Astronomers Model Early Evolution of 2021 RS Ophiuchi Nova Explosion
Researchers analyzed the first 42 days of the seventh recorded explosion of the recurrent symbiotic nova RS Ophiuchi, which occurred on August 8, 2021, using spectroscopy and photometry data. The study reveals that the explosion produced a bipolar ejecta structure with a dense equatorial disk and low-density polar regions, likely shaped by the white dwarf's rotation. This finding helps explain how internal shocks and gamma-ray emission are generated during such stellar explosions.
An international team of astronomers examined the early evolution of RS Ophiuchi's 2021 explosion through detailed spectral energy distribution modeling, combining optical spectroscopy, multi-band photometry (BVRcIc, JHKL), and ultraviolet data. By comparing observations with data from the star's previous explosions in 2006 and 1985, the researchers identified a distinctive bipolar structure in the ejected material—featuring a flared, density-enhanced equatorial disk surrounded by lower-density regions extending toward the poles. The team's models indicate that internal shocks within the equatorial outflow produce significant luminosity comparable to radiation from the white dwarf's pseudophotosphere, suggesting that shock reprocessing accounts for a substantial portion of the observed radiation. The researchers propose that the white dwarf's rotation drives the formation of this bipolar geometry, providing a natural mechanism for generating the strong internal shocks responsible for gamma-ray emission detected during such explosions.
What different sources said
- arXiv astro-phCenter
The first hours and days of the 2021 explosion of the recurrent symbiotic nova RS Ophiuchii
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