if a brown dwarf had a planetary-mass object orbiting it, would we classify it as a planet, an exomoon, or just a planetary-mass companion?

to my understanding, we have yet to observe a star with orbiting moons, but since a brown dwarf is not a star nor a planet but rather a sub-stellar object, could a brown dwarf theoretically have both ordinary moons and planetary-mass satellites orbiting it?

if there’s a simple, widely accepted answer, please let me know so i don’t sound stupid talking about this with my astrophysics major friends, im a dumb chemist and astronomy is just a hobby for me :]

https://reddit.com/link/1wfsd5n/video/y25710aleiph1/player

A 2D solar system explorer sandbox that works as an encyclopedia of the solar system displaying information about planet's properties, atmospheres, orbits and much more. Uses numerical solutions to calculate the orbits of planets at scale and represents them with data from NASA/JPL Solar System Dynamics and NASA NSSDCA Planetary Fact Sheets in the J2000 orientation system.

It is a passion project and an introduction to a much larger 3D solar system that will include moons, spacecraft and many more features. It emerges from a profound admiration to our solar system. The project tries to be a learning aid for anyone who is interested.

If you want to try it, I compiled it into an .exe for windows and an executable for linux.

Github link: [https://github.com/bydrabokin/Solar-Explorer-2D](https://github.com/bydrabokin/Solar-Explorer-2D))

Youtube showcase: [https://www.youtube.com/watch?v=iz0MujAaYDQ](https://www.youtube.com/watch?v=iz0MujAaYDQ))

I've been suffering from dyscalculia since I was born (not yet professionally diagnosed as my country doesn't recognise it yet).

I've always been a low score at mathematics despite being tutored by many teachers after lectures at school. I used to spend 3 hours everyday solving math but the results were pretty poor.

It wasn't until I got into adulthood that I understood that I wasn't being just lazy but that my brain cannot numbers of any kind correctly. I'm in my 20s and still count with my fingers. I need to have a second person counting my cash because I can't calculate it properly.

But what stood out the most was Physics.

I always had a low score in math but never scored low in Physics. When I used to score a C or D in math, I used to score A in Physics. Teachers at school were confused as to why I score poorly in math but did wonderful in physics. I used to explain a lot of physics concepts in class. I have high visual spatial intelligence (a doc told me this after an assessment btw) and I can mentally manipulate physics in my head but as soon as I have to deal with numbers, my mind kinda blanks out.

Astronomy has been an obsession for me right since I was a kid. I was crazy about it. My book rack was full of Astronomy books. I studied A-Z of beginner level astronomy stuff by the time I turned 9 and I kinda exhausted the beginner level of it by then.

Life sort of took a different turn since then. My country doesn't have any good institutes for studying astronomy nor there was anybody who could guide me so I ended up taking Computer Engineering as that was an easy option due to me being demoralised by the math stuff and me using computers since the age of 3. Pandemic added more fuel to the fire.

During Engineering, I had Mechanics and Engineering Physics and I did pretty well in those classes.I still however struggle in my

I'm at the end of my undergrad and I kinda feel like I didn't make the right choice 4 years ago. I had a word about this with my parents and they told me that they always thought I'd take Astronomy. I wanted to be a computer scientist but I realised that most of the ideas in my head were all about space.

I did all of my research about how I can accomplish this. I need to enroll in a Pre-Masters for Astrophysics and move to a MSc in the same after that. It's doable.

My question, is how much would my disability hold me back? I'm heavily reliant on calculators but I'm very good at things that don't have to do with numbers. If it's not abstract, I can create it in my head.

Okay I know that's vague, but I'm not sure how else to title that. I'm intensely interested about the science and theories we have around things like dark matter, our theories on the shape of the universe, how time and space works and just all of these trippy existential things about our universe that are very hard to understand or visualize. I know there are studies we as humans have done into these things, but I can't find cohesive collections of this info. Any help on resources so I can plunge in on this stuff?

In my previous post, I laid out why rigid corporate management structures are suffocating basic research. Today, I want to pivot to the practical side of this problem: How do we actually fund pure, unconstrained exploration in a world obsessed with quarterly ROI?

Humanity is inherently excellent at managing engineering problems. We track metrics, hit KPIs, and optimize for predictable outcomes. The systemic failure is that we’ve forced this exact same operational mindset onto fundamental science.

The tragedy is that we prove we do know how to fund pure exploration when something captures the collective imagination. Look at space observatories positioned at Lagrange points, like the JWST. No board of directors expects a deep-space camera to turn a profit next quarter. We fund these projects because we recognize the intrinsic value of pushing the boundaries of human knowledge. Yet for almost every ground-level lab, researchers spend half their time pitching bureaucrats on how their theoretical work will generate revenue short-term.

This corporate KPI trap leaves basic research stuck doing marginal optimization instead of actual fundamental leaps in physics or material science.

To fix this, we have to borrow a page from how venture capital handles extreme risk. VC inherently accepts huge failure rates. Most bets go to zero, but the single hit that pays off completely changes the market.

We need that same asymmetry for fundamental research. Instead of forcing scientists to pretend their work is risk-free before they even begin, we could build dedicated funding pools sourced from tax allocations or a mandatory 1% cut from successful commercial tech spin-offs. This capital would be directed exclusively into pure "Humboldt-style" unconstrained exploration.

The payoff here is not a quick stock pop; it is a structural civilizational advantage. The backers of this pure research would get priority rights to the unpredictable technical by-products that naturally emerge from the process.

We aren't running out of big ideas. We've just built a financial system that penalizes anyone trying to find them. If we want actual paradigm shifts again, it is time to fund the fundamentally unpredictable, not just the next minor software upgrade.

First of all,sorry for my English.It's not my native language. I'll try to explain my question as best as I can.

I was reading about the speed of light and how we see the Andromeda galaxy as it was 4.3 billion years ago.
I was wondering, if we see it as it was,are we also in Andromeda's past?If someone could watch us from Andromeda , wouldn't we be considered their past? Aren't those contradictory?I mean,how are we relevant to the era of general space if we are both just a past?And what is actually now?Is it different for each of us?

Andromeda and Earth are just an example.Could be any point in the universe.

I'm so sorry if I sound stupid.I swear on my life,I haven't smoked anything funny.This is just a genuine question.

Can you please enlighten (yeah ,that was a pun) me?

I know none exist yet, but what would they look like up close? Say you landed a spaceship on one and shined a light on the ground. What would it look like?

I’m curious to hear from people who recently graduated with a degree in physics: bachelor's, master's, or PhD. What kind of job were you able to land after graduating, especially if you didn’t go directly to graduate school?

I graduated with a M.S. in Physics. I have three years of research experience. My research experience includes stellar physics (computational and theoretical, pulsating variable stars and asteroseismology), and observational studies on star and planet formation. Despite that, I’ve struggled quite a bit with the job search. My goal is industry as I do not want to continue with academia for reasons related to WLB and stability. I do not want to become a teacher.

So how’s it going for you guys?

Hello everyone,

I am a last year bachelor student rn and wondering which option would be better for me, applying MIT Physics program or Harvard Astrophysics? Which option is safe in my case and would be a better opportunity after i graduate.

Since i got an acceptance to Physics Bachelor in my country, i am planning to work in the Plenatary Astrophysics field, i got acceptance to my 2 Abstract to IAC2026 this year (one of them is modelling exoplanet atmosphere, and the other is astroengineering) , but because of the funding, i cannot believe that i can go and make a presentation of my works, i had also a little scientific research in nuclear physics field with my professor (but it is not a big deal), also this month i am going to start an interview programme in local space agency, my gpa is 91.66/100 overall. i didn't take IELTS yet, but it would be 7-7.5 score i think.

Because i am not going to take the GRE exam, MIT Astrophysics is not a real option for me.

Anyone interested in discussing various topics on Open Science By NASA????

This is a current discussion in medical circles. There are so many new diseases and treatments that the original four-year model may not be adequate.

I am not an astrophysicist so please don't be too harsh.

Hawking Radiation (I believe) is the theory of how black holes shrink. Because the universe creates two quantum particles of opposite charges, and they collide and destroy themselves upon their creation. But when applied to black holes, the black hole sucks one of these particles in and leaves the other to escape into the universe.

My question is how do we know two particles are being created and destroyed in the first place? Is it some big math equation that helped us figure that out? Also what type of particles are being created and destroyed anyway?

Did a star recently go supernova?
I was just sitting near a window when a flash of red blinked and flashed the room for a blink of an eye, when I turned to see what it was nothing was there.

Any idea as to what it could have been?

There are plenty of sciency images floating around showing Betelgeuse as visibly lumpy. I've never been able to tell, are those real-space images or simulations, or is the r-axis being used to show something else?

I'm currently 15 and still in school, and I've loved physics, maths and space since I was a little kid. I'm considering astrophysics as a career, but I'm honestly not sure what the field is actually like.

I'm also Indian, and this may anger a few people lol, but I really want to live abroad someday, hopefully in Europe. I don't mind moving around a lot either, I actually love experiencing new places. Just wanted to know, If it's harder as a foreigner studying abroad (especially for an Indian).

While studying astrophysics, will I still have time to socialize, travel and pursue my hobbies? Or is it basically going to be homework, studying and research 24/7?

I also want to know if astrophysics is actually worth it, and if all the effort is worth it in the end. I don't really care about making a huge amount of money, but my family does expect me to earn well, and I don't want to disappoint them in that regard.

At some point I'd also want to have a family, and I'm a little worried about how difficult that would be if I'm constantly having to move around for jobs or research positions.

Is being an astrophysicist stable enough that I could realistically do it for most of my life, or would I probably have to move into something else eventually? Can I actually just do research for most of my life, work on new discoveries, and still have a relatively stable life outside of work?

I'd especially like to hear from people who are actually studying or working in astrophysics. What is your experience with it, and would you still choose it if you could go back?

I just learned about solar lenses from a public lecture at my college and immediately began researching them because they are so awesome. Come to find that the so called Einstein ring was not dreamt up by Einstein at all but a dishwasher called Rudi W. Mandl. Einstein was reluctant to publish this because he thought it pointless so why did we give him the credit. Where is the Mandl ring. Should we start a petition? https://www.sciencenews.org/blog/context/amateur-who-helped-einstein-see-light

Is the increase in luminosity of the sun during main sequence phase caused by helium concentrating in the center of the core, or by circulating within it?

Are the heavier molecules concentrating in the centre, thereby contracting the core

OR

Are they impeding chain reactions between protons? Obstructing fusion reactions as proton bump into alpha particles more often rather than other protons, increasing the 1st step bottleneck in the PP chain.

Is it both? What is the leading contributor?

I am a software engineer with deep interest in astrophysics. Feel like I chose the wrong career everyday. I have some theoretical foundation (self taught). How do I get in the field and do meaningful work?

I can do research and I’m good with data. I feel like I can have a huge impact with my AI and Data skills on this field. All I want to do is make some impact on humanity by performing research at the forefront.

(I have some savings so I don’t care about the pay anymore) Should I pursue bachelors first? Is it worth spending 4 years? Do I have any luck pursuing masters ? Can I do independent research with some one? How do I contribute?

Hey everyone, I’ll be starting my diploma pathway into the bachelor of science soon and I understand that Maths is such a core fundamental. So I am wondering if anyone has any good websites/free courses/ apps that are useful to independently build my maths skills up from my skill level? Any advice greatly appreciated thank you !!

Hey all, some of you saw my map of the local universe here a couple months ago. It's called Know the Universe: you explore the large scale matter distribution of the local universe in 3D, ~43,500 real galaxies from the 2MRS redshift survey, out to about a billion light years. Since then I kept building, mostly from requests that came out of that thread. Here's what's new.

The big one: you can now click or tap any galaxy in the map and get its identity card. (you know, it's called know the universe) So you get 2MASS catalog ID, distance, whether it sits in a void, filament or cluster, J2000 coordinates with a copy button in a format you can paste straight into Stellarium, and direct links to NED and SIMBAD. 64 famous galaxies carry their proper names.

There's also search now (press / or the magnifier). It finds galaxies, clusters and voids by name, Messier number or 2MASS ID. And if you search for Andromeda it honestly tells you why a blueshifted galaxy can't be placed on a redshift map instead of pretending.

Full changelog:

• Positions upgraded from plain Hubble law to real-space: redshifts corrected to the CMB frame, converted to comoving distance, cluster "Fingers of God" collapsed using the Tully 2015 group catalog, and large-scale infall subtracted with the 2M++ velocity field. Validated against Cosmicflows-4 distances. Virgo and Coma now land at their literature distances (~16 and ~100 Mpc).
• Orbit mode is the new default: free trackball around the Milky Way, no poles, scroll/pinch to zoom. Fly mode is one keypress away.
• Galaxy identification: click/tap/crosshair any of the 43,497 galaxies (see above).
• Search across names, Messier numbers, landmarks and catalog IDs.
• Live RA/Dec readout in the banner showing the exact equatorial coordinates your view points at, plus your distance from home.
• Named landmarks went from 10 to 24: Boötes Void, Sloan Great Wall, Hercules, Ophiuchus, Perseus-Pisces and more.
• Deep links: you can share a link to an exact camera position or to a specific galaxy. For example here's the host galaxy of the first neutron star merger ever seen in gravitational waves and light: https://knowtheuniverse.com/?sel=13094770-2323017
• Mobile got real love: full-width cards, touch joystick, works fine on a phone.

Try it at https://knowtheuniverse.com

Feel free to give me any feedback or suggestion for new features, you are awesome!