Expert: Jayendra Upadhye - 7/31/2008

Question

so let me get this straight...

-so a galaxy with high metal content diffuses the spin on stars and diffuses most gamma ray bursts when they explode as supernovae, and if there is they are probably very weak bursts?

-the blast funnels out along a narrow 12 degree cone, so since they estimate a 16 degree axis tilt away from us were somewhat safe?

-so gamma radiation from 8000 light years, even in a concentrated shots is diluted, but concentrated shots are rare right?

-isn't it true that a solar flare brought down skylab back in the 70's which depleted something like near 40% of our ozone layer? (So if we did get hit from a gamma ray burst that took away 50% of our ozone layer couldn't we still survive?)

this is is going to be the last question  

Answer
Nikki, ask as many as you need to.
I'm not complaining..only ask them separately. There are many people reading our exchanges, and scrolling down so much is a boring task!

1 - High metallicity helps couple the enrgy of the blast to the spin (by way of electromagnetic coupling to my belief, but i am not exactly sure), also there is opacity of the stellar envelop. If it is more, the gamma ray burst is absorbed by the envelop that then proceeds to expand and convert it into a mechanical blast energy.

2 - The funnel is 12 deg, right, but the axis of WR104 IS tilted at close to 16 degrees to us, thereby allowing the funnel to completely evade us perchance.

3 - Gamma rays decrease in intensity as per the inverse square law.
Intensity reduction would be same if it were a spherical blast, but in case of the funneled blast, all the gamma rays that would otherwise have come out over the whole spherical blast surface, get channelised into two opposing beams in the polar regions. The particle flux is also in that direction. This increases the starting intensity of the supernova anisotropically more along preferred directions (polar). Thereby increasing the starting intensity itself many fold.

4 - I dont know! But though flares cause electromagnetic havoc, the wind is incapable of dislodging objects as heavy as skylab was. these winds are tenuous indeed. If skylab had fallen due to kinetic energy transfer from the flare, why not much smaller satellites? All would have come tumbling down. But that did not happen. It most likely came down as it ran out of "stationkeeping fuel" that is required by even geostationary satellites 36000 km away! The lab was only 100 km above earth in an LEO (LOW EARTH ORBIT), and atmospheric drag brought it down. At later stages, it was retarded and induced to fall over safe regions.

Flares do deplete the layer but to a very small extents as the earth's magnetic field traps the charged particled that do the damage by "kinetic impacts", into the van allen belts! These then harmlessly spiral into the poles causing the aurae borealis! It is a huge vacuum tube discharge actually, and mega amperes of current flows into the earth thru space as charge frome these particles. It is a corona discharge in rarefied gas.

regards,
Jayen