A high-resolution, ultraviolet composite

Do yourself a favour and take a moment to just sit and look at this:

As I’m sure you’ve figured out already, that’s the Sun. This image is a composite of a couple of hundred ultraviolet photos taken over a few hours on 9 March by the European Space Agency and NASA’s Solar Orbiter. The dark areas are filaments – large loops, thousands of miles long, of (relatively) cool plasma extending out from the photosphere. The bright areas are coronal loops, driven by powerful magnetic fields.

We’re currently about half way through solar cycle 25 (which began at the end of 2019) and the Sun’s activity should be more or less at its peak now. That’s easy to believe when you look at it – there’s an incredible amount going on on the Sun’s surface in this image. All this activity is what drives space weather events, which can disrupt satellites and which also creates aurorae.

There have been several noteworthy aurorae recently, occurring much further south than usual. Those of us who have been lucky enough to see those have the solar maximum to thank. Understanding space weather is one of the areas where astronomy can actually directly benefit people’s lives, and missions like Solar Orbiter are important for keeping an eye on the Sun’s activity so that we can understand what drives the solar cycle.

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Solar System

• NASA has released new photos of the asteroid Donaldjohanson taken by Lucy on its recent flyby. [Popular Science, Universe Today, Space.com]

• The PUNCH mission – four satellites working together to study the solar wind – has taken its first images. Eventually the mission will produce images of the solar wind without interference from background stars and the zodiacal light. [Space.com, Universe Today]

• A more precise measurement of the rotation of Uranus (thanks to Hubble) shows that its day is 28 seconds longer than thought (17h 14m 52s). That’s actually within the margin of error for the previous length — the new mesurement is just a lot more precise. [New Scientist]

• Satellite data from the European Space Agency shows the surface temperature of the oceans is warming 4.5 times faster than they were at the end of the ‘80s. It’s not easy to predict climate change, and the reality keeps turning out worse than we thought it would be. [ESA]

Galaxy

• An exoplanet has been found in a polar orbit around binary brown dwarfs. That’s unusual for two reasons: planets normally orbit more or less in line with the star’s equator, and brown dwarfs don’t often have binary companions. [Space.com, EarthSky, Universe Today]

• Call it Icarus: a planet is orbiting so close to its star that it’s falling apart like a comet, losing an Everest-sized load of rock during each 30 hour orbit. [Space.com, MIT, EarthSky]

• The first known isolated black hole, discovered in 2022, has been confirmed to have a mass around seven times greater than the Sun. This is thanks to ongoing observations from Hubble and Gaia, measuring how the black hole’s gravity is deflecting the light from background stars. [ScienceNews]

Universe

• Ionised neon gas in M83 indicates the presence of an active galactic nucleus – a supermassive black hole which is feeding on infalling material. [ESA, Space.com]

• ESA’s XMM-Newton has observed extreme quasi-periodic eruptions from a supermassive black hole. These are normally caused by the black hole tearing apart a star, but in this case that doesn’t seem to be what’s happening, suggesting there are more ways for QPEs to be triggered. [Sky & Telescope, Universe Today]

• Something is weird about Andromeda! It has almost all its satellite galaxies on the side closest to the Milky Way and no-one knows why. [Space.com]

• Gravitational lensing has found the missing merger companion of the Perseus cluster, connected by a “bridge” of dark matter to the main cluster. It’s been suspected that the cluster has undergone a merger, but this is the first proof. [Space.com]

Finally

The latest XKCD highlights how the Trump administration is attacking both university research and immigrants:

What is Three Alpha? Other than being the name of the newsletter you’re reading now, the name “three alpha” comes from the triple-alpha process, a nuclear chain reaction in stars which turns helium into carbon. Read more here.

Who writes this? My name is Dr. Adam McMaster. I’m an astronomer in the UK, where I mainly work on finding black holes. You can find me on BlueSky, @adammc.space.

Let me know what you think! You can send comments and feedback by hitting reply or by emailing [email protected].