Changes

In 1998, observations of the apparent magnitude of several type 1a supernovae in other galaxies, resulted in the surprising finding that the universe is expanding at an accelerated rate, due to [[Dark energy|Dark Energy]].<ref>http://arxiv.org/abs/astro-ph/9805201</ref>

In 1998, observations of the apparent magnitude of several type 1a supernovae in other galaxies, resulted in the surprising finding that the universe is expanding at an accelerated rate, due to [[Dark energy|Dark Energy]].<ref>http://arxiv.org/abs/astro-ph/9805201</ref>

===Type 1b and Ic===

===Type 1b and 1c===

Type lb and Ic supernovae, like Type II supernovae, are from massive stars that are running out of core fuel for fusion.  The stars for type Ib explosions had their outer shell of [[hydrogen]] lost or striped away. The stars for type Ic explosions have lost most of both their hydrogen and subsequent [[helium]] shell. This loss is either due to intense stellar winds, or from interaction with a nearby binary companion of sufficient mass.<ref>http://adsabs.harvard.edu/abs/1997rdbs.conf..153P</ref>  It is believed that type 1b supernovae are from exploding [[Wolf-Rayet star|Wolf-Rayet stars]].  There is some evidence that a small percentage of type Ic supernovae are the source of [[Gamma-Ray Bursts|Gamma Ray Bursts]].<ref>http://adsabs.harvard.edu/abs/2004MNRAS.349.1093R</ref>

Type lb and Ic supernovae, like Type II supernovae, are from massive stars that are running out of core fuel for fusion.  The stars for type Ib explosions had their outer shell of [[hydrogen]] lost or striped away. The stars for type Ic explosions have lost most of both their hydrogen and subsequent [[helium]] shell. This loss is either due to intense stellar winds, or from interaction with a nearby binary companion of sufficient mass.<ref>http://adsabs.harvard.edu/abs/1997rdbs.conf..153P</ref>  It is believed that type 1b supernovae are from exploding [[Wolf-Rayet star|Wolf-Rayet stars]].  There is some evidence that a small percentage of type Ic supernovae are the source of [[Gamma-Ray Bursts|Gamma Ray Bursts]].<ref>http://adsabs.harvard.edu/abs/2004MNRAS.349.1093R</ref>