APOD: Supernova Remnant Puppis A (2014 Sep 12)

Comments and questions about the APOD on the main view screen.
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Nitpicker
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Re: APOD: Supernova Remnant Puppis A (2014 Sep 12)

Post by Nitpicker » Mon Sep 15, 2014 12:15 pm

starsurfer wrote:
Ann wrote:
ta152h0 wrote:how far does " nearby " have to be to not be " nearby " anymore ?
Well, that depends.

Since the approximate radius of the Milky Way is about 50,000 light-years, a supernova 7,000 light-years away is pretty nearby.

Ann
I thought the radius of the Milky Way was approximately 100,000 light years?
I suppose it depends on where you define the edge to be, but Wikipedia says a radius of 50,000 to 60,000 light years.

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Re: APOD: Supernova Remnant Puppis A (2014 Sep 12)

Post by rstevenson » Mon Sep 15, 2014 1:03 pm

starsurfer wrote:I thought the radius of the Milky Way was approximately 100,000 light years?
The diameter of the Milky Way is about 100,000 to 120,000 ly.

Rob

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Re: APOD: Supernova Remnant Puppis A (2014 Sep 12)

Post by jsmunroe » Mon Sep 15, 2014 1:10 pm

starsurfer wrote:
Ann wrote:
ta152h0 wrote:how far does " nearby " have to be to not be " nearby " anymore ?
Well, that depends.

Since the approximate radius of the Milky Way is about 50,000 light-years, a supernova 7,000 light-years away is pretty nearby.

Ann
I thought the radius of the Milky Way was approximately 100,000 light years?
Nope. diameter is 100k. Radius is 50k.

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bystander
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Re: APOD: Supernova Remnant Puppis A (2014 Sep 12)

Post by bystander » Mon Sep 15, 2014 9:23 pm

starsurfer wrote:
I thought the radius of the Milky Way was approximately 100,000 light years?
Wikipedia wrote:
The Milky Way is a barred spiral galaxy some 100,000–120,000 light-years in diameter, which contains 100–400 billion stars.

That would be 50-60 thousand light-years in radius.
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Re: APOD: Supernova Remnant Puppis A (2014 Sep 12)

Post by starsurfer » Tue Sep 16, 2014 6:23 am

Oh I must have got the two mixed up! :oops:

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Re: APOD: Supernova Remnant Puppis A (2014 Sep 12)

Post by bystander » Tue Sep 16, 2014 2:12 pm

I admit, you had me confused. I had to go look to make sure.
Know the quiet place within your heart and touch the rainbow of possibility; be
alive to the gentle breeze of communication, and please stop being such a jerk.
— Garrison Keillor