Dwarfs

Researchers have discovered why some white dwarf stars stop cooling, challenging previous understandings and affecting how astronomers determine the age of stars. This finding, stemming from the behavior of solid crystals within the stars, prompts a reevaluation of stellar age assessment and galaxy formation theories. Credit: SciTechDaily.comNew research reveals that white dwarf stars stop cooling due to floating crystals in their interior, offering insights into stellar aging processes.In a paper published on March 6 in…

By Milan P. Ilnyckyj, Canadian Institute for Theoretical Astrophysics March 8, 2024New research challenges the traditional view of white dwarfs as mere remnants of dead stars by explaining the prolonged luminosity of delayed white dwarfs. Credit: SciTechDaily.comResearchers discovered why some white dwarfs remain luminous for billions of years: a core process where lighter crystals rise and denser liquids sink, balancing the energy and maintaining surface brightness.Your astronomy textbook might describe white dwarfs as…

Chinese astronomers have observed the complete transformation of dwarf galaxies into ultra-compact dwarf galaxies (UCDs), revealing a crucial intermediate stage in galactic evolution and solving longstanding mysteries about UCD origins.A team of Chinese astronomers has successfully observed the full transformation of dwarf galaxies into ultra-compact dwarf galaxies (UCDs). This significant discovery was detailed in a study recently published in the journal Nature.Traditionally, galaxies and star clusters have been viewed…

Creative Assembly has revealed Forge Of The Chaos Dwarfs, an upcoming race pack for Total War: Warhammer 3 that will introduce the industrial Chaos Dwarf faction to the game. After months of teasing, the Chaos Dwarfs were revealed today (March 14) and are set to launch on April 13. The first trailer for Forge Of The Chaos Dwarfs shows the faction fielding a mix of industrial siege weaponry, armoured infantry and monstrous units to achieve victory over their Dwarf rivals. https://www.youtube.com/watch?v=OiHvsinEn58 The…

This illustration depicts a brown dwarf – an object that is too heavy to be characterized as a planet, but not massive enough to power itself by nuclear fusion the way stars do. Credit: NASA’s Goddard Space Flight CenterA recent study directly images four new brown dwarfs.Brown dwarfs are mysterious celestial bodies that fall between the heaviest planets and the lightest stars, exhibiting both stellar and planetary traits. These perplexing objects’ hybrid nature makes them essential for advancing our knowledge of both…

Ask astronomers about dark matter and one of the things they talk about is that this invisible, mysterious 'stuff' permeates the universe. In particular, it exists in halos surrounding most galaxies.  The mass of the halo exerts a strong gravitational influence on the galaxy itself, as well as on others in the neighborhood. That's pretty much the standard view of dark matter and its influence on galaxies.However, there are problems with the idea of those halos. Apparently, some oddly shaped dwarf galaxies exist that look…

When a star dies, what happens to its planets? Well, if that star is a certain white dwarf 86 light-years away, those planets are currently in the process of being torn apart and eaten by the star, like some grotesque cosmic performance of Kronos devouring his children.  This is not entirely unusual for white dwarfs. But this particular star, named G238-44, is a glutton: for the first time, astronomers have seen one of these stars swallowing material from both the inner and outer reaches of its planetary system at the…

We all know that a humongous black hole exists at the center of our galaxy. It's called Sagittarius A* (Sgr A* for short) and it has the mass of 4 million suns. We got to see a radio image of it a few weeks back, showing its accretion disk.  So, we know it's there. Astronomers can chart its actions as it gobbles up matter occasionally and they can see how it affects nearby stars.What astronomers are still trying to understand is how Sgr A* formed.The answer looks like it involves smaller black holes, especially ones from…

Multiple star systems are very common in the Milky Way. While most of these systems are binary systems consisting of two stars, others contain three, four, or even six stars.These systems tend to be pretty stable since unstable systems tend to break apart or merge fairly quickly, but sometimes you can get a kind of meta-stable system. One that lasts long enough for stars to evolve while still being stable in the end. And that end could be a supernova.  It all comes down to gravitational dynamics. In Newtonian physics,…

This illustration is an artist’s impression of the thin, rocky debris disc discovered around the two Hyades white dwarfs. Rocky asteroids are thought to have been perturbed by planets within the system and diverted inwards towards the star, where they broke up, circled into a debris ring, and were then dragged onto the star itself. Credit: NASA, ESA, STScI, and G. Bacon (STScI)White dwarfs were once normal stars similar to the Sun but then collapsed after exhausting all their fuel. Historically, these interstellar…