Stars have been exploding for billions of years, and some of those explosions are so massive that we can see them with the naked eye here on earth. Novae and supernovae (novae's more explosive older sibling), are the result of runaway nuclear fusion at the heart of white dwarf stars, and their brightness often outshines entire galaxies.
Despite their size and brightness, supernovae are relatively rare — especially those bright enough to be seen with the naked eye — and they often fade within weeks or months. Records of supernovae visible to the naked eye crop up roughly every 250 years, and several cultures with written histories have recorded the dozen or so such events over the past 2,000 years.
|The Crab Nebula, a remnant from a supernova that occurred in the year 1054.|
Image Credit: NASA/ESA
But some supernovae are only visible in the southern hemisphere, where many cultures have passed down oral traditions instead of written histories. Consequently, there may be evidence of more historical supernovae lurking in the oral traditions of indigenous cultures.
Although some oral traditions allude to possible supernovae in the past, confirmation remains elusive.
This prompted Duane Hamacher, an astronomer at the University of New South Wales in Australia who studies indigenous cultures, to scrutinize oral traditions with purported references of supernovae and create a list of criteria for confirming such events. His paper, to be published in the Journal of Astronomical History and Heritage, is available as a preprint on the arXiv.
In his paper, Hamacher lists 14 bright supernovae observations before the modern era of advanced detection techniques and equipment, with the first of these sightings dating to over 10,000 years ago. These were all confirmed in written histories, but several more supernovae have been inferred from oral traditions.
|An animation of supernova sightings since the late 1800's. Modern astronomical techniques and surveys has led to an explosion of discoveries that aren't visible to the naked eye.|
Image Credit: RCThomas via Wikimedia Commons
How reliable are oral and material (e.g. pictograms in caves) traditions, however? As Hamacher writes in his paper, "descriptions in oral traditions are generally ambiguous and motifs in material culture are sometimes open to interpretation."
With this in mind, Hamacher has proposed the following list of evidence necessary to confirm supernovae reports in oral (O) and material (M) traditions:
1. O: There is a description of a “new star” appearing in the sky;
2. OM: The location on Earth from which the “new star” was seen;
3. OM: The period in time when the “new star” appeared;
4. OM: The location of the “new star” in the sky.
5. M: Evidence that the motif represents a star.
6. OM: Novae/supernova remnant located where “new star” was visible.
So how do the speculative cases hold up against these criteria? For most of them, not so well.
|Anaszi rock art found in Chaco Canyon, New Mexico. Some researchers believed this depicted SN 1054, a supernova that occured in 1054 which in turn created the crab nebula supernova remnant. More recently, however, several anthropologists and astronomers have cast doubt on that claim.|
Image Credit: Vincent Murphy via flickr
Nonetheless, one nova (not supernova) sighting by the Boorong Aboriginal people from 1840's was confirmed. This account stands alone because an Englishman spoke with the Boorong people and recorded important facts about the Boorong people's astronomy around the time of the supernova, verifying the Boorong people's observation.
Hamacher remains confident that other indigenous cultures have incorporated supernovae sightings into their oral traditions, but the preponderance of evidence necessary to confirm these claims remains steep.
He also believes that this research could impact current astronomical research. In fact, supernovae alluded to in oral traditions could help astronomers find undiscovered supernovae remnants today, according to Hamacher.
To discover more of the possible supernovae sightings that Hamacher researched, check out his paper on the arXiv.