A new image released this week shows the spiral galaxy NGC 5643 as captured by the Hubble Space Telescope. The galaxy, located in the constellation of Lupus, is around 60 million light-years away and is around twice the width of the Milky Way, at 100,000 light-years across.
To capture such a large galaxy from a great distance, Hubble had to take a number of exposures to make sure the image was crisp and highly detailed. These 30 different exposures were taken over nine hours and combined to create this stunning image.
This particular galaxy is notable for being the site of two supernovas, one spotted in 2013 and one in 2017. The 2013 supernova was spotted by an amateur astronomer from New Zealand named Stuart Parker as part of the Backyard Observatory Supernova Search (BOSS) project, in which a small group of astronomers from Australia and New Zealand collaborate to search out objects in the southern sky. Parker and his friends have discovered a large number of supernovas and are continuing to search the sky, with their most recent finding occurring earlier this year.
The supernova spotted in 2017 was discovered using the Carnegie Institution for Science’s Carnegie Institution for Science at the Las Campanas Observatory, located in the Chilean desert.
Both the 2013 supernova and the 2017 supernova were Type 1a supernovas, in which a low-mass star undergoes a thermonuclear explosion. Normally, supernovas only occur in higher-mass stars, but low-mass stars can also go supernova when they are part of a binary system. This is where the low-mass star, a white dwarf, has a companion star, with the two orbiting each other. The white dwarf can siphon off mass from its companion, eventually gaining so much mass that it explodes in an extremely bright supernova event which lights up its part of the galaxy.