Betelgeuse about to Supernova

[Duckie]

You need to find darker skies then. I'm half blind and I can tell it's red on a clear night in the Brecon Beacons.

But like you I've never seen Mars being red. But I haven't seen Mars since starting my Astronomy degree so I haven't seen it through a scope yet.

I thought you just said a second ago you thought it was Blue?

[Eternal_Freedom]

Sorry, that wasn't too clear. Betelgeuse was a blue star on the main sequence until it swelled up to become a red supergiant. My apologies for the misunderstanding. At any rate, you need darker skies to see the colour.

[Zaune]

Good to know. I'd find it very hard to enjoy the spectacle if I thought there was a possibility we were also watching a civilisation die.

[Chaotic Neutral]

Good to know. I'd find it very hard to enjoy the spectacle if I thought there was a possibility we were also watching a civilisation die.

On the other hand, you could think about the planet that's going to receive a baby with superpowers.

[starslayer]

Sorry, that wasn't too clear. Betelgeuse was a blue star on the main sequence until it swelled up to become a red supergiant. My apologies for the misunderstanding. At any rate, you need darker skies to see the colour.

No you don't; you just need practice. When I was a kid, I had a really hard time seeing color in stars and the planets, except Venus. After getting more into astronomy, I began to be able to see stellar color much more clearly. The more you go out, the more you'll notice the color. To me, Mars is a brilliant red most of the time, and Betelgeuse is ruddy orange. I live only a couple of miles from the city center too.

[Broomstick]

Some people find binoculars provide just enough magnification to make the stellar colors more apparent.

[Mayabird]

Some of it might be air and light pollution. The stars are clearer and more colorful in Washington state (barring clouds) than in georgia or Iowa, at least in my experience. I could look up and see that yes, that star is very red, or orange, or blue, or whatever, instead of just being a spot of light.

[starslayer]

Some people find binoculars provide just enough magnification to make the stellar colors more apparent.

It's not the magnification - it's the binoculars improved light gathering power over the human eye due to their larger aperture. And yes, it does help; a brighter image is obviously easier to see color in. The threshold for color vision is usually stated as a mag 2-3 star, IIRC; Betelgeuse is 1st magnitude at its dimmest, as is Mars. Severe light or air pollution like that found in large cities can make it very difficult to see their color, but it's usually not impossible with plenty of practice. A similar phenomenon occurs when I or my fellow amateur astronomers show people fainter objects, like galaxies, or the planets, which sport lots of fine detail under good conditions. We can almost always see more than they can, mostly because we're used to the kind of observing technique required to tease out fine and/or faint detail. So it goes with stellar color.

Some of it might be air and light pollution. The stars are clearer and more colorful in Washington state (barring clouds) than in Georgia or Iowa, at least in my experience. I could look up and see that yes, that star is very red, or orange, or blue, or whatever, instead of just being a spot of light.

Both of the things you mentioned are factors, light pollution more so. Humidity highly affects transparency as well; the higher the humidity, the worse atmospheric extinction tends to be.

Light pollution reaches amazingly far from its source; Death Valley used to be a prime observing spot (extremely dry, calm weather, almost never cloudy, ink black 7-8th mag skies), but the skies are rapidly being destroyed due to light pollution from Las Vegas (the beam from the Luxor pyramid is visible from Death Valley) and Los Angeles, despite the fact that LA is ~200 miles away. It's still about the darkest you can get in Southern California, but going further north into Nevada is a safer bet for clear, dark skies these days.

For kicks, here's a big light pollution map of the US.

[Seggybop]

Good to know. I'd find it very hard to enjoy the spectacle if I thought there was a possibility we were also watching a civilisation die.

If there are any other systems within ~25ly, they'd still receive an interesting experience =/

[Eternal_Freedom]

Good to know. I'd find it very hard to enjoy the spectacle if I thought there was a possibility we were also watching a civilisation die.

If there are any other systems within ~25ly, they'd still receive an interesting experience =/

That's certainly true. Supernovae kick out a shitload of radiation, certainly enough to sterilise worlds within a few light years or so. Plus the huge mass fragmanets moving at ~10-30% c. Given that some of them can be solar-mass level lumps of Iron or Nickel, thet'll ruin anyone's day.

[starslayer]

That's certainly true. Supernovae kick out a shitload of radiation, certainly enough to sterilise worlds within a few light years or so. Plus the huge mass fragmanets moving at ~10-30% c. Given that some of them can be solar-mass level lumps of Iron or Nickel, thet'll ruin anyone's day.

Um, no. The ejected mass is distributed fairly equally in space, and contains relatively little iron-group elements, being the envelope and not the core.

[Eternal_Freedom]

That's certainly true. Supernovae kick out a shitload of radiation, certainly enough to sterilise worlds within a few light years or so. Plus the huge mass fragmanets moving at ~10-30% c. Given that some of them can be solar-mass level lumps of Iron or Nickel, thet'll ruin anyone's day.

Um, no. The ejected mass is distributed fairly equally in space, and contains relatively little iron-group elements, being the envelope and not the core.

Depends on the star. SN2006gy kicked out 40 solar masses worth of Nickel-56. Admittedly that star was a lot bigger than Betelgeuse.

At any rate, a nearby supernova would tend to remove potential life.

[Darkdrium]

I'm fuzzy on the physics of astronomy. Apparently Beltegeuse going nova would be like a second sun in the sky for a few weeks. Would that be only light or would we be receiving some heat as well? I suppose that at those distances we wouldn't be recieving much of anything but I'm curious.

[Broomstick]

Just light.

It would be visible during the day, but I'd expect not quite as bright as the sun (though if I'm wrong someone correct me - I'm not an astrophysicist). Do wonder how well it would like up the night sky, though.

[Eternal_Freedom]

According to my lecturers it would probably be between Venus and a full moon in brightness, depending on how big it is. Our best geusses are about 5-20 solar masses so there's a lot of room to maneuvre.

[Seggybop]

Just light.

It would be visible during the day, but I'd expect not quite as bright as the sun (though if I'm wrong someone correct me - I'm not an astrophysicist). Do wonder how well it would like up the night sky, though.

Is there some reason to think the light we receive from the supernova would contain substantially less IR proportionally than what we get from the sun?

[Simon_Jester]

No, but it's over six hundred light years away.

Venus gives off infrared radiation too, but we don't feel any noticeable warming-up from Venuslight. That's the key parameter here: sheer distance.

[starslayer]

The supernova would be a broad-spectrum radiator, just like the Sun is; it would give off both blackbody radiation and a lot of emission line stuff too. It's radiation peak would be somewhere in the UV or X-rays considering how hot it would be, but it wouldn't amount to anything dangerous because it's so far away. As far as visual brightness goes, it would be about as bright as the Full Moon, which is some 500,000 to a million times fainter than the Sun. It would however hurt to look at, because it would be a simple point source, instead of appearing about as large as a dime held at arm's length like the Moon.

So, the night sky would get a lot brighter for about six months, and amateur astronomers would probably start grumbling after about a week. But I think we would gladly deal with it for the sight of a lifetime.

[Ugolino]

So is this the Collapsing Hrung disaster?

[CaptainChewbacca]

So is this the Collapsing Hrung disaster?

Could be, although I don't think anyone ever explained what a Hrung was or why it chose to collapse where it did.