Space

A black widow lurks 3000 light years away Space

A black widow lurks 3000 light years away

Astronomers love analogies from the animal kingdom. For a fast rotating neutron star, which feeds on its life partner, they have coined the term "black widow", although neutron stars are of course neither black nor widows. The star from which these pulsars (which otherwise would quickly come to rest on an astronomical scale) draw fresh energy for their rotation is still alive. Normally, such systems - about two dozen are known in the Milky Way alone - are identified by the X-rays and gamma rays that the pulsars emit like celestial lighthouses. However, not every pulsar also radiates in…
Greenhouse effect taken to the extreme Space

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

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.…
Surprising cold on Neptune Space

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…
4 mile high ice volcanoes on Pluto Space

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

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…)
Earendel: The farthest star Space

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…
How old is the Milky Way? Space

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…