Notices by CosmicRami (cosmicrami@aus.social)

Happy B’day today to one of the greatest science communicators of our time!

Sir David Attenborough!

100 today!

He has inspired millions along the way with his excellent work — nearly every person you know has watched him and learned something new about our world at some point.

📸 People mag

First PoC and first woman to go around another world.

Don't stop talking about this point.

It's important.

📸 NASA

#ArtemisII #Astrodon #SpaceExploration #NASA #astronauts

I built a more accurate Galactic GPS for aliens to find us!

In the 1970s, the Pioneer and Voyager spacecraft were launched into deep space - each carrying a message from Earth in the form of plaques and golden records. These included a now-famous diagram: the pulsar map, originally proposed by Carl Sagan, Linda Salzman Sagan, and Frank Drake.

It uses the positions and spin periods of 14 pulsars to show where we are in the galaxy, effectively a cosmic return address.

But there’s a catch: the original map used canonical pulsars, which we now know can glitch and show timing instabilities. Back then, millisecond pulsars hadn’t yet been discovered (they came in the early '80s), so they weren’t included.

As someone studying millisecond pulsars and their long-term timing stability for my PhD, I decided to write some code to rebuild this iconic map - with a little upgrade.

Enter: the Millisecond Pulsar Map.

This version features:

- A top-down view of the Galaxy, with a central measuring bar showing our distance (8 kiloparsecs) from the Galactic Centre.
- Radial lines showing the distance to each millisecond pulsar. These can be measured against the central measuring bar to work out this distance
- Binary encodings for each pulsar's spin period and spin-down rate. These parameters will remain much more stable over the long term.
- A decoding scale to interpret the binary inscriptions.

With 40+ years of high-precision timing data, millisecond pulsars are far more stable than their slower cousins - making them ideal for building a map that could stand the test of cosmic time.

This also highlights how millisecond pulsars could be used as an intergalactic GPS network (because these stable pulsars are like cosmic clocks distributed across the sky). This might be an application for future spacecraft to navigate around the Solar System. Have a read of this article for how we are already building this technology now: https://www.spaceaustralia.com/feature/breaking-free-shackles-terrestrial-time

So, if some distant civilisation stumbles upon this new pulsar map ... well, they’ll know exactly where to find us.

The question is: do we really want to leave our full galactic home address out there?!

#Pulsars #RadioAstronomy #Astrophysics #GPS #Astrodon

Aurora Australis from Royal National Park! This is AMAZING.

The big solar storm that is passing us this week, triggered nu a coronal mass ejection from the Sun has produced a class G4 / G5 geomagnetic storm.

Our magnetosphere deflects most of the particles from Sun away, but near the poles, some spiral down and excite our atmosphere - producing aurora.

This storm was powerful enough to generate aurora sightings as far north as Coonabarabran and the Siding Spring Observatory. That's around 340 km NW of Sydney (closer to the equator, at 31 degrees south!)

While city lights drowned out the view for many, those under darker skies were treated to an extraordinary show. This stunning timelapse footage, captured by my friend Filippo Rivetti from Royal National Park south of Sydney, offers a glimpse of the awe-inspiring beauty and planetary-scale force of this event.

A reminder of the vast, dynamic forces at play: a star lashing out across space, and a planet, our home planet with its protective magnetic shield - hosting the only life we know of so far in the Universe, safely within.

https://www.youtube.com/watch?v=cXP49hxf9ck

#AuroraAustralis #SolarStorm #SpaceWeather #Astrophysics #CMEs #Magnetosphere #Astrodon

I was happy to help Filippo out and annotate the beautiful still of his image (non-annotated version sent to @apod as I really think it is worthy).

You could do so much science communication from this one image:

- galaxies (plural!)
- aurora
- stellar evolution
- nearest system

This is such a beautiful image!

Stunning work from Filippo Rivetti!

#Astrodon

Incredible new #JWST deep field (120 hours!) released by folks from ESA/NASA Webb teams.

Not only is nearly everything in this image a galaxy (the two spiky stars are not), but those curved arcs are images of galaxies beyond this cluster, which are projected and warped into our view thanks to the power of gravity!

It's called a gravitational lens. To visualise what's happening, take a look at this diagram.

There are distant galaxies that we can't normally see. There's also a galaxies between them and us, with lots of mass.

This mass warps space-time and bends the distant galaxy light towards us so we see them.

I am amazed. You should be amazed. This is a really epic image.

Galaxy image and alt-text credit: ESA/Webb, NASA & CSA, H. Atek, M. Zamani (ESA/Webb)

Diagram credit: NASA, ESA & L. Calçada

#Galaxies #GravitationalLensing #GalaxyCluster #Astrodon

Really epic image featured on @apod today!

Captured by AJ Smadi from Washington (state), in daytime skies (11:57am) on April 5th — the image shows ISS and the crescent of Venus.

The planning this would have taken to get right — very nice work!👏🏽👏🏽👏🏽

(I annotated the rough distances)

#SpaceStation #Venus #ISS #astrodon

A while back (around seven months ago) I posted an image of ISS (first image), but captured FROM ABOVE (higher orbit). This is the work of Aussie company HEO!

This type of work is really fascinating as things (like satellites) are all moving at high velocities up there (28,000 km/h) - so other things (like other satellites or space stations) zip past quickly. You would then need to 'de-zip' the object to make a crisp clear image.

Well, they've done it again.

This time, imaging the Chinese Space Station (second image) from a distance of 83 kilometres (resolution of 0.17 m/px) 🤯

This is really cool stuff. I promise.

📸 BlackSky / HEO

#Space #EarthObservation #SpaceStation #Astrodon

Just saw this post on US Senator Cory Booker's Instagram account and honestly .... I reckon a big portion of the world is thinking the same thing right now.

C'mon America - please do the right thing!

Whoa! 🚀💥

Starship's explosion put a 1-hour hole in the ionosphere.

GPS data (multi-frequency) tells us about the total electron content (TEC) in the ionosphere (varies naturally). But the shock wave from this explosion caused a temporal depletion of TEC, as measured from 2500 ground stations.

https://www.nature.com/articles/d41586-024-02841-4

This adds to the growing need for a better understanding of rockets' impacts in the high atmosphere. We don't have the modelling yet, and more and more rockets are going up each year.

Read the paper findings here: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2024GL109284

#Rockets #SpaceX #Starship #Astrodon #Ionosphere

I come from a business / digital background, so digital accessibility has always been big on my radar. When I started in science a few years back, I was very surprised to see that arXiv - a service that allows scientists to put their pre-prints (papers before peer review) was not accessible.

This meant that all science papers that were open access (away from journal subscriptions) were only available as PDFs - which means people with digital accessibility needs could not access them.

Access to science should be open to everyone (the pandemic showed us how important this is), and whilst there is a need for papers to undergo the formal peer-review process, that does not mean we can't adhere to global digital accessibility standards.

So, I am extremely glad to see that arXiv is now moving toward digital accessibility, with its second accessibility forum in Sept. 2024. They've also been moving to make papers in HTML format (instead of PDFs only) which adheres to these standards.

If you are interested in accessibility and science, you might consider attending this forum. It's free to all and only requires remote participation.

https://accessibility2024.arxiv.org/index.html

#science #accessibility #digital #astrodon #arxiv

Wooooaaahhhh!

The new JWST image of a small bit of the Horsehead Nebula is INCREDIBLE.

To give you a sense of scale here, here’s an image of the nebula from my backyard. That small white box … that’s the JWST field of view! 🤯🤯🤯

Look at ALL those galaxies, all in that tiny white box.

JWST image credit: ESA/Webb, NASA, CSA, K. Misselt and A. Abergel. [updated]

Dodgy image with white boxes is my own.

#JWST #SpaceTelescope #HorseheadNebula #Astronomy #Galaxies #Astrodon

OTD in 2020, Jupiter & Saturn came into conjunction (closest since 1643). MeerKAT (radio interferometer in South Africa) also turned its gaze towards the planets to observe their radio emissions.

They serendipitously discovered a pulsar in the background!

Here in the first inset, you can see Jupiter (which is a bright radio source in our sky), as well as Saturn (annotated 'S' - note that it is not as bright a radio source as Jupiter) and the pulsar (annoyed 'P' which stands for pulsar with anomalous refraction recurring on odd timescales - PARROT).

Also (last two insets), can we all appreciate how incredible Jupiter looks in radio with MeerKAT 𝐵-field vectors overplotted? Radiation belts FTW!

Oh, and those other sources - they aren't stars ... they are all supermassive black holes in distant galaxies in the background! (look at those jets!)

📸 https://arxiv.org/abs/2312.12165

#Planets #SolarSystem #RadioAstronomy #Astrodon

The fastest spinning object ever measured is a millisecond pulsar, rotating at ~24% the speed of light.

A new study says that with SKA, we should find a handful more of these that could be spinning slightly faster. But there are unlikely any sub-millisecond pulsars.

There are numerous reasons / theories as to why there is an upper limit for pulsars spinning at higher frequencies, for example, the breakup velocity (they are very well held together!) and the spin-down induced by gravitational radiation.

This science tells us about matter under these extreme conditions!

https://arxiv.org/abs/2312.12185

#Pulsars #RadioAstronomy #Astrophysics #NuclearPhysics #Astrodon

Moaaar photos I took during our radio school trip to the Australian Telescope Compact Array (ATCA) last week.

📡📡📡📡📡

How many kangaroos can you spot? 🦘

(note - last image is a night shot!)

#Astrodon #RadioAstronomy #Telescopes #Australia #Narrabri

Just arrived in Narrabri to visit the Compact Array this week!

Big sky land, and dark skies … I can’t way to see the Milky Way again, away from the city lights!

Then doing some radio astronomy learning with these magnificent giants ….

#Astrodon #RadioAstronomy

The atmosphere is a (wonderful) fluid.

Also …. Home.

Wowowow @markmccaughrean !!!

EXPLOSION FINGERS?!?!?!?

JWST’s new images from Orion Nebula are spectacular! Look at this structure 🥹🤩😱

📸 JWST / ESA / NASA / CSA / M. McCaughrean / S. Pearson

#JWST #Astrodon #OrionNebula #Astronomy

Friends, tomorrow is Wear It Purple day - an annual day we wear purple to acknowledge, support & celebrate young LGBTIQA+ people.

It won't change the world, but it does send a signal to young LGBTIQA+ folks that we see them!

Wear something purple + share your pics across your socials to spread support. Would love to see you in it, so tag me if you do this!

Pass it on!

🏳️🌈🏳️⚧️

Yesterday I gave my first PhD talk at the Astronomical Society of Australia’s Annual Science Meeting on my fav millisecond pulsar - PSR J1713+0747.

The pulsar that threw a tantrum!

Millisecond pulsars are used in pulsar timing arrays as they’re considered stable rotators over the long term. That is vote to helping us search for gravitational wave backgrounds - the big news that we announced last week.

But this very well know millisecond pulsar decided to undergo a massive magnetospheric reconfiguration in 2021 - only the second millisecond pulsar that we know off to exhibit this strange behavior!

In my PhD I will be exploring to see why this happened and if other millisecond pulsars might be doing this on a smaller scale. Maybe they’re not so stable after all … ask me again in three years!

#Astrodon #RadioAstronomy #Astrophysics #Pulsars #PulsarTiming #GravitationalWaves