A star’s death throes have so violently disrupted its planetary system that the dead star left behind, called a white dwarf, is siphoning off debris from both the system’s inner and outer reaches. This is the first time astronomers have observed a white dwarf star that is consuming both rocky-metallic and icy material, the ingredients of planets.
Archival data from NASA’s Hubble Space Telescope and other NASA observatories were essential in diagnosing this case of cosmic cannibalism. The findings help describe the violent nature of evolved planetary systems and can tell astronomers about the makeup of newly forming systems.
Our Milky Way galaxy is haunted. The vast gulf of space between the stars is plied by the dead, burned-out and crushed remnants of once glorious stars. These black holes cannot be directly seen because their intense gravity swallows light. Like legendary wandering ghosts, their presence can only be deduced by seeing how they affect the environment around them.
The majestic spiral galaxy NGC 1300’s arms hold blue clusters of young stars, pink clouds of star formation, and dark lanes of dust.
To represent this image with sound, scientists assigned louder volume to brighter light. Light farther from the center is pitched higher as a counterclockwise radar scans across the galaxy. NGC 1300 resides nearly 70 million light-years away in the constellation Eridanus.
Video credit: NASA Goddard
Sonification credits: SYSTEM Sounds (M. Russo, A. Santaguida)
NASA’s Perseverance Mars rover used its Mastcam-Z camera system to shoot video of Phobos, one of Mars’ two moons, eclipsing the Sun. It’s the most zoomed-in, highest frame-rate observation of a Phobos solar eclipse ever taken from the Martian surface.
Several Mars rovers have observed Phobos crossing in front of the Sun over the past 18 years. Spirit and Opportunity made the first observations back in 2004; Curiosity in 2019 was the first to record video of the event. Each time these eclipses are observed, they allow scientists to measure subtle shifts in Phobos’ orbit over time. The moon’s tidal forces pull on the deep interior of the Red Planet, as well as its crust and mantle; studying how much Phobos shifts over time reveals something about how resistant the crust and mantle are, and thus what kinds of materials they’re made of.
The Imaging X-ray Polarimetry Explorer, commonly known as IXPE, is a space observatory with three identical telescopes designed to measure the polarization of cosmic X-rays. The mission will study exotic astronomical objects and permit mapping the magnetic fields of black holes, neutron stars, pulsars, supernova remnants, magnetars, quasars, and active galactic nuclei. The high-energy X-ray radiation from these objects’ surrounding environment can be polarized – vibrating in a particular direction. Studying the polarization of X-rays reveals the physics of these objects and can provide insights into the high-temperature environments where they are created.
The IXPE mission was announced on 3 January 2017. It is being developed by NASA’s Small Explorer program (SMEX) and is slated for launch on 9 December 2021. The estimated cost of the mission and its two-year operation is US$188 million (the launch cost is US$50.3 million). The goal of the IXPE mission is to expand understanding of high-energy astrophysical processes and sources, in support of NASA’s first science objective in astrophysics: “Discover how the universe works”. By obtaining X-ray polarimetry and polarimetric imaging of cosmic sources, IXPE addresses two specific science objectives: to determine the radiation processes and detailed properties of specific cosmic X-ray sources or categories of sources; and to explore general relativistic and quantum effects in extreme environments.
During IXPE’s two-year mission, it will study targets such as active galactic nuclei, quasars, pulsars, pulsar wind nebulae, magnetars, accreting X-ray binaries, supernova remnants, and the Galactic Center.
About 5,000 light-years from Earth, the stunning nebula NGC 2392 formed after the demise of a star like our Sun.
In this sonification, the image is scanned clockwise like a radar. The radius is mapped to pitch, so light farther from the center is higher pitched. The outline of the nebula’s shell can be heard in the rising and falling of pitch, punctuated by its spokes. Brightness controls the volume.
The nebula was discovered by William Herschel on January 17, 1787, in Slough, England. He described it as “A star 9th magnitude with a pretty bright middle, nebulosity equally dispersed all around. A very remarkable phenomenon. NGC 2392 WH IV-45 is included in the Astronomical League’s Herschel 400 observing program.