University of Göttingen | 2019 May 03
Observation including Göttingen participation confirms one of the oldest Chinese measurements
For the first time, a European research team involving the University of Göttingen has discovered the remains of a nova in a galactic globular cluster. A nova is an explosion of hydrogen on the surface of a star which makes it much brighter. The remains have formed a glowing nebula. The remnant is located near the centre of the globular cluster Messier 22 and has recently been observed using modern instruments. ...Near the centre of the globular cluster Messier 22,
the team of scientists discovered the remains of a nova.
Credit: ESA/Hubble and NASA, F Göttgens (IAG)
"The position and brightness of the remains match an entry from 48 BC in an ancient collection of observations by Chinese astronomers," says first author Fabian Göttgens ... "They probably saw the original nova in the same place." This means modern measurements confirm one of the oldest observations of an event outside the solar system. ...
Globular clusters are large, spherical clusters of several hundreds of thousands of very old stars that orbit together around their home galaxy. There are 150 known globular clusters orbiting our galaxy, the Milky Way. Messier 22 is one of these star clusters, it lies in the constellation Sagittarius in the direction of the centre of the Milky Way. ...
The newly discovered remains of the nova form a red shining nebula of hydrogen gas and other gases, which has a diameter of about 8,000 times the distance between Earth and Sun. Despite its size, the nebula is relatively light, with a mass about 30 times that of Earth, because the gas was dispersed by the explosion.
Discovery of an Old Nova Remnant in the Galactic Globular Cluster M22 ~ Fabian Göttgens et al
- arXiv.org > astro-ph > arXiv:1904.11515 > 25 Apr 2019