Will Bright Star Betelgeuse Supernova? | Hacker News Reader

Will Bright Star Betelgeuse Supernova?

space.com

27 pointsscottlocklin41 comments

Honest title would be: It's probably a natural dimming cycle and the star will not be blowing up right now. If it did, not to worry, it's ~650 light years away, and it shouldn't hurt us (don't they always say that ;-)). It would be as bright as the moon if it went nova for a while.

Phil Plait of Bad Astronomy fame agrees with you:

https://www.syfy.com/syfywire/dont-panic-betelgeuse-is-almos...

This guy is consistently entertaining and I recommend his stuff, even if it is hosted on the somewhat obnoxious SyFy site (that name...)

If it were as bright as the moon but visually a point source, would it be safe to look at with the naked eye?

Yes.

If it does go, it will remove the left shoulder of Orion, a constellation has been with us for all human history. A bit of a loss.

and bladerunner will make no sense.

I don't think Rutger says exactly which shoulder.

Nah, Blade Runner is set in 2019, so it's fine.

We'll have to update our myths. Artemis shot it off in a hunting accident, maybe?

That would be a shame. Write to your congress person and let them know.

They mention it in the article, but it's really fascinating how we've documented previous nearby (relatively) supernovae.

Modern scientists have identified that the Crab Nebula (6k light years away) was created by a supernovae. Historians then recognized that Chinese astronomers had actually seen that supernovae in 1054 AD. This was corroborated by historical records from Islamic astronomers as well.

Similar attempts have been made to identify the Star of Bethlehem, but I don't believe there's consensus on that one.

(Some of the above may be inaccurate, I just love how long people have been studying the night sky.)

Just FYI, supernovae (with an e at the end) is plural. The singular is supernova.

Imagine being alive when it goes supernova (relatively to us on earth). That would be a spectacular thing to witness.

I am sure it will be cloudy where I am.

Betelgeuse would be visible for weeks, and be at its brightest point (as bright as the full moon) for several days.

Even if you live in the tropics and it’s during the rainy season, you still have a good chance of seeing one. It’s not like a solar eclipse where you have very short time period to view it, it could last weeks to years (of course the peak would be shorter, but probably still on the order of days to weeks, at least long enough to travel to a clear location):

> Supernova SN 1054 was another widely observed event, with Arab, Chinese, and Japanese astronomers recording the star's appearance in 1054 AD. It may also have been recorded by the Anasazi as a petroglyph. This explosion appeared in the constellation of Taurus, where it produced the Crab Nebula remnant. At its peak, the luminosity of SN 1054 may have been four times as bright as Venus, and it remained visible in daylight for 23 days and was visible in the night sky for 653 days.

https://en.wikipedia.org/wiki/History_of_supernova_observati...

If you're anywhere near Pete from the UK's The Sky At Night programme, when a camera is on him, you can be guaranteed to be clouded out!

I am surprised it didn't happen. I think it's 1 star that goes supernova per galaxy every 100 years. Why didn't we see any yet? Reference: https://www.space.com/6638-supernova.html

"On average, a supernova will occur about once every 50 years in a galaxy the size of the Milky Way"

Why don't we see them with the naked eye?

> Why don't we see them with the naked eye?

Same reason you can't read a book by looking at the binding. Most are obscured by gas, the galactic core, etc. as we view the galaxy edge-on.

They also have to be fairly close to be visible to the naked eye. For example, https://en.wikipedia.org/wiki/SN_1987A was only about as far away as the other side of the Milky Way, and was perhaps barely visible in a dark sky at its peak magnitude.

We don't see all of the Milky way as is, like the other side of the milky way is out of our view. https://www.universetoday.com/23173/the-milky-way-from-earth... So that metric could be correct, but the supernova is outside of what we see.

Let’s do some back-of-the-envelope reasoning. https://en.wikipedia.org/wiki/Supernova: ”The peak optical luminosity of a supernova can be comparable to that of an entire galaxy”

There are over 2 trillion galaxies (https://en.wikipedia.org/wiki/Galaxy), of which less than 10 (https://en.wikipedia.org/wiki/Galaxy#Distinction_from_other_...) are visible with the naked eye.

⇒ ballpark, it seems only about one in 200 billion supernovae will be visible to the naked eye.

Taking 1/50th supernova per galaxy per year, we get 4 billion supernovae per year, so we would expect to see one every 50 years, on average.

Also, that can be as comparable may be fairly exceptional, the Milky Way may be above average size for a galaxy, or we just didn’t notice them (unless it were very bright, few people would notice a new ‘star’ showing up for a few days/weeks, and they may have been ‘behind’ other stars. That can easily happen for stars in the galactic plane of the Milky Way)

Certainly, historically, we simply didn’t really look. It was not as if we had a world-wide scan for supernovae even 50 years ago (do we even have one today, or are we mostly discovering them by going through decades-old photos?)

Something not experienced since the Great Collapsing Hrung Disaster of Gal./Sid./Year 03758!

Out of curiosity, I wonder what the closest star to Sol system is that is large enough to supernova?

Maybe Gacrux (Gamma Crucis), a red giant 88 light years away:

https://www.space.com/23710-gacrux-gamma-crucis.html

I presume this will be then the Great Collapsing Hrung Disaster of Gal./Sid./Year 03758, which Ford Prefect‘s father was the only person to survive

I'll save you some time: Yes.

When? Nobody knows. Might have already happened.

Checks the sky. No it hasn't happened. So it's either not happened yet or events of your post and Betelgeuse going supernova are separated by spacelike interval and as such they do not belong in before-after relation.

"It hasn't happened" = it's not in our past light cone. "It's not happened yet" = it's in our future light cone.

The speed of light sucks.

Fair enough. There's no such thing as a universal now. I should have said "No information about a supernova event has reached us."

What would it look like, a really bright star? Or would we actually see something that resembles an explosion

Man this would be awesome to observe. Hopefully it's not the 100,000 year estimate.

Mods, can you add "Go" before Supernova in the title? Supernova is not a verb.

>Supernova is not a verb.

Well, people use it as one, so apparently it is. (source: I googled around a bit)

I think in a language with, say "He's podiumed in five of his past six races" and "She medaled in three of four races", to supernova isn't a particularly bad offender. Anyway, why problem verbing?

It is now. It's been verbed.

Source?

It sounds like one of those "how to summer" bastardizations.

In defiance of Betteridge's law on headlines, technically the answer to this one is, yes, with an approximately 100% certainty. The question is not "if" but "when". However, the answer to "when" is unlikely to be anytime soon, from the point of view of an individual human being.

I would feel so, so fortunate to witness a supernova in my lifetime were it to occur..

Unless it were our Sun. Then we might not feel so fortunate. :-)

If only it were big enough.

You're in luck, they happen all the time: https://sne.space/

OTOH: https://earthsky.org/space/ligo-gravitational-wave-burst-nea...

Reply on news.ycombinator.com