Wanna learn more about Astronomy?
The stars, the galaxies, everything amazing about the Universe. There’s so much to know and learn, and that can’t always happen because while many would love to add it to their fanworks (Trying to put the Doctor into better character, really cool things to have happen with the Tardis, amazing sights to describe, help creating new planets) or even just because out of desire for the knowledge -- but it doesn’t always feel very accessible, and Uni classes are expensive.
Eff that. Here is some free stuff to help you out!
Open Courseware Classes
You can take classes from big name universities for free, online. All course materials are completely free, lectures, etc.
Introduction to Astronomy - MIT (Massachusetts Institute of Technology)
Astronomy 101 - Penn State University
Exploring Black Holes: General Relativity & Astrophysics - MIT
Astronomy & Astrophysics - Yale University
Introduction to Quantum Mechanics - Oxford University
The Relativistic Universe - Open University
Astrophysics 101 - Colorado School of Mines
Lecture Series on Space Studies - Keck Institute for Space Studies
Flight and Orbital Mechanics - Delft University of Technology
Aircraft Systems Engineering - MIT
Introduction to Aerospace Engineering (AE101) - Delft University of Technology
Introduction to Aerospace Engineering (AE102) - Delft University of Technology
Astronomy 102 - Open University
Cosmology - Stanford University
Astrophysics: Frontiers & Controversy - Yale University
Super Symmetry, Grand Unification, & String Theory - Stanford University
Introduction to Modern Cosmology - MIT
Astrobiology & Space Exploration - Stanford University
Outer Planets & Planetary Atmospheres - The University of Arizona
Survey of Astronomy - Missouri State University
Galaxies One & Two - The University of Arizona
Introduction to Stellar Astronomy - Pennsylvania C.C.
Introduction to Galaxy Interaction & Motion - The University of Arizona
Stars 101, 102, & 103 - The University of Arizona
The Big Bag, Inflation, & General Cosmology - The University of Arizona
Planetary Astronomy - The University of Arizona
The Solar System - The University of Arizona
Planetary Science - Open University
Solar Neighborhood & Space Exploration - The University of Arizona
Astronomy & Astrophysics - University of Chicago
Deep Space & High Energy Phenomena - The University of Arizona
Astronomy: The Frontiers of Science - Columbia University
Introduction to General Astronomy - UC Berkeley
Lectures
Introduction to Astrobiology & Space Exploration - Professor Lynn Rothschild, Stanford University
Astrophysics: An Introduction - Oxford University
Astronomy Public Lecture Series - Florida Institute of Technology
Cosmic Origins Lecture Series - The University of Arizona
Steward Observatory Public Evening Lecture Series - University of Arizona, College of Science, Department of Astronomy and Steward Observatory
Silicon Valley Astronomy Lecture Series - Foothill College
Steward/NOAO Joint Colloquium Series - Steward Observatory and National Optical Astronomy Observatory
Naked Astronomy - Naked Scientists
Astronomy Public Lectures - Swinburne Institute of Technology
NASA’s Jet Propulsion Laboratory - NASA
Human Spaceflight - NASA
Space Lecture Series - California Academy of Sciences
Astronomy Maths Help One & Two - Professor Lindsay Rocks
Stargazing Lecture Series - Oxford University
Earth and Space Science - Teachers domain material
Leadership on Spacecraft - NASA
Earth & Environmental Science - Dr. Christian Shorey
Earth Explorations - Dr. Christian Shorey
The Carnegie Astronomy Lecture Series - Carnegie Hall
Ancient Astronomy - 9th Grade Lessons
Cosmo 2013, a conference of top lecturers in their fields - International Conference on Particle Physics and Cosmology at Cambridge University
Moons - Open University
Space & the Cosmos - Aspen Ideas
Craters on the Moon - Open University
Waters on Moons - Open University
Cosmic Origins - The University of Arizona
Hidden Dimensions: Exploring Hyperspace - World Science Festival
Black Holes & Holographic Worlds - World Science Festival
A Thin Sheet of Reality: The Universe as a Hologram - World Science Festival
Documentaries
Explore Mars Series
The Big Idea
Space Missions
Astronomy Documentary Series
Life in the Universe
Journey to the Edge of the Universe
Documentary Playlist - An Introduction to the Planets
Strange Side of the Universe
How the Universe Works
Exploring Our Stars
Mathematics Explains the Universe
Ancient Astronomy
White Dwarf: The Universe’s Sleeping Monster
Inside the Milky Way
Solar Superstorms
Gravitational Waves
Parallel Universes
Nasa’s Untold Stories
Journey to Deepest Space
How the Universe Works
The Life Cycle of a Star
Living in a Parallel Universe
Colossal Black Holes
Magnetars, Black Holes, Pulsars & Quasars
Playlist of 58 Astrophysics Documentaries
575 Space Playlist of Documentaries (Literally there are 575 documentaries in here)
Books
Ask Magazine - Academy of Program/Project and Engineering Leadership (APPEL) & Nasa
Modern Observational Cosmology
A Modern Astronomy
Popular History of Astronomy during the 19th Century
A Simple Guide to Backyard Astronomy
Astronomical Discovery
Astronomy for Amateurs
Astronomy Today
Astronomy with an Opera Glass
Basic Positional Astronomy
Black Hole Phenomenology
Curiosities of the Sky
Elementary Mathematical Astronomy
Elements of Astrophysics
Exoplanet Observation for Amateurs
Great Astronomers
History of Astronomy
Introduction to Cosmology
Letters on Astronomy
Pioneers of Science
Practical Astronomy
Practical Astronomy for Engineers
Primer of Celestial Navigation
Publications for the Astronomical Society of the Pacific
Complete Star Atlas
Nasa’s Mystery of the Sun
Stargazer’s Handbook
Supernovae
Recreations in Astronomy
Short History of Astronomy
The Beginning & the End
The Complete Idiot’s Guide to the Sun
The Geology of Our Planets
The Moon
The Story of Eclipses
The Story of the Heavens
The World According to the Hubble Space Telescope
Scholarpedia’s Astrophysics Main Page is def. a thing to check out as well!
If you’re interested, we are also running a weekly freeform event where if you contribute, your name will be put into a randomizer each week to win a star!
Hope you enjoy my stash!
-Mod @natural--blues
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Exploring physical features of anisotropic strange stars beyond standard maximum mass limit in $f\left(R,\mathcal{T}\right)$ gravity. (arXiv:1810.07678v3 [gr-qc] UPDATED)
We study a specific model of anisotropic strange stars in the modified $f\left(R,\mathcal{T}\right)$-type gravity by deriving solutions to the modified Einstein field equations representing a spherically symmetric anisotropic stellar object. We take a standard assumption that $f(R,\mathcal{T})=R+2\chi\mathcal{T}$, where $R$ is Ricci scalar, $\mathcal{T}$ is the trace of the energy-momentum tensor of matter, and $\chi$ is a coupling constant. To obtain our solution to the modified Einstein equations, we successfully apply the `embedding class 1' techniques. We also consider the case when the strange quark matter (SQM) distribution is governed by the simplified MIT bag model equation of state given by $p_r=\frac{1}{3}\left(\rho-4B\right)$, where $B$ is bag constant. We calculate the radius of the strange star candidates by directly solving the modified TOV equation with the observed values of the mass and some parametric values of $B$ and $\chi$. The physical acceptability of our solutions is verified by performing several physical tests. Interestingly, besides the SQM, another type of matter distribution originates due to the effect of coupling between the matter and curvature terms in the $f\left(R,\mathcal{T}\right)$ gravity theory. Our study shows that with decreasing the value of $\chi$, the stellar systems under investigations become gradually massive and larger in size, turning them into less dense compact objects. It also reveals that for $\chi<0$ the $f\left(R,\mathcal{T}\right)$ gravity emerges as a suitable theory for explaining the observed massive stellar objects like massive pulsars, super-Chandrasekhar stars and magnetars, etc., which remain obscure in the standard framework of General Relativity (GR).
from gr-qc updates on arXiv.org http://bit.ly/2GMz569
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Study on charged strange stars in $f\left(R,\mathcal{T}\right)$ gravity. (arXiv:1812.11736v1 [gr-qc])
We investigate effects of the modified $f(R, \mathcal{T})$ gravity on the charged strange quark stars for the standard choice of $f(R, \mathcal{T})=R+2\chi \mathcal{T}$. These types of stars are supposed to be made of strange quark matter (SQM) whose distribution is governed by the phenomenological MIT bag EOS as $p=1/3(\rho-4B)$, where $B$ is the bag constant, while the form of charge distribution is chosen to be $q\left(r\right)=Q\left(r/R\right)^3=\alpha r^3$ with $\alpha$ as a constant. We derive the values of the unknown parameters by matching the interior spacetime to the exterior Reissner-Nordstr{\"o}m metric followed by the appropriate choice of the values of the parameters $\chi$ and $\alpha$. Our study under the $f(R, \mathcal{T})$ gravity reveals that besides SQM, a new kind of matter distribution originates due to the interaction between the matter and the geometric term, while the modification of the Tolman-Oppenheimer-Volkoff (TOV) equation invokes the presence of a new force $F_c$. The accumulation of the electric charge distribution reaches its maximum at the surface. To examine the physical validity of our solutions, we perform tests of the energy conditions, stability against equilibrium of the forces, adiabatic index, etc., and find that the proposed $f(R, \mathcal{T})$ model survives from all these critical tests and hence not only can explain the non-singular charged strange stars but also viability to justify the supermassive compact stellar objects having their masses beyond the maximum mass limit for the compact stars in the standard scenario. Therefore, the present $f(R, \mathcal{T})$ gravity model seems promising regarding the existence of several exotic astrophysical objects, like super-Chandrasekhar white dwarfs, massive pulsars, and even magnetars, which remain unexplained in the framework of General Relativity (GR).
from gr-qc updates on arXiv.org http://bit.ly/2SwHijt
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