Supernova Remnant Video From NASA's Chandra Is Decades in Making

A new video shows changes in Kepler’s Supernova Remnant using data from NASA’s Chandra X-ray Observatory captured over more than two and a half decades with observations taken in 2000, 2004, 2006, 2014, and 2025. In this video, which is the longest-spanning one ever released by Chandra, X-rays (blue) from the telescope have been combined with an optical image (red, green, and blue) from Pan-STARRS.

Kepler’s Supernova Remnant, named after the German astronomer Johannes Kepler, was first spotted in the night sky in 1604. Today, astronomers know that a white dwarf star exploded when it exceeded a critical mass, after pulling material from a companion star, or merging with another white dwarf. This kind of supernova is known as a Type Ia and scientists use it to measure the expansion of the Universe.

Supernova remnants, the debris fields left behind after a stellar explosion, often glow strongly in X-ray light because the material has been heated to millions of degrees from the blast. Kepler’s Supernova Remnant is located in the Milky Way galaxy about 17,000 light-years from Earth. Although this is relatively close in cosmic terms, only Chandra, with its sharp X-ray images and longevity, can see changes like those seen here.

The video allows astronomers to watch as the remains from this shattered star expand and crash into material already thrown out into space. The researchers found that the fastest parts of the remnant are traveling at about 13.8 million miles per hour — or about 2% of the speed of light — moving towards the bottom of the image. Meanwhile, the slowest parts are traveling towards the top at about 4 million miles per hour. This is a large difference in speed, and astronomers think it comes from the fact that the gas that the remnant is plowing into towards the top of the image is denser than the gas towards the bottom. This gives scientists information about the environments into which this star exploded.

Supernova explosions and the elements they hurl into space are the lifeblood of new stars and planets. Understanding exactly how they behave is crucial to knowing our cosmic history.

Jessye Gassel (George Mason University) presented the new Chandra video and the associated research at the 247th meeting of the American Astronomical Society (AAS) meeting in Phoenix, AZ. Quotes from Gassel and co-author Brian Williams from NASA’s Goddard Space Flight Center are provided in our press release.

NASA's Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program. The Smithsonian Astrophysical Observatory's Chandra X-ray Center controls science operations from Cambridge, Massachusetts, and flight operations from Burlington, Massachusetts