Seeing Both Sides of the Sun at the Same Time

Solar Orbiter's view of a solar outburst from AR3664 on May 21st, 2024. The views are in two different wavelengths of ultraviolet light. Courtesy: ESA & NASA/Solar Orbiter/EUI Team
Solar Orbiter's view of a solar outburst from AR3664 on May 21st, 2024. The views are in two different wavelengths of ultraviolet light. Courtesy: ESA & NASA/Solar Orbiter/EUI Team

As everybody who saw May’s spectacular auroral displays knows, the Sun is in its most active period in 11 years. The active region sunspot group that unleased the giant X-class flare rotated around the Sun, away from our direct view. But, that isn’t keeping the Solar Orbiter from spotting what’s happening with it and other active regions as they travel around on the Sun.

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Cepheid Variables are the Bedrock of the Cosmic Distance Ladder. Astronomers are Trying to Understand them Better

One of the brightest Cepheid variable stars, RS Puppis. Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)-Hubble/Europe Collaboration
One of the brightest Cepheid variable stars, RS Puppis. Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)-Hubble/Europe Collaboration

One of the most fundamental questions astronomers ask about an object is “What’s its distance?” For very faraway objects, they use classical Cepheid variable stars as “distance rulers”. Astronomers call these pulsating stars “standard candles”. Now there’s a whole team of them precisely clocking their speeds along our line of sight.

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Black Hole Bullies Shut Down Star Formation in Their Galaxies

An artist’s impression of a quasar wind (in light blue) being launched off of the accretion disk (red-orange) around a supermassive black hole. Inset at right are two spectra from the quasar SBS 1408+544, showing the leftward shift of absorbed light that revealed the acceleration of gas pushed by quasar winds. Image: NASA/CXC/M. Weiss, Catherine Grier and the SDSS collaboration
An artist’s impression of a quasar wind (in light blue) being launched off of the accretion disk (red-orange) around a supermassive black hole. Inset at right are two spectra from the quasar SBS 1408+544, showing the leftward shift of absorbed light that revealed the acceleration of gas pushed by quasar winds. Image: NASA/CXC/M. Weiss, Catherine Grier and the SDSS collaboration

A supermassive black hole in the heart of a galaxy is the ultimate 800-pound gorilla of astrophysics. Not only do the most active ones suck in material and hide it away, but their accretion disks also blast strong quasar winds out to space. Those winds push things around, and in the process, they sometimes shut down star formation.

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Astronomers See a Black Hole Wake Up from its Ancient Slumber

The galaxy SDSS1335+0728 (shown here) suddenly started shining brighter than ever before and was classified as having an active galactic nucleus, powered by a massive black hole in the galaxy’s core. This is the first time the awakening of a massive black hole has been observed in real time. This artist’s impression shows the growing disc of material being pulled in by the black hole as it feeds on the gas available in its surroundings, making the galaxy light up. Credit: ESO/M. Kornmesser
The galaxy SDSS1335+0728 (shown here) suddenly started shining brighter than ever before -- waking up and giving off strong radiation. Credit: ESO/M. Kornmesser

Four years ago, the supermassive black hole hidden in the heart of galaxy SDSS1335+0728 roared awake and announced its presence with a blast of radiation. It marks the first time astronomers witnessed a sudden activation of a supermassive black hole in real time.

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A New Way to Prove if Primordial Black Holes Contribute to Dark Matter

Depiction of a primordial black hole forming amid a sea of hot, color-charged quarks and gluons, a tiny fraction of a second after the Big Bang. Credits:Credit: Image by Ka?a Bradonji?
Depiction of a primordial black hole forming amid a sea of hot, color-charged quarks and gluons, a tiny fraction of a second after the Big Bang. Credits:Credit: Image by Ka?a Bradonji?

The early Universe was a strange place. Early in its history—in the first quintillionth of a second—the entire cosmos was nothing more than a stunningly hot plasma. And, according to researchers at the Massachusetts Institute of Technology (MIT), this soup of quarks and gluons was accompanied by the formation of weird little primordial black holes (PHBs). It’s entirely possible that these long-vanished PHBs could have been the root of dark matter.

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Echoes of Flares from the Milky Way’s Supermassive Black Hole

Michigan State University researcher Grace Sanger-Johnson found nine previously undiscovered flares from Sagittarius A*, the Milky Way’s central supermassive black hole, by sifting through a decade’s worth of X-ray data. Credit: NuSTAR/NASA
Michigan State University researcher Grace Sanger-Johnson found nine previously undiscovered flares from Sagittarius A*, the Milky Way’s central supermassive black hole, by sifting through a decade’s worth of X-ray data. Credit: NuSTAR/NASA

The supermassive black hole at the heart of our Milky Way Galaxy is a quiet monster. However, Sagittarius A* (or Sgr A* for short) is not totally dormant. Occasionally it gobbles down a blob of molecular gas or even a star and then suffers a bit of indigestion. That emits x-ray flares to surrounding space.

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A Recent Solar Storm Even Had an Impact on Mars

During the May 20 solar storm, so much energy from the storm struck the surface that black-and-white images from Curiosity’s navigation cameras danced with “snow” — white streaks and specks caused by charged particles hitting the cameras. Courtesy: NASA/JPL-Caltech
During the May 20 solar storm, so much energy from the storm struck the surface that black-and-white images from Curiosity’s navigation cameras danced with “snow” — white streaks and specks caused by charged particles hitting the cameras. Courtesy: NASA/JPL-Caltech

Planet Earth is in for some amazing geomagnetic storms in the next year or so. That’s because it’s in a period of peak activity called “solar maximum” (solar max, for short). But, what happens at other planets, especially Mars, during this time? Mars mission scientists got a sneak peek at the effect of a major solar storm thanks to one hitting the Red Planet on May 20th, 2024.

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Globular Clusters Should Contain More Intermediate-mass Black Holes

The M15 Globular Cluster (aka. Great Hercules Cluster). Astronomers suspect the existence of one or more intermediate-mass black holes at its heart. Credit: NASA/ESA/HST
The M15 Globular Cluster (aka. Great Hercules Cluster). Astronomers suspect the existence of one or more intermediate-mass black holes at its heart. Credit: NASA/ESA/HST

We live in a Universe studded with black holes. Countless stellar mass and supermassive ones exist in our galaxy and most others. It’s likely they existed as so-called “primordial” black holes in the earliest epochs of cosmic history. Yet, there seems to be a missing link category: intermediate-mass black holes (IMBH). Astronomers have searched for these rare beasts for years and there’s only one possible observation thanks to gravitational-wave data. So, where are they?

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Two Seismometers are Going to the Moon to Measure Moonquakes

The Moon is shrinking and causing moonquakes. New seismometers will go there to measure them.
The Moon is shrinking and causing moonquakes. New seismometers will go to Shrodinger Basin to measure them.

Our Moon is shrinking and has been doing so since just after its formation ~4.5 billion years ago from a collision with the young Earth. That shrinkage, along with a constant rain of micrometeorites, causes lunar seismic activity. NASA plans to send two instruments to the Moon to measure its moonquakes. Those dual seismometers share technology first used on Mars by the InSight lander to measure more than a thousand marsquakes.

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