Trestan

Title bar of "Polarization Diagnostics Applied to Coronal Mass Ejeections and the Background Solar Wind", a newly published paper in the journal Solar Physics

<thud>! Another PUNCH paper dropped today! Congratulations to Sarah Gibson on this omnibus theoretical treatment of polarization in solar wind structures. Given the simplicity of the Thomson scattering mechanism, it's pretty amazing how deep the rabbit hole can go. 🧪☀️⚛️🔭🛰️
bit.ly/4qT9Kvs

How to Advocate for Trans Rights in Your Community Want to push back against the bigoted attacks targeting trans and gender-nonconforming people? Here are specific ways you can help—with your time, money, and everyday actions.

Unprompted by anything specific… worth noting that WIRED’s ASME award nominated package, “How To Win a Fight,” includes a piece on how to advocate for your trans and nonbinary neighbors:

www.wired.com/story/how-to...

"60 mm/a (0.075 in/Ms)" is from the wikitext conversion template {{cvt|60|mm/yr}}. The "to units" parameter was left empty, so the template just uses the default conversion for each unit: mm to in and yr to Ms. I do not think that geologists actually use in/Ms.
en.wikipedia.org/wiki/Module:...

New development: Wikipedia has deprecated archive.ph/is/today, and will eventually remove hundreds of thousands of existing links. Massive thread here: en.wikipedia.org/wiki/Wikiped... (and FWIW I just verified the malicious code is still active on the captcha page)

Yes: Hinode and TRACE. But I do not think SSO is ideal because their orbits regularly pass thru the South Atlantic Anomaly where elevated cosmic ray flux produces noise in the image data. There are also solar imagers in GEO (GOES, SDO), Sun-Earth L1 (SOHO, Aditya-L1), and heliocentric (PSP, STEREO).

Yes. Satellites monitor solar activity 24/7. NOAA's GOES series of satellites in particular. There is also a global network of ground-based solar telescopes (GONG).

Space telescopes :)

www.swpc.noaa.gov/products/goe...

Solar cycle 25 is expected to start winding down, and solar activity is pretty low right now. There were a few large flares at the beginning of the month with the third largest flare of this cycle (~11 years) on Feb 1st iirc.

We do not have this problem in solar astronomy

The full circle disk image of the sun in hydrogen-alpha light (false color applied) depicts our local star with flame-like prominences at multiple locations around the rim -- the filament/prominence -- filaprom -- feature is at about the fout o'clock position on the disk.

Here's a full-disk view of Sun as it appeared yesterday. We were so excited capturing the filaprom that we let the full disk view go. This really shows off the extraordinary prominence activity that was going on midday, February 16! #sun #astronomy #solarobserving

Very clear solar physics bubble next to "Professional Astronomers & Astrophysicists" #heliophysics

Farewell to Active Region 4366 -- Giant sunspot complex seen in Sun's northwest. The region continues to issue flares but is showing signs of decay. Soon the sunspot will disappear over the Solar limb. Sky was clear, and winds were light, but seeing was not good. We take what we can get! #sunspots

via MollyHaleIsMyFriend

The "I am going to drink ocean water" guy is still active and uploads both.

It's good to talk about your love for Wikipedia. It's good to donate. But I firmly believe that it's even better to become an editor. Create an account. Make an edit (don't worry, you can't break things). Visit the Teahouse. Not necessarily in that order.

Here is how I have been contributing to Wikipedia in 2025! Edits: 585, Discussions: 74, Thanks: 7, Thanked: 3 #wikipediaYIR

Here is how I have been contributing to Wikipedia in 2025. Happy New Year! #wikipediaYIR

The atomic ensemble time scale at the NIST Boulder campus has failed.

The second step (deconvolution) helps further reduce blurring, but subsequent processing appears to be cosmetic. For example, the brightness of the solar disk appears to have been inverted here; brightness should decrease with distance from center disk, and the dark splotches should appear bright.

Many of the individual frames will be heavily blurred/distorted due to turbulence in the Earth's atmosphere, so the idea of the first step ("lucky imaging") is to average over the frames that appear the least blurred. This produces a more accurate and better looking image.

#heliophysics

A sunspot group over about an hour on 2022-09-03. It starts showing the photosphere on the "blue side" (shorter wavelength) of H-alpha, then shifts into H-alpha and finally goes back to the photosphere on the "red side" (longer wavelength).
#sun #sunspots #hydrogenalpha #astronomy

SOFTWARE TERMINOLOGY Then: application, program, operating system, script, shell, batch file, compiler, daemon, service, game, patch, software. Now: app, app, app, app, app, app, app, app, app, app, app, app.

They existed. This image is from 2012 at the latest

A close-crop of two sunspots viewed in hydrogen-alpha light -- an extensive field of filaments surrounds the spots.

The northeast quadrant of the Sun recorded October 3, 2025 in hydrogen-alpha light. Various features of the chromosphere are visible including several filaments, and prominences.

A few adjustments in data capture parameters was all it took to make a big difference in image processing and results! We're very pleased with Barlow-boosted views though we're still having some issues with achieving even lighting across whole-disk views...
#sunspots

Wikipedia is under attack — and how it can survive The site’s volunteers face threats from Trump, billionaires, and AI.

This long read in The Verge does a remarkable job of describing how Wikipedia's editing community works, the project's strengths and weaknesses, and the threats it faces.

www.theverge.com/cs/features/...

Testing this with SDO/AIA imagery of a series of eruptions from 2023 ☀️

What might we expect to see during @esa.int Solar Orbiter's upcoming remote-sensing windows; now with an inclined orbit. Here's the PFSS connectivity of Orbiter during the remote-sensing window of spring 2026 (17th Feb to 6th March), using the current coronal magnetic field and in-situ wind speeds.

Sunflower head soon to open

Sunflower head and a bee

Seven sunflower heads, three of which have bloomed, and one blurred bee

Not the usual Sun I study

We ran a randomized controlled trial to see how much AI coding tools speed up experienced open-source developers.

The results surprised us: Developers thought they were 20% faster with AI tools, but they were actually 19% slower when they had access to AI than when they didn't.

The Sun's Alfvén Surface | PUNCH mission The Alfvén surface – the outer boundary of the Sun's corona – is very complex. This visualization of the Sun's Alfvén surface, with regions below the surface shown using a total eclipse image from ast...

It's an exciting time as we ramp up the data reduction pipeline. Here's the first of several items about the legwork we've done as the science team prepares to execute our science! 🧪☀️

Our recent solar flare research was published! We present the first spectral observations of ‘Supra-Arcade Downflows’ (SADs) since 2003. SADs are dark finger-like downflows seen above solar flare loops, but their origins remain elusive! What do we find? 1/6