Mysterious hot spots observed in Betelgeuse

On 4/27/13 11:56 AM, Poutnik wrote:

Yousuf Khan posted Sat, 27 Apr 2013 13:34:29 -0400



On 26/04/2013 9:46 PM, wrote:
If Betelgeuse goes supernova there is a pretty good chance you can say
bye bye to life on earth

Only if the GRB it produces is pointed towards us. That means that its
polar jets need to be pointed towards us within 2 degrees. The most
recent study done shows that its polar jets are pointed away from us by
about 20 degrees, so we're safe.

What about expected radiation spectrum ?

Even sourcee weaker then Sun
can have unpleasant high energy spectrum part.



Ozone and oxygen in the earth's atmosphere blocks most gamma,
x-ray and hard UV.

Sam Wormley posted Sat, 27 Apr 2013 16:02:26 -0500



On 4/27/13 11:56 AM, Poutnik wrote:

Yousuf Khan posted Sat, 27 Apr 2013 13:34:29 -0400



On 26/04/2013 9:46 PM, wrote:
If Betelgeuse goes supernova there is a pretty good chance you can say
bye bye to life on earth

Only if the GRB it produces is pointed towards us. That means that its
polar jets need to be pointed towards us within 2 degrees. The most
recent study done shows that its polar jets are pointed away from us by
about 20 degrees, so we're safe.

What about expected radiation spectrum ?

Even sourcee weaker then Sun
can have unpleasant high energy spectrum part.



Ozone and oxygen in the earth's atmosphere blocks most gamma,
x-ray and hard UV.

I do know that, the question is, if that is enough.

The Sun eruptions and solar winds have influence as well.

--
Poutnik

On 27/04/2013 5:06 PM, Poutnik wrote:

Sam Wormley posted Sat, 27 Apr 2013 16:02:26 -0500
Ozone and oxygen in the earth's atmosphere blocks most gamma,
x-ray and hard UV.

I do know that, the question is, if that is enough.

The Sun eruptions and solar winds have influence as well.

The only thing that can overpower the Earth's Ozone layer from space is
a close GRB pointed straight at us, i.e. it's polar jets are pointed to
within 2 degrees of our solar system. The GRB also has to be somewhere
less than 3000-13000 light-years from us, and directly aimed at us to
have any effect on us. Betelgeuse is 600 light-years away, and it will
go supernova, but it may not become a GRB. Even if it does become a GRB,
it still has to be pointed towards us, and it doesn't look like its
polls are.

Yousuf Khan

On Sat, 27 Apr 2013 16:02:26 -0500, Sam Wormley
wrote:



What about expected radiation spectrum ?

Even sourcee weaker then Sun
can have unpleasant high energy spectrum part.



Ozone and oxygen in the earth's atmosphere blocks most gamma,
x-ray and hard UV.

UV yes but the gamma will only burn off the ozone

On Sat, 27 Apr 2013 18:01:35 -0400, Yousuf Khan
wrote:



The only thing that can overpower the Earth's Ozone layer from space is
a close GRB pointed straight at us, i.e. it's polar jets are pointed to
within 2 degrees of our solar system. The GRB also has to be somewhere
less than 3000-13000 light-years from us, and directly aimed at us to
have any effect on us. Betelgeuse is 600 light-years away, and it will
go supernova, but it may not become a GRB. Even if it does become a GRB,
it still has to be pointed towards us, and it doesn't look like its
polls are.

Yousuf Khan


Close? is over 1000 LY considered close a GRB at that distance would
totally burn off the ozone

On 4/27/13 5:22 PM, wrote:
On Sat, 27 Apr 2013 16:02:26 -0500, Sam Wormley
wrote:

Ozone and oxygen in the earth's atmosphere blocks most gamma,
x-ray and hard UV.

UV yes but the gamma will only burn off the ozone


Electromagnetic Radiation: Interactions in the Atmosphere
http://www.geo.oregonstate.edu/class...S/lecture3.pdf

Dear bil...:

On Saturday, April 27, 2013 3:22:20 PM UTC-7, wrote:
....
UV yes but the gamma will only burn off the ozone

The particle accelerator folks have to scrub ozone in and around their machines. They do this, because *all* ionizing radiation makes ozone.

If we get hit with a GRB, we will have plenty of ozone. We will have ozone and NOx, the skies will turn dark brown as our entire facing atmosphere will have the worst case of "photochemical smog" Earth may ever have seen.

David A. Smith

On 4/27/13 5:24 PM, wrote:
On Sat, 27 Apr 2013 18:01:35 -0400, Yousuf Khan
wrote:



The only thing that can overpower the Earth's Ozone layer from space is
a close GRB pointed straight at us, i.e. it's polar jets are pointed to
within 2 degrees of our solar system. The GRB also has to be somewhere
less than 3000-13000 light-years from us, and directly aimed at us to
have any effect on us. Betelgeuse is 600 light-years away, and it will
go supernova, but it may not become a GRB. Even if it does become a GRB,
it still has to be pointed towards us, and it doesn't look like its
polls are.

Yousuf Khan


Close? is over 1000 LY considered close a GRB at that distance would
totally burn off the ozone


There is no known star in "our neighborhood" that can produce a gamma
ray burst that can harm us.

On 4/26/13 8:46 PM, wrote:


If Betelgeuse goes supernova there is a pretty good chance you can say
bye bye to life on earth


Will Betelgeuse Go Supernova in ...
http://space.about.com/b/2011/01/24/...va-in-2012.htm

If you believe the reports floating around in the internet, the
exploding star will appear as a second Sun in the day time, and
illuminate the night. And, worse yet, the sheer energy from the blast
will have devastating effects on the Earth, particularly our
atmosphere!

Uhh, no.

While an exact distance to Betelgeuse is difficult to assess (late
stage red giants have tenuous outer envelopes, thwarting traditional
attempts to measure distance accurately), our best estimate is that
it is about 600 light-years from Earth. This is actually quite close
in galactic terms (our Sun is about 8 light-minutes from Earth), so I
am not totally shocked how the blogosphere has crescendoed to near
panic levels over this.

But instead of panicking, let's do a little back-of-the-envelope
calculation. Typically Type II supernova (a supernova resulting from
the collapse of a massive star) of this size have a peak luminosity
(integrated over all wavelengths) approaching about 1 billion times
the power of our Sun. Quite impressive. It sounds like a lot of
energy is being generated very quickly and it is. So why am I not
worried?

Because the apparent luminosity (effectively the amount of energy
that arrives at Earth per second) falls off with the square of the
distance. In Laymen's terms, if our Sun were ten times further away
from us, its apparent luminosity would be 100 times less.

So given the 600 light-year distance to Betelgeuse (about 40 million
times further away from us than our Sun), the apparent peak
luminosity of the supernova explosion will be roughly 0.00006% of our
Sun's apparent luminosity. Clearly that is such a small percentage
that the additional flux will have zero effect on our planet.

On 27/04/2013 6:24 PM, wrote:
On Sat, 27 Apr 2013 18:01:35 -0400, Yousuf Khan
wrote:



The only thing that can overpower the Earth's Ozone layer from space is
a close GRB pointed straight at us, i.e. it's polar jets are pointed to
within 2 degrees of our solar system. The GRB also has to be somewhere
less than 3000-13000 light-years from us, and directly aimed at us to
have any effect on us. Betelgeuse is 600 light-years away, and it will
go supernova, but it may not become a GRB. Even if it does become a GRB,
it still has to be pointed towards us, and it doesn't look like its
polls are.

Yousuf Khan


Close? is over 1000 LY considered close a GRB at that distance would
totally burn off the ozone

As I said above, the GRB has to be less than 3000 LY to be dangerous.
Some really powerful GRB's that are less than 13000 LY might also be
dangerous, at the outer limits.

Yousuf Khan