RX Puppis, marked with crosshairs in the image above, is a symbiotic star: a binary system containing a puffy red giant and a compact white dwarf or neutron star. As the compact object accretes matter from the red giant, the stolen gas can ignite in a flash of nuclear fusion, powering a nova outburst that brightens the system for anywhere from days to decades. In the 1970s, researchers observed a slowly evolving outburst from RX Puppis. But nova outbursts from symbiotic stars usually recur — is there any evidence of previous outbursts from this sytem? Using the 1-meter Swope telescope in Las Campanas, Chile, and the Southern African Large Telescope, Krystian Iłkiewicz (University of Warsaw, Durham University) and collaborators discovered an arc-like emission feature that appears to be the remnant of a shell of gas ejected during an outburst roughly 1,300 years ago. They also discovered a hint of a second shell that might be from an eruption 7,000 years ago. Given the locations of these two shells and the timing of the 1970s outburst, Iłkiewicz’s team concluded that the rate at which the white dwarf amasses gas from its companion has increased by a factor of three over the past 10,000 years. This is the first time a change in mass transfer rate has been measured in a binary system over such a long timescale. To learn more about this discovery, be sure to check out the full research article linked below.
By Kerry Hensley
Citation
“Ancient Nova Shells of RX Pup Indicate Evolution of Mass Transfer Rate,” Krystian Iłkiewicz et al 2024 ApJL 972 L14. doi:10.3847/2041-8213/ad6e5a
