[net.astro] StarDate: October 10 Kepler's Star

dipper@utastro.UUCP (Debbie Byrd) (10/10/85)

The last naked-eye supernova in recorded history was first seen on
today's date in 1604.  More about it -- when we come back.

October 10  Kepler's Star

On today's date in the year 1604, a sky watcher saw a bright new star
in the constellation Ophiuchus.  He hurried to the home of Johannes
Kepler, the respected mathematician and astronomer.  When he heard
about the new star, Kepler thanked the man -- but didn't believe him.

But when Kepler looked himself, he did see a strange thing in Ophiuchus
-- a conspicuous new star!  That star is now known as Kepler's star
because he continued to study it until it faded from view several
months later.  It's thought that Kepler's star was a supernova, an
outburst of light that signals a cataclysmic stellar explosion.
Although supernovae are predicted to be common in our galaxy, only a
handful have been seen in recorded history.  The last one in the Milky
Way was Kepler's star, nearly four centuries ago.

To Kepler and thousands of years of astronomers before him, these
bright supernovae were new stars.  Today's we've learned that these
stars aren't new at all -- instead, they're old.  A supernova is simply
a very massive star, explosively engaged in the process of dying.

In 1604, the concept of star death was unheard-of.  The heavens were
thought to be unchanged from everlasting to everlasting, and thus the
new star was an unthinkable mystery.  Some considered it an
astrological sign.  But Kepler thought the new star really was new --
and that it was ignited as a sign of the will of God.



Script by Deborah Byrd.


(c) Copyright 1984, 1985 McDonald Observatory, University of Texas at Austin

nyssa@abnji.UUCP (nyssa of traken) (10/14/85)

>But when Kepler looked himself, he did see a strange thing in Ophiuchus
>-- a conspicuous new star!  That star is now known as Kepler's star
>because he continued to study it until it faded from view several
>months later.  It's thought that Kepler's star was a supernova, an
>outburst of light that signals a cataclysmic stellar explosion.
>Although supernovae are predicted to be common in our galaxy, only a
>handful have been seen in recorded history.  The last one in the Milky
>Way was Kepler's star, nearly four centuries ago.

I thought that there wereradio sitings of supernovae in our galaxy, but
because they weren't near enough to earth, they couldn't be seen.
-- 
James C. Armstrong, Jnr.	{ihnp4,cbosgd,akgua}!abnji!nyssa

I'll keep an eye on the old man, he seems to have a knack for getting
himself into trouble!

-who said it, what story?

ethan@utastro.UUCP (Ethan Vishniac) (10/16/85)

> 
> I thought that there wereradio sitings of supernovae in our galaxy, but
> because they weren't near enough to earth, they couldn't be seen.
> -- 
> James C. Armstrong, Jnr.	{ihnp4,cbosgd,akgua}!abnji!nyssa

Supernova remnants are large regions of disturbed and heated gas,
roughly spherical (very roughly) and sometimes shell-like.  They are
often very conspicuous in the radio.  They mark the location of
supernovae that have gone off in the last few tens of thousands of years.
-- 
"Superior firepower is an      Ethan Vishniac
 important asset when          {charm,ut-sally,ut-ngp,noao}!utastro!ethan
 entering into                 ethan@astro.UTEXAS.EDU
    negotiations"              Department of Astronomy
                               University of Texas