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.
Continue reading “Seeing Both Sides of the Sun at the Same Time”Cepheid Variables are the Bedrock of the Cosmic Distance Ladder. Astronomers are Trying to Understand them Better
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.
Continue reading “Cepheid Variables are the Bedrock of the Cosmic Distance Ladder. Astronomers are Trying to Understand them Better”Black Hole Bullies Shut Down Star Formation in Their Galaxies
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.
Continue reading “Black Hole Bullies Shut Down Star Formation in Their Galaxies”Astronomers See a Black Hole Wake Up from its Ancient Slumber
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.
Continue reading “Astronomers See a Black Hole Wake Up from its Ancient Slumber”A New Way to Prove if Primordial Black Holes Contribute to Dark Matter
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.
Continue reading “A New Way to Prove if Primordial Black Holes Contribute to Dark Matter”Echoes of Flares from the Milky Way’s Supermassive Black Hole
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.
Continue reading “Echoes of Flares from the Milky Way’s Supermassive Black Hole”A Recent Solar Storm Even Had an Impact on Mars
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.
Continue reading “A Recent Solar Storm Even Had an Impact on Mars”A New Way to Search for the First Stars in the Universe
Observing the earliest stars is one of the holy Grails of astronomy. Now, a team at the University of Hong Kong led by astronomer Jane Lixin Dai is proposing a new method for detecting them. If it works, the approach promises to open a window on the origin of the cosmos itself.
Continue reading “A New Way to Search for the First Stars in the Universe”Globular Clusters Should Contain More Intermediate-mass Black Holes
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?
Continue reading “Globular Clusters Should Contain More Intermediate-mass Black Holes”Two Seismometers are Going to the Moon to Measure Moonquakes
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.
Continue reading “Two Seismometers are Going to the Moon to Measure Moonquakes”