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IceCube Just Spent 10 Years Searching for Dark Matter

Neutrinos are tricky little blighters that are hard to observe. The IceCube Neutrino Observatory in Antarctica was built to detect neutrinos from space. It is one of the most sensitive instruments built with the hope it might help uncover evidence for dark matter. Any dark matter trapped inside Earth, would release neutrinos that IceCube could detect. To date, and with 10 years of searching, it seems no excess neutrinos coming from Earth have been found! Neutrinos are subatomic particles which are light and carry no electrical charge. Certain events, such as supernovae and solar events generate vast quantities of neutrinos. By now, the universe will be teeming with neutrinos with trillions of them passing through every person every second. The challenge though is that neutrinos rarely interact with matter so observing and detecting them is difficult. Like other sub-atomic particles, there are different types of neutrino; electron neutrinos, muon neutrinos and tau neutrinos, with each...

Star Devouring Black Hole Spotted by Astronomers

A team of astronomers have detected a surprisingly fast and bright burst of energy from a galaxy 500 million light years away. The burst of radiation peaked in brightness just after 4 day and then faded quickly. The team identified the burst, which was using the Catalina Real-Time Transient Survey with supporting observations from the Gran Telescopio Canarias, as the result of a small black hole consuming a star. The discovery provides an exciting insight into stellar evolution and a rare cosmic phenomenon. Black holes are stellar corpses where the gravity is so intense that nothing, not even light can escape. They form when massive stars collapse under their own gravity at the end of their life forming an infinitely small point known as a singularity. The region of space around the singularity is bounded by the event horizon, the point beyond which, nothing can escape. Despite the challenges of observing them, they can be detected by observing the effects of their gravity on ne...

What Makes Brown Dwarfs So Weird?

Meet the brown dwarf: bigger than a planet, and smaller than a star. A category of its own, it’s one of the strangest objects in the universe. Brown dwarfs typically are defined to have masses anywhere from 12 times the mass of Jupiter right up to the lower limit for a star. And despite their names, they are not actually brown . The largest and youngest ones are quite hot, giving off a steady glow of radiation. In fact, the largest brown dwarfs are almost indistinguishable from red dwarfs, the smallest of the stars. But the smallest, oldest, and coldest ones are so dim they can only be detected with our most sensitive infrared telescopes. Unlike stars, brown dwarfs don’t generate their own energy through nuclear fusion, at least not for very long. Instead they emit radiation from the leftover heat of their own formation. As that heat escapes, the brown dwarf continues to dim, sliding from fiery red to mottled magenta to invisible infrared. The greater the mass at its birth, the mor...

Archaeology On Mars: Preserving Artifacts of Our Expansion Into the Solar System

In 1971, the Soviet Mars 3 lander became the first spacecraft to land on Mars, though it only lasted a couple of minutes before failing. More than 50 years later, it’s still there at Terra Sirenum. The HiRISE camera NASA’s Mars Reconnaissance Orbiter may have imaged some of its hardware, inadvertently taking part in what could be an effort to document our Martian artifacts. Is it time to start cataloguing and even preserving these artifacts so we can preserve our history? Some anthropologists think so. Justin Holcomb is an assistant research professor of anthropology at the University of Kansas. He and his colleagues argue that it’s time to take Martian archaeology seriously, and the sooner we do, the better and more thorough the results will be. Their research commentary, “ The emerging archaeological record of Mars, ” was recently published in Nature Astronomy. Artifacts of the human effort to explore the planet are littered on its surface. According to Holcomb, these artifacts ...

A Binary Star Found Surprisingly Close to the Milky Way's Supermassive Black Hole

Binary stars are common throughout the galaxy. Roughly half the stars in the Milky Way are part of a binary or multiple system, so we would expect to find them almost everywhere. However, one place we wouldn’t expect to find a binary is at the center of the galaxy, close to the supermassive black hole Sagittarius A*. And yet, that is precisely where astronomers have recently found one. There are several stars near Sagittarius A*. For decades, we have watched as they orbit the great gravitational well. The motion of those stars was the first strong evidence that Sag A* was indeed a black hole. At least one star orbits so closely that we can see it redshift as it reaches peribothron . But we also know that stars should be ever wary of straying too close to the black hole. The closer a star gets to the event horizon of a black hole, the stronger the tidal forces on the star become. There is a point where the tidal forces are so strong a star is ripped apart. We have observed several o...

The Mysterious Case of the Resurrected Star

The star HD 65907 is not what it appears to be. It’s a star that looks young, but on closer inspection is actually much, much older. What’s going on? Research suggests that it is a resurrected star. Astronomers employ different methods to measure a star’s age. One is based on its brightness and temperature. All stars follow a particular path in life, known as the main sequence. The moment they begin fusing hydrogen in their cores, they maintain a strict relationship between their brightness and temperature. By measuring these two properties, astronomers can roughly pin down the age of a star. But there are other techniques, like measuring the amount of heavy elements in a stellar atmosphere. Older stars tend to have fewer of these elements, because they were born at a time before the galaxy had become enriched with them. Going by its temperature and brightness, HD 65907 is relatively young, with an age right around 5 billion years old. And yet it contains very little heavy elements....