Which Stars are Lethal to their Planets?

Many years ago, there was a viral YouTube video called “History of the entire world, i guess,” which has been an endless source of internet memes since its release. One of the most prominent is also scientifically accurate—when describing why animals couldn’t start living on land, the video’s creator, Bill Wurtz, intones, “The Sun is a deadly laser.” 

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New Simulation Explains how Supermassive Black Holes Grew so Quickly

Supermassive Black Hole Survey. Credit: ESA/XMM-Newton/PSU/F. Zou et al./N.Trehnl/The TNG Collaboration

One of the main scientific objectives of next-generation observatories (like the James Webb Space Telescope) has been to observe the first galaxies in the Universe – those that existed at Cosmic Dawn. This period is when the first stars, galaxies, and black holes in our Universe formed, roughly 50 million to 1 billion years after the Big Bang. By examining how these galaxies formed and evolved during the earliest cosmological periods, astronomers will have a complete picture of how the Universe has changed with time.

As addressed in previous articles, the results of Webb‘s most distant observations have turned up a few surprises. In addition to revealing that galaxies formed rapidly in the early Universe, astronomers also noticed these galaxies had particularly massive supermassive black holes (SMBH) at their centers. This was particularly confounding since, according to conventional models, these galaxies and black holes didn’t have enough time to form. In a recent study, a team led by Penn State astronomers has developed a model that could explain how SMBHs grew so quickly in the early Universe.

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Black Holes are Firing Beams of Particles, Changing Targets Over Time

Black holes seem to provide endless fascination to astronomers. This is at least partly due to the extreme physics that takes place in and around them, but sometimes, it might harken back to cultural touchpoints that made them interested in astronomy in the first place. That seems to be the case for the authors of a new paper on the movement of jets coming out of black holes. Dubbing them “Death Star” black holes, researchers used data from the Very Long Baseline Array (VLBA) and the Chandra X-ray Observatory to look at where these black holes fired jets of superheated particles. And over time the found they did something the fiction Death Star could also do – move.

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NASA is Planning to Shut Down One of the Great Observatories to Save Money

Artist's illustration of Chandra

The US Government budget announcement in March left NASA with two billion dollars less than it asked for. The weeks that followed have left NASA with some difficult decisions forcing cuts across the agency. There will be a number of cuts across the agency but one recent decision came as quite a shock to the scientific community. NASA have just announced they are no longer going to support the Chandra X-Ray Observatory which has been operational since 1999 and made countless discoveries. 

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JWST and Chandra Team Up for a Stunning View of Supernova Remnant Cassiopeia A

This image of Cassiopeia A comes from a combination of data from the Chandra X-ray telescope and the James Webb Space Telescope. Credit: X-ray: NASA/CXC/SAO; Optical: NASA/ESA/STScI; IR: NASA/ESA/CSA/STScI/Milisavljevic et al., NASA/JPL/CalTech; Image Processing: NASA/CXC/SAO/J. Schmidt and K. Arcand

NASA’s long-lived Chandra X-ray Observatory teamed up with JWST for the first time, producing this incredibly detailed image of the famous supernova remnant Cassiopeia A. JWST first looked at the remnant in April 2023, and noticed an unusual debris structure from the destroyed star, dubbed the “Green Monster.” The combined view has helped astronomers better understand what this unusual structure is, plus it uncovered new details about the explosion that created Cas A.

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Multiple Supernova Remnants Merging in a Distant Nebula

The nebula 30 Doradus B seen in x-ray, optical, and visible light. Credit: X-ray: NASA/CXC/Penn State Univ./L. Townsley et al.; Optical: NASA/STScI/HST; Infrared: NASA/JPL/CalTech/SST; Image Processing: NASA/CXC/SAO/J. Schmidt, N. Wolk, K. Arcand

The key to astronomy is careful observation. Unlike many sciences, astronomers can’t often do their work in a lab. Sure, they can build space telescopes and large ground observatories, but even with tools as simple as sticks and stones astronomers were able to change our understanding of the Universe with patience and observation. That tradition still holds true today, as a recent study in The Astronomical Journal shows.

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Spider Pulsars are Tearing Apart Stars in the Omega Cluster

Omega Centauri is the brightest globular cluster in the night sky. It holds about 10 million stars and is the most massive globular cluster in the Milky Way. It's possible that globulars and nuclear star clusters are related in some way as a galaxy evolves. Image Credit: ESO.
Omega Centauri is the brightest globular cluster in the night sky. It holds about 10 million stars and is the most massive globular cluster in the Milky Way. It's possible that globulars and nuclear star clusters are related in some way as a galaxy evolves. Image Credit: ESO.

Pulsars are extreme objects. They’re what’s left over when a massive star collapses on itself and explodes as a supernova. This creates a neutron star. Neutron stars spin, and some of them emit radiation. When they emit radiation from their poles that we can see, we call them pulsars.

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Hubble Sees a Mysterious Flash in Between Galaxies

Artist’s concept of one of brightest explosions ever seen in space: a Luminous Fast Blue Optical Transient (LFBOT). Credit: NASA

While the night sky may appear tranquil (and incredibly beautiful), the cosmos is filled with constant stellar explosions and collisions. Among the rarest of these transient events are what is known as Luminous Fast Blue Optical (LFBOTs), which shine intensely bright in blue light and fade after a few days. These transient events are only detectable by telescopes that continually monitor the sky. Using the venerable Hubble Space Telescope, an international team of astronomers recently observed an LFBOT far between two galaxies, the last place they expected to see one.

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What Caused Eta Carinae’s 1840 “Great Eruption?”

Hubble image of Eta Carinae. Credit: NASA, ESA, N. Smith (University of Arizona), and J. Morse (BoldlyGo Institute)

In 1840 an unassuming star in the Southern Hemisphere brightened suddenly. What had been a 5th magnitude star became so bright by 1843 that it was the second brightest star in the sky. The star, known as Eta Carinae, had been known to vary in brightness before, but this change was so sudden and so dramatic that it became known as the Great Eruption.

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A Collection of New Images Reveal X-Rays Across the Universe

NASA/CXC/SAO, JPL-Caltech, MSFC, STScI, ESA/CSA, SDSS, ESO.

One of the miracles of modern astronomy is the ability to ‘see’ wavelengths of light that human eyes can’t. Last week, astronomers put that superpower to good use and released five new images showcasing the universe in every wavelength from X-ray to infrared.

Combining data from both Earth- and ground-based telescopes, the five images reveal a diverse set of astronomical phenomena, including the galactic centre, the death throes of stars, and distant galaxies traversing the cosmos.

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