Space and astronomy news
In 1936 astronomers watched as FU Orionis, a dim star in the Orion constellation, brightened dramatically. The star’s brightness increased by a factor of 100 in a matter of months. When it peaked, it was 100 times more luminous than our Sun.
Astronomers had never observed a young star brightening like this.
Continue reading “The Hubble and FU Orionis: a New Look at an Old Mystery”
The dividing line between stars and planets is that stars have enough mass to fuse hydrogen into helium to produce their own light, while planets aren’t massive enough to produce core fusion. It’s generally a good way to divide them, except for brown dwarfs. These are bodies with a mass of about 15–80 Jupiters, so they are large enough to fuse deuterium but can’t generate helium. Another way to distinguish planets and stars is how they form. Stars form by the gravitational collapse of gas and dust within a molecular cloud, which allows them to gather mass on a short cosmic timescale. Planets, on the other hand, form by the gradual accumulation of gas and dust within the accretion disk of a young star. But again, that line becomes fuzzy for brown dwarfs.
Continue reading “An Explanation for Rogue Planets. They Were Eroded Down by Hot Stars”
This stunning image of a star cluster in the Small Magellanic Cloud (SMC) is more than just a pretty picture. It’s part of a scientific effort to understand star formation in an environment different from ours. The young star cluster is called NGC 602, and it’s very young, only about 2 or 3 million years old.
Continue reading “The Webb Discovers a Rich Population of Brown Dwarfs Outside the Milky Way”
When the James Webb Space Telescope was launched on Christmas Day in 2021, it faced a whole host of intriguing questions. By the time it finally launched, astronomers had a big list of targets begging for the type of detailed observations that only the powerful infrared space telescope could perform. One of the targets was an ancient, massive galaxy that’s basically dead and forms no new stars.
The results are in, and an international team of astronomers know what happened to the quiescent galaxy.
Continue reading “A Black Hole has Almost Halted Star Formation in its Galaxy”
The Milky Way’s outer reaches are coming into view thanks to the JWST. Astronomers pointed the powerful space telescope to a region over 58,000 light-years away called the Extreme Outer Galaxy (EOG). They found star clusters exhibiting extremely high rates of star formation.
Continue reading “The Outer Reaches of the Milky Way are Full of Stars, and the JWST is Observing Them”
Understanding the star formation rate (SFR) in a galaxy is critical to understanding the galaxy itself. Some galaxies are starburst galaxies with extremely high SFRs, some are quenched or quiescent galaxies with very low SFRs, and some are in the middle. Researchers used the JWST to observe a pair of galaxies at Cosmic Noon that are just beginning to merge to see how SFRs vary in different regions of both galaxies.
Continue reading “JWST Reveals Star Formation at Cosmic Noon”
Some galaxies experience rapid star formation hundreds or even thousands of times greater than the Milky Way. Astronomers think that mergers are behind these special galaxies, which were more abundant in the earlier Universe. But new results suggest no mergers are needed.
Continue reading “No Merger Needed: A Rotating Ring of Gas Creates A Hyperluminous Galaxy”
Look at most spiral or barred spiral galaxies and you will see multiple regions where stars are forming. These star forming regions are comprised of mostly hydrogen gas with a few other elements for good measure. The first galaxies in the Universe had huge supplies of this star forming gas. Left unchecked they could have burned through the gas quickly, generating enormous amounts of star formation. Life fast though and die young for such an energetic burst of star formation would soon fizzle out leaving behind dead and dying stars. In some way it seems, galaxies seem to regulate their star formation thanks to supermassive black holes at their centre.
Continue reading “Galaxies Regulate their Own Growth so they Don’t Run Out of Star Forming Gas”
Wherever the JWST looks in space, matter and energy are interacting in spectacular displays. The Webb reveals more detail in these interactions than any other telescope because it can see through dense gas and dust that cloak many objects.
In a new image, the JWST spots a young protostar only 100,000 years old.
Continue reading “Webb Sees a Star in the Midst of Formation”
The Gemini Observatory has unveiled a striking new image that shows star formation within the irregular galaxy NGC 4449. This galaxy is categorised as a “Magellanic-type” galaxy due to its similarities with the Magellanic Clouds, although it is smaller in size. Surrounding NGC 4449 is a halo of smaller dwarf galaxies, two of which are currently merging with it. This merger is causing clouds of gas to collide, fuelling the surge in star formation observed in NGC 4449.
Continue reading “Merging Galaxies Make for Explosive Star Formation”