A bit concerned

[Baron von Richthofen]

The giant sun Betelgeuse which has a diameter of approximately 744,000,000 miles and approaching the end of its short life of several million years and only 640 light years away I am wondering when it supernova which will be clearly seen with the unaided eye, even in daylight, will it cause a mass extension on earth

[renormalised]

No...too far away. Have to be at least 30ly away before we'd have to worry about that.

It'll just put on a fantastic fireworks display:)

[rogerg]

I'd be concerned too if the Sun was Betelgeuse :lol:

[sjastro]

I'd be more concerned about Sirius B the white dwarf companion star of Sirius.

If Sirius B is extracting mass from the main star it could be a candidate for a type I supernova, and it's only 8.6 light years away.

Regards

Steven

[pgc hunter]

Would Sirius be massive enough for a supernova?

[starlooker]

Never fear, the USA will save the earth's bacon, like in the movies.

[erick]

That's interesting re Sirius. I guess the mass change would be picked up through changes in orbital period? Or is that a centre-of-mass thing and won't be affected? Perhaps then, relative magnitudes?

[renormalised]

No, it's only 2 solar masses. Stars need to be between 8-11 before they're big enough to go off as supernovae. Why the size range??. Depends on what happens to the stars of that size late in life...specifically, how much mass they have left over after the AGB stage. If the core accumulates more than 1.4 solar masses of material, then they're destined to become supernovae. If it falls short, then you get a rare type of white dwarf called a Oxygen-Neon White Dwarf...very small, very heavy.

I don't think Sirius B is in a tight enough orbit to be collecting mass from Sirius itself (it's a 50 year orbit), but if it was, and it was collecting it at a high enough rate, then you could get a Type I supernova going off. If it went off tomorrow, we'd be toast...literally.

[pgc hunter]

Hopefully all the world's lamb, beef and pork will be saved aswell.

However, if all the vegetables on Earth were destroyed, I'd be extremely happy and would call for a massive BBQ and booze party. :party:

[renormalised]

See your location listed in the header....that's what would happen to this planet. I'm afraid even if the bacon, lamb, beef, chicken and fish survived, you'd be eating "glow in the dark" meat that'd probably have extra legs and God knows what else attached to it!!!:P:P:D:D

[pgc hunter]

As long as it's meat I'm happy :D The glow-in-the-darkness would make it easier to see while cooking it at my evening BBQ party :D :party:

[renormalised]

Problem is....that glow in the dark means that the proteins in the meat are most likely highly poisonous because their structure has been altered by the radiation. It would be one, short BBQ:P:P:D:D

[pgc hunter]

One short, but one hell of an awesome BBQ :D

[toryglen-boy]

Well, not for 8 1/2 years


:P

[JimmyH155]

Isn't the closest and biggest supernova candidate, Eta Carina??:shrug: It looks awesome in my scope, and whenever I look at it I hope it to go pop so I can phone up someone and claim the honour of being first;)
Then there is this concentrated beam of particles coming off a black hole that could fry us if it was pointed at us.
I think I'll take a chance and cook up the roo fillet on the barbie anyway:lol::thumbsup:

[sjastro]

If Sirius B was gaining mass at the expense of Sirius A, the centre of mass would be moving towards Sirius B and hence the orbital period of Sirius B would decrease. All of this however is very long term.

I imagine if mass is spiraling into Sirius B, then Sirius B should be an irregular variable.

Steven

[renormalised]

True, but toast we'd be:D

Or, you could always douse yourself in 11 secret herbs and spices:P:D

[toryglen-boy]

Who do you think i am? Colonel Sanders?

:lol:


you calling me "chicken" ?

:lol:

[pgc hunter]

8.5 years of drinking and eating meat like an animal :D


I do that every Friday night :D

then regret it every Saturday morning :o

[sjastro]

It's interesting that Sirius B is one of the most massive white dwarfs known.

It has a solar mass of around 1, white dwarfs are in the range 0.5-0.6.
I wonder where Sirius B has picked up the extra mass.:D

Regards

Steven

[pgc hunter]

Does Sirius A taste like chicken? If so, I wouldn't be surprised :lol:

[renormalised]

True...but given the separation of the two (around 20 AU) I can't see anything happening somehow (thankfully!!!!)

If Sirius was losing mass to the WD, the most likely outcome would be we'd have a recurrent nova in the system. Pretty spectacular from 8.6ly away, but we'd be relatively safe...a lot safer than if it really went pop!!!.

Where Type I's normally occur is in binary systems where one of the stars has filled its Roche Lobe (i.e. it's a red giant/supergiant itself) and the WD is sucking gas from a weakly held surface. In systems where the star is a normal MS star (rare), the WD is orbiting almost on top of the primary, so its tidal disturbances of the star are ripping gas off the surface.

[sjastro]

Clearly Sirius A tastes of Dog.

Steven

[renormalised]

The original star was B type, so you're looking at a 4-5 solar mass star. Bigger the star....larger the WD left over. Most normal MS stars produce WD's in the size range you mentioned, although there are quite a few smaller ones.

[erick]

I reckon anyone outside or near a window will know. "Hey? How come it's suddenly daytime again???"

[renormalised]

That's right...it ain't "Chookus Major":P:D:D

[renormalised]

Ok "Marty", no need to get your temporal paradox in a twist:P:P:D:D:lol:

[GrahamL]

Would a blast dissperse angularly as you moved away from it ?
by that I mean by the time the chicken wings and dog legs arrive
would they be scattered over a fairly broad area or is this one two close?

Whats that other type of explosion that jetisons material
straight out of the polar axis? of a star( I'm sketchy memeroied here)
bit like looking down a gun barrel if I remember how it was described. Is there a particularly nasty example pointing at us ?

cheers graham

[kinetic]

You would HAVE to have rock band DISASTER AREA hired for the party, PGC.
Along with Hotblack Desiato on keyboards.
Did you know he spent a year dead for tax reasons? :)
They are the loudest band in the universe.
This band is so loud that fans have to listen from a bunker 30 miles
away :)

for Douglas Adams fans........ :D

Steve

[sjastro]

Gamma rays which are high energy photons are scattered over distance. Any intervening matter such as interstellar gas and dust, solar particles etc will absorb some of the photons energy and change the photon's trajectory.

Even the photons themselves collide with each other and scatter.

Quasars, Seyfert galaxies , galaxies with active centres can shoot off plasma, X-rays, and UV radiation.

Although the mechanism is not fully understood, a rotating black hole is the common denominator with all these beasties. Some of the rotational energy of the black hole is transferred to the photons or particles in the jet.

Regards

Steven

[MrB]

How many blokes would really be concerned about a mass extension?

[renormalised]

42

[dugnsuz]

:lol: