New research shows that other sunlike stars in our galaxy aren’t so kind to their planets. Up to a quarter of them may consume planets before they even establish a solar system. That consumption leaves behind a distinct chemical fingerprint in the stars, which can help researchers understand how common planetary systems are…and how often they get destroyed.Continue reading “Many Sunlike Stars Gobbled up Some of Their Planets”
About 97% of all stars in our Universe are destined to end their lives as white dwarf stars, which represents the final stage in their evolution. Like neutron stars, white dwarfs form after stars have exhausted their nuclear fuel and undergo gravitational collapse, shedding their outer layers to become super-compact stellar remnants. This will be the fate of our Sun billions of years from now, which will swell up to become a red giant before losing its outer layers.
Unlike neutron stars, which result from more massive stars, white dwarfs were once about eight times the mass of our Sun or lighter. For scientists, the density and gravitational force of these objects is an opportunity to study the laws of physics under some of the most extreme conditions imaginable. According to new research led by researchers from Caltech, one such object has been found that is both the smallest and most massive white dwarf ever seen.Continue reading “A Nearby White Dwarf Might be About to Collapse Into a Neutron Star”
In the past decade, the discovery of extrasolar planets has accelerated immensely. To date, 4,424 exoplanets have been confirmed in 3,280 star systems, with another 7,453 awaiting confirmation. So far, most of these planets have been gas giants, with about 66% being similar to Jupiter or Neptune, while another 30% have been giant rocky planets (aka. “Super-Earths). Only a small fraction of confirmed exoplanets (less than 4%) have been similar in size to Earth.
However, according to new research by astronomers working at NASA Ames Research Center, it is possible that Earth-sized exoplanets are more common than previously thought. As they indicated in a recent study, there could be twice as many rocky exoplanets in binary systems that are obscured by the glare of their parent stars. These findings could have drastic implications in the search for potentially habitable worlds since roughly half of all stars are binary systems.Continue reading “There are Probably Many More Earth-Sized Worlds Than Previously Believed”
In this week’s edition of new unexplained astronomical phenomena, a team of astronomers led by Dr. Leigh Smith from Cambridge found a star 100 times larger than our sun that nearly disappears from the sky every few decades. They also have no idea why it does so.Continue reading “Astronomers Find a Blinking Star Near the Center of the Milky Way”
In theory, a black hole is easy to make. Simply take a lump of matter, squeeze it into a sphere with a radius smaller than the Schwarzschild radius, and poof! You have a black hole. In practice, things aren’t so easy. When you squeeze matter, it pushes back, so it takes a star’s worth of weight to squeeze hard enough. Because of this, it’s generally thought that even the smallest black holes must be at least 5 solar masses in size. But a recent study shows the lower bound might be even smaller.Continue reading “Smallest, Closest Black Hole Ever Discovered is Only 1,500 Light-Years Away”
Binary star systems are everywhere. They make up a huge percentage of all known solar systems: from what we can tell, about half of all Sun-like stars have a binary partner. But we haven’t really had a chance to study them in detail yet. That’s about to change. Using data from the European Space Agency’s Gaia spacecraft, a research team has just compiled a gigantic new catalog of nearby binary star systems, and it shows that at least 1.3 million of them exist within 3000 light-years of Earth.Continue reading “Our Part of the Galaxy is Packed with Binary Stars”
Dancing is a favorite pastime of many couples. Swinging around a dance floor, using the laws of physics to twirl at just the right moment, and hopefully not step on any toes, is an art unto itself. The same laws of physics that govern couples on a dance floor also govern (to some extent) the much larger dance of stellar objects. And recently astronomers have started to understand the intricacies of how binary stars dance with each other – turns out it’s not quite as simple as doing the tango.Continue reading “Massive Binary Stars Huddle Up Surprisingly Quickly”
A white dwarf isn’t your typical kind of star. While main sequence stars such as our Sun fuse nuclear material in their cores to keep themselves from collapsing under their own weight, white dwarfs use an effect known as quantum degeneracy. The quantum nature of electrons means that no two electrons can have the same quantum state. When you try to squeeze electrons into the same state, they exert a degeneracy pressure that keeps the white dwarf from collapsing.Continue reading “Strange Green Star is the Result of a Merger Between two White Dwarfs”
We recently observed the strongest magnetic field ever recorded in the Universe. The record-breaking field was discovered at the surface of a neutron star called GRO J1008-57 with a magnetic field strength of approximately 1 BILLION Tesla. For comparison, the Earth’s magnetic field clocks in at about 1/20,000 of a Tesla – tens of trillions of times weaker than you’d experience on this neutron star…and that is a good thing for your general health and wellbeing.
Neutron stars are the “dead cores” of once massive stars which have ended their lives as supernova. These stars exhausted their supply of hydrogen fuel in their core and a power balance between the internal energy of the star surging outward, and the star’s own massive gravity crushing inward, is cataclysmically unbalanced – gravity wins. The star collapses in on itself. The outer layers fall onto the core crushing it into the densest object we know of in the Universe – a neutron star. Even atoms are crushed. Negatively charged electrons are forced into the atomic nuclei meeting their positive proton counterparts creating more neutrons. When the core can be crushed no further, the outer remaining material of the star rebounds back into space in a massive explosion – a supernova. The resulting neutron star, made of the crushed stellar core, is so dense that a single sugar-cube-sized sampling would weigh billions of tons – as much as a mountain (though if you’re “worthy” you MIGHT able to lift it since Thor’s Hammer is made of the stuff). Neutron stars are typically about 20km in diameter and can still be a million degrees Kelvin at the surface.
But if they’re “dead,” how can neutron stars be some of the most magnetic and powerful objects in the Universe?Continue reading “Astronomers Measure a 1-billion Tesla Magnetic Field on the Surface of a Neutron Star”
About 460 light years away lies the Rho Ophiuchi cloud complex. It’s a molecular cloud—an active star-forming region—and it’s one of the closest ones. R. Ophiuchi is a dark nebula, a region so thick with dust that the visible light from stars is almost completely obscured.
But scientists working with ALMA have pin-pointed a pair of young proto-stars inside all that dust, doing the busy work of becoming active stars.Continue reading “This is a Binary Star in the Process of Formation”