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Type 1a supernovae are extremely powerful events that occur in binary systems containing at least one white dwarf star \u2013 the core remnant of a Sun-like star. Sometimes, the white dwarf\u2019s powerful gravity will siphon material from its companion star until it reaches critical mass and explodes. In another scenario, a binary system of two white dwarfs will merge, producing the critical mass needed for a supernova. Unlike regular supernovae, which occur every fifty years in the Milky Way, Type Ia supernovae happen roughly once every five hundred years.<\/p>\n
In addition to being incredible events, Type 1a supernovae are useful astronometric tools. As part of the Cosmic Distance Ladder, these explosions allow astronomers to measure the distances to objects millions or billions of light-years away. This is vital to measuring the rate at which the Universe is expanding, otherwise known as the Hubble Constant. Thanks to an international team of researchers, a catalog of Type 1a Supernovae has just been released that could change what we know of the fundamental physics of supernovae and the expansion history of the Universe.<\/p>\n
<\/p>\n This new catalog constitutes the second data release (DR2) from the Zwicky Transient Facility (ZTF), a wide-field astronomical survey that began in 2018. This survey relies on the ZTF camera on the 1.2-meter (4-foot) Samuel Oschin Telescope at the Palomar Observatory near San Diego, California. It has classified over 8,000 supernovae, including 3628 nearby Type 1a supernovae (SNe Ia), more than doubling the number of known SNe Ia\u2019s discovered in the past 30 years. Despite being rare, the ZTF\u2019s depth and survey strategy have allowed the ZTF Collaboration to detect nearly four per night.<\/p>\n \n