Superluminous Supernova - SN2017 egm

Superluminous Supernova SN2017 egm in the barred spiral galaxy NGC 3191 - PIRATE ART telescope-telescope.org - Open University. Image by Pip Stakkert

"Superluminous supernova are usually found in metal poor galaxies, so this superluminous supernova in a metal rich barred spiral galaxy is unusual to say the least. Superluminous supernova are typically 10 times more luminous than other supernovae.  A number of models for the conditions that may produce a SLSN exist:

• Collapsar Model: The collapse of a rotating star giving rise to stellar mass black hole with the production of relatavistic jets.
• Circumstellar material Model:  An initial normal supernova explosion meets dense nebular material or dust close to the star, the shockwave converts kinetic energy efficiently into visible radiation thus increasing luminosity and duration of the supernova.
• Magnetar energy release Model: A magnetar is a type of neutron star with an extremely powerful magnetic field. Models of the creation and subsequent spin down of a magnetar yield much higher luminosities than regular supernova.
• Other Models: There are models for SLSN explosions which are produced from binary systems, white dwarf or neutron stars in unusual arrangements or undergoing mergers.

SN2017 egm is a Type 1 supernova, first observed by the Gaia Satellite in May 2017, and light curves obtained from observations have been used and found to be consistent with a Magnetar central engine model. The supernova was discovered in the barred spiral galaxy NGC3191 which is estimated to be 420 million light years distant. The measured magnitude of the supernova is 14.5 and at its distance, its calculated absolute magnitude is -21.1, which in luminosity terms is comparable to the output of our entire Milky Way galaxy.  It turns out that SN2017 egm is the closest hydrogen poor superluminous supernova ever found. This type of 'hypernova' which create millesecond spinning neutron stars are thought to be one of the progenitors of long duration gamma ray bursts - LRGBs.

Closer to home, may I take this opportunity to extend our congratulations to our Instrumentation Engineer- Jolene McSquint and our Facilities Manager- May Fleming who this week surprised the Jodrell Plank Observatory Team by announcing their engagement".  Kurt Thrust- current Director of the Jodrell Plank Observatory.


Credits: Open University, Wikipedia and IRIDA Observatory