Star Definition and 1000 Threads

I recently saw a short video describing some characteristics of neutron star, 4U 1820-30, in the Sagittarius constellation, i.e., in that direction. For some reason, it made the news recently, e.g., NICER X-ray Telescope Discovers Fast-Spinning Neutron Star, probably because some results were...

This article caught my attention with the claims. It's not exactly a new star, but some folks paid more attention to it recently, and probably someone finally got around to analyzing the spectrum. Discovery of a Metal-Poor Red Giant Star with the Highest Ultra-Lithium Enhancement...

In the "Andromeda Nebula" novel the author (Yefremov, 1957) describes dramatic story of a starship being inadvertently directed into the neighborhood of the "Infrared (Iron) Star" - so it was not discovered by navigators until too late. The ship is on the return route and doesn't have enough...

Until very recently I thought that according to general relativity masses curve spacetime as a whole, i.e. the complete abstract 4-dimensional spacetime. It came as a complete surprise to me to learn that you can take away the time-component and are left with a curved 3-dimensional space, which...

Considering that when you compress a gas, the gas will heat, then when a neutron star collapses to a black hole, I would expect the neutron matter to be heated to extreme values as the collapse proceeds. I would have thought this would lead to a last gasp pulse of em radiation before gravity...

I'm just starting out with amateur astronomy and decided to buy a 10x50 Celestron Up-close G2 binoculars. I believe that tomorrow is the planet parade (the aligning of 6 planets) and I'd like to catch a glimpse of it. In the bortle 7 location that I'm in, I could only see a handful of stars...

Though not near-term, if you had access to kilo-tonnes of generic, trans-Neptunian tholins, what could you do with such 'Star Tar' ?? Perhaps gleaned from a Kuiper belt 'iceteroid', typically thirds each of ices, silicates and tholins...

For this problem, My working, (a) ##d = a~ly = ac~y## ##v = \frac{d}{\Delta t} = \frac{ac}{b} \frac{m}{s}## (b) Lorentz factor is ##γ = \frac{1}{1 - \frac{a^2}{b^2}}## Thus time dilation is ##\Delta t = \frac{b}{1 - \frac{a^2}{b^2}} y##, however, I think my arugment is only valid if ##a >> b##...

In the following article it is stated: https://skyandtelescope.org/astronomy-news/measuring-neutron-stars-exactly/ "We're seeing the gas whipping around just outside the neutron star's surface," said Edward Cackett (University of Michigan), in a press release. "And since the inner part of the...

I analyzed the relationship between the surface temperature and luminosity of stars of similar mass using a regression model. Through this, I was able to obtain a regression line. Since stars of similar mass show similar evolutionary paths, I believe this regression line can be viewed as a rough...

I have the key answer for this (choosing 1 answer) A. 0,018 B. 1,134 C. 0,278 D. 0,974 E. 0,982

when a star goes supernova, does it eject out earth, mercury and mars sized chunks. Surely the asteroids that are even the size of Texas won't have enough gravity to compact hard enough to become one chunk. What is the current belief on how large of chunks are ejected from a supernova. Thanks

I have been learning a little Differential Geometry lately and recently came across the Hodge Star. So far I have been unable to find an explanation for its calculation that I can understand. I believe some ways of computing it were only valid in an orthonormal basis, but I would like to be able...

I finally got around to watching the movie "Avatar", which takes place in the Alpha Centauri system. I was thinking that a great little scene between the 2 main characters (i.e., the paraplegic Earthling and the Centauri woman) would have been looking up at the night sky and seeing Sol as a...

Happy Star Wars Day everybody. May the 4th be with you! And only 138 days until Talk Like a Pirate day.

I am attempting to calculate the proportional luminosity of a fictitious star using surface area and temperature in kelvin. To what level of accuracy can I expect from the formula L ∝ AT^4? Where L = Luminosity, A = surface area and T = Temperature L ∝ AT^4 L ∝ 4π · (r)^2 · (T)^4 If I replace...

There's a some things I've been wanting to look into for a while now I just don't know where to access that kind of information. 1. I'm interested in any information/journals concerning Physicist Norma G. Sanchez (I might be wrong on her title, please correct me if I am) work on a unifying...

Can T-tauri stars, due to the fact that they loose matter, become a Brown dwarf?

Hi I need the below data for the thousand or so stars in M44 the Beehive Cluster. What would be the easiest way to get this data? Thank you. RA, Dec, distance, apparent magnitude, absolute magnitude, spectrum

Hi guys, I can't seem to be able to get to $$ (\rho + p) \frac {d\Phi} {dr} = - \frac {dp} {dr} $$ from $$T^{\alpha\beta}_{\,\,\,\,;\beta} = 0$$ the only one of these 4 equations (in the case of a spherically symmetric static star) that does not identically vanish is that for ##\alpha=r##...

Does the Nemesis star really exist? I don't think it does. If the Sun had a companion star it should have been detected by now. Stars don't go hidden.

If a neutron star and an anti neutron star collided, would they 1) completely annihilate each other, 2) form a black hole, or 3) partially annihilate each other with the remaining stars being pushed away from each other by the energy created?

In the short story "Neutron Star" by Larry Niven, the narrator, Beowulf Shaeffer, is piloting a spaceship on a hyperbolic orbit that is supposed to make a close approach to a neutron star. He says at one point that he sees incoming light from distant stars blueshifted in all directions, and...

Type 1a supernovas unbind a white dwarf. Is there some theoretically possible scenario in which a neutron star could be unbound and thus turned into degenerate matter or even regular matter? For example, by a high speed glancing collision with another neutron star or by tidal disruption by a...

I'm trying to grok what this would look like to an observer on an Earth-like planet around a star in the center of such a cluster.

Hi. I am studying the wavefront evolution of light from a star. In the papers I have read, the star is often treated as a point source and the light is approximated as a line (geodesics), but this approximation is not very useful when I study the wavefront evolution, so I want to extend the...

Thanks to the JWST, we have this stunning picture. The APOD description says What are the processes that eject material at this stage?

could this explains the 3rd peak of the CMB and dark matter cold Primordial neutron star High Energy Physics - Phenomenology [Submitted on 7 Sep 2022 (v1), last revised 12 Sep 2022 (this version, v2)] Primordial neutron star; a new candidate of dark matter M. Yoshimura Z-boson exchange...

https://www.scientificamerican.com/article/first-known-map-of-night-sky-found-hidden-in-medieval-parchment/ Hipparchus worked on the Greek island of Rhodes three centuries before, roughly between 190 and 120 BC, astronomer Claudius Ptolemy in Alexandria, Egypt compiled a star catalogue...

I'm looking for a database of binary stars within 10 PC of Earth, including information such as eccentricity of orbits, their distance from one another, etc. I'm hoping to find a list with this information, or just a collection of pages with this information. I've tried Simbad but I can't find...

Basically, after seeing a meteor transit our atmosphere below 30,000 feet altitude too fast for my eyes to register yet leaving what looked like a beam of plasma from hanging from 1 side of the sky to the other for 3 seconds which I realized was a trail of smashed atoms of the atmosphere that...

Actress Nichelle Nichols, best known for her groundbreaking portrayal of Lt. Nyota Uhura in “Star Trek: The Original Series,” has died at age 89, of natural causes. Besides being on the first Star Trek show, she was also central to some important racial firsts on US TV: The Rev. Martin...

Referencing this posted on the Webb thread: https://www.quantamagazine.org/two-weeks-in-the-webb-space-telescope-is-reshaping-astronomy-20220725/ So will they able to do spectroscopy on GLASS-z13, the galaxy dating 300M after the big bang? Do they expect to see any heavier elements in a galaxy...

I wasn't sure if I should post this in astrophysics or particle physics, so I'll try particle physics first, mods feel free to move it to a more appropriate forum. So I was wondering if hypothetical Strange stars exist, would the strange quarks arrange themselves into baryons (i.e. Lambda-0 or...

Probably a misguided question, but would the intense magnetic field of a magnetar increase the overall pull an object would feel at the surface of the magnetar as compared to a regular neutron star? Or would it possibly lessen the amount of gravitational pull the object would feel at the...

I’m sure that when a star is in the process of becoming a black hole, there must therefore be one inside it at some point during the process (correct me if I’m wrong on that). But if so, how long does that take? Could there exist a supergiant star that has a black hole inside it for a long...

Hello, I need a bit of help. My age and fading competence are showing (no complaints, just facing up to it). I have an optical SETI observatory in Panama with a 20" Newtonian and a piggybacked 14" Cassy. I wish to mask a portion of stellar Airy disks with an E-W wire on a small photometer...

Hello, I have a question. If a star tracker in space faces the sun directly then could it be possible that the sun completely burns the image sensor? To be specific we are a student satellite team (Student satellite program IIT Bombay) developing a star tracker and we don't have an exact idea...

[Thread moved from the technical forums to the schoolwork forums by the Mentors] Hi i have this assignment for homework: There is only one battery for the circuit, E=10V, R=4 Ohms and L=1H it asks me to find the time constant of the circuit. i know that a time constant in a RL circuit is t=L/R...

So, I think it's possible to place an object in an orbit such that it remains perpetually in the planet's shadow, like in my awesome graphical representation. But is it?

Images of stars taken by Earth based telescopes can be enlarged by atmospheric fluctuations, but images of bright stars taken by Hubble are also large. Is this the result of some electronic effect in the camera pixels whereby the intensity of light falling on a pixel can cause adjacent pixels to...

Fusion power is mentioned a lot in Star Wars. In the Bad Batch arc of the second to last season of Clone Wars, the Separatist facility was powered by a fusion reactor. The A-wing is powered by fusion. GNK droids are walking fusion batteries and they have made fusion furnaces the size of a small...

Hello! I would appreciate it if anyone could help me figure this out. I’ve been struggling to find info on my own but so far nothing’s turned up. I am a little confused on the timeline of the generations of stars. I know that our sun is considered an early Population I star. However, I could...

From NASA.gov Mar 30, 2022 Record Broken: Hubble Spots Farthest Star Ever Seen. NASA’s Hubble Space Telescope has established an extraordinary new benchmark: detecting the light of a star that existed within the first billion years after the universe’s birth in the big bang – the farthest...

So far I have not made much meaningful progress beyond two equations; \begin{align*} \rho \frac{D\mathbf{u}}{Dt} = - \nabla p \implies \rho \left( \frac{\partial}{\partial t} + u \frac{\partial}{\partial r} \right)u = - \frac{\partial p}{\partial r} \end{align*}and thermal energy:\begin{align*}...

So there is a post going around the facebook groups about what would happen if we could pour a Sun sized bucket of water onto the sun, the claim being that the sun would gain mass and become a bigger, hotter burning blue star. I know this cannot happen but I was just curious as to what would...

I just watched this episode of Star Trek the Next Generation; The Inner Light. One of my favorites. edit: I just found this from a google search

This old nut is often dismissed as flawed thinking by a naive student. It’s been discussed here too, I know. However, when you do the math in standard (Schwarzschild-like) coordinates: Dustball collapse and evaporation in standard coordinates (Arxiv) A. the (coordinate) speed of light...

> In the movie "Star Wars: A new Hope", Luke Skywalker blows up the 'death star'. Assume that the 'death star' is a perfectly spherical spaceship with uniform mass distribution. The mass of 'Death Star' ##M=1021 \mathrm{kg}## and the radius ##R=667\mathrm{km}## Estimate the amount of the energy...