According to the most widely-accepted theory about star formation (Nebular Hypothesis), stars and planets form from huge clouds of dust and gas. These clouds undergo gravitational collapse at their center, leading to the birth of new stars, while the rest of the material forms disks around it. Over time, these disks become ring structures that accrete to form systems of planets, planetoids, asteroid belts, and Kuiper belts. For some time, astronomers have questioned how interactions between early stellar environments may affect their formation and evolution.
For instance, it has been theorized that gravitational interactions with a passing star or shock waves from a supernova might have triggered the core collapse that led to our Sun. To investigate this possibility, an international team of astronomers observed three interacting twin disc systems using the Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE) on the ESO’s Very Large Telescope (VLT). Their findings show that due to their dense stellar environments, gravitational encounters between early-stage star systems play a significant role in their evolution.
Pictures of galaxies never cease to amaze, and astronomers are consistently coming up with new ones that provide a different viewpoint on the universe and maybe some exciting science along with it. A recent picture of the galaxy NGC 7582, taken with the Very Large Telescope (VLT), shows an active supermassive black hole at the galaxy’s core. However, something appears to be redirecting its “wind” away from the rest of the spiral galaxy.
Planets aren’t the only celestial objects with moons – asteroids can have them too. They are usually other, smaller asteroids in orbit around a larger central one. Now, a team of Thai and French astronomers found an asteroid system with three satellites. The new four-body system makes complex gravitational problems like the three-body problem look simple by comparison.
In August of 2016, astronomers with the European Southern Observatory (ESO) announced that they had discovered an exoplanet orbiting in neighboring Proxima Centauri. Based on Radial Velocity measurements (aka. Doppler Photometry), the discovery team estimated that the planet was roughly the same size and mass as Earth and orbited with Proxima Centauri’s Circumsolar Habitable Zone (HZ). In 2020, this planet was confirmed by follow-up observations.
In that same year, a second exoplanet (Proxima c) roughly seven times the mass of Earth (a Super-Earth or mini-Neptune) was confirmed. As if that wasn’t enough, an international team of astronomers with the ESO recently announced that they detected a third exoplanet around Proxima Centauri – Proxima d! This Mars-sized planet orbits about halfway between its host star and Proxima b and is one of the lightest exoplanets ever discovered.
For literally being black in the truest sense of the word, black holes are surprisingly easy to spot. Astronomers have spent decades at this point purposely searching for them and have found thousands already, with potentially 100 billion existing in our part of the universe. We are still finding new types and configurations of black holes consistently. Now, new research led by Dr. Karina Voggel of the Strasbourg Observatory found a pair of black holes that hold the new records of being both the closest supermassive black hole pair to Earth and the closest together pair ever seen.
The search for planets beyond our Solar System has grown immensely during the past few decades. To date, 4,521 extrasolar planets have been confirmed in 3,353 systems, with an additional 7,761 candidates awaiting confirmation. With so many distant worlds available for study (and improved instruments and methods), the process of exoplanet studies has been slowly transitioning away from discovery towards characterization.
For example, a team of international scientists recently showed how combining data from multiple observatories allowed them to reveal the structure and composition of an exoplanet’s upper atmosphere. The exoplanet in question is WASP-127b, a “hot Saturn” that orbits a Sun-like star located about 525 light-years away. These findings preview how astronomers will characterize exoplanet atmospheres and determine if they are conducive to life as we know it.
Interferometers are some of the most highly advanced sensor instruments that humans have made. They are used in everything from astronomy to quantum mechanics and have profoundly impacted our understanding of science. But not all interferometers have to be functional. A Dutch astronomer named Frans Snik has just designed one that, while it isn’t function, is inspiring all the same – and it happens to be made out of Lego.
I’d never seen galaxy images like this before. Nobody had! These images highlight star forming regions in nearby(ish) galaxies. There are still a number of unanswered questions surrounding how star formation actually occurs. To answer those questions, we are observing galaxies that are actively forming stars within giant clouds of gas. Until recently, we didn’t have the resolution needed to clearly image the individual gas clouds themselves. But images released by a project called PHANGS (Physics at High Angular resolution in Nearby GalaxieS) in a collaboration between the European Southern Observatory Very Large Telescope and the Atacama Large millimeter/submillmeter Array (ALMA) have provided never before seen detail of star forming clouds in other galaxies.
When it comes to finding exoplanets, size matters, but so does weight. The larger and heavier the planet, the more likely they will be discovered by the current crop of telescopes. Both the techniques to find exoplanets and the telescopes using those techniques are biased toward larger, heavier planets. So when even the current crop of telescopes manages to find one that is about half the mass of Venus, it is cause for celebration. That is precisely the size of the planet a team from the European Southern Observatory’s Very Large Telescope has found orbiting a star called L98-59.
Planetary formation is a complicated, multilayered process. Even with the influx of data on exoplanets, there are still only two known planets that are not yet fully formed. Known as PDS 70b and PDS 70c, the two planets, which were originally found by the Very Large Telescope, are some of the best objects we have to flesh out our planetary formation models. And now, one of them has been confirmed to have a moon-forming disk around it.