Starship Asterisk*

by **emc** » Sat Mar 15, 2008 8:26 pm

neufer wrote:"For in the end what are we, who are convinced that suicide is obligatory and yet cannot resolve to commit it, other than the weakest, the most inconsistent and, speaking frankly, the most stupid of people, making such a song and dance with our banalities?"

Allliteration is intrinsic amusement... Anna Karenin only died in a dream

What fate awaits Eta Carinae... ka-boom and careen, no longer to be seen bearing the same sheen

by **orin stepanek** » Sat Mar 15, 2008 4:31 pm

Hi henk21cm; thanks for the info but I was referring to wr104 being a bigger threat than Eta Carinae and the beam it would create if it collapsed into a black hole. I may be wrong but I don't think Eta Carinae is in that category; although it may be close enough to create some problems. But I think both stars are far enough that I don't believe there is too much threat from either one.

Orin

by **henk21cm** » Sat Mar 15, 2008 3:01 pm

orin stepanek wrote:It would have to be aimed precisely toward us;

Eta Carinae might not be so much of a direct thread to us. WR104 is more frightening.

You further wrote: besides it would have a narrow beam and still it is about 8000ly away.

The angle of the beam is ≅ 0.2 radian. The characteristic width of the bundle would be approx. 1500ly.

You further wrote: how long would a planet take to pass through the beam? Everything is moving along pretty fast through space.

That depends on the releative tangential motion between the source and recipient. Like on the highway: everybody is moving pretty fast, yet when a large truck takes over another truck, it takes some time, due to a small difference in their relative motion.

The speed of the sun around the center of galaxy is approx. 300 km/s, (or was it 200 km/s?) so 0.001 of the speed of light. To pass the bundle it would take an odd one million years, if eta Carinae isn't moving.

Regards,
Henk

by **orin stepanek** » Sat Mar 15, 2008 1:36 pm

It would have to be aimed precisely toward us; besides it would have a narrow beam and still it is about 8000ly away.

I'm not worried for me but someday it may pose a problem. Also how long would a planet take to pass through the beam? Everything is moving along pretty fast through space.

Orin

by **bystander** » Fri Mar 14, 2008 1:27 pm

orin stepanek wrote:There must be other stars like wr 104 in the galaxy that it can be compared to. What happened when one of those went kaboom? Or is this a unique creature?

Wolf-Rayet stars have been known since 1867. There are over 200 in our galaxy and another 100 in the nearby Magellanic Clouds. Some WR stars are thought to collapse into black holes and become Gamma Ray Bursters. GRBs were discovered in the 1960s by nuclear test detection satellites. In 2004 the Swift Observatory was launched by NASA to study GRBs. There is also another pinwheel nebula, WR 98a. More are suspected to exist in the Quintuplet Cluster near the galactic center.

As for the danger of WR 104:

It may go GRB
It's spin axis is aimed at us (approximately)
It's relatively close (< 10,000 ly)

by **orin stepanek** » Fri Mar 14, 2008 12:37 pm

There must be other stars like wr 104 in the galaxy that it can be compared to. What happened when one of those went kaboom? Or is this a unique creature?

Orin

by **Qev** » Fri Mar 14, 2008 5:37 am

orin stepanek wrote:This massive star may be sculpting the South pillar but it is doomed.
when she blows there will probably be a brightness in the southern skies that will last for a long time. Who knows what effects it will have on our area being only 10,000 light years distant.
Orin

I don't think Eta Carinae is close enough to be a significant threat to the Earth, but anything's possible I suppose. This fellow strikes me as just a bit more threatening.

by **neufer** » Fri Mar 14, 2008 3:04 am

bystander wrote:
orin stepanek wrote:This massive star may be sculpting the South pillar but it is doomed. when she blows there will probably be a brightness in the southern skies that will last for a long time. Who knows what effects it will have on our area being only 10,000 light years distant.
They say Eta Carinae could go hypernova within our lifetimes. Wouldn't that be a sight.

"For in the end what are we, who are convinced that suicide is obligatory and yet cannot resolve to commit it, other than the weakest, the most inconsistent and, speaking frankly, the most stupid of people, making such a song and dance with our banalities?"
http://www.madisonavenuejournal.com/images/anna5.jpg

by **bystander** » Thu Mar 13, 2008 8:23 pm

orin stepanek wrote:This massive star may be sculpting the South pillar but it is doomed.
when she blows there will probably be a brightness in the southern skies that will last for a long time. Who knows what effects it will have on our area being only 10,000 light years distant.

They say Eta Carinae could go hypernova within our lifetimes. Wouldn't that be a sight. Of course for us to see it, it had to go about 8,000 BC.

An annotated Hubble Mosaic of the Carina Nebula Region

Zoomable version
Interactive version

A nice movie showing Carina in Context

by **orin stepanek** » Thu Mar 13, 2008 12:36 pm

http://apod.nasa.gov/apod/ap080313.html

http://apod.nasa.gov/apod/ap980816.html

http://images.google.com/images?sourcei ... rinae&um=1

This massive star may be sculpting the South pillar but it is doomed.
when she blows there will probably be a brightness in the southern skies that will last for a long time. Who knows what effects it will have on our area being only 10,000 light years distant.
Orin

Starship Asterisk*

Sculpting The South Pillar (APOD 13 Mar 2008)

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Moving through a beam of gamma rays

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Sculpting The South Pillar (APOD 13 Mar 2008)