See the ghosts of dead stars

Thomas Foshee,Dallas Texas — Fri, 30 May 2008 05:43:25 GMT

This is a great site,my first time viewing it and I love it.

See the ghosts of dead stars

Bryan, OR — Fri, 30 May 2008 09:09:23 GMT

These images are larger than any God we could ever imagine.

See the ghosts of dead stars

Wade Whitlock, Aberdeen, MD — Fri, 30 May 2008 17:04:56 GMT

Please correct me, if I'm wrong, but isn't the age of a supernova roughly equal to its distance in lightyears? If a SN occurred 11,000 ly away and was seen today its age is still 11,000 years. If a SN at the center of the galaxy is 23,000 ly away wouldn't its age be 23,000 years old?

Let's pound on the science reporters to get this straight, shall we? I have been seeing this all over the place with people confusing the date of observation with the time of occurrance. We are dealing with some serious space-time here!

See the ghosts of dead stars

Thomas Ashby, Calgary — Fri, 30 May 2008 20:19:34 GMT

It's something that supernova are not created equal. The crab nebula remanant http://www.creatingspace4u.net/userfiles/Crab_Nebula.jpg
is a grand example of this fact.

See the ghosts of dead stars

Curt, Houston, TX — Sat, 31 May 2008 13:19:44 GMT

Wade, what's your beef? I think Alan does a good job of separating the distance from observed age. It can be a confusing issue and the articles need to be readable. If the authors used the event date every time instead of the observed date, we could not follow the historical context for us here on Earth.

As examples, "Cass A is about 11,000 light-years away, and its supernova blast reached Earth in the year 1680", and "...light from the original explosion, seen from Earth 300 years ago". It is clear to me that Alan is addressing the observation date on Earth, not the time of the event.

See the ghosts of dead stars

Frank Glover Rochester, NY — Sat, 31 May 2008 15:19:42 GMT

"Please correct me, if I'm wrong, but isn't the age of a supernova roughly equal to its distance in lightyears? If a SN occurred 11,000 ly away and was seen today its age is still 11,000 years. If a SN at the center of the galaxy is 23,000 ly away wouldn't its age be 23,000 years old?"

In your example, you are indeed seeing an event that happened 11,000 years ago, but it should be understood that a star stays in a nova/supernova state for only a few weeks or so. It's long since become a white dwarf, neutron star or black hole (depending largely on its remaining mass), we just can't see that yet, the speed of light and the distance being what they are.

Therefore, it's also a bit semantically miseading to speak of the 'age' of a supernova as it's a very brief event in a star's life...

See the ghosts of dead stars

Thomas Ashby, Calgary — Mon, 02 Jun 2008 19:36:01 GMT

Maybe these magnetars keep aliens away. Nothing worse than having a nice 5000 ly journey to earth brought to a halt by an exploding magnetar or star.

See the ghosts of dead stars

Brianna VT — Sun, 08 Jun 2008 17:15:01 GMT

I insist from staying away from any remarks that insult people of religious backgrounds. There is no reason not to believe in both a God and the wonders of space. Thank you.

See the ghosts of dead stars

Matt, Quesnel — Fri, 13 Jun 2008 18:47:20 GMT

Lets not stray from the wonders of space to the topic of gods.