Massive Binary Stars Huddle Up Surprisingly Quickly

Dancing is a favorite pastime of many couples.  Swinging around a dance floor, using the laws of physics to twirl at just the right moment, and hopefully not step on any toes, is an art unto itself.  The same laws of physics that govern couples on a dance floor also govern (to some extent) the much larger dance of stellar objects.  And recently astronomers have started to understand the intricacies of how binary stars dance with each other – turns out it’s not quite as simple as doing the tango.

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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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Wow! An Actual Picture of Multiple Planets Orbiting a Sunlike Star

This image, captured by the SPHERE instrument on ESO’s Very Large Telescope, shows the star TYC 8998-760-1 accompanied by two giant exoplanets. This is the first time astronomers have directly observed more than one planet orbiting a star similar to the Sun. The image was captured by blocking the light from the young, Sun-like star (on the top left corner) using a coronagraph, which allows for the fainter planets to be detected. The bright and dark rings we see on the star’s image are optical artefacts. The two planets are visible as two bright dots in the centre and bottom right of the frame. Image Credit: ESO/Bohn et al, 2020

We’ve detected thousands of exoplanets, but for the most part, nobody’s ever seen them. They’re really just data, and graphs of light curves. The exoplanet images you see here at Universe Today and other space websites are the creations of very skilled illustrators, equal parts data and creative license. But that’s starting to change.

The European Southern Observatory’s Very Large Telescope (VLT) has captured images of two exoplanets orbiting a young, Sun-like star.

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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 2nd Planet has been Confirmed for Proxima Centauri

An artist's illustration of the Proxima Centauri system. Proxima b in on the left, while Proxima C is on the right. Image Credit: Lorenzo Santinelli

Our closest stellar neighbour is Proxima Centauri, a small red dwarf star about 4.2 light years away from us. It’s the third member of the Alpha Centauri group, and even though it’s so close, it can’t be seen with the naked eye. In 2016 astronomers discovered a planet orbiting Proxima Centuari, named Proxima Centauri b. That planet was confirmed only a few days ago.

Now, astronomers have confirmed the existence of a second planet, Proxima Centauri c.

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Astronomers Can Actually See the Clouds and Weather on Brown Dwarf 6.5 Light-Years Away

This artist's conception illustrates the brown dwarf named 2MASSJ22282889-431026, observed by NASA's Hubble and Spitzer space telescopes. Brown dwarfs are more massive and hotter than planets but lack the mass required to become stars. Image credit: NASA
This artist's conception illustrates the brown dwarf named 2MASSJ22282889-431026, observed by NASA's Hubble and Spitzer space telescopes. Brown dwarfs are more massive and hotter than planets but lack the mass required to become stars. Image credit: NASA

Brown dwarfs are in a tough spot. Not quite a star, not quite a planet, they occupy a place between gas giants and stars. They have more mass than gas giants like Jupiter, but not enough to ignite fusion and become a star.

But astronomers still study them. How could they resist?

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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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Astronomers Might Have Imaged a Second Planet Around Nearby Proxima Centauri – and it Might Have a Huge Set of Rings

An artist's illustration of the Proxima Centauri system. Proxima b in on the left, while Proxima C is on the right. Image Credit: Lorenzo Santinelli

In 2016, astronomers working for the European Southern Observatory (ESO) confirmed the existence of a terrestrial planet around Earth’s closest stellar neighbor – Proxima Centauri. The discovery of this nearby extrasolar planet (Proxima b) caused no shortage of excitement because, in addition to being similar in size to Earth, it was found to orbit within the star’s habitable zone (HZ).

Thanks to an INAF-led team, a second exoplanet (a super-Earth) was found early this year around Proxima Centauri using the Radial Velocity Method. Based on the separation between the two planets, another INAF-led team attempted to observe this planet using the Direct Imaging Method. While not entirely successful, their observations raise the possibility that this planet has a system of rings around it, much like Saturn.

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Your Umbrella is Insufficient on a Planet Where it Rains Iron

Work by the Geneva cartoonist Frederik Peeters: «Singing in the Iron Rain: An Evening on WASP-76b». (Detail - © Frederik Peeters)

Imagine a planet where it rained iron. Sounds impossible. But on one distant exoplanet, which is tidally locked to its star, the nightside has to contend with a ferrous downpour.

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Black Holes Were Already Feasting Just 1.5 Billion Years After the Big Bang

This illustration depicts a gas halo surrounding a quasar in the early Universe. The quasar, in orange, has two powerful jets and a supermassive black hole at its centre, which is surrounded by a dusty disc. The gas halo of glowing hydrogen gas is represented in blue. A team of astronomers surveyed 31 distant quasars, seeing them as they were more than 12.5 billion years ago, at a time when the Universe was still an infant, only about 870 million years old. They found that 12 quasars were surrounded by enormous gas reservoirs: halos of cool, dense hydrogen gas extending 100 000 light years from the central black holes and with billions of times the mass of the Sun. These gas stashes provide the perfect food source to sustain the growth of supermassive black holes in the early Universe.

Thanks to the vastly improved capabilities of today’s telescopes, astronomers have been probing deeper into the cosmos and further back in time. In so doing, they have been able to address some long-standing mysteries about how the Universe evolved since the Big Bang. One of these mysteries is how supermassive black holes (SMBHs), which play a crucial role in the evolution of galaxies, formed during the early Universe.

Using the ESO’s Very Large Telescope (VLT) in Chile, an international team of astronomers observed galaxies as they appeared about 1.5 billion years after the Big Bang (ca. 12.5 billion years ago). Surprisingly, they observed large reservoirs of cool hydrogen gas that could have provided a sufficient “food source” for SMBHs. These results could explain how SMBHs grew so fast during the period known as the Cosmic Dawn.

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