a black hole, we’d all die from lack of energy, but the Earth would continue in the exact same orbit as before. [/QUOTE] Warning! Longstanding gripe forthcoming: I learned this back in physics class, and I don’t know how many people I’ve told it to, and not a single one has ever believed me. Maybe next time I’ll try to convince them that this really smart science guy on some Internet message board said it, too, so it must be right. Eh, that doesn’t sound so good. I’ll stick with “My part-time adjunct professor at my community college told me so.” ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [October 9, 2007, 4:30am UTC](https://boards.straightdope.com/t/what-would-it-be-called-if-a-galaxy-exploded/422001/19 "2007-10-09T04:30:08Z")
[QUOTE=danceswithcats] A Ford with greatly diminished trade-in value. [/QUOTE] That’s why I like my LTD, don’t have to worry about those pesky hypothetical explosions. (The Nova on the other hand…) ---
**Author:** ![commasense](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/commasense/32/3017_2.png) [@commasense](https://boards.straightdope.com/u/commasense)\ **Post date:** [October 9, 2007, 5:00am UTC](https://boards.straightdope.com/t/what-would-it-be-called-if-a-galaxy-exploded/422001/20 "2007-10-09T05:00:46Z")
If no one else is willing to give the OP a straightforward answer, I will, in the best tradition of naming astronomical concepts like the Big Bang. It would be called a Super-Duper Nova[sup]TM[/sup]. So there. [Next page](https://boards.straightdope.com/t/what-would-it-be-called-if-a-galaxy-exploded/422001.md?page=2)