NASA's recently retired cosmic telescope, Kepler, was known for its ability to spot thousands of extrasolar planets. But this year, she presented a mysterious observation of the supernova.
Kepler offered scientists another chance to look at the light that comes from before, during and after a supernova. These "exceptional" data, according to the scientists who wrote about this, have deepened the mystery of why these types of super-type type 1a shine so lightly shortly after the impact and which causes their last explosion.
Scientists were initially alerted to the presence of a supernova, now called 2018oh, through a set of five telescopes around the world (called All Sky Automated Surveying for SuperNovae), which provided the images obtained on February 4, 2018.
Fortunately, the galaxy in which a supernova happened, called UGC 478, was part of a campaign to track the galaxy of the Kepler space telescope. Scientists could then combine Kepler's sensitive data with special observations of the supernova color, using other telescopes, including the dark energy camera and the Pan-STARRS1 telescope.
It could sound strange – why is a hunter of exoplanets in distant galaxies? Kepler repeatedly takes wide images from the same research points, and can observe thousands of galaxies at the same time. In addition, they should be sensitive to small changes in the amount of light emitted by objects, as it usually looks for the transient changes in light caused by planets passing through distant stars.
2018oh is a type 1a supernova, based on the way its light looks like. The models show that these supernovae come from a pair of stars in which one, white dwarf, instills a lot of masses from the other before it explodes. This is the fourth supernova type 1a observed in Kepler's research, and this is the closest and brightest with the most accurate data.
A number of researchers recently reported cleaned supernova analyzes. Two such results showed that the graph of the "light curve", or the amount of light over time, did not appear as a flat curve. Instead, there was an upward slice of a piece, where the supernova shone brighter than the expected five days before it was played up, indicating that two different processes took place.
They also noticed that supernova appeared stronger than others.
So, what caused a two-part illumination of this supernova? There are several ideas. Perhaps the light communicated with a nearby star, who offered fuel for the blast. Or perhaps on the surface of the white dwarf there was a helium shell, which provided more ignition materials. Or maybe there was a piece of radioactive nickel unevenly stuck in the star, which would add light to the signature. Further observations with the X-ray Swift telescope seemed to exclude dust interactions around the exploding star.
One researcher we talked to thought was too early for an answer – and maybe it's time to go back to the drawing. "Theory must return to the books and model the various ways that this early emission could be created," said Maximilian Stritzinger, a physicist at Aarhus University in Denmark, who studied the colors emitted by these type 1a supernatants, for Gizmodo.
Supernova is included in the list of difficult to describe type 1a, according to studies. But I hope. Kepler can still notice more supernovae, and these data can further help scientists solve the mystery.[ApJ, ApJ, ApJL, ApJL]