Spitzer reveals secrets of nearby supernova

The infrared scope peers through the dust to observe recent discovery in M82

The supernova SN 2014J is seen in this image near its peak brightness in the first week of February 2014. It appears as a faint star to the lower right of the central region of its host galaxy M82.

The new supernova is of a particular kind known as a Type Ia. This type of supernova results in the complete destruction of a white dwarf star-the small, dense, aged remnant of a typical star like our Sun. Two scenarios are theorized to give rise to Type Ia supernovas: In a binary star system, a white dwarf gravitationally pulls in matter from its companion star, accruing mass until the white dwarf crosses a critical threshold and blows up.  Alternatively, two white dwarfs in a binary system spiral inward toward each other and eventually explosively collide.

Studying SN 2014J will help with understanding the processes behind Type Ia detonations to further refine theoretical models.

In the image, light from Spitzer's infrared channels are colored blue at 3.6 microns and green at 4.5 microns.

The supernova SN 2014J is seen in this image near its peak brightness in the first week of February 2014. It appears as a faint star to the lower right of the central region of its host galaxy M82. Image Credit: NASA / JPL Caltech

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The discovery of a supernova in nearby galaxy M82 has led to a global observation campaign.

A legion of telescopes, both ground and space based, have observed the new object, including NASA’s Spitzer Space Telescope.

M82, or the Cigar Galaxy, is filled with dust, obscuring the view for optical and high-energy observations with instruments like the Hubble and Fermi Gamma-ray Space Telescopes.

Spitzer, however, observes in infrared light, allowing the telescope to peer through the haze.

Students and staff at University College London first spotted the supernova, SN 2014J, on 21 January 2014.

Word of the exciting discovery spread to observing teams all over the world, who quickly turned their telescopes towards the new object.

Luckily, Spitzer was already scheduled to observe the galaxy only a week later. Along with subsequent observations, the telescope was able to observe the supernova as its brightness peaked and faded, gleaning new information about how supernova evolve.

SN 2014J is a Type Ia supernova.

Type Ia supernovae occur when a white dwarf star steals gas from a nearby stellar companinon, eventually reaching a critical mass which causes the it to explode. As this critical mass is always the same, so to is the brightness of the explosion.

This means Type Ia supernova can be used as ‘standard candles’, objects with a known brightness that astronomers can use to determine distances, making them extremely important to researchers.

Knowing the precise measurements of SN 2014J will allow scientists to better refine models of these special supernovae, making for better distance measurements in the future.

“At this point in the supernova’s evolution, observations in infrared let us look the deepest into the event,” says Mansi Kasliwal the principal investigator for the Spitzer observations.

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“Spitzer is really good for bypassing the dust and nailing down what’s going on in and around the star system that spawned this supernova.”