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Reposted by Stefan Payne-Wardenaar

ESA Space Science @science.esa.int · 9d

Stars in our galaxy make a stadium wave, Gaia finds 🙌

Our Milky Way galaxy never sits still: it rotates and wobbles 🌀

But #ESAGaia has just revealed that our galaxy also has a giant wave rippling outwards from its centre 👉 www.esa.int/Science_Expl... 🔭 🧪 ☄️

This image consists of two sides. Left side: A top-down view of a spiral galaxy is shown. It has a bright central bulge with several spiral arms radiating outward. Overlaid on the lower part of the galaxy is a data visualisation, with colours ranging from blue to red. A label reading ‘Sun’ marks a specific location within this overlay. Right side: An edge-on view of the same spiral galaxy is presented. It reveals the galaxy's thin disc and central bulge from the side. Coloured points are scattered along the disc, representing the same data as the overlay on the left side.

The image features a dark background with a thin, bright horizontal line running across the centre. This is our galaxy’s disc. Above and below this line, numerous white arrows point upward and downward. These arrows vary in length and are spread evenly along the line. Scattered among the arrows are small red and blue dots. The visual resembles an astronomical data visualisation, illustrating positions and motions of stars in our galaxy.

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Stefan Payne-Wardenaar @stefanpw.bsky.social · 14d

An update of this classic diagram, using a top-down view with the updated Hα from McCallum et. al. 2025, and a new side-view from a different angle than previous ones to show the Sun's location. From this angle the disk is warping "down" towards the camera!

www.esa.int/ESA_Multimed...

An artist’s impression of our Milky Way galaxy, a roughly 13 billon-year-old ‘barred spiral galaxy’ that is home to a few hundred billion stars.

On the left, a face-on view shows the spiral structure of the Galactic Disc, where the majority of stars are located, interspersed with a diffuse mixture of gas and cosmic dust. The disc measures about 100 000 light-years across, and the Sun sits about half way between its centre and periphery.

On the right, an edge-on view reveals the flattened and warped shape of the disc. In this orientation, the disc warps 'down' towards our point-of-view: the dust lanes in the foreground are coming down from the galactic plane.

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Stefan Payne-Wardenaar @stefanpw.bsky.social · 19d

Jumping into the grit of Owl House finales/climaxes but right away :)

Frankie! <3

Aww that's cute, she's missing some teeth, must have gotten into some scrapes!
(Later) ... Oh ...

Reposted by Stefan Payne-Wardenaar

ESA Space Science @science.esa.int · 24d

🐦 Fly through a 3D map of stellar nurseries ✨

Scientists have created the most accurate 3D map of star-formation regions in our Milky Way galaxy, based on data from #ESAGaia.

The map extends to a distance of 4000 light-years from us, with the Sun at the centre 👉 www.esa.int/Science_Expl... 🔭 🧪

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Reposted by Stefan Payne-Wardenaar

Space Telescope Science Institute @stsci.edu · Sep 2

Watch as the familiar pattern of the Scorpius constellation distorts into a whole new perspective.

The opening of the sequence pans up to Scorpius in the night sky. The brightest star in the constellation, Antares, is a red supergiant known as the "heart of the Scorpion." 🔭 🧪

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Stefan Payne-Wardenaar @stefanpw.bsky.social · Aug 12

You made me rethink assumptions about my own OCs...

Enhancing my tomboy's early frustration, maybe they were not fast friends, but after learning more and standing up for each other they became friends. That's probably more narratively satisfying and engaging, highlighting her struggles and flaws.

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Stefan Payne-Wardenaar @stefanpw.bsky.social · Aug 12

What kinda changes? O3o

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Stefan Payne-Wardenaar @stefanpw.bsky.social · Aug 10

Technically incorrect: while 46.5 bly is the current radius of the observable universe, unless expansion slows light will be too slow to ever reach objects at that proper distance.

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Stefan Payne-Wardenaar @stefanpw.bsky.social · Jul 22

Thanks for the correction: I misremembered the timeframe of PMS stars.

Which reminds me of an anecdote from a geo prof: Many people once thought the Sun shone from gravitational collapse alone, until radiometric dating showed the earth was much older than the ~20my that would last!

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Stefan Payne-Wardenaar @stefanpw.bsky.social · Jul 21

Need to update my Betelgeuse model...
noirlab.edu/public/news/...

Gemini North Discovers Long-Predicted Stellar Companion of Betelgeuse - Gemini North telescope in Hawai‘i reveals never-before-seen companion to Betelgeuse, solving millennia-old mystery

Astronomers have discovered a companion star in an incredibly tight orbit around Betelgeuse using the NASA and U.S. National Science Foundation-funded ‘Alopeke instrument on Gemini North, one half of ...

noirlab.edu

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Stefan Payne-Wardenaar @stefanpw.bsky.social · Jul 21

That two independent teams predicted it last year has my hopes up.

That it's supposedly a way younger pre-MS star is crazy (if true).

Urge to animate it... But I've got plenty of other work to get through first ;p

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Stefan Payne-Wardenaar @stefanpw.bsky.social · Jul 17

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Stefan Payne-Wardenaar @stefanpw.bsky.social · Jul 17

Iggy is down by the student camp / basement entrance.

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Stefan Payne-Wardenaar @stefanpw.bsky.social · Jun 15

<3. Carcharo? Giga?

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Stefan Payne-Wardenaar @stefanpw.bsky.social · May 31

Nice looking Milky Way at 1:55, atleast ;)

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Stefan Payne-Wardenaar @stefanpw.bsky.social · May 27

That closeup shot with the egg is by far my favorite shot from ep 1

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Stefan Payne-Wardenaar @stefanpw.bsky.social · May 23

Here's the paper. arxiv.org/abs/2309.07209
Tilted ~30 degrees they suggest, and probably not quite that thin (but still 'triaxial': different x, y, z lengths).
Hmm, I might be underestimating the flare in my model...

A Tilted Dark Halo Origin of the Galactic Disk Warp and Flare

The outer disk of the Milky Way Galaxy is warped and flared. Several mechanisms have been proposed to explain these phenomena, but none have quantitatively reproduced both features. Recent work has de...

arxiv.org

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Stefan Payne-Wardenaar @stefanpw.bsky.social · May 23

Our supermassive black hole (Sag A*) is 4.3 million solar masses... but the Milky Way is about 1.5 trillion.
Several thousand stars directly orbit the central black hole, but unlike in the solar system, things orbit the center of mass of the whole galaxy (icl dark matter whch dominates further out)

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Stefan Payne-Wardenaar @stefanpw.bsky.social · May 23

All spiral galaxies are rather flat like this, the up and down motion of gas tends to cancel out, making the thin disk of newer stars pretty thin. We can measure this directly now with GAIA, along with just the visual clue Galileo figured out that the Milky Way appears as a band.

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Stefan Payne-Wardenaar @stefanpw.bsky.social · May 23

It uses data on real stars and dust near the sun, then transitions to procedural details further out, informed by H.

It's made in Blender, using a number of base-textures constructed from data and Hubble images,then used to inform procedural volumetrics and star particles!
(it's stupid complicated)

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Stefan Payne-Wardenaar @stefanpw.bsky.social · May 23

This is my rendering. It incorporates some new data where possible (on the structure of dust near the sun, a new angle of the bar, etc), but is a best-guess for areas further out.

Stefan Payne-Wardenaar @stefanpw.bsky.social · May 23

The two main proposals to explain the warp are that it's caused by a colliding dwarf galaxy (probably Sag dSph, seen faintly bottom left of center), or from a non-spherical dark matter halo.

The Galaxy Song

YouTube video by StefanPW

youtu.be

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Stefan Payne-Wardenaar @stefanpw.bsky.social · May 23

I made a version of that song with my old galaxy model and some updated lyrics.
Need to make an updated one with my new model... and better singing / music ;p

youtu.be/hFGXmO5GqeQ?...

The Galaxy Song

YouTube video by StefanPW

youtu.be

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Stefan Payne-Wardenaar @stefanpw.bsky.social · May 23

We are close to the axis of warpage, and close enough to the center that the warpage mostly doesn't affect us :)

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Stefan Payne-Wardenaar @stefanpw.bsky.social · May 23

The two main proposals are that it's caused by a colliding dwarf galaxy (probably Sag dSph, seen faintly bottom left of center), or from a non-spherical dark matter halo.