While supernovas get all of the undeserved astronomical attention like they’re some kind of stellar Kardashians, classical novas – more common explosions of white dwarfs caused by a nearby star – are treated like extras in a galactic blockbuster movie. That will change as astronomy paparazzi looking at old photos found a set of never before seen before-during-and-after pictures of a nova explosion.
According to a press release, the white dwarf in the binary star system V1213 Centauri (Nova Centauri 2009) exploded unexpectedly in May 2009, causing many astronomers to wish they’d been watching it more closely. Images of the explosion, which occurred in the Centaurus constellation 23,000 light years from Earth, were collected by the 1.3-m Warsaw Telescope located at Las Campanas Observatory, Chile.
Luckily, someone remembered a small long-term project being conducted by a team of Polish astronomers at the University of Warsaw. Their Optical Gravitational Lensing Experiment had been surveying dark matter since 2003 and had images of V1213 Centauri leading up to the explosion.
The V1213 Centauri binary system consists of a dim red dwarf star and a dead white dwarf – in this case, orbiting each other at a distance of merely one solar radius. The white dwarf was siphoning matter and energy from the red dwarf and occasionally creating small explosions known as dwarf novae. Eventually, the white dwarf absorbed enough hydrogen and helium under high pressure and temperatures to create the thermonuclear fusion reaction called a classical nova which occurred in May 2009.
According to study author Przemek Mróz, the classical nova is impressive but not fatal. The stars survive and the process continues again. However, the before-and-after photos showed something that had been theorized but never seen before.
What we observed is that before the eruption, the mass transfer rate in the binary was very low and was unstable. After the eruption, it appears that the mass transfer is much higher and is stable. That means that the explosion we observed changed the properties of the binary.
Mróz believes this proves the theory of “hibernation” where the binary system goes dark and the white dwarf barely nibbles at the red dwarf between explosions. The theory that the buildup is very slow and the classical nova is big and sudden seems to be shown by the images.
Like those sometimes hard-to-believe before-and-after photos of people using weight loss pills, is this definitive proof of classical nova hibernation? Astronomer Christian Knigge from the University of Southampton wants to see more pictures and especially more data.
This is very circumstantial. I do think this data is going to shed light on classical nova theory – but from my perspective it’s too early to claim that this is a clear case of a hibernating system that’s now erupted.
It’s time for astronomers to pull their eyes away from those Kardashian supernovas and pay more attention to these much more interesting classical novas.