Black holes have always held a special fascination for me ever since I was a geeky kid looking up at the stars. Their intense forces are the stuff of science fiction and can tear a star to pieces. This process is violent and can send bursts of electromagnetic radiation across the Cosmos. A paper recently published announces the discovery of 18 new tidal events just like this, doubling the number of identified shredded stars.
Continue reading “Astronomers See 18 Examples of Stars Getting Torn Apart by Black Holes”Is this the Lightest Black Hole or Heaviest Neutron Star?
About 40,000 light-years away, a rapidly spinning object has a companion that’s confounding astronomers. It’s heavier than the heaviest neutron stars, yet at the same time, it’s lighter than the lightest black holes. Measurements place it in the so-called black hole mass gap, an observed gap in the stellar population between two to five solar masses. There appear to be no neutron stars larger than two solar masses and no black holes smaller than five solar masses.
Continue reading “Is this the Lightest Black Hole or Heaviest Neutron Star?”A Giant Star is Fading Away. But First, it Had an Enormous Eruption
About 16,000 light-years away, a massive star experienced an unusual dimming event. This can happen in binary stars when one star passes in front of the other. It can also be due to intrinsic reasons like innate variability. But this star dimmed by as much as one-third, a huge amount.
What happened?
Continue reading “A Giant Star is Fading Away. But First, it Had an Enormous Eruption”Three Baby Stars Found at the Heart of the Milky Way
The core of our Milky Way is buzzing with stars. Recently astronomers reported that it contains at least one ancient star that formed outside our galaxy. Now, an international research team reports finding a grouping of very young ones there, as well. Their presence upends ideas about star birth in that densely packed region of space.
Continue reading “Three Baby Stars Found at the Heart of the Milky Way”Vampire Stars Get Help from a Third Star to Feed
Some stars are stuck in bad binary relationships. A massive primary star feeds on its smaller companion, sucking gas from the companion and adding it to its own mass while diminishing its unfortunate partner. These vampire stars are called Be stars, and up until now, astronomers thought they existed in binary relationships.
But new research shows that these stars are only able to feed on their diminutive neighbour because of a third star present in the system.
Continue reading “Vampire Stars Get Help from a Third Star to Feed”Can a Dead Star Keep Exploding?
In September 2022, an automated sky survey detected what seemed to be a supernova explosion about one billion light-years away. The Zwicky Transient Facility (ZTF) spotted it and gave it the name AT2022tsd. But something was different about this supernova. Supernovae explode and shine brightly for months, while AT2022tsd exploded brightly and then faded within days.
Continue reading “Can a Dead Star Keep Exploding?”A Star Threw Off a Sun’s Worth of Material. And Then it Exploded!
What happens just before a massive star explodes as a supernova? To figure that out, astronomers need to look at very “young” supernovae across multiple wavelengths of light. That’s what happened when SN 2023ixf occurred in May 2023. It turns out its aging progenitor star blew off a solar mass worth of material just before it died. Now, the big question is: why?
Continue reading “A Star Threw Off a Sun’s Worth of Material. And Then it Exploded!”When the Sun Dies, it Could Produce a Fantastic Ring in Space, Like This New Image From JWST
Planetary nebulae were first discovered in the 1700s. Legend tells us that through the small telescopes of the time, they looked rather planet-like, hence the name. Real history is a bit more fuzzy, and early objects categorized as planetary nebulae included things such as galaxies. But the term stuck when applied to circular emission nebulae centered around a dying star. As new observations show, planetary nebulae have a structure that is both simple and complex.
Continue reading “When the Sun Dies, it Could Produce a Fantastic Ring in Space, Like This New Image From JWST”Is This How You Get Magnetars?
Imagine a living star with a magnetic field at least 100,000 times stronger than Earth’s field. That’s the strange stellar object HD 45166. Its field is an incredible 43,000 Gauss. That makes it a new type of object: a massive magnetic helium star. In a million years, it’s going to get even stranger when it collapses and becomes a type of neutron star called a “magnetar”.
Continue reading “Is This How You Get Magnetars?”A New Simulation Reveals One Entire Stage of a Star's Life
Nuclear fusion is at the center of stellar evolution. Most of a star’s life is a battle between gravity and nuclear power. While we understand this process on a broad scale, many of the details still elude us. We can’t dive into a star to see its nuclear furnace, so we rely on complex computer simulations. A recent study has made a big step forward by modeling the entire fusion cycle of a single element.
Continue reading “A New Simulation Reveals One Entire Stage of a Star's Life”