All posts tagged: White Dwarf

Student astronomer discovers rare white dwarf star feeding on a red dwarf companion

Student astronomer discovers rare white dwarf star feeding on a red dwarf companion

Published by Jenni Sidey

ASKAP J1745-5051 did not look like an easy answer to anything. It flashed radio waves every 1.4 hours, then went quiet for stretches. Then it lit up again with a pattern astronomers had trouble classifying. That odd behavior has now helped pin down one of astronomy’s stranger new mysteries. In a study published in Nature Astronomy, an international team reports that ASKAP J1745-5051 is a compact binary system. In this system, a white dwarf is pulling material from a low-mass red dwarf companion. The finding offers some of the strongest evidence yet that at least some long-period radio transients come from white dwarf binaries. Previously, many had suspected they came from slowly spinning neutron stars. The system was first spotted in an untargeted search for circularly polarized radio sources with the Australian Square Kilometre Array Pathfinder, or ASKAP. Additionally, follow-up observations with MeerKAT sharpened its position. Astronomers matched it to a faint optical source in Gaia data. What they found next changed the story. Artist’s impression of the white dwarf binary ASKAP J1745-5051. The smaller, …

Astronomers spot an ‘impossible’ shock wave around a dead star system

Astronomers spot an ‘impossible’ shock wave around a dead star system

Published by Jenni Sidey

Astronomers at Durham University and collaborators at the University of Warwick used the European Southern Observatory’s Very Large Telescope to spot something that should not exist: a bright bow-shaped shock wave wrapped around a compact dead star system called RXJ0528+2838. The finding suggests this tiny stellar remnant is pushing material into space far more strongly than current models allow. “We found something never seen before and, more importantly, entirely unexpected,” says Simone Scaringi, an associate professor at Durham University and a co-lead author. “The surprise that a supposedly quiet, discless system could drive such a spectacular nebula was one of those rare ‘wow’ moments,” Scaringi says. Krystian Ilkiewicz, a postdoctoral researcher at the Nicolaus Copernicus Astronomical Center in Warsaw and a co-lead author, says the observations point to a major gap in understanding. “Our observations reveal a powerful outflow that, according to our current understanding, shouldn’t be there,” he says. Astronomers use “outflow” to describe matter ejected from an object into space. This image from the Digitized Sky Survey (DSS) shows the region of the …