An international team led by astronomers from the Max Planck Institute for Extraterrestrial Physics has announced the discovery of a unique binary star system in which matter flows onto the white dwarf from its companion. The system was found due to bright, so-called super-soft X-rays, which originate in the nuclear fusion of the overflowed gas near the surface of the white dwarf. The unusual thing about this source is that it is helium and not hydrogen that overflows and burns. The paper presenting the results of this study has been published in the Nature journal. Optical observations of the system collected by the OGLE project led by prof. Andrzej Udalski from the Astronomical Observatory of the University of Warsaw – co-author of the paper – played an important role in its characterization.

The stars circle each other every 51 minutes, confirming a decades-old prediction.

Nearly half the stars in our galaxy are solitary like the sun. The other half comprises stars that circle other stars, in pairs and multiples, with orbits so tight that some stellar systems could fit between Earth and the moon.

An international group of astronomers with the participation of scientists from the Astronomical Observatory of the University of Warsaw discovered a “dormant” stellar-mass black hole in the Large Magellanic Cloud, a neighbor galaxy to our own. It is the first object of this type found outside the Milky Way. The discovery was made thanks to six years of spectroscopic observations obtained with the European Southern Observatory’s (ESO’s) Very Large Telescope (VLT) and nearly 20 years of photometric observations carried out as part of the Polish OGLE project with the Warsaw Telescope in Chile.

The Milky Way galaxy is expected to host over 100 million isolated black holes. Two independent teams of scientists, including astronomers from the Astronomical Observatory of the University of Warsaw, have for the first time discovered what may be a free-floating black hole.

Illustration of a close-up look at a black hole drifting through our Milky Way galaxy. The black hole is the crushed remnant of a massive star that exploded as a supernova. The surviving core is several times the mass of our Sun. The black hole traps light due to its intense gravitational field. The black hole distorts the space around it, which warps images of background stars lined up almost directly behind it. This gravitational “lensing” effect offers the only telltale evidence for the existence of lone black holes wandering our galaxy, which may be a population of 100 million.
(Credit: NASA, STScI, image: FECYT, IAC).

An international team of astronomers found evidence for a unique pair of supermassive black holes orbiting each other in the center of a quasar. Dr Przemysław Mróz from the Astronomical Observatory of the University of Warsaw is one of the co-authors of the study published in The Astrophysical Journal Letters.

Caught in an epic cosmic waltz 9 billion light-years away, two supermassive black holes appear to be orbiting around each other every two years. The two massive bodies are each hundreds of millions of times the mass of our sun and span a distance roughly fifty times the size of our own solar system. When the pair merge in roughly 10,000 years, the titanic collision is expected to shake space and time itself, sending gravitational waves across the universe.

The U.S. company SpaceX plans to build a constellation of 42,000 low-Earth-orbit communication satellites called Starlink. A new study, led by Przemek Mróz of the Astronomical Observatory of the University of Warsaw, looks at the impact of satellites on ground-based astronomical research. Since 2019, SpaceX has been launching an increasing number of internet satellites into orbit around Earth. The satellite network, also called a constellation, now includes nearly 1,800 members orbiting at altitudes of about 550 kilometers. Astronomers have expressed concerns that these objects, which can appear as streaks in telescope images, could hamper their scientific observations.

To quantify these effects, a team of researchers studied archival images captured by the Zwicky Transient Facility (ZTF), an instrument that operates from the Palomar Observatory near San Diego, California, US. ZTF scans the entire night sky every two days, cataloguing cosmic objects that explode, blink, or otherwise change over time. This includes everything from supernovae to near-Earth asteroids. The team says that they decided to specifically study the effects of Starlink satellites because these satellites currently represent the largest low-earth orbit constellation and they have well-characterized orbits.

Dr Dorota Skowron from the UW Astronomical Observatory was awarded the European Research Council (ERC) Starting Grant for her project “A MISTery of Long Secondary Periods in Pulsating Red Giants – Traces of Exoplanets?” (LSP-MIST). Dr Skowron will work on a new method to discover exoplanets in the farthest regions of our Galaxy and in […]