Too bad supernovae are always so far away

Always it seems in the billions of light-years. Though there have been some in the past which might have been closer. I don't want one blowing up and ruining observing by outshining the moon, but maybe mag. -6 would be interesting?

http://www.bbc.com/news/science-environment-35315509

On Thu, 14 Jan 2016 15:26:01 -0800 (PST), RichA
wrote:

Always it seems in the billions of light-years. Though there have been some in the past which might have been closer. I don't want one blowing up and ruining observing by outshining the moon, but maybe mag. -6 would be interesting?

http://www.bbc.com/news/science-environment-35315509

Many of the supernovas we observe are in nearby galaxies. All of those
visible to the naked eye have been in our own galaxy (we might make an
exception for SN 1987A, which reached mag 3 and was in the LMC). We're
statistically overdue for a supernova in our galaxy. Some of those can
be seen in the day.

Lucky supernovae are far away.

A stellar explosion almost 600 billion times brighter than the
sun pushes the limits of physics
http://www.scientificamerican.com/ar...A_SPC_20160114

Astronomers have glimpsed the most powerful supernova ever seen, a
star in a galaxy billions of light-years away that exploded with such
force it briefly shone nearly 600 billion times brighter than our Sun
and 20 times brighter than all the stars in the Milky Way combined.
The explosion released 10 times more energy than the Sun will radiate
in 10 billion years.

If the supernova took place in our own galaxy, it would be easily
seen by the naked eye even during the day; if it were 10,000
light-years away, it would appear to us at night as bright as the
crescent Moon. If it were only as far away as Sirius, which at a
distance of 8.6 light-years is the brightest star in the nighttime
sky, it would blaze overhead almost as powerfully as the Sun. If it
were as close as Pluto, it would vaporize the Earth and all the other
worlds in our solar system.

On Thursday, January 14, 2016 at 3:26:04 PM UTC-8, RichA wrote:

Always it seems in the billions of light-years. Though there have been some in the past which might have been closer. I don't want one blowing up and ruining observing by outshining the moon, but maybe mag. -6 would be interesting?

http://www.bbc.com/news/science-environment-35315509

The Crab Nebula, at a distance of about 6500 light-years, is more-or-less the poster child of Supernovae within our galaxy...

http://www.space.com/16989-crab-nebula-m1.html

.... it was visible during the daytime for almost a month, and was naked-eye at night for about 2 years, starting in 1054 AD...

\Paul A

On Thursday, January 14, 2016 at 6:02:28 PM UTC-7, Sam Wormley wrote:
Lucky supernovae are far away.

Yes, but it is unlucky that one far enough away to be safe, but close enough to
be easily observable, took place just before the invention of the telescope.

If the Crab Nebula event were to have happened just long enough ago to be seen today, it would be very useful to astrophysics.

John Savard

On Thursday, January 14, 2016 at 4:26:04 PM UTC-7, RichA wrote:
I don't want one blowing up and ruining observing by outshining the moon,

or, as Sam Wormley has already pointed out, doing rather much worse. But, yes, the Crab Nebula happened much too soon.

John Savard

On 1/14/16 3:26 PM, RichA wrote:
"Too bad supernovae are always so far away"

Unclear on the concept...

RichA:
"Too bad supernovae are always so far away"

lal_truckee:
Unclear on the concept...

Ditto. This might better be expressed as "Lucky thing for us that
supernovae have been far, far away in human history." Close enough to
study, not close enough to kill us all.

--
I agree with almost everything that you have said and almost everything that
you will say in your entire life.

usenet *at* davidillig dawt cawm

On Thu, 14 Jan 2016 16:49:38 -0700, Chris L Peterson
wrote:
On Thu, 14 Jan 2016 15:26:01 -0800 (PST), RichA

wrote:

Always it seems in the billions of light-years. Though there have
been some in the past which might have been closer. I don't want one
blowing up and ruining observing by outshining the moon, but maybe
mag. -6 would be interesting?

http://www.bbc.com/news/science-environment-35315509

Many of the supernovas we observe are in nearby galaxies. All of
those
visible to the naked eye have been in our own galaxy (we might make
an
exception for SN 1987A, which reached mag 3 and was in the LMC).
We're
statistically overdue for a supernova in our galaxy. Some of those
can
be seen in the day.

Another exception is S Andromedae, a supernova in M31 which reached
magnitude 5.85 in 1885.

On Thu, 14 Jan 2016 19:14:53 -0800 (PST), Quadibloc
wrote:
On Thursday, January 14, 2016 at 6:02:28 PM UTC-7, Sam Wormley
wrote:
Lucky supernovae are far away.

Yes, but it is unlucky that one far enough away to be safe, but
close enough to
be easily observable, took place just before the invention of the
telescope.

If the Crab Nebula event were to have happened just long enough ago
to be seen today, it would be very useful to astrophysics.

Otoh we would then have to wait some 1000 years before we could see
the Crab nebula as we see it today.