Astronomers Spot Three Interacting Systems with Twin Discs

Artist's conceptualization of the dusty TYC 8241 2652 system as it might have appeared several years ago when it was emitting large amounts of excess infrared radiation. Credit: Gemini Observatory/AURA artwork by Lynette Cook. https://www.gemini.edu/node/11836

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.

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Astronomers Directly Image Debris Disk and find a Jupiter-Sized Planet Orbiting a Sunlike Star

Astronomers with the SHINE collabortion observed a debris disk containing a Super-Jupiter around a young star. Credit: ALMA (ESO/NAOJ/NRAO); M. Weiss (NRAO/AUI/NSF)

According to the most widely-accepted theory, planetary systems form from large clouds of dust and gas that form disks around young stars. Over time, these disks accrete to create planets of varying size, composition, and distance from their parent star. In the past few decades, observations in the mid- and far-infrared wavelengths have led to the discovery of debris disks around young stars (less than 100 million years old). This has allowed astronomers to study planetary systems in their early history, providing new insight into how systems form and evolve.

This includes the SpHere INfrared survey for Exoplanets (SHINE) consortium, an international team of astronomers dedicated to studying star systems in formation. Using the ESO’s Very Large Telescope (VLT), the SHINE collaboration recently directly imaged and characterized the debris disk of a nearby star (HD 114082) in visible and infrared wavelengths. Combined with data from NASA’s Transiting Exoplanet Space Satellite (TESS), they were able to detect a gas giant many times the size of Jupiter (a “Super-Jupiter”) embedded within the disk.

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Astronomers Find 70 Planets Without Stars Floating Free in the Milky Way

This artist’s impression shows an example of a rogue planet with the Rho Ophiuchi cloud complex visible in the background. Rogue planets have masses comparable to those of the planets in our Solar System but do not orbit a star, instead roaming freely on their own.

The field of extrasolar planet studies continues to reveal some truly amazing things about our Universe. After decades of having just a handful of exoplanets available for study, astronomers are now working with a total of 4,884 confirmed exoplanets and another 8,288 awaiting confirmation. This number is expected to increase exponentially in the coming years as next-generation missions like the James Webb Space Telescope (JWST), Euclid, PLATO, and the Nancy Grace Roman Space Telescope (RST) reveal tens of thousands more.

In addition to learning a great deal about the types of exoplanets that are out there and what kind of stars are known to give rise to them, astronomers have also made another startling discovery. There is no shortage of exoplanets in our galaxy that don’t have a parent star. Using telescopes from around the world, a team of astronomers recently discovered 70 additional free-floating planets (FFPs), the largest sample of “Rogue Planets” discovered to date, and nearly doubling the number of FFPs available for study.

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Astronomers see a Moon-Forming Disk Around a Super-Jupiter

Recently, astronomers have been finding protoplanetary discs around certain stars.  Their discovery has helped kick off a new work in planetary formation theory.  But planets aren’t the objects that form from discs of material in space.  Moons do too.  Now, scientists led by Dr. Tomas Stolker of Leiden University and his team have delved deeper into the characteristics of a “protolunar” disc surrounding a “super Jupiter” exoplanet about 500 light-years away.

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Astronomers Detect Clouds on an Exoplanet, and Even Measure Their Altitude

Credit:

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.

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Those are Exoplanets. You’re Looking at Actual Exoplanets 63 Light-Years Away!

Credit: Axel Quetz / MPIA Graphics Department

Located 63.4 light-years from Earth in the constellation Pictor is the young and bright blue star, Beta Pictoris. In 2008, observations conducted from the ESO’s Paranal Observatory in Chile confirmed the presence of an extrasolar planet. This planet was Beta Pictoris b, a Super-Jupiter with an orbital period of up between 6890 and 8890 days (~19 to 24 years) that was confirmed by directly imaging it as it passed behind the star.

In August of 2019, a second planet was detected (another Super-Jupiter) orbiting closer to Beta Pictoris. However, due to its proximity to its parent star, it could only be studied through indirect means (radial velocity measurements). After conducting a reanalysis of data obtained by the VLT, astronomers with the GRAVITY collaboration were able to confirm the existence of Beta Pictoris c through direct imaging.

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A Giant Galaxy Seen Lighting Up the Universe Shortly After the Big Bang

An illustration of cosmic expansion. Credit: NASA's Goddard Space Flight Center Conceptual Image Lab

About 370,000 years after the Big Bang, the Universe experienced a period that cosmologists refer to as the “Cosmic Dark Ages.” During this period, the Universe was obscured by pervasive neutral gas that obscured all visible light, making it invisible to astronomers. As the first stars and galaxies formed over the next few hundred millions of years, the radiation they emitted ionized this plasma, making the Universe transparent.

One of the biggest cosmological mysteries right now is when “cosmic reionization” began. To find out, astronomers have been looking deeper into the cosmos (and farther back in time) to spot the first visible galaxies. Thanks to new research by a team of astronomers from University College London (UCL), a luminous galaxy has been observed that was reionizing the intergalactic medium 13 billion years ago.

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A Star is Orbiting the Milky Way’s Black Hole and Moving Exactly How Einstein Predicted it Should

Observations made with ESO’s Very Large Telescope (VLT) have revealed for the first time that a star orbiting the supermassive black hole at the centre of the Milky Way moves just as predicted by Einstein’s theory of general relativity. Its orbit is shaped like a rosette and not like an ellipse as predicted by Newton's theory of gravity. This effect, known as Schwarzschild precession, had never before been measured for a star around a supermassive black hole. This artist’s impression illustrates the precession of the star’s orbit, with the effect exaggerated for easier visualisation.

At the center of our galaxy, roughly 26,000 light-years from Earth, is the Supermassive Black Hole (SMBH) known as Sagittarius A*. The powerful gravity of this object and the dense cluster of stars around it provide astronomers with a unique environment for testing physics under the most extreme conditions. In particular, it offers them a chance to test Einstein’s Theory of General Relativity (GR).

For example, in the past thirty years, astronomers have been observing a star in the vicinity of Sagittarius A* (S2) to see if its orbit conforms to what is predicted by General Relativity. Recent observations made with the ESO’s Very Large Telescope (VLT) have completed an observation campaign that confirmed that the star’s orbit is rosette-shaped, once again proving that Einstein theory was right on the money!

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100,000 Supernovae Exploded Near the Core of the Milky Way

Taken with the HAWK-I instrument on ESO’s Very Large Telescope in the Chilean Atacama Desert, this stunning image shows the Milky Way’s central region with an angular resolution of 0.2 arcseconds. This means the level of detail picked up by HAWK-I is roughly equivalent to seeing a football (soccer ball) in Zurich from Munich, where ESO’s headquarters are located. The image combines observations in three different wavelength bands. The team used the broadband filters J (centred at 1250 nanometres, in blue), H (centred at 1635 nanometres, in green), and Ks (centred at 2150 nanometres, in red), to cover the near infrared region of the electromagnetic spectrum. By observing in this range of wavelengths, HAWK-I can peer through the dust, allowing it to see certain stars in the central region of our galaxy that would otherwise be hidden.   

Thanks to the latest generation of sophisticated telescopes, astronomers are learning things a great deal about our Universe. The improved resolution and observational power of these instruments also allow astronomers to address previously unanswered questions. Many of these telescopes can be found in the Atacama Desert in Chile, where atmospheric interference is minimal and the cosmos can be seen with greater clarity.

It is here that the European Southern Observatory (ESO) maintains many observatories, not the least of which is the Paranal Observatory where the Very Large Telescope (VLT) resides. Recently, an international team of astronomers used the VLT to study the center of the Milky Way and observed evidence of ancient starbursts. These indicate that the central region of our galaxy experienced an intense period of star birth in the past.

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A Fast Radio Burst has Finally Been Traced Back to its Source: the Outskirts of a Galaxy 4 Billion Light-Years Away

Artist’s impression of CSIRO’s Australian SKA Pathfinder (ASKAP) radio telescope finding a fast radio burst and determining its precise location. The KECK, VLT and Gemini South optical telescopes joined ASKAP with follow-up observations to image the host galaxy. Credit: CSIRO/Dr Andrew Howells

Fast-Radio Bursts (FRBs) are one of the most puzzling phenomena facing astronomers today. Essentially, FRBs are brief radio emissions from distant astronomical sources whose cause remains unknown. In some cases, FRBs that have been detected that have been repeating, but most have been one-off events. And while repeating sources have been tracked back to their point of origin, no single events have ever been localized.

Until now. Using the Australian Square Kilometer Array Pathfinder (ASKAP) and other radio telescopes from around the world, an Australian-led team of astronomers managed to confirm the distance to an intense radio burst that flashed for just a thousandth of a second. The constitutes the first non-repeating FRB to be traced back to its source, which in this case was a galaxy located 4 billion light-years away.

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