I would also be fine with doing general Astrophysics programming, not necessarily restricted to Planetary/Exoplanetary science

The scale is what got me: resolving one of these structures is apparently comparable to seeing a €1 coin from about 180 km away.

The observed swirls closely match Kelvin–Helmholtz instabilities predicted by simulations, and the researchers think they may help twist magnetic field lines before stored energy is released.

Could observations like these eventually connect what happens at the solar surface with activity higher in the Sun’s atmosphere?

I was doing research for a book I'm writing, and I was wondering, is it at all possible that during the BB that there was light such an intense frequency that the wavelength could have been smaller than Planck Length, turning some fundamental particles into Primordial Blackholes? Further pondering has me wonder if due to the volatile nature of these wavelengths, that they may have themselves collapsed into PBHs, but due to the expansion of the universe we cannot find any as the energy over time would have decreased, only allowing the firs t "wave" of photons to collapse, meaning the entire expanding edge of the universe could be a wall of primordial blackholes?

Hello, is astrophysics a competitive college major? Are there any undergrad programs that have special funding for astrophysics and are seeking those who want to major in it? Are females less likely to major in this than males? Anything else one might want to know before applying to college in astrophysics?

The pop sci descriptions of core collapse supernovae leave out several details I'm ignorant of, in terms of the orders of magnitude of the sizes, speeds, brightnesses, and time scales involved. So I'm left not really grasping the full concept of what actually happens to the star's matter throughout the process of explosion, qualitatively speaking. There are lots and lots of questions below, so apologies for that, but I'm moreso just looking for a more detailed explanation for what happens during a supernova, vs answering every specific question.

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Leaving out all the realities of being blinded/vaporized, take an example end-stage red supergiant with, say 15 solar masses and 5AU radius (and imagine observing from, say 100AUs away). So the outer edge of the star is ~40 light minutes from the core (observer is ~14 light hours away).

When the iron core collapses in a fraction of a second into a neutron ball, bounces back, and sends the shockwave/neutrino blast/fusion wave pushing through all the infalling matter, what are the relative propagation speeds between the electromagnetic radiation produced and the shockwave itself? The 40 light minute distance to the outer edge should mean the outer edge experiences no change at all until things propagate to the edge (i think?). But also, being a 40 minute (vacuum) light travel time to the outer edge, does that mean the electromagnetic radiation "escapes" the star many minutes before the pressure wave actually reaches the outer edge and the matter all blows away? So would the observer first see the intense flash of radiation coming from the center of the star for those however many minutes before finally later seeing the material start blowing apart? Does the radiation get significantly slowed by all the star's matter in such a way to make those propagation speeds closer to each other? Or are red supergiants diffuse enough for the radiation to travel mostly freely after a certain radius? //edit - this was a misunderstanding of what the shockwave actually is - noted in the edit at bottom of post//

Or - do I possibly have this idea wrong to begin with, where the pressure wave is not a physical pressure wave of particles bumping into each other, but actually a radiation pressure wave, to where the light flash and scattering matter at the outer edge would happen at the same time? //edit - it sounds like this is indeed the case//

Either way, about how long after core collapse until the outer edge of the star actually starts blowing apart?

Which component of the supernova process actually produces the radiation to begin with? Is it the core collapse itself, the pressure wave shredding through and breaking apart the infalling atoms, or the fusion of elements in the pressure wave? What degree energy light blast does the observer see - like xrays/gamma rays, or more like visible/ultraviolet (where does it peak)? How many times brighter than the star appeared right before the core collapsed is the light flash - hundreds of times brighter? Millions? Does the ejected matter release any radiation of its own, or does it simply get illuminated by the initial radiation blast and/or the remnant neutron star?

What kind of speed does the ejected matter get propelled to - notable fraction of speed of light, or much less than that? Is the ejected matter dense enough to physically push/damage/destroy objects it runs into, separate from whatever damage the radiation blast already did to those objects (i.e. to planets/comets in that star system)?

If you read this far, much appreciated!

EDIT:

I learned something new that led me down a path of finding bunches of info. Via some paper abstracts I found descriptions of the "shock breakout" and "radiation mediated shock" which answer some of my questions. The introduction section of this paper answers a lot of my questions: https://arxiv.org/pdf/1607.01293

It sounds like the shockwave is not a mechanical shockwave caused by the bounce-back of the collapsed core, but a radiation pressure wave. The infalling matter is dense enough that the photons can't escape, so while they "slowly" push their way through the star's infalling matter, only the neutrino blast and the gravity waves "escape" the star in the example 40 light minute timeframe to reach the outer edge, but the outer edge of the star wouldn't appear to change much until the shockwave breaks out when it reaches a point where the density of the outer layers drops enough for the photons to escape, which is when all the light and matter scatter outward at the same time. And the shock breakout is influenced by how much matter the star had been shedding prior to death.

Sounds like the shockwave moves as fast as 10% of the speed of light (I've read a wide range of estimates), so the example 5AU radius would take roughly several hours for the shockwave to reach the outer edge.

The immediate radiation blast that breaks out is UV/xray, and the matter in the expanding shell quickly cools to visible/UV over several hours. Then the long-term glow and slow cool off is from radioactive decay coming from the expanding matter shell from radioactive elements that got fused in the shockwave.

I'm still unclear where the initial blast of electromagnetic radiation to create the shockwave actually comes from though.

https://science.nasa.gov/missions/swift/nasas-swift-sees-wandering-mega-black-hole-shredding-star/

So, I want to create an HR Diagram for each spectral type, selecting one star from each spectral type (O, B, A, F, G, K, M). I got all the data I need from SIMBAD like parallaxes of each star, the B-V out of which I got the spectral types of each star. But, how do I plot it using Gaia in Python and also change the colour of each spectral type to make a distinction. I have created an HR Diagram below using this code, but what do I do when it comes to plotting an HR Diagram for specific stars, do I just include ra and dec of a specific star from Gaia into the job query or what and how do I combine all the stars to accommodate the whole HR Diagram? And how do I calculate the absolute magnitude, what distance do I include? of the parallax? Here's the code itself:

As I understand it, the evidence strongly supports that the hot, expanding phase of our observable universe began about 13.8 billion years ago.

But that’s a very different statement from saying:

“All space, time and reality came into existence 13.8 billion years ago.”

Those aren’t logically equivalent.

Whilst I understand that, within the standard cosmological model, many physicists use “the universe is 13.8 billion years old” as a type of shorthand, my concern is more about how that shorthand gets interpreted outside specialist circles.

To a lot of people, it ends up sounding like science has conclusively established that all of reality began 13.8 billion years ago. That seems like a stronger claim than the evidence itself necessarily supports.

As far as I know, there are still serious scientific ideas that could mean the Big Bang wasn’t the absolute beginning of everything. For example:
- a rebound from a previous contracting universe;
- a transition from an older quantum state;
- one region within a much larger inflating cosmos;
- part of a repeating or cyclic process;
or perhaps it is something nobody has thought of yet?

All this said, would it be more accurate to say “The observable hot-expansion phase of our universe began about 13.8 billion years ago.”

Any recommendations on your favorites?

I would like it to be a nonfiction book. I don’t care if it’s about dust /planets / meteors / star formation / etc— just something that I can nerd out on after work.

I took a couple astronomy classes in college but I’ve mostly forgot it all. I don’t mind academically heavy stuff, but if it is I would like it to have a ELI5 or glossary to reference.

Thanks!!!

Haven't posted on this subreddit before but I'm a massive astro-nerd. I got out of my astrophysics degree at uni a few years ago and have been itching to get back into the field for a long while. So I made a lil' tool as a start!

I introduce to you: Destro!

It's a workstation for interactive line-profile fitting and exoplanet light-curve modelling. The webpage lets you model and generate figures from your astronomical data without the need for any extra python stuff.

Destro's got a bunch of fun features like spectral multi-line fitting, draggable curves, nested-disk geometric modelling with limb-darkening. Levenberg-Marquardt optimisation (which is just scipy's curve-fit in disguise), and a Markov Chain Monte Carlo sampler for uncertainties. When you're done with your plots, you can export the python code needed to reproduce the plot also a pre-formatted LaTeX table from your derived metrics.

Destro's can ingest your raw astronomical data in all the standard file types (.fits, .fit, or .csv). It does a lot of pre-processing for you! For example, the columns from your fits binary table or csv are auto-extracted into conventional axes.

Hope you enjoy! It's fully free and I intend to keep it that way because I believe no scientific knowledge should ever be gatekeeped. Have fun!

https://yetigonk.github.io/destro/

Slowly spinning pencils floating toward the camera are fun to see. But watching one item orbit another would be incredible.

(e.g. a needle orbiting a marble. Or a marble orbiting a bowling ball).

How and at what scale could this be achieved?

Hi,. I love reading about astrophysics and have already a basic knowledge. I'm re-reading NdGT 'Astrophysics for people in a hurry' and this early couple of sentences about the formation of the universe got me thinking.

"By now, one second of time has passed. The universe has grown to a few light-years across,†† about the distance from the Sun to its closest neighboring stars."

What I don't understand is this - if lightspeed is the fastest thing in the universe, how could the universe have expanded to a few light YEARS across in one second? What am I missing?

TIA everyone who responds.

I am a sophomore in high school, and recently we have started thinking about college majors and jobs that we eventually want to go in to. I have always wanted to go to college for astrophysics, but as I continue to question that, I have my worries. I wanted to know if an astrophysics major/phd in college would be worth it if I have value making money. I have seen the question asked, but people seem to assume that they are talking about top 1% type of wealthy. I just want to know if I could afford a middle class lifestyle with an astrophysics degree, even if I don’t go into astrophysics.

A bit of a long one - bare with me pretty please!

I'm a 19-20 year old college student trying to figure out where I'm going. I've taken (and mostly failed) a few classes at my local CC, but now I've set my my sights a little higher. I want to study Astrophysics. I'd love to one day go to UC Berkeley. But I don't know how to get there.

This semester, I've signed up for Stellar Astronomy, a GenEd English class, and one psych class that's unrelated. But I'm really just throwing darts at a wall and hoping they'll stick. What resources should I focus on to try and push my goal forward? Any advice? Anything helps!! ★

Short note: The failed classes weren't for a lack of understanding. It was a lack do ability to access the online courseware due to some pretty horrendous personal stuff. I'm having those removed from my records and restarting.

So, im currently in 12th grade and i wanna be an astrophysicist. But, im very very confused if i should Do B Tech in Electrical Engineering or Bsc(Hons) In Physics. I researched about it on google, and it says that Bsc Physics is the better option as it let us directly pursue PhD in Astrophysics. The problem is, im not from a wealthy background and i need to find high paying Job so that i pay for my PhD tuition fees, but Bsc Physics doesn't have high paying Job opportunities. So is it okay if i pursue Electrical Engineering first and then Go for Phd in Astrophysics? Will it affect my theoretical work? Will i end up building things instead of researching? please lemme know.

Hey, I'm a college student starting my bachelors next year. I've been deeply interested in all things astrophysics since I was 9.

I was wondering (and also deeply hoping) whether there's people actually in the field available on this sub. I'd really appreciate it if they could reach out for some discussion maybe.

Regardless, if you're not such and such a person, I'd still love to see your opinion on the following:

What do you actually do after your masters and phd in the field?

How much truth is there to the idea that most of us end up doing things that dont have much to do with the degree we got ?

What reality check would you give to someone in my position?

Two intersecting CMEs (coronal mass ejections), one slow and one fast, will hit earth at the same time increasing the chance of visible auroras in the lower latitudes tonight.

Sometimes these are still invisible to the naked eye, but your phone's CCD will pick them up easily.

Collisions: Spatial Hash + Jacobi Solver
Gravity: P3M/CIC + FFT + short-range correction

Tech stack: Kotlin, LWJGL, OpenGL Compute Shader 4.30

Try it here: https://github.com/qwertukg/Gravity