An international team of astronomers observed the second one of the two supermassive black holes circling each other in an active galaxy OJ 287.
In the latest issue of the journal Nature, an international team including astronomers from University of Turku reveal the origin of a thermonuclear supernova explosion. Strong emission lines of helium and the first detection of such a supernova in radio waves show that the exploding white dwarf star had a helium-rich companion.
A new study sheds light on the bright outbursts of radiation that are created when a star is destroyed by a supermassive black hole. The outbursts do not necessarily form in the close vicinity of the black hole, but are created by tidal shocks that occur when gas from the destroyed star hits itself while circling the black hole.
When neutron stars collide, they produce a violent explosion. Data from the only well observed collision show that the explosion was perfectly spherical, completely contrary to expectations. How this is possible remains a mystery, but the discovery may provide a new key to fundamental physics and to measuring the age of the Universe. The discovery was made by an international collaboration led by astrophysicists from the University of Copenhagen and including researchers from the University of Turku. The research has just been published in the journal Nature.
Astronomers from the University of Turku to scan the sky in search of optical signals from gravitational waves
The department of Physics and Astronomy at the University of Turku is a partner in the international Gravitational-wave Optical Transient Observer (GOTO) project, which will play a key role in shepherding in a new era of gravitational wave science. The GOTO observatory is made up of two identical telescope arrays on opposite sides of the planet that will track down sources of gravitational waves resulting from violent cosmic events that create ripples in the fabric of space-time itself.
Researchers from Aalto University, the University of Turku and the Finnish Centre for Astronomy with ESO were part of the international research group in taking a revolutionary picture.
Researchers from the University of Turku found that the axis of rotation of a black hole in a binary system is tilted more than 40 degrees relative to the axis of stellar orbit. The finding challenges current theoretical models of black hole formation.
Radio observations made by Metsähovi, Finland’s only astronomical radio observatory, and Caltech's Owens Valley Radio Observatory (OVRO) in California have revealed that radiation from the remote PKS 2131-021 quasar is subject to periodic variation. Researchers at the University of Turku participated in the analysis of the observational data.
Observations of the centres of galaxies reveal the hidden destruction of stars by lurking supermassive black holes (Dissertation defence Nov 4 2021, MSc Thomas Reynolds, astronomy)
We know that in the centres of the majority of galaxies lies a supermassive black hole. New observations of certain galaxies reveal that these black holes may be consuming stars at a higher rate than previously known. The energy produced by the destruction of the star can be revealed in the infrared, as heat from cosmic dust warmed by the explosion.
Polarization of Light Helps to Better Understand Emission Sources in the Vicinity of Stellar-Mass Black Holes (Dissertation Defence, MSc Ilia Kosenkov, 8 Oct 2021, Astronomy)
Stellar-mass black holes that are part of binary systems sometimes show variable polarization of optical emission. The degree, angle and variability pattern of polarization is characteristic of the physical processes occurring in the vicinity of a black hole. By studying black holes astronomers learn how matter and energy behave under extreme conditions.