Where do they come from, those beguiling singularities that flummox astrophysicists—and the rest of us. Sure, we understand the processes behind stellar mass black holes, and how they form from the gravitational collapse of a star.
But what about the staggering behemoths at the center of galaxies, those supermassive black holes (SMBH) that can grow to be billions of times more massive than our Sun?
How do they get so big?
Continue reading “Supermassive Black Holes Grew by Consuming Gas and Entire Stars”
The Milky Way has a number of satellite galaxies; nearly 60 of them, depedending on how we define them. One of them, called the Sagittarius Dwarf Spheroidal Galaxy (Sgr d Sph), may have played a huge role when it comes to humans, our world and our little civilization. A collision between the Milky Way and the Sgr d Sph may have created the Solar System itself.
Continue reading “The Solar System Might Not Exist if There Wasn’t a Huge Galactic Collision with the Milky Way Billions of Years Ago”
Astronomers like observing distant young stars as they form. Stars are born out of a molecular cloud, and once enough of the matter in that cloud clumps together, fusion ignites and a star begins its life. The leftover material from the formation of the star is called a circumstellar disk.
As the material in the circumstellar disk swirls around the now-rotating star, it clumps up into individual planets. As planets form in it, they leave gaps in that disk. Or so we think.
Continue reading “Are the Gaps in These Disks Caused by Planets?”
Stars exhibit all sorts of behaviors as they evolve. Small red dwarfs smolder for billions or even trillions of years. Massive stars burn hot and bright but don’t last long. And then of course there are supernovae.
Some other stars go through a period of intense flaring when young, and those young flaring stars have caught the attention of astronomers. A team of researchers are using the Atacama Large Millimeter/sub-millimeter Array (ALMA) to try to understand the youthful flaring. Their new study might have found the cause, and might have helped answer a long-standing problem in astronomy.
Continue reading “Both Stars in This Binary System Have Accretion Disks Around Them”
For some time, astronomers have known that collisions or mergers between galaxies are an integral part of cosmic evolution. In addition to causing galaxies to grow, these mergers also trigger new rounds of star formation as fresh gas and dust are injected into the galaxy. In the future, astronomers estimate that the Milky Way Galaxy will merge with the Andromeda Galaxy, as well as the Small and Large Magellanic Clouds in the meantime.
According to new results obtained by researchers at the Flatiron Institute’s Center for Computational Astrophysics (CCA) in New York city, the results of our eventual merger with the Magellanic Clouds is already being felt. According to results presented at the 235th meeting of the American Astronomical Society this week, stars forming in the outskirts of our galaxy could be the result of these dwarf galaxies merging with our own.
Continue reading “An Upcoming Impact With the Magellanic Clouds is Already Causing Star Formation in the Milky Way”
The world’s largest airborne telescope, SOFIA, has peered into the core of the Milky Way and captured a crisp image of the region. With its ability to see in the infrared, SOFIA (Stratospheric Observatory For Infrared Astronomy) is able to observe the center of the Milky Way, a region dominated by dense clouds of gas and dust that block visible light. Those dense clouds are the stuff that stars are born from, and this latest image is part of the effort to understand how massive stars form.
Continue reading “This is the Core of the Milky Way, Seen in Infrared, Revealing Features Normally Hidden by Gas and Dust”
Thanks to the latest generation of sophisticated telescopes, astronomers are learning things a great deal about our Universe. The improved resolution and observational power of these instruments also allow astronomers to address previously unanswered questions. Many of these telescopes can be found in the Atacama Desert in Chile, where atmospheric interference is minimal and the cosmos can be seen with greater clarity.
It is here that the European Southern Observatory (ESO) maintains many observatories, not the least of which is the Paranal Observatory where the Very Large Telescope (VLT) resides. Recently, an international team of astronomers used the VLT to study the center of the Milky Way and observed evidence of ancient starbursts. These indicate that the central region of our galaxy experienced an intense period of star birth in the past.
Continue reading “100,000 Supernovae Exploded Near the Core of the Milky Way”
Neutron stars are the end-state of massive stars that have spent their fuel and exploded as supernovae. There’s an upper limit to their mass, because a massive enough star won’t become a neutron star; it’ll become a black hole. But finding that upper mass limit, or tipping point, between a star that becomes a black hole and one that becomes a neutron star, is something astronomers are still working on.
Now a new discovery from astronomers using the National Science Foundation’s (NSF) Green Bank Telescope (GBT) have found the most massive neutron star yet, putting some solid data in place about the so-called tipping point.
Continue reading “The Most Massive Neutron Star has been Found. It’s ALMOST the Most Massive Neutron Star That’s Even Possible”
The Orion Nebula is one of the most observed and photographed objects in the night sky. At a distance of 1350 light years away, it’s the closest active star-forming region to Earth.
This diffuse nebula is also known as M42, and has been studied intensely by astronomers for many years. From it, astronomers have learned a lot about star formation, planetary system formation, and other bedrock topics in astronomy and astrophysics. Now a new discovery has been made which goes against the grain of established theory: stellar winds from newly-formed massive stars may prevent other stars from forming in their vicinity. They also play a much larger role in star formation, and in galaxy evolution, than previously thought.
Continue reading “Newborn Stars in the Orion Nebula Prevent Other Stars from Forming”
It’s relatively easy for galaxies to make stars. Start out with a bunch of random blobs of gas and dust. Typically those blobs will be pretty warm. To turn them into stars, you have to cool them off. By dumping all their heat in the form of radiation, they can compress. Dump more heat, compress more. Repeat for a million years or so.
Eventually pieces of the gas cloud shrink and shrink, compressing themselves into a tight little knots. If the densities inside those knots get high enough, they trigger nuclear fusion and voila: stars are born.
Continue reading “New Research Reveals How Galaxies Stay Hot and Bothered”