Space

Apr 26 2022

Greenhouse effect taken to the extreme

Our solar system is relatively unusual with its division into four rocky worlds on the inside and another four gas and ice planets on the outside. What it lacks, for example, is a so-called "Hot Jupiter": a gas giant the size of our Jupiter, which orbits very close to its parent star and thus heats up extremely strongly. Therefore, if you want to learn something about Hot Jupiters, you have to look into the distance. Such a specimen appears in many of the more than 5000 planetary systems catalogued so far. What do these types of planets have in…

Astronomers discover a new type of stellar explosion: micronovae

Astrophysics

Apr 20 2022

Astronomers discover a new type of stellar explosion: micronovae

A team of astronomers has observed a new type of stellar explosion - a micronova - using the Very Large Telescope (VLT) at the European Southern Observatory (ESO). These outbursts occur on the surface of certain stars and consume an amount of stellar material equivalent to the mass of 3.5 billion Cheops pyramids in a few hours. In astronomical terms, this is still small - hence the name. Micronovae are much less energetic than the stellar explosions known as novae. Both types of explosions occur on white dwarfs. "Micronovae challenge our understanding of how thermonuclear explosions occur in stars.…

Space

Apr 11 2022

Surprising cold on Neptune

Neptune, the outermost planet of our solar system, does not belong to the ice giants with its neighbor Uranus for nothing. The enormous distance to our central star ensures that the temperature out there falls below minus 200 degrees Celsius (-238 °F). Exactly how warm it gets depends, of course, on its current position in orbit. However, distinct seasons are not really to be expected: Neptune has an almost circular orbit, so it only moves away from or comes close to the Sun minimally, and at the same time it stands on this orbit with a very low axial…

Space

Apr 2 2022

4 mile high ice volcanoes on Pluto

The exploration of the dwarf planet Pluto is divided into two eras: Before the arrival of NASA's New Horizons probe, the celestial body was thought to be an icy, unspectacular Kuiper Belt object. But New Horizons then delivered images and data that sent astronomers into raptures. The composition of Pluto's surface shows that there are a variety of ages here, from relatively old, heavily cratered regions to very young surfaces with few to no impact craters. One of the regions with very few impact craters is dominated by huge mountains with humpbacked flanks not found anywhere else in the…

Peas, blueberries and grapes – not every galaxy is like the Milky Way

Space

Apr 1 2022

Peas, blueberries and grapes – not every galaxy is like the Milky Way

Elliptical galaxies, spiral galaxies, barred spiral galaxies, you've probably heard of them. But did you know that there are types of galaxies named after green peas, blueberries, or purple grapes? When a group of amateurs within the "Galaxy Zoo," a project conducted by citizen scientists, classified galaxies observed by the Sloan Digital Sky Survey (SDSS) by color and morphology, they found 251 very special galaxies that didn't easily fit into the known galaxy types. These galaxies, which looked round and dense like beans and appeared green on digital images, were later named "Green Pea Galaxies." (more…)

Space

Mar 30 2022

Earendel: The farthest star

Far-away stars, however luminous, cannot be photographed individually even with the best space-based telescopes. But this would be extremely interesting for researchers, because with increasing distance we are entering the early days of the universe, about which we still know too little. But with a bit of luck, the universe itself is helping astronomers - by placing powerful galaxies in such a convenient way that they amplify the light of a star that is actually much too distant - in this case in the form of the galaxy cluster WHL0137-08. For example, the Hubble Space Telescope recently succeeded in…

Space

Mar 23 2022

How old is the Milky Way?

Our home galaxy contains up to 400 billion stars, and to cross it would take 200,000 years even at the speed of light. Such a huge object (which is rather average in cosmic comparison) does not come into being overnight. The Milky Way was actually born relatively early - at a time when the universe was still quite young. But when exactly, and how do you measure that? Quite simply, if you want to know how old a forest is, you determine the age of its trees. The stars of the Milky Way do not have annual rings, but…

Shrouded in ash: New type of star discovered

Space

Feb 20 2022

Shrouded in ash: New type of star discovered

Most stars follow the main sequence of the Hertzsprung-Russell diagram in their life cycle. This is because they fuse certain elements in each part of their life, starting with hydrogen, followed by helium. Only particularly large or small stars deviate from this, or binaries that, for example, get fresh material from their neighbors despite their small size. But there are deviations from the rule, and lots of them. A team of German astronomers led by Klaus Werner of the University of Tübingen has discovered another exception. To do so, the researchers took a closer look at the light from white…