Space

Searching for the super supernova Astrophysics
Apr 30 2020

Searching for the super supernova

A supernova is a powerful explosion at the end of the life of many stars. All massive stars with an initial mass greater than eight solar masses will eventually be torn apart by a supernova, but that fate also awaits smaller stars that are unlucky enough, after their actual end as a white dwarf, to accrete more material from a partner star, with which they form a binary system. Without supernovae, there would be no life, because it’s the only way heavy elements can be spread around the cosmos. On the whole, this process is understood. Particularly energetic supernovae,…
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Einstein was right – and Sagittarius A* is a giant black hole Astrophysics
Apr 29 2020

Einstein was right – and Sagittarius A* is a giant black hole

Physical theories have one downside that physicists are very aware of: they cannot be proven true for always. Instead, they can be considered correct just until someone can demonstrate that they’re wrong. That applies to Einstein’s theories too. His General Theory of Relativity, however, has been amazingly robust so far. Einstein himself proposed three tests for his revolutionary theory, which wasn’t based on experimental findings, but on an almost philosophical line of thinking. His first test concerned the orbit on which the planet Mercury moved around the Sun. Its point closest to the sun (perihelion) changes in a very…
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Kepler-1649c: an Earth twin with a short-tempered host star Astrophysics
Apr 28 2020

Kepler-1649c: an Earth twin with a short-tempered host star

The Kepler telescope has already been shut down, but astronomers are still finding new exoplanets in its data. Kepler-1649c, which is 300 light-years from Earth, is one of these recently discovered treasures. The planet was overlooked by the first, automated search through the data. The rocky planet has one very intriguing characteristic: it is the most Earth-like exoplanet discovered to date. Kepler-1649c is only 1.06 times larger than Earth. Its host star supplies it with about three-quarters of the energy that the Earth receives from the Sun. That means that water, if it exists there, would be liquid on…
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The Sun as a lens: A new method for taking high-resolution photographs of exoplanets Astrophysics
Apr 17 2020

The Sun as a lens: A new method for taking high-resolution photographs of exoplanets

The universe is damn large and, in comparison, everything that exists inside it is extremely small. Sometimes, astronomers are lucky and get some help in their observations of, for example, an individual star in a far-away galaxy: help delivered by the gravity of other massive objects, which refract and amplify the light of even-more distant objects like a lens. The effect is called a gravitational lens. This effect, however, has one big disadvantage: we can’t intentionally create a gravitational lens for any object we want. To be able to use this effect to view a certain object, there must…
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50,000 solar masses – and that’s just a midsize black hole Astrophysics
Apr 9 2020

50,000 solar masses – and that’s just a midsize black hole

Astronomers have been looking for medium-sized black holes for a long time. You’ve probably heard about the giant black holes at the center of galaxies and those that start with the mass of one star as a result of a supernova. But as small black holes, like from a supernova, gradually grown into giants, they must pass through intermediate stages sometime. The only problem is that these midsize black holes are not very easy to find. The Hubble Space Telescope has now delivered some important evidence that such black holes actually exist. In 2006, the Chandra and XMM-Newton X-ray…
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Review: eVscope, the telescope for amateur astronomers who want to stay warm and cozy Space
Apr 8 2020

Review: eVscope, the telescope for amateur astronomers who want to stay warm and cozy

I built my first telescope myself when I was around ten years old. I built it using an optics kit that I got after burning a finger while trying to solder something in an electronics kit (yes, back in the good old days, some toys actually had parts that could burn down your house or at least melt solder). The Moon always appeared upside down in that telescope, which always struck me as odd. After all, my binoculars showed everything right side up. I had the suspicion that the grown-ups were trying to prevent me from using the telescope…
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Triple system made from brown dwarfs discovered Space
Apr 7 2020

Triple system made from brown dwarfs discovered

Brown dwarfs are celestial objects that were a little bit too small to develop into proper stars. That doesn’t mean that they can’t be hot – under some circumstances, fusion reactions can still take place inside them just like in our Sun, only at a smaller extent or with different initial products, such as deuterium instead of hydrogen. For astronomers, they are very interesting, because they might offer any planets orbiting them even better chances of life than for larger red dwarfs, which, unfortunately, tend to have strong outbursts of radiation. Brown dwarfs, on the other hand, are relatively…
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Today’s forecast: cloudy with a 100% chance of iron rain in the evening Space
Mar 21 2020

Today’s forecast: cloudy with a 100% chance of iron rain in the evening

The exoplanet, WASP-76b, about 640 light-years from Earth, orbits its host star, WASP-76, once every approximately 1.8 days at the relatively small distance of only 0.03 astronomical units (AU). The Earth, in contrast, is at a distance of 1 AU from the Sun. The star, WASP-76, is somewhat larger and hotter than the Sun, but that doesn’t make much of a difference for the planet orbiting around it. At such a small distance, the planet would be damn hot no matter how big the star was. The planet, almost as massive as our Jupiter, is therefore classified as a…
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