NGC 4414, a typical spiral galaxy in the constellation Coma Berenices, is about 56,000 light-years in diameter and approximately 60 million light-years distant

Astrophysics is the branch of astronomy that deals with the physics of the universe, including the physical properties (luminosity, density, temperature, and chemical composition) of celestial objects such as stars, galaxies, and the interstellar medium, as well as their interactions. NGC 4414 is an Unbarred spiral galaxy about 62 million Light-years away in the Constellation Coma Berenices. A spiral galaxy is a Galaxy belonging to one of the three main classes of galaxy originally described by Edwin Hubble in his 1936 work “The Realm of the In common usage a constellation is a group of celestial bodies that are connected together in some arrangement typically stars to form a visible figure or picture Coma Berenices ( Berenice 's Hair) is a traditional asterism that has since become a Constellation. A light-year or light year (symbol ly) is a unit of Length, equal to just under ten trillion Kilometres As defined by Astronomy (from the Greek words astron (ἄστρον "star" and nomos (νόμος "law" is the scientific study Physics (Greek Physis - φύσις in everyday terms is the Science of Matter and its motion. The Universe is defined as everything that Physically Exists: the entirety of Space and Time, all forms of Matter, Energy Luminosity has different meanings in several different fields of science The density of a material is defined as its Mass per unit Volume: \rho = \frac{m}{V} Different materials usually have different Temperature is a physical property of a system that underlies the common notions of hot and cold something that is hotter generally has the greater temperature Chemistry (from Egyptian kēme (chem meaning "earth") is the Science concerned with the composition structure and properties s are significant physical entities, associations or structures which current Science has confirmed to exist in Space. A star is a massive luminous ball of plasma. The nearest star to Earth is the Sun, which is the source of most of the Energy on Earth A galaxy is a massive gravitationally bound system consisting of Stars an Interstellar medium of gas and dust, and Dark matter The study of cosmology is theoretical astrophysics at the largest scales where Albert Einstein's general theory of relativity plays a major role. Physical cosmology, as a branch of Astronomy, is the study of the large-scale structure of the Universe and is concerned with fundamental questions about its Albert Einstein ( German: ˈalbɐt ˈaɪ̯nʃtaɪ̯n; English: ˈælbɝt ˈaɪnstaɪn (14 March 1879 – 18 April 1955 was a German -born theoretical General relativity or the general theory of relativity is the geometric theory of Gravitation published by Albert Einstein in 1916

Because astrophysics is a very broad subject, astrophysicists typically apply many disciplines of physics, including mechanics, electromagnetism, statistical mechanics, thermodynamics, quantum mechanics, relativity, nuclear and particle physics, and atomic and molecular physics. Mechanics ( Greek) is the branch of Physics concerned with the behaviour of physical bodies when subjected to Forces or displacements Electromagnetism is the Physics of the Electromagnetic field: a field which exerts a Force on particles that possess the property of Statistical mechanics is the application of Probability theory, which includes mathematical tools for dealing with large populations to the field of Mechanics In Physics, thermodynamics (from the Greek θερμη therme meaning " Heat " and δυναμις dynamis meaning " Quantum mechanics is the study of mechanical systems whose dimensions are close to the Atomic scale such as Molecules Atoms Electrons This page is about the scientific concept of relativity for philosophical or sociological theories about relativity see Relativism. Nuclear physics is the field of Physics that studies the building blocks and interactions of Atomic nuclei. Particle physics is a branch of Physics that studies the elementary constituents of Matter and Radiation, and the interactions between them Atomic molecular, and optical Physics is the study of Matter -matter and Light -matter interactions on the scale of single In practice, modern astronomical research involves a substantial amount of physics. The name of a university's department ("astrophysics" or "astronomy") often has to do more with the department's history than with the contents of the programs. Astrophysics can be studied at the bachelors, masters, and Ph.D. levels in aerospace engineering, physics, or astronomy departments at many universities. A bachelor's degree is usually an Undergraduate Academic degree awarded for a course or major that generally lasts for three four or in some cases and "PhD" redirects here for other uses see PhD (disambiguation. Aerospace engineering is the branch of Engineering behind the design construction and science of Aircraft and Spacecraft. A university is an institution of Higher education and Research, which grants Academic degrees in a variety of subjects

History

Although astronomy is as ancient as recorded history itself, it was long separated from the study of physics. In the Aristotelian worldview, the celestial world tended towards perfection—bodies in the sky seemed to be perfect spheres moving in perfectly circular orbits—while the earthly world seemed destined to imperfection; these two realms were not seen as related. Aristotle (Greek Aristotélēs) (384 BC – 322 BC was a Greek philosopher a student of Plato and teacher of Alexander the Great.

Aristarchus of Samos (c. Aristarchus (Ἀρίσταρχος 310 BC - ca 230 BC) was a Greek Astronomer and Mathematician, born on the island of 310 – c. 250 BC) first put forward the notion that the motions of the celestial bodies could be explained by assuming that the Earth and all the other planets in the Solar System orbited the Sun. EARTH was a short-lived Japanese vocal trio which released 6 singles and 1 album between 2000 and 2001 A planet, as defined by the International Astronomical Union (IAU is a celestial body Orbiting a Star or stellar remnant that is The Solar System consists of the Sun and those celestial objects bound to it by Gravity. The Sun (Sol is the Star at the center of the Solar System. Unfortunately, in the geocentric world of the time, Aristarchus' heliocentric theory was deemed outlandish and heretical, and for centuries, the apparently common-sense view that the Sun and other planets went round the Earth went basically unquestioned. In Astronomy, heliocentrism is the theory that the Sun is at the center of the Solar System. Then an astronomer, named Nicolaus Copernicus, revived the heliocentric model in the 16th century. In 1609 Galileo Galilei discovered the four brightest moons of Jupiter, and documented their orbits about that planet, which contradicted the geocentric dogma of the Catholic Church of his time, and escaped serious punishment only by maintaining that his astronomy was a work of mathematics, not of natural philosophy (physics), and therefore purely abstract. Galileo Galilei (15 February 1564 &ndash 8 January 1642 was a Tuscan ( Italian) Physicist, Mathematician, Astronomer, and Philosopher Mathematics is the body of Knowledge and Academic discipline that studies such concepts as Quantity, Structure, Space and

The availability of accurate observational data (mainly from the observatory of Tycho Brahe) led to research into theoretical explanations for the observed behavior. Tycho Brahe, born Tyge Ottesen Brahe ( December 14 1546 &ndash October 24 1601) was a Danish nobleman At first, only empirical rules were discovered, such as Kepler's laws of planetary motion, discovered at the start of the 17th century. A central concept in Science and the Scientific method is that all Evidence must be empirical, or empirically based that is dependent on evidence In Astronomy, Kepler's Laws of Planetary Motion are three mathematical laws that describe the motion of Planets in the Solar System. As a means of recording the passage of Time, the 17th Century was that Century which lasted from 1601 - 1700 in the Gregorian calendar Later that century, Isaac Newton bridged the gap between Kepler's laws and Galileo's dynamics, discovering that the same laws that rule the dynamics of objects on Earth rule the motion of planets and the moon. Sir Isaac Newton, FRS (ˈnjuːtən 4 January 1643 31 March 1727) Biography Early years See also Isaac Newton's early life and achievements Celestial mechanics, the application of Newtonian gravity and Newton's laws to explain Kepler's laws of planetary motion, was the first unification of astronomy and physics. Celestial mechanics is the branch of Astrophysics that deals with the motions of Celestial objects The field applies principles of Physics, historically Gravitation is a natural Phenomenon by which objects with Mass attract one another

After Isaac Newton published his book, Philosophiae Naturalis Principia Mathematica, maritime navigation was transformed. The Philosophiæ Naturalis Principia Mathematica ( Latin: "mathematical principles of natural philosophy" often Principia Navigation is the process of reading and controlling the movement of a craft or vehicle from one place to another Starting around 1670, the entire world was measured using essentially modern latitude instruments and the best available clocks. Latitude, usually denoted symbolically by the Greek letter phi ( Φ) gives the location of a place on Earth (or other planetary body north or south of the Circadian Locomotor Output Cycles Kaput, or Clock is a gene which encodes proteins regulating Circadian rhythm. The needs of navigation provided a drive for progressively more accurate astronomical observations and instruments, providing a background for ever more available data for scientists.

At the end of the 19th century, it was discovered that, when decomposing the light from the Sun, a multitude of spectral lines were observed (regions where there was less or no light). The 19th century of the Common Era began on January 1, 1801 and ended on December 31, 1900, according to the Gregorian calendar A spectral line is a dark or bright line in an otherwise uniform and continuous spectrum, resulting from an excess or deficiency of photons in a narrow frequency range compared Experiments with hot gases showed that the same lines could be observed in the spectra of gases, specific lines corresponding to unique chemical elements. A chemical element is a type of Atom that is distinguished by its Atomic number; that is by the number of Protons in its nucleus. In this way it was proved that the chemical elements found in the Sun (chiefly hydrogen) were also found on Earth. Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 Indeed, the element helium was first discovered in the spectrum of the Sun and only later on Earth, hence its name. Helium ( He) is a colorless odorless tasteless non-toxic Inert Monatomic Chemical Etymology is the study of the History of Words &mdash when they entered a language from what source and how their form and meaning have changed over time During the 20th century, spectroscopy (the study of these spectral lines) advanced, particularly as a result of the advent of quantum physics that was necessary to understand the astronomical and experimental observations. The twentieth century of the Common Era began on Spectroscopy was originally the study of the interaction between Radiation and Matter as a function of Wavelength (λ Quantum mechanics is the study of mechanical systems whose dimensions are close to the Atomic scale such as Molecules Atoms Electrons ^[1]

See also:

• Timeline of knowledge about galaxies, clusters of galaxies, and large-scale structure
• Timeline of white dwarfs, neutron stars, and supernovae
• Timeline of black hole physics
• Timeline of gravitational physics and relativity

Becoming an astrophysicist

To become a classic research astronomer (someone who runs a telescope, analyzes data, publishes papers), astrophysicists need to get a Ph. Timeline of galaxies, clusters of galaxies, and Large-scale structure of the cosmos Pre-20th Century 400s BC Timeline of White dwarfs Neutron stars and Supernovae Note that this list is mainly about the development of knowledge but also about some Timeline of Black hole Physics 1640 - Ismael Bullialdus suggests an inverse-square gravitational force Timeline of Gravitational physics and General relativity 800s - Ja'far Muhammad ibn Mūsā ibn Shākir hypothesizes D. degree. Support positions such as telescope operators, observers, and software developers typically require a Bachelor's degree, although some positions may require a Master's degree or higher. [1] ^[2]

Observational astrophysics

The Pleiades, an open cluster of stars observed in the constellation of Taurus. The Pleiades (ˈpliːədiːz or /ˈplaɪədiːz/ also known as M 45, the '''Seven Sisters''', Seven Stars, SED, Matariki An open cluster is a group of up to a few thousand Stars that were formed from the same Giant molecular cloud, and are still loosely gravitationally In common usage a constellation is a group of celestial bodies that are connected together in some arrangement typically stars to form a visible figure or picture Taurus (it looks like a bull (ˈtɔrəs bull, symbol, Unicode ♉ is one of the Constellations of the Zodiac. NASA photo

The majority of astrophysical observations are made using the electromagnetic spectrum. The National Aeronautics and Space Administration ( NASA, ˈnæsə is an agency of the United States government, responsible for the nation's public space program The electromagnetic (EM spectrum is the range of all possible Electromagnetic radiation frequencies

• Radio astronomy studies radiation with a wavelength greater than a few millimeters. Radio astronomy is a subfield of Astronomy that studies celestial objects at radio frequencies. In Physics wavelength is the distance between repeating units of a propagating Wave of a given Frequency. The Millimetre ( American spelling: millimeter, symbol mm) is a unit of Length in the Metric system, equal to Radio waves are usually emitted by cold objects, including interstellar gas and dust clouds. Radio waves are electromagnetic waves occurring on the Radio frequency portion of the Electromagnetic spectrum. The cosmic microwave background radiation is the redshifted light from the Big Bang. In Physics and Astronomy, redshift occurs when Electromagnetic radiation – usually Visible light – emitted or reflected by The Big Bang is the cosmological model of the Universe that is best supported by all lines of scientific evidence and Observation. Pulsars were first detected at microwave frequencies. Pulsars are highly magnetized rotating Neutron stars that emit a beam of Electromagnetic radiation in the form of radio waves Microwaves are electromagnetic waves with Wavelengths ranging from 1 mm to 1 m or frequencies between 0 The study of these waves requires very large radio telescopes. A radio telescope is a form of directional Radio antenna used in Radio astronomy and in tracking and collecting data from Satellites
• Infrared astronomy studies radiation with a wavelength that is too long to be visible but shorter than radio waves. Infrared ( IR) radiation is Electromagnetic radiation whose Wavelength is longer than that of Visible light, but shorter than that of Infrared observations are usually made with telescopes similar to the usual optical telescopes. Objects colder than stars (such as planets) are normally studied at infrared frequencies.
• Optical astronomy is the oldest kind of astronomy. Telescopes paired with a charge-coupled device or spectroscopes are the most common instruments used. A charge-coupled device ( CCD) is an analog Shift register, that enables the transportation of analog signals (electric charges through successive stages (capacitors A spectrometer is an Optical instrument used to measure properties of Light over a specific portion of the Electromagnetic spectrum, typically used The Earth's atmosphere interferes somewhat with optical observations, so adaptive optics and space telescopes are used to obtain the highest possible image quality. An atmosphere (from Greek ατμός - atmos, " Vapor " + σφαίρα - sphaira, " Sphere " Adaptive optics (AO is a Technology used to improve the performance of optical systems by reducing the effects of rapidly changing optical distortion A space observatory is any instrument in Outer space which is used for observation of distant planets galaxies and other outer space objects In this range, stars are highly visible, and many chemical spectra can be observed to study the chemical composition of stars, galaxies and nebulae. A galaxy is a massive gravitationally bound system consisting of Stars an Interstellar medium of gas and dust, and Dark matter A nebula (from Latin: "mist" pl nebulae or nebulæ, with ligature or nebulas) is an Interstellar cloud of
• Ultraviolet, X-ray and gamma ray astronomy study very energetic processes such as binary pulsars, black holes, magnetars, and many others. Ultraviolet ( UV) light is Electromagnetic radiation with a Wavelength shorter than that of Visible light, but longer than X-rays X-ray astronomy is an observational branch of Astronomy, which deals with the study of X-ray emission from celestial objects Gamma-ray astronomy is the astronomical study of the Cosmos with Gamma rays. A binary pulsar is a Pulsar with a binary companion, often another Pulsar, White dwarf or Neutron star. A black hole is a theoretical region of space in which the Gravitational field is so powerful that nothing not even Electromagnetic radiation (e A magnetar is a Neutron star with an extremely powerful Magnetic field, the decay of which powers the emission of copious amounts of high-energy Electromagnetic These kinds of radiation do not penetrate the Earth's atmosphere well. There are two possibilities to observe this part of the electromagnetic spectrum—space-based telescopes and ground-based imaging air Cherenkov telescopes (IACT). A space observatory is any instrument in Outer space which is used for observation of distant planets galaxies and other outer space objects The IACT or Imaging Atmospheric Cherenkov Technique is the method whereby very high energy Gamma-ray Photons in the 50  GeV to 50  TeV Observatories of the first type are RXTE, the Chandra X-ray Observatory and the Compton Gamma Ray Observatory. An observatory is a location used for observing terrestrial and/or celestial events The Rossi X-ray Timing Explorer ( RXTE) is a satellite that observes the time structure of astronomical x-ray sources The Chandra X-ray Observatory is a Satellite launched on STS-93 by NASA on July 23, 1999. IACTs are, for example, the High Energy Stereoscopic System (H. HESS-dark-fulljpg|thumb|All four telescopes in operation at night]] High Energy Stereoscopic System or H E. S. S. ) and the MAGIC telescope. MAGIC ( Major Atmospheric Gamma-ray Imaging Cherenkov Telescope) is a Gamma-ray telescope situated at the Roque de los Muchachos Observatory on La Palma

Other than electromagnetic radiation, few things may be observed from the Earth that originate from great distances. A few gravitational wave observatories have been constructed, but gravitational waves are extremely difficult to detect. In Physics, a gravitational wave is a Fluctuation in the Curvature of Spacetime which propagates as a wave, traveling outward from Neutrino observatories have also been built, primarily to study our Sun. Neutrinos are Elementary particles that travel close to the Speed of light, lack an Electric charge, are able to pass through ordinary matter almost Cosmic rays consisting of very high energy particles can be observed hitting the Earth's atmosphere. For the 1962 Bruce Conner film see Cosmic Ray (film Cosmic rays are energetic particles originating from space that impinge on

Observations can also vary in their time scale. Most optical observations take minutes to hours, so phenomena that change faster than this cannot readily be observed. However, historical data on some objects is available spanning centuries or millennia. A century (from the Latin centum, meaning one hundred is One hundred consecutive Years Centuries are numbered ordinally (e A millennium (pl millennia) is a period of Time equal to one thousand Years (from Latin la mille, thousand and la annum On the other hand, radio observations may look at events on a millisecond timescale (millisecond pulsars) or combine years of data (pulsar deceleration studies). A millisecond pulsar ( MSP) often referred to as "recycled pulsar", is a Pulsar with a rotational period in the range of about 1-10 Milliseconds Rotation-powered pulsar is one of the major classes of Pulsars A Rotation-powered pulsar is a rapidly rotating Neutron star, whose Electromagnetic The information obtained from these different timescales is very different.

The study of our own Sun has a special place in observational astrophysics. Due to the tremendous distance of all other stars, the Sun can be observed in a kind of detail unparalleled by any other star. Our understanding of our own sun serves as a guide to our understanding of other stars.

The topic of how stars change, or stellar evolution, is often modeled by placing the varieties of star types in their respective positions on the Hertzsprung-Russell diagram, which can be viewed as representing the state of a stellar object, from birth to destruction. Stellar evolution is the process by which a Star undergoes a sequence of radical changes during its lifetime The Hertzsprung-Russell diagram (usually referred to by the abbreviation H-R diagram or HRD, also known as a colour-magnitude diagram, or CMD The material composition of the astronomical objects can often be examined using:

• Spectroscopy
• Radio astronomy
• Neutrino astronomy (future prospects)

Theoretical astrophysics

Theoretical astrophysicists use a wide variety of tools which include analytical models(for example, polytropesto approximate the behaviors of a star) and computationalnumerical simulations. Spectroscopy was originally the study of the interaction between Radiation and Matter as a function of Wavelength (λ Radio astronomy is a subfield of Astronomy that studies celestial objects at radio frequencies. Neutrino astronomy is the branch of astronomy that observes astronomical objects with neutrino detectors in special observatories Note The term model has a different meaning in Model theory, a branch of Mathematical logic. In Astrophysics, a polytrope refers to a solution of the Lane-Emden equation in which the Pressure depends upon the Density in the form P A star is a massive luminous ball of plasma. The nearest star to Earth is the Sun, which is the source of most of the Energy on Earth Computation is a general term for any type of Information processing. Numerical analysis is the study of Algorithms for the problems of continuous mathematics (as distinguished from Discrete mathematics) Each has some advantages. Analytical models of a process are generally better for giving insight into the heart of what is going on. Numerical models can reveal the existence of phenomena and effects that would otherwise not be seen. ^[3][4]Theorists in astrophysics endeavor to create theoretical models and figure out the observational consequences of those models. This helps allow observers to look for data that can refute a model or help in choosing between several alternate or conflicting models. Theorists also try to generate or modify models to take into account new data. In the case of an inconsistency, the general tendency is to try to make minimal modifications to the model to fit the data. In some cases, a large amount of inconsistent data over time may lead to total abandonment of a model. Topics studied by theoretical astrophysicists include: stellar dynamicsand evolution; galaxy formation; large-scale structureof matterin the Universe; origin of cosmic rays; general relativityand physical cosmology, including stringcosmology and astroparticle physics. Stellar dynamics is the branch of Astrophysics which describes in a statistical way the collective motions of Stars subject to their mutual Gravity. Stellar evolution is the process by which a Star undergoes a sequence of radical changes during its lifetime The study of galaxy formation and evolution is concerned with the processes that formed a heterogeneous universe from a homogeneous beginning the formation of the first galaxies the way In Physical cosmology, the term large-scale structure refers to the characterization of observable distributions of Matter and Light Matter is commonly defined as being anything that has mass and that takes up space. The Universe is defined as everything that Physically Exists: the entirety of Space and Time, all forms of Matter, Energy For the 1962 Bruce Conner film see Cosmic Ray (film Cosmic rays are energetic particles originating from space that impinge on General relativity or the general theory of relativity is the geometric theory of Gravitation published by Albert Einstein in 1916 Physical cosmology, as a branch of Astronomy, is the study of the large-scale structure of the Universe and is concerned with fundamental questions about its String theory is a still-developing scientific approach to Theoretical physics, whose original building blocks are one-dimensional extended objects called strings Astroparticle physics is a term used to indicate that branch of Particle physics that studies elementary particles of astronomical origin and their relation to Astrophysics Astrophysical relativity serves as a tool to gauge the properties of large scale structures for which gravitation plays a significant role in physical phenomena investigated and as the basis for black hole(astro)physicsand the study of gravitational waves. A black hole is a theoretical region of space in which the Gravitational field is so powerful that nothing not even Electromagnetic radiation (e Physics (Greek Physis - φύσις in everyday terms is the Science of Matter and its motion. In Physics, a gravitational wave is a Fluctuation in the Curvature of Spacetime which propagates as a wave, traveling outward from Some widely accepted and studied theories and models in astrophysics, now included in the Lambda-CDM modelare the Big Bang, Cosmic inflation, dark matter, and fundamental theories of physics. &LambdaCDM or Lambda-CDM is an abbreviation for Lambda-Cold Dark Matter. The Big Bang is the cosmological model of the Universe that is best supported by all lines of scientific evidence and Observation. In Physical cosmology, cosmic inflation is the idea that the nascent Universe passed through a phase of exponential expansion that In Physics and cosmology, dark matter is hypothetical Matter that does not interact with the electromagnetic force but whose presence can be inferred from Physics (Greek Physis - φύσις in everyday terms is the Science of Matter and its motion. A few examples of this process:

Dark matter and dark energy are the current leading topics in astrophysics, as their discovery and controversy originated during the study of the galaxies. Nucleosynthesis is the process of creating new atomic nuclei from preexisting Nucleons (protons and neutrons Gravitation is a natural Phenomenon by which objects with Mass attract one another A radio telescope is a form of directional Radio antenna used in Radio astronomy and in tracking and collecting data from Satellites In Theoretical astrophysics, the Nordtvedt effect refers to the relative motion between the Earth and the Moon which would be observed if the A star system or stellar system is a small number of Stars which orbit each other bound by gravitational attraction. In Physics and Nuclear chemistry, nuclear fusion is the process by which multiple- like charged atomic nuclei join together to form a heavier nucleus Spectroscopy was originally the study of the interaction between Radiation and Matter as a function of Wavelength (λ Stellar evolution is the process by which a Star undergoes a sequence of radical changes during its lifetime Nucleosynthesis is the process of creating new atomic nuclei from preexisting Nucleons (protons and neutrons The Big Bang is the cosmological model of the Universe that is best supported by all lines of scientific evidence and Observation. The Hubble Space Telescope ( HST; also known colloquially as "the Hubble" or just "Hubble" is a space telescope that was carried into The metric expansion of space is the averaged increase of metric (i The age of the Universe is the time elapsed between the theory of the Big Bang and the present day In Quantum physics, a quantum fluctuation is the temporary change in the amount of energy in a point in space arising from Werner Heisenberg 's Uncertainty principle In Physical cosmology, cosmic inflation is the idea that the nascent Universe passed through a phase of exponential expansion that The flatness problem is a cosmological Fine-tuning problem within the Big Bang model i Gravitational collapse in Astronomy is the inward fall of a massive body under the influence of the force of Gravity. X-ray astronomy is an observational branch of Astronomy, which deals with the study of X-ray emission from celestial objects General relativity or the general theory of relativity is the geometric theory of Gravitation published by Albert Einstein in 1916 A black hole is a theoretical region of space in which the Gravitational field is so powerful that nothing not even Electromagnetic radiation (e The Andromeda Galaxy (ænˈdrɒmədə also known as Messier 31, M31, or NGC 224; often referred to as the Great Andromeda The CNO cycle (for Carbon - Nitrogen - Oxygen) or sometimes Bethe-Weizsäcker-cycle, is one of two sets of fusion reactions A star is a massive luminous ball of plasma. The nearest star to Earth is the Sun, which is the source of most of the Energy on Earth In Physics and cosmology, dark matter is hypothetical Matter that does not interact with the electromagnetic force but whose presence can be inferred from In Physical cosmology, dark energy is a hypothetical exotic form of Energy that permeates all of space and tends to increase the rate of expansion of the universe

See also

• Astronomical observatories
• Important publications in astrophysics
• List of astrophysicists
• Nucleosynthesis
• Particle accelerator
• Astrodynamics
• Astrochemistry

References

External links

• [http://www.intellecttoday.com/ Scientific Discussion: Astrophysics
• Cosmic Journey: A History of Scientific Cosmology from the American Institute of Physics
• Prof. Sir Harry Kroto, NL, Astrophysical Chemistry Lecture Series. 8 Freeview Lectures provided by the Vega Science Trust.
• Stanford Linear Accelerator Center, Stanford, California
• Institute for Space Astrophysics and Cosmic Physics
• Astrophysical Journal
• Astronomy and Astrophysics, a European Journal
• [2]
• Master of Science in Astronomy and Astrophysics