The only thing worse than drifting through space for an eternity is doing it alone. Observations with the Hubble Space Telescope show that brown dwarfs that once had companions suffer that fate. Binary brown dwarfs that were once bound to each other tend to drift apart as time passes.
Continue reading “Brown Dwarf Pairs Drift Apart in Old Age”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”Giant Tidal Waves are Crashing Onto the Surface of an Enormous Star
Binary star systems often appear as variable stars. When we can’t see the individual stars because they are either too close together or too far away, we can see the gradual brightening and dimming of a single point of light as the stars orbit each other. Sometimes if the stars are particularly close when they pass each other they can brighten in unusual ways. One example of this is known as a heartbeat star.
Continue reading “Giant Tidal Waves are Crashing Onto the Surface of an Enormous Star”Evidence for Modified Gravity Found in the Motions of Binary Stars
With our continued failure to discover dark matter particles, it’s worth considering alternatives. While dark matter is the most widely supported model, the alternatives fall into two broad paths. One is that we should look to extended models of general relativity, such as conformal gravity. The other argues we should modify the very nature of Newtonian dynamics. The first approach tends to be popular with theorists since it focuses on an abstract theory in the same vein as Einstein’s original ideas. The second, often known as Modified Newtonian Dynamics, or MoND, tends to be more popular with observational astronomers.
Continue reading “Evidence for Modified Gravity Found in the Motions of Binary Stars”A Neutron Star is Unwinding a Companion Star
Close binary stars play several important roles in astronomy. For example, Type Ia supernovae, used to measure galactic distances, occur when a neutron star in a binary system reaches critical mass. These stars are also the source of x-ray binaries and microquasars, which help astronomers understand supermassive black holes and active galactic nuclei. But the evolutionary process of close binaries is still not entirely understood. That’s changing thanks in part to a new discovery of a close binary in its intermediate stage.
Continue reading “A Neutron Star is Unwinding a Companion Star”Each Planetary Nebula is Unique. Why Do They Look So Different?
When it comes to cosmic eye candy, planetary nebulae are at the top of the candy bowl. Like fingerprints—or maybe fireworks displays—each one is different. What factors are at work to make them so unique from one another?
Continue reading “Each Planetary Nebula is Unique. Why Do They Look So Different?”These Stars are Already Merging, but Their Future Will Be Catastrophic
Close-orbiting binaries are a ticking time bomb. Over time they spiral ever closer to each other until they merge in a cataclysmic explosion such as a supernova. But in the middle of their story, things can get interesting. Some stars collapse into a white dwarf before merging with their partner, others edge so close to each other that their surfaces touch for a time, becoming contact binaries before finally colliding. But one newly discovered binary system will have a wild ride before its final demise.
Continue reading “These Stars are Already Merging, but Their Future Will Be Catastrophic”Binary Dwarf Stars Found Orbiting Each Other Every 20 Hours. They Were Once Almost Touching
A team of astrophysicists has discovered a binary pair of ultra-cool dwarfs so close together that they look like a single star. They’re remarkable because they only take 20.5 hours to orbit each other, meaning their year is less than one Earth Day. They’re also much older than similar systems.
Continue reading “Binary Dwarf Stars Found Orbiting Each Other Every 20 Hours. They Were Once Almost Touching”Trading Spaces: How Swapping Stars Create Hot Jupiters
Star clusters tend to host more hot Jupiters than average, but why? A team of astronomers have proposed a new solution, and it involves a lot of swapping of stellar neighbors.
Continue reading “Trading Spaces: How Swapping Stars Create Hot Jupiters”Two Stars Orbiting Each Other Every 51 Minutes. This Can’t End Well
We don’t have to worry too much about our Sun. It can burn our skin, and it can emit potent doses of charged material—called Solar storms—that can damage electrical systems. But the Sun is alone up there, making things simpler and more predictable.
Other stars are locked in relationships with one another as binary pairs. A new study found a binary pair of stars that are so close to each other they orbit every 51 minutes, the shortest orbit ever seen in a binary system. Their proximity to one another spells trouble.
Continue reading “Two Stars Orbiting Each Other Every 51 Minutes. This Can’t End Well”