Brandon Q. Morris's Blog, page 31

A better weather report for the seven worlds of the Trappist system

The red dwarf Trappist-1 is orbited by seven rocky planets. For a long time, this large number of planets has made it seem likely that at least one of them might be habitable. Now, in an article in the Astrophysical Journal, astronomers have reported on their results from calculations using previously known data to produce more precise atmospheric models for the seven worlds.

The results have somewhat deflated the hopes of finding planets like Earth in this system. Trappist-1 apparently expe...

Where did the extrasolar comet ʻOumuamua come from?

This past year, our Solar System had an interstellar visitor. ʻOumuamua, which was discovered in October 2017, was first thought to be an asteroid. Then it was determined that it had changed its course by itself (and not due to gravitational interaction with the Sun or the planets). Its “propulsion system” is thought to be volatile substances that sublimated during the object’s approach to the Sun – typical behavior for a comet.

But where did this extrasolar comet come from?

Using data from...

Dark matter: the universe has gotten lumpier

Four-fifths of the matter in the universe is invisible. Nevertheless, this “dark matter” will determine the fate of the cosmos. But how is it distributed? That can be determined by measuring its gravitational effects. Gravity also changes the path that light takes as it travels from distant galaxies. The Hyper Suprime-Cam (HSC) of the Japanese Subaru telescope has studied these effects for approximately ten million galaxies. The farther away a galaxy is, the longer it takes its light to reach...

Right in the neighborhood: a super-Earth orbiting Barnard’s Star

The closest individual star to the Sun is apparently orbited by a rocky planet. This was discovered by astronomers using the radial velocity method. This method is based on the fact that stars and planets affect each other. With each revolution of a planet around its host star, the star will also move a little, toward and away from the Earth. This produces a red-shift or blue-shift in the star’s light and this shift can be measured.

However, the effect is very small, so very precise observati...

Epsilon Indi C: a moon as massive as 70 Jupiters?

The star Epsilon Indi is just barely visible with the naked eye in the southern sky. It is at a distance of 11.8 light-years from the Earth and has approximately the same size as the Sun but is somewhat older. It has also turned the usual classification of star, planet, and moon upside down.

This is because what we see is only Epsilon Indi A, but the star is orbited by a brown dwarf with a mass of 75 Jupiters and this brown dwarf has, in turn, a companion with a mass of 70 Jupiters.

Thus, Ep...

Can gravitational waves be used to transmit data?

Albert Einstein predicted the existence of gravitational waves, but these rhythmic changes in the structure of space-time were not proven until 2016. Could it be possible to impress information on them – like with electromagnetic radiation – and to read this information back without distortion or loss of information?

Yes, a team of Russian mathematicians has now shown. This is not obvious, because space-time, as a “medium,” appears to have special characteristics that are not handled by the t...

How do microquasars work?

Quasars are active galactic nuclei. Markarian 231, for example, consists of a pair of ultra-massive black holes that have masses of 4 and 150 million solar masses, orbiting each other at an enormous speed at a distance of 600 million light-years from our Solar System and emitting electromagnetic radiation in the whole spectrum.

The brightest objects in the universe are too far away to study them in high resolution. Therefore, astronomers were excited about the discovery of microquasars. What...

Bacteria survive one year on the outer shell of the ISS

Bacteria of genus Deinococcus are known for their ability to survive even the harshest conditions. Deinococcus radiodurans, for example, is barely bothered by radiation. If a person receives a dose of 10 Gy, he will die within one to two weeks (as happened to the victims of atomic bombings). Deinococcus radiodurans, in contrast, will begin to gradually sicken starting at 10,000 Gy, but will then recover. At 17,500 Gy, a third of the population will still survive; individual specimens can surv...

Superflare from red dwarf observed

2MASS J02365171-5203036 is a rather inconspicuous red dwarf of spectral class M2. It travels through the universe approximately 123 light years from Earth and normally has a luminosity of approximately one-thousandth of that of our Sun’s. On 9 August 2017, however, it experienced an outburst that made it noticeable even in the Hubble Space Telescope’s data: it released energy of 1.3 * 1032 erg over a very short period of time – for comparison, a typical solar eruption measures approximately 1...

Physicist describes a wormhole’s shape

Wormholes are shortcuts through space and time – and up to now purely a product of science fiction and theory. More precisely, their existence can only be deduced and calculated from current theories. Of course, this doesn’t mean that they actually exist. And it certainly doesn’t mean that they can be used to travel through space. But what would they look like and what shape would they have? This has been calculated by the Ukrainian physicist Roman Konoplya – or more precisely: he has shown h...