An image captured by the Hubble Space Telescope depicts R Aquarii, a binary system consisting of a red giant and a white dwarf. Four different filters of the WFC3 (Wide Field Camera 3) instrument were used in visible light to create the most recent observation of R Aquarii conducted with Hubble. This allowed to examine the changes that have occurred in particular in the nebula surrounding the pair.
The R Aquarii system is in the cosmic neighborhood, being about 650 light-years from Earth. For this reason, it has been the subject of study with different instruments since the two stars that make up the pair, which are invisible to the naked eye, were discovered. For example, it was the subject of a test using a subsystem of the SPHERE instrument installed on ESO’s VLT in Chile.
The Hubble Space Telescope can detect details of the nebula surrounding R Aquarii, also known as Cederblad 211. It could be the result of various violent eruptions that lead to the emission of what become bright filaments of gas. This type of phenomenon is caused by the accumulation of materials stripped from the red giant that end up in a disk surrounding the white dwarf, which continues until it reaches a critical mass that triggers a nova.
The filaments of gas are distorted by the explosions and by powerful magnetic fields. They’re bright because of the radiation emitted by the two stars of R Aquarii. This allows to capture the details with a telescope such as Hubble but also the scale of the entire nebula with materials that are up to 400 billion kilometers away from the two stars. The complex structure was analyzed in an article published a few months ago in the journal “Monthly Notices of the Royal Astronomical Society” using data collected with various instruments.
The various observations of R Aquarii conducted with the Hubble Space Telescope between 2014 and 2023 allowed to create a video (NASA, ESA, M. Stute, M. Karovska, D. de Martin & M. Zamani (ESA/Hubble), N. Bartmann (ESA/Hubble)) in which it’s possible to see the changes in the system. The red giant is a Mira variable, which means that it’s of the pulsating type with a pulsation period of over 100 days and a certain level of variation in its brightness that is visible in the video.
The results of the observations are spectacular and at the same time help us understand how chemical elements generated in stars are ejected into interstellar space. Carbon, nitrogen, and oxygen could end up in new systems in the formation phase and these are crucial elements for the formation of life forms such as those on Earth.
