T Scorpii, or Nova Scorpii 1860, was a

nova A nova (plural novae or novas) is a transient astronomical event that causes the sudden appearance of a bright, apparently "new" star (hence the name "nova", which is Latin for "new") that slowly fades over weeks or months. Causes of the dramati ...

in the

globular cluster A globular cluster is a spheroidal conglomeration of stars. Globular clusters are bound together by gravity, with a higher concentration of stars towards their centers. They can contain anywhere from tens of thousands to many millions of membe ...

Messier 80 Messier 80 (also known as M80 or NGC 6093) is a globular cluster in the constellation Scorpius. It was discovered by Charles Messier in 1781, being one of his first discoveries. This star cluster is, as to its angle from the solar system, midwa ...

(M80). It was discovered on 21 May 1860 by Arthur von Auwers at

Koenigsberg Observatory Koenigsberg Observatory (german: Sternwarte Königsberg; Königsberger Universitätssternwarte; obs. code: 058) was an astronomical observatory and research facility which was attached to the Albertina University in Königsberg, what is now Kal ...

and was independently discovered by Norman Pogson on May 28th at Hartwell observatory. It was at magnitude 7.5 at discovery, reaching a maximum of magnitude 6.8, outshining the whole cluster.Stoyan, Ronald et al, Atlas of the Messier Objects, Cambridge University Press, 2008 page 275 T Scorpii was the first nova ever observed in any type of star cluster. As of 2019 it was still the only classical nova known for certain to have occurred in a globular cluster. T Scorpii faded by more than 3 magnitudes in 26 days, which means it was a "fast nova". Auwers reported that he had been observing M80 frequently since the beginning of 1859, and the nova was not visible when he observed it on 18 May 1860, 3 days before he first saw the nova. The nova was located less than 3 arc seconds from the center of M80. Astronomers recognized the significance of this object and for at least seven years after its discovery they closely monitored M80's appearance, but the star was never seen again by 19th century observers. In 1995 Shara and Drissen announced that they had identified the quiescent nova using

Hubble Space Telescope The Hubble Space Telescope (often referred to as HST or Hubble) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the first space telescope, but it is one of the largest and most versa ...

images, however in 2010 Dieball ''et al.'' identified a different star as the quiescent nova, based on

ultraviolet Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nanometer, nm (with a corresponding frequency around 30 Hertz, PHz) to 400 nm (750 Hertz, THz), shorter than that of visible light, but longer than ...

and

X-ray An X-ray, or, much less commonly, X-radiation, is a penetrating form of high-energy electromagnetic radiation. Most X-rays have a wavelength ranging from 10 picometers to 10 nanometers, corresponding to frequencies in the range 30&nb ...

observations. Subsequent publications support the Dieball ''et al.'' identification.

References

External links

* {{Novae Novae Scorpius (constellation) 1860 in science Scorpii, T