I saw an article last night about gravitational waves, that a black hole merger was detected by not just the Laser Interferometer Gravitational Wave Observatory (LIGO), but by another project altogether, the Virgo collaboration. This is the first gravitational wave detection confirmed by two separate groups, and it marks the beginning of a new era of experimental science, the first in astronomy in over two decades. Around 1.8 Billion years ago, to black holes merged in a faroff galaxy. They had masses of 31 and 25 times that of the Sun, though with their incredible density they would each be...
Last week, while looking at some of the best images from the Cassini spacecraft, I commented on the fact that the smooth rings of Saturn are small, varied chunks of ice and rock when you get down to the smaller scales. Reflecting on that this morning, I was thinking about how observing objects in our universe at smaller scales gives new insight into the variety and complexity of natural phenomena. Not long after, I came across a story of a new interesting object in our own Solar System. A new binary asteroid was discovered. This in itself isn’t too different...
As I was watching the grand finale of Cassini and listening to the mission team talk about the accomplishments of the mission, I learned a little bit about propellors. Not your typical airplane propellor, but the name used to describe this fascinating feature in Saturn’s rings. Seeing Saturn’s rings from afar, or even relatively close with Cassini, we see the rings as perfect. How do we end up with strange features and imperfections like this one? Looking elsewhere in the rings, we can find clues. The first clue is the namesake of the mission itself. The Cassini spacecraft was named for...
Not just the title of an excellent Futurama episode, but now a real place. A planet has been found orbiting in a triple star system, a surprising find that may be more common than once thought. Astronomers from the University of Arizona used the European Southern Observatory (ESO)’s Very Large Telescope (VLT) in Chile to directly image the new planet as it orbits the brightest star in a triple system 320 light years away, in the constellation Centaurus. Orbits like this are thought to be extremely unstable due to the varying gravitational field in the system. “HD 131399Ab is one of the few exoplanets that...
In the early Universe, things were quite different. The first stars were much more massive than stars today, and contained mostly Hydrogen. Astronomers have good ideas about how they formed, but other objects from around this time, namely black holes, are much tougher to account for. Early black holes were huge, with no explanation for how they grew so large. “Early” means “first Billion years after the Big Bang,” but even in that time, it’s hard to determine how observed black holes could grow as large as 100,000 solar masses. I say 100,000 solar masses, because that is the mass of two ‘seed’ black holes, discovered...
Dark matter could be almost anything. With little data other than how much total dark matter mass exists, we can’t decode much about what individual chunks of dark matter might be made of. I’ve talked before about Massive Compact Halo Objects (MACHOs) and Weakly Interacting Massive Particles (WIMPs), but these are just two possibilities. Other theorists have talked about Modified Newtonian Gravity (MNG), where gravity may work differently on the grand scale than it does on our small Earth scales. Or perhaps it’s something I haven’t seen before. Maybe what we call dark matter is just a large population of ancient black holes....
Hubble just discovered the newest moon in the solar system, a tiny rock orbiting the dwarf planet Makemake, far beyond the orbit of Neptune. The new moon is about 250 Km across, compared to the 1,400 Km wide Makemake. It orbits in approximately 12 days, and has an edge on orbit, making it difficult to spot. “Our preliminary estimates show that the moon’s orbit seems to be edge-on, and that means that often when you look at the system you are going to miss the moon because it gets lost in the bright glare of Makemake,” said Alex Parker of...
A supernova is the death blast of a giant star, far larger than our Sun. Massive stars go out with a bang, outshining entire galaxies, allowing us to see them across the universe. A supernova observed in 2013 occurred in a distant galaxy and took over 30 Million years to reach Earth, where the timing was perfect for us to observe and study it. And now that it’s been studied, the explosion was truly the death of a giant. The supernova, named 2013 ej, was discovered in June 2013 in the galaxy M74 in the constellation Pisces. It was the closest supernova...
Neutron stars are the most extreme objects in the universe that have been proven to exist. Black holes are very likely, but we’re still not 100% sure about them. A black hole is like a giant squid in the ocean. We’re pretty sure they exist, but nobody has caught one. The neutron star on the other hand is like a blue whale, everybody knows they exist, and they are massive, rare, and beautiful. Of course, once we know something exists, the next logical step is to figure out how it behaves, to characterize and generalize it, and to identify where it’s...
As I’ve said before, the most powerful, most energetic, most intense processes happen in the center. The gravitational center of the Earth, the Sun, and the galaxy are all places where temperature, pressure, and interactions of matter and energy are pushed to their limits. When you look up to the sky it’s easy to see the Milky Way (unless you live in an urban center). Do you ever wonder where the middle of it is? Where that supermassive black hole lies? Astronomers know where it is, but you need infrared cameras to see it past the thick dust that blocks...
