Neutron Stars, Black Holes, and Relativity

Vocabulary flashcards based on the lecture notes about neutron stars, black holes, and relativity.

Neutron Star

A stellar remnant composed primarily of neutrons, formed when a massive star undergoes supernova and collapses.

Black Hole

An object with a gravitational pull so strong that not even light can escape from it.

Pulsar

A highly magnetized rotating neutron star that emits beams of electromagnetic radiation.

Type I Supernova

A type of supernova that occurs in binary star systems, where one star is a white dwarf that accretes mass from its companion.

Type II Supernova

A supernova that results from the rapid collapse of a massive star's core.

Lucia Principle

A fundamental principle that describes the universal tendency of light speed.

General Relativity

Albert Einstein's theory that describes how gravity affects the fabric of space and time.

Special Relativity

Einstein's theory that describes the behavior of objects moving at constant speeds close to the speed of light, focusing on the physics of moving bodies.

Schwarzschild Radius

The radius of a black hole within which light cannot escape.

Event Horizon

The boundary around a black hole beyond which no light or other radiation can escape.

Gravitational Time Dilation

The effect of gravity on the passage of time, where time runs slower in stronger gravitational fields.

Time Dilation

The phenomenon where time runs slower for objects moving relative to a stationary observer.

Mass Limit for Neutron Stars

Above about 3 solar masses, neutron stars cannot support themselves and will collapse into black holes.

Light House Effect

The phenomenon in pulsars where beams of emitted radiation sweep across space, causing pulses of brightness.

Hubble's Law

The observation in physical cosmology that galaxies are moving away from us and that more distant galaxies are receding faster.

Big Bang

The leading explanation about how the universe began, proposing that it was once a singularity and has been expanding ever since.

Cosmic Microwave Background (CMB)

The thermal radiation filling the universe, a remnant from the Big Bang.

Dark Matter

Matter that does not emit light or energy but exerts gravitational forces.

Dark Energy

A mysterious force pushing the galaxies apart, contributing to the acceleration of the universe's expansion.

Olbers' Paradox

The question of why the night sky is dark if the universe is infinite and populated by an infinite number of stars.

Luminosity

The total amount of energy radiated by a star, galaxy, or other astronomical object per unit time.

Gravitational Lensing

The bending of light from a distant object due to the gravitational field of a closer object.

Redshift

The phenomenon where light from an object is shifted to longer wavelengths as the object moves away from the observer.

Blueshift

The phenomenon where light from an object is shifted to shorter wavelengths as the object moves towards the observer.

Singularity

A point in space-time where gravitational forces cause matter to have infinite density.

Quasar

An extremely luminous active galactic nucleus powered by a supermassive black hole.

Galaxy Cluster

A structure that consists of hundreds to thousands of galaxies held together by gravity.

Acoustic Wave

A wave that propagates through a medium such as air or water.

Galactic Bulge

The densely packed group of stars in the center of a spiral galaxy.

Galactic Disk

The flat, rotating disk that contains the majority of a galaxy's component stars, gas, and dust.

Galactic Halo

The spherical region that surrounds the galaxy and contains older stars, globular clusters, and dark matter.

Cosmological Principle

The assumption that the Universe is homogeneous and isotropic when viewed on a large enough scale.

Event Horizon

A boundary in spacetime beyond which events cannot affect an observer.

Angular Momentum

The quantity of rotation of a body, which is transferred during collisions between objects.

Big Crunch

A hypothetical scenario for the ultimate fate of the universe where it eventually collapses back into a singularity.

Hubble's Constant

The current rate of expansion of the universe.

Kepler's Laws

Three laws describing the motion of planets around the Sun.

Emission Spectrum

The spectrum of light emitted from atoms or molecules during energy transitions.

Doppler Effect

The change in frequency or wavelength of a wave in relation to an observer moving relative to the wave source.

Massive Star

A star that is significantly larger than the Sun and has a short lifespan due to high rates of fusion.

Variable Star

A star whose brightness changes due to intrinsic or extrinsic factors.

Pulsating Variable Star

A type of variable star that changes brightness due to periodic expansion and contraction.

Carbon Detonation

A type of supernova explosion that occurs when a white dwarf star reaches a critical mass.

Gravitational Waves

Ripples in spacetime caused by accelerating massive objects, predicted by Einstein's general theory of relativity.

Accretion Disk

A rotating disk of dense gas surrounding an astronomical object, from which it may draw material.

Supernova Remnants

The remnants of a supernova explosion, which can include gases, dust, and neutron stars.

Stellar Evolution

The process by which stars change over time from formation to their eventual death.

Red Giant Star

A large star that has expanded and cooled after exhausting its hydrogen fuel.

Hot Star

A star that emits a large amount of energy and appears blue to white in color.

Metal-rich Stars

Stars that contain a larger proportion of elements heavier than helium.

Gravitation

A force that attracts two bodies toward each other, proportional to their masses and inversely proportional to the distance between them.

Neutron Degeneracy Pressure

The pressure arising from the quantum mechanical effects of neutrons in a neutron star, balancing gravitational collapse.

Planetary Nebula

A ring-shaped nebula formed by the gas ejected from red giant stars.

Observation

The action or process of observing something carefully to gain information.

Active Galactic Nucleus (AGN)

A compact region at the center of a galaxy that is extremely bright and energetic.

Antimatter

A type of matter composed of antiparticles, the counterparts to the normal particles that make up matter.

Radiation Pressure

The pressure exerted by electromagnetic radiation on surfaces.

Supermassive Black Hole

A black hole with a mass ranging from hundreds of thousands to billions of solar masses.

Thermodynamics

The branch of physics that deals with the relationships between heat and other forms of energy.

Stellar Density

The concentration of stars in a specific volume of space.

H-R Diagram

A scatter plot of stars showing the relationship between the stars' absolute magnitudes versus their stellar classifications.

Core Collapse

The process occurring in a star where the core becomes denser and hotter, often leading to a supernova.

Cosmological Redshift

The redshift caused by the expansion of the universe, which stretches the wavelength of light.

Kilonova

An astronomical event that occurs when two neutron stars merge.

Brightness

The perception of how much light or electromagnetic radiation is emitted by a star or galaxy.

Galactic Evolution

The process by which galaxies change over time through star formation, collisions, and mergers.

Scale Factor

A number describing how the size of the Universe changes with time, used in cosmology.

Universal Force

The fundamental forces acting throughout the cosmos, including gravity.

Ballistic Trajectory

A path that an object follows under the influence of gravity and initial propulsion.

Stellar Mass

The mass of a star, which determines its lifecycle and characteristics.

Solar System

The gravitationally bound system comprising the Sun and the objects that orbit it.

Local Group

A group of galaxies that includes the Milky Way and its nearest neighbors.

Matter Density

The amount of matter in a designated volume of space.

Mass Energy Equivalence

The principle that mass can be converted into energy and vice versa.

Big Chill

A scenario for the fate of the universe where it keeps expanding at an accelerating rate, leading to low temperatures.

Baryonic Matter

Normal matter composed of baryons, such as protons and neutrons.

Hydrostatic Equilibrium

The condition where the gravitational force balances the pressure gradient force in a star.

Rotational Velocity

The velocity at which an object rotates about an axis.

Supernovae Type Ia

A type of supernova explosion that occurs in binary systems.

Galactic Structure

The arrangement and composition of different components of a galaxy.

Collective Motion

The motion of a group of entities acting together.

Precise Measurements

Accurate and exact values or readings taken during observation or tests.

Gravitational Collapse

The process by which an astronomical object collapses under its own gravity.

Astronomy

The scientific study of celestial bodies, space, and the universe.

Stellar Winds

Streams of charged particles ejected from the upper atmosphere of stars.

Model Building

The process of creating representations to simulate potential outcomes.

Spatial Distribution

The arrangement of various elements across space.

Electron Degeneracy Pressure

A quantum mechanical pressure that arises from the Pauli exclusion principle.

Spectroscopy

The study of the interaction between matter and electromagnetic radiation.

Efficient Star Formation

The process by which new stars are created at an optimal rate.

Hubble Deep Field

An image of a small region of space taken by the Hubble Space Telescope.

Cosmic Structures

Large-scale arrangements of matter in the universe, like galaxies and clusters.

Magnetic Field

A field produced by electric currents, which influences charged particles.

Thermal Radiation

Electromagnetic radiation generated by the thermal motion of charged particles.

Gravitational Binding Energy

The energy required to disassemble an object into its constituent parts at an infinite distance.

Astrophysics

The branch of astronomy concerned with the physical properties and interactions of celestial bodies.

Helianthum

A process by which light from a star can be measured based on its photometric data.

Cosmic Inflation

A theory that states the universe underwent an exponential expansion in the first moments after the Big Bang.

Quantum Mechanics

The branch of physics that deals with the behavior of matter and energy at atomic and subatomic scales.

Volatility

A measure of how easily an object can be removed or changed in a state.