. In 1670, European Astronomers observed a stunning explosion in the skies. The European Southern Observatory said it was not a new nova but rather a rare, more violent type of stellar collision. This was two stars colliding into one another. The initial explosion 345 was visible to the naked eye. Scientists were unable to determine what caused the explosion, as it left so few traces, they had to use submillimetre telescopes for three centuries. These findings were published in Nature, an academic journal (citation below). Modern instruments show the remnant of the nova 1670. (Credit: ESO/T. Kaminski. A variety of 17th century astronomers including Cassini and Hevelius (father of lunar cartography) carefully recorded the appearance of a star in the sky as 1670.. Hevelius described it as a Nova Sub Capite Cygni, a new star located under the Swan’s head. It is known by the acronym Nova Vulpeculaer 1670.. A nova in astronomy is a star that has its brightness increase suddenly (because it explodes), then gradually returns to its initial state after a few months. The historical records of novae are very important to modern astronomers, as they are rare. Nova Vulpeculaer 1670 was the first nova to have been recorded and it is also believed that it is the smallest nova ever recovered. Nova Vulpeculaer appeared less and less like the nova lead author Tomasz Kaminski. He works at ESO, the European Southern Observatory, Bonn and the Max Planck Institute of radio Astronomy. The object disappeared, then reappeared twice more before disappearing completely. It was documented well, but given the time it happened, pioneering astronomers didn’t have the technology or equipment necessary to unravel the mystery surrounding the apparent nova. Hevelius recorded the nova of 1670. Image: ESO. Nova Vul 1670 was a mysterious object for many years. Astronomers discovered in the 20th Century that the most common novae can be explained by runaway explosive behavior of nearby binary stars (two star systems). Nova Vul 1670 didn’t fit the model and was a mystery. Astronomers thought that the apparent nova left no trace up until the 1980s. A team of scientists discovered a faint nebula around the spot where they thought that some remnants of the star had been located. These observations, although they are linked to the event more than three centuries earlier, did not provide any insight into the cause of the explosion. Kaminski stated that they have “now probed the region with submillimetre wavelengths and radio wavelengths. The surrounding area of the fragment is bathed with a cool, rich gas rich in molecules. This gas has a unique chemical composition. They wrote that this gave them a detailed picture of the surrounding area. This allowed for an assessment of possible origins of this material. The material’s mass was too large to have been caused by a nova blast, they found. The isotopes measured in Nova Vul 1670 did not match what you would expect for a nova. What was the reason it wasn’t considered a nova? This was an amazing stellar collision. It was more spectacular than a Supernova but less bright than a Nova, which creates a red transient. This is a rare event in which two stars collide, then explode and spew matter into space. Eventually, a small remnant of material remains in cool, moist, rich environment rich in molecules and dust. The profile of Nova Vul 1670 fits this class of eruptive star, which was only recently recognized. Karl Menten was co-author and said: “This type of discovery is most enjoyable: something completely unexpected!” Citation. “Nuclear outflow and ashes in Nova Vul 1670,” Tomasz Kaminski and Romuald Tylenda. Nature. Publication online: March 23, 2015. DOI: 10.1038/nature14257. Video Zooming In on Nova Vul
