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About Cystic Fibrosis | CF Foundation

Watch a video that provides a glimpse into the everyday life of Kaitlyn Broadhurst, a 25-year-old living with cystic fibrosis.

People with cystic fibrosis are at greater risk of getting lung infections because thick, sticky mucus builds up in their lungs, allowing germs to thrive and multiply. Lung infections, caused mostly by bacteria, are a serious and chronic problem for many people living with the disease. Minimizing contact with germs is a top concern for people with CF.

The buildup of mucus in the pancreas can also stop the absorption of food and key nutrients, resulting in malnutrition and poor growth. In the liver, the thick mucus can block the bile duct, causing liver disease. In men, CF can affect their ability to have children.

Breakthrough treatments have added years to the lives of people with cystic fibrosis. Today the median predicted survival age is close to 40. This is a dramatic improvement from the 1950s, when a child with CF rarely lived long enough to attend elementary school.

Because of tremendous advancements in research and care, many people with CF are living long enough to realize their dreams of attending college, pursuing careers, getting married, and having kids.

While there has been significant progress in treating this disease, there is still no cure and too many lives are cut far too short.

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About Cystic Fibrosis | CF Foundation

Cf Industries Holdings, Inc. – CF – Stock Price Today – Zacks

Zacks Earnings ESP (Expected Surprise Prediction) looks to find companies that have recently seen positive earnings estimate revision activity. The idea is that more recent information is, generally speaking, more accurate and can be a better predictor of the future, which can give investors an advantage in earnings season.

The technique has proven to be very useful for finding positive surprises. In fact, when combining a Zacks Rank #3 or better and a positive Earnings ESP, stocks produced a positive surprise 70% of the time, while they also saw 28.3% annual returns on average, according to our 10 year backtest.

Visit the Earnings ESP Center

See the Full List of Stocks To Beat Earnings

( = Change in last 30 days)

View All Zacks Rank #1 Strong Buys

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Cf Industries Holdings, Inc. – CF – Stock Price Today – Zacks

MyCF | My CF

This is a reminder that all students will undergo a mandated change to their CF Portal password on or after Feb. 16, 2018. This is for the portal login only. Your new password must contain at least one of each of the following: one number, one lowercase letter, one uppercase letter, and one of these characters inside the parenthesis (@#$%^&+=) and must be between 8 and 12 characters in length.

Be sure not to use part of your name or CF ID.

You will also be asked to agree to Terms and Conditions for Network use at the College of Central Florida.

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MyCF | My CF

Astrophysics – Wikipedia

This article is about the use of physics and chemistry to determine the nature of astronomical objects. For the use of physics to determine their positions and motions, see Celestial mechanics. For the physical study of the largest-scale structures of the universe, see Physical cosmology. For the journal, see Astrophysics (journal).

Astrophysics is the branch of astronomy that employs the principles of physics and chemistry “to ascertain the nature of the astronomical objects, rather than their positions or motions in space.”[1][2] Among the objects studied are the Sun, other stars, galaxies, extrasolar planets, the interstellar medium and the cosmic microwave background.[3][4] Their emissions are examined across all parts of the electromagnetic spectrum, and the properties examined include luminosity, density, temperature, and chemical composition. 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.

In practice, modern astronomical research often involves a substantial amount of work in the realms of theoretical and observational physics. Some areas of study for astrophysicists include their attempts to determine: the properties of dark matter, dark energy, and black holes; whether or not time travel is possible, wormholes can form, or the multiverse exists; and the origin and ultimate fate of the universe.[3] Topics also studied by theoretical astrophysicists include: Solar System formation and evolution; stellar dynamics and evolution; galaxy formation and evolution; magnetohydrodynamics; large-scale structure of matter in the universe; origin of cosmic rays; general relativity and physical cosmology, including string cosmology and astroparticle physics.

Although astronomy is as ancient as recorded history itself, it was long separated from the study of terrestrial physics. In the Aristotelian worldview, bodies in the sky appeared to be unchanging spheres whose only motion was uniform motion in a circle, while the earthly world was the realm which underwent growth and decay and in which natural motion was in a straight line and ended when the moving object reached its goal. Consequently, it was held that the celestial region was made of a fundamentally different kind of matter from that found in the terrestrial sphere; either Fire as maintained by Plato, or Aether as maintained by Aristotle.[5][6] During the 17th century, natural philosophers such as Galileo,[7] Descartes,[8] and Newton[9] began to maintain that the celestial and terrestrial regions were made of similar kinds of material and were subject to the same natural laws.[10] Their challenge was that the tools had not yet been invented with which to prove these assertions.[11]

For much of the nineteenth century, astronomical research was focused on the routine work of measuring the positions and computing the motions of astronomical objects.[12][13] A new astronomy, soon to be called astrophysics, began to emerge when William Hyde Wollaston and Joseph von Fraunhofer independently discovered that, when decomposing the light from the Sun, a multitude of dark lines (regions where there was less or no light) were observed in the spectrum.[14] By 1860 the physicist, Gustav Kirchhoff, and the chemist, Robert Bunsen, had demonstrated that the dark lines in the solar spectrum corresponded to bright lines in the spectra of known gases, specific lines corresponding to unique chemical elements.[15] Kirchhoff deduced that the dark lines in the solar spectrum are caused by absorption by chemical elements in the Solar atmosphere.[16] In this way it was proved that the chemical elements found in the Sun and stars were also found on Earth.

Among those who extended the study of solar and stellar spectra was Norman Lockyer, who in 1868 detected bright, as well as dark, lines in solar spectra. Working with the chemist, Edward Frankland, to investigate the spectra of elements at various temperatures and pressures, he could not associate a yellow line in the solar spectrum with any known elements. He thus claimed the line represented a new element, which was called helium, after the Greek Helios, the Sun personified.[17][18]

In 1885, Edward C. Pickering undertook an ambitious program of stellar spectral classification at Harvard College Observatory, in which a team of woman computers, notably Williamina Fleming, Antonia Maury, and Annie Jump Cannon, classified the spectra recorded on photographic plates. By 1890, a catalog of over 10,000 stars had been prepared that grouped them into thirteen spectral types. Following Pickering’s vision, by 1924 Cannon expanded the catalog to nine volumes and over a quarter of a million stars, developing the Harvard Classification Scheme which was accepted for worldwide use in 1922.[19]

In 1895, George Ellery Hale and James E. Keeler, along with a group of ten associate editors from Europe and the United States,[20] established The Astrophysical Journal: An International Review of Spectroscopy and Astronomical Physics.[21] It was intended that the journal would fill the gap between journals in astronomy and physics, providing a venue for publication of articles on astronomical applications of the spectroscope; on laboratory research closely allied to astronomical physics, including wavelength determinations of metallic and gaseous spectra and experiments on radiation and absorption; on theories of the Sun, Moon, planets, comets, meteors, and nebulae; and on instrumentation for telescopes and laboratories.[20]

Around 1920, following the discovery of the Hertsprung-Russell diagram still used as the basis for classifying stars and their evolution, Arthur Eddington anticipated the discovery and mechanism of nuclear fusion processes in stars, in his paper The Internal Constitution of the Stars.[22][23] At that time, the source of stellar energy was a complete mystery; Eddington correctly speculated that the source was fusion of hydrogen into helium, liberating enormous energy according to Einstein’s equation E = mc2. This was a particularly remarkable development since at that time fusion and thermonuclear energy, and even that stars are largely composed of hydrogen (see metallicity), had not yet been discovered.[non-primary source needed]

In 1925 Cecilia Helena Payne (later Cecilia Payne-Gaposchkin) wrote an influential doctoral dissertation at Radcliffe College, in which she applied ionization theory to stellar atmospheres to relate the spectral classes to the temperature of stars.[24] Most significantly, she discovered that hydrogen and helium were the principal components of stars. Despite Eddington’s suggestion, this discovery was so unexpected that her dissertation readers convinced her to modify the conclusion before publication. However, later research confirmed her discovery.[25]

By the end of the 20th century, studies of astronomical spectra had expanded to cover wavelengths extending from radio waves through optical, x-ray, and gamma wavelengths.[26] In the 21st century it further expanded to include observations based on gravitational waves.

Observational astronomy is a division of the astronomical science that is concerned with recording data, in contrast with theoretical astrophysics, which is mainly concerned with finding out the measurable implications of physical models. It is the practice of observing celestial objects by using telescopes and other astronomical apparatus.

The majority of astrophysical observations are made using the electromagnetic spectrum.

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. Neutrino observatories have also been built, primarily to study our Sun. Cosmic rays consisting of very high energy particles can be observed hitting the Earth’s atmosphere.

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. On the other hand, radio observations may look at events on a millisecond timescale (millisecond pulsars) or combine years of data (pulsar deceleration studies). The information obtained from these different timescales is very different.

The study of our very 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 HertzsprungRussell diagram, which can be viewed as representing the state of a stellar object, from birth to destruction.

Theoretical astrophysicists use a wide variety of tools which include analytical models (for example, polytropes to approximate the behaviors of a star) and computational numerical simulations. 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.[27][28]

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 dynamics and evolution; galaxy formation and evolution; magnetohydrodynamics; large-scale structure of matter in the universe; origin of cosmic rays; general relativity and physical cosmology, including string cosmology and astroparticle physics. 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)physics and the study of gravitational waves.

Some widely accepted and studied theories and models in astrophysics, now included in the Lambda-CDM model, are the Big Bang, cosmic inflation, dark matter, dark energy and fundamental theories of physics. Wormholes are examples of hypotheses which are yet to be proven (or disproven).

The roots of astrophysics can be found in the seventeenth century emergence of a unified physics, in which the same laws applied to the celestial and terrestrial realms.[10] There were scientists who were qualified in both physics and astronomy who laid the firm foundation for the current science of astrophysics. In modern times, students continue to be drawn to astrophysics due to its popularization by the Royal Astronomical Society and notable educators such as prominent professors Lawrence Krauss, Subrahmanyan Chandrasekhar, Stephen Hawking, Hubert Reeves, Carl Sagan and Neil deGrasse Tyson. The efforts of the early, late, and present scientists continue to attract young people to study the history and science of astrophysics.[29][30][31]

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Astrophysics – Wikipedia

Astrophysics – Play it now at Coolmath-Games.com

‘); } else { //console.log(“User may have come from google or is within the free game limit “+ (freeGameLimit-userPlayedGames) ); //TODO Display Game removeAdSwfJWPLayer(); } } //display to user how many free games left once page load completes. if (window.addEventListener) window.addEventListener(‘load’, checkPageLoad, false); else if (window.attachEvent) window.attachEvent(‘onload’, checkPageLoad); else window.onload = checkPageLoad; }}function checkPageLoad() {//console.log(“checkPageLoad: Checkers test “); if(freeGameLimit) { freeGamesLeft = ((freeGameLimit – userPlayedGames)); } else { freeGamesLeft = 0; } if(freeGamesLeft === 0) { var zeroFreeGamesLeftUsers =localStorage.getItem(“zeroFreeGamesLeftUsers”); if(zeroFreeGamesLeftUsers == null) { localStorage.setItem(“zeroFreeGamesLeftUsers”,”1″); __gaTracker(‘send’, { ‘hitType’: ‘event’, // Required. ‘eventCategory’: “ZeroFreeGamesLeftUsers”, // Required. ‘eventAction’: subscriberLeg, // Required. ‘eventLabel’: document.title, ‘eventValue’: “0”, ‘nonInteraction’: 1 }); } } //Replace Go Ad Free header promo with parents and teachers promo if(typeof freeTrialUser !== ‘undefined’ && freeTrialUser && typeof targeted_state !== ‘undefined’ && targeted_state && jQuery(‘.panel-pane.pane-block.pane-bean-subscriber-promo’).length) { jQuery(‘.panel-pane.pane-block.pane-bean-subscriber-promo’).replaceWith(”) } else if(typeof freeTrialUser !== ‘undefined’ && freeTrialUser && typeof targeted_state !== ‘undefined’ && targeted_state && jQuery(‘.panel-pane.pane-block .pane-bean-subscriber-promo’).length) { jQuery(‘.panel-pane.pane-block .pane-bean-subscriber-promo’).replaceWith(”) } subscriptionSignUpUrl(); if(Drupal.settings.isSubscriptionActive == false && getCookie(‘cmg_l’) !== null) { subscribeNowAlienClass = “subscribe-now-alien-subscribe”; }else if(getCookie(‘cmg_l’) == null) { subscribeNowAlienClass = “subscribe-now-alien”; }else if(getCookie(‘cmg_l’) == null && subscriberLeg == ‘Default Leg’) { subscribeNowAlienClass = “subscribe-now-signup”; } var alreadySubscriberText = ‘

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Company Seven | Astro-Optics Index Page

To learn more about how this site is arranged and how to navigate it, or for those new to Company Seven please Click Here. To learn more about the latest activities, web page changes, and developments at Company Seven then visit our News and Developments page. For those new to astronomy, we also provide Observing Plan Aids to help them learn the sky.

We fondly remember:

Bruce Roy Wrinkle (b. 7 August 1945, d. 28 April 2013) was the soul of our showroom; kind, witty, intelligent, and able to greet you with a funny joke. Bruce was was amazingly well read, able to hold conversations with doctors and scientists on matters from prions to dark matter. And he was our friend, a true friend in every sense of the word and every day without him lacks some luster.

And Robert Kim Carter (b. 18 Jan 1962, d. 23 April 2005) whose friendship and support originally brought this site on line in 1994. Robert founded one of the first Internet Service Providers of “Internet Valley”, Digital Gateway Systems, Inc. in Vienna, Virginia. DGS used to be to ISP’s, as Company Seven is to our industry.

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Company Seven | Astro-Optics Index Page

Astronomy Ireland | Studying Astronomy

Astronomy Ireland are run a twice yearly series of Evening Classes in many towns and cities all around the country.More details HERE

As the national astronomy society in Ireland with 3,000 active members and an even bigger public following we receive a lot ofrequests for information like this so we are very keen to provide a listing of every course in Ireland and you can help us bykeeping us up to date on changes or additions so we may keep this website up to date at all times.

Astronomy Ireland takes on people/students for Work Experience. Typically these are young people doing Transition Year studentsbut we also take on people doing FS courses and others. Email office@astronomy.ie or call 086 06 46 555.

There are still some copies of the Astronomy and Space educationsupplement with what to study and where. Be sure you get your copy.

Astrophysics DeptTel:(021) 4903211

B.Sc in Physics with AstronomyCourse Director: Dr. Enda McGlynnTel: (01) 7005000

Physics with Astronomy and Space ScienceCourse Director: Lorraine HanlonTel: (01) 7162214

B.Sc. in Physics with AstrophysicsCourse Director: Ray ButlerTel: (091) 493788Email: ray.butler@nuigalway.ie

Physics with AstrophysicsHead of Department: Prof. J. Anthony MurphyTel: (01) 7083771

Physics with AstrophysicsHead of School: Prof. James Lunney.Head of Astrophysics: Dr. Peter Gallagher Tel: (01) 896 1300

The Department of Applied Physics& Instrumentation offers postgraduate studies in astrophysics, with emphasis on the development of high-speed imagingdevices.Tel: (021) 4326369

The Department of Physics and AstronomyDepartmental Office physics@qub.ac.ukTel 028 9097 3941

There is an active research community of about 150 Irish astronomers (2007) in the universities of Ireland and D.I.A.S. who canbe contacted at: http://www.arm.ac.uk/asgi

The ASGI holds 2 meetings a year in one of the member institutions, usually around the date of the equinoxes, that last 1 or 2days where short talks on a wide variety of subjects are present and a guest speaker from abroad is usually invite. ASGI also hasan emailing list with notices of meetings, study and job vacancies, etc. Contact the secretary at their website.

If you have any comments, additions or changes email to tom@astronomy.ie

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Astronomy Ireland | Studying Astronomy

Astrophysics – Wikipedia

This article is about the use of physics and chemistry to determine the nature of astronomical objects. For the use of physics to determine their positions and motions, see Celestial mechanics. For the physical study of the largest-scale structures of the universe, see Physical cosmology. For the journal, see Astrophysics (journal).

Astrophysics is the branch of astronomy that employs the principles of physics and chemistry “to ascertain the nature of the heavenly bodies, rather than their positions or motions in space.”[1][2] Among the objects studied are the Sun, other stars, galaxies, extrasolar planets, the interstellar medium and the cosmic microwave background.[3][4] Their emissions are examined across all parts of the electromagnetic spectrum, and the properties examined include luminosity, density, temperature, and chemical composition. 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.

In practice, modern astronomical research often involves a substantial amount of work in the realms of theoretical and observational physics. Some areas of study for astrophysicists include their attempts to determine: the properties of dark matter, dark energy, and black holes; whether or not time travel is possible, wormholes can form, or the multiverse exists; and the origin and ultimate fate of the universe.[3] Topics also studied by theoretical astrophysicists include: Solar System formation and evolution; stellar dynamics and evolution; galaxy formation and evolution; magnetohydrodynamics; large-scale structure of matter in the universe; origin of cosmic rays; general relativity and physical cosmology, including string cosmology and astroparticle physics.

Although astronomy is as ancient as recorded history itself, it was long separated from the study of terrestrial physics. In the Aristotelian worldview, bodies in the sky appeared to be unchanging spheres whose only motion was uniform motion in a circle, while the earthly world was the realm which underwent growth and decay and in which natural motion was in a straight line and ended when the moving object reached its goal. Consequently, it was held that the celestial region was made of a fundamentally different kind of matter from that found in the terrestrial sphere; either Fire as maintained by Plato, or Aether as maintained by Aristotle.[5][6] During the 17th century, natural philosophers such as Galileo,[7] Descartes,[8] and Newton[9] began to maintain that the celestial and terrestrial regions were made of similar kinds of material and were subject to the same natural laws.[10] Their challenge was that the tools had not yet been invented with which to prove these assertions.[11]

For much of the nineteenth century, astronomical research was focused on the routine work of measuring the positions and computing the motions of astronomical objects.[12][13] A new astronomy, soon to be called astrophysics, began to emerge when William Hyde Wollaston and Joseph von Fraunhofer independently discovered that, when decomposing the light from the Sun, a multitude of dark lines (regions where there was less or no light) were observed in the spectrum.[14] By 1860 the physicist, Gustav Kirchhoff, and the chemist, Robert Bunsen, had demonstrated that the dark lines in the solar spectrum corresponded to bright lines in the spectra of known gases, specific lines corresponding to unique chemical elements.[15] Kirchhoff deduced that the dark lines in the solar spectrum are caused by absorption by chemical elements in the Solar atmosphere.[16] In this way it was proved that the chemical elements found in the Sun and stars were also found on Earth.

Among those who extended the study of solar and stellar spectra was Norman Lockyer, who in 1868 detected bright, as well as dark, lines in solar spectra. Working with the chemist, Edward Frankland, to investigate the spectra of elements at various temperatures and pressures, he could not associate a yellow line in the solar spectrum with any known elements. He thus claimed the line represented a new element, which was called helium, after the Greek Helios, the Sun personified.[17][18]

In 1885, Edward C. Pickering undertook an ambitious program of stellar spectral classification at Harvard College Observatory, in which a team of woman computers, notably Williamina Fleming, Antonia Maury, and Annie Jump Cannon, classified the spectra recorded on photographic plates. By 1890, a catalog of over 10,000 stars had been prepared that grouped them into thirteen spectral types. Following Pickering’s vision, by 1924 Cannon expanded the catalog to nine volumes and over a quarter of a million stars, developing the Harvard Classification Scheme which was accepted for worldwide use in 1922.[19]

In 1895, George Ellery Hale and James E. Keeler, along with a group of ten associate editors from Europe and the United States,[20] established The Astrophysical Journal: An International Review of Spectroscopy and Astronomical Physics.[21] It was intended that the journal would fill the gap between journals in astronomy and physics, providing a venue for publication of articles on astronomical applications of the spectroscope; on laboratory research closely allied to astronomical physics, including wavelength determinations of metallic and gaseous spectra and experiments on radiation and absorption; on theories of the Sun, Moon, planets, comets, meteors, and nebulae; and on instrumentation for telescopes and laboratories.[20]

Around 1920, following the discovery of the Hertsprung-Russell diagram still used as the basis for classifying stars and their evolution, Arthur Eddington anticipated the discovery and mechanism of nuclear fusion processes in stars, in his paper The Internal Constitution of the Stars.[22][23] At that time, the source of stellar energy was a complete mystery; Eddington correctly speculated that the source was fusion of hydrogen into helium, liberating enormous energy according to Einstein’s equation E = mc2. This was a particularly remarkable development since at that time fusion and thermonuclear energy, and even that stars are largely composed of hydrogen (see metallicity), had not yet been discovered.[non-primary source needed]

In 1925 Cecilia Helena Payne (later Cecilia Payne-Gaposchkin) wrote an influential doctoral dissertation at Radcliffe College, in which she applied ionization theory to stellar atmospheres to relate the spectral classes to the temperature of stars.[24] Most significantly, she discovered that hydrogen and helium were the principal components of stars. Despite Eddington’s suggestion, this discovery was so unexpected that her dissertation readers convinced her to modify the conclusion before publication. However, later research confirmed her discovery.[25]

By the end of the 20th century, studies of astronomical spectra had expanded to cover wavelengths extending from radio waves through optical, x-ray, and gamma wavelengths.[26] In the 21st century it further expanded to include observations based on gravitational waves.

Observational astronomy is a division of the astronomical science that is concerned with recording data, in contrast with theoretical astrophysics, which is mainly concerned with finding out the measurable implications of physical models. It is the practice of observing celestial objects by using telescopes and other astronomical apparatus.

The majority of astrophysical observations are made using the electromagnetic spectrum.

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. Neutrino observatories have also been built, primarily to study our Sun. Cosmic rays consisting of very high energy particles can be observed hitting the Earth’s atmosphere.

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. On the other hand, radio observations may look at events on a millisecond timescale (millisecond pulsars) or combine years of data (pulsar deceleration studies). The information obtained from these different timescales is very different.

The study of our very 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 HertzsprungRussell diagram, which can be viewed as representing the state of a stellar object, from birth to destruction.

Theoretical astrophysicists use a wide variety of tools which include analytical models (for example, polytropes to approximate the behaviors of a star) and computational numerical simulations. 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.[27][28]

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 dynamics and evolution; galaxy formation and evolution; magnetohydrodynamics; large-scale structure of matter in the universe; origin of cosmic rays; general relativity and physical cosmology, including string cosmology and astroparticle physics. 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)physics and the study of gravitational waves.

Some widely accepted and studied theories and models in astrophysics, now included in the Lambda-CDM model, are the Big Bang, cosmic inflation, dark matter, dark energy and fundamental theories of physics. Wormholes are examples of hypotheses which are yet to be proven (or disproven).

The roots of astrophysics can be found in the seventeenth century emergence of a unified physics, in which the same laws applied to the celestial and terrestrial realms.[10] There were scientists who were qualified in both physics and astronomy who laid the firm foundation for the current science of astrophysics. In modern times, students continue to be drawn to astrophysics due to its popularization by the Royal Astronomical Society and notable educators such as prominent professors Lawrence Krauss, Subrahmanyan Chandrasekhar, Stephen Hawking, Hubert Reeves, Carl Sagan and Neil deGrasse Tyson. The efforts of the early, late, and present scientists continue to attract young people to study the history and science of astrophysics.[29][30][31]

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Astrophysics – Wikipedia

NASA Astrophysics | Science Mission Directorate

In the Science Mission Directorate (SMD), the Astrophysics division studies the universe.The science goals of the SMD Astrophysics Division are breathtaking: we seek to understand the universe and our place in it. We are starting to investigate the very moment of creation of the universe and are close to learning the full history of stars and galaxies. We are discovering how planetary systems form and how environments hospitable for life develop. And we will search for the signature of life on other worlds, perhaps to learn that we are not alone.

NASA’s goal in Astrophysics is to “Discover how the universe works, explore how it began and evolved, and search for life on planets around other stars.” Three broad scientific questions emanate from these goals.

Astrophysics comprises of three focused and two cross-cutting programs. These focused programs provide an intellectual framework for advancing science and conducting strategic planning. They include:

The Astrophysics current missions include three of the Great Observatories originally planned in the 1980s and launched over the past 27 years. The current suite of operational Great Observatories include the Hubble Space Telescope, the Chandra X-ray Observatory, and the Spitzer Space Telescope. Additionally, the Fermi Gamma-ray Space Telescope explores the high-energy end of the spectrum.Innovative Explorer missions, such as the Swift Gamma-ray Explorer and NuSTAR, as well as Mission of Opportunity NICER, complement the Astrophysics strategic missions. SOFIA, an airborne observatory for infrared astronomy, is in its operational phase and the Kepler mission is now actively engaged in K2 extended mission operations. All of the missions together account for much of humanity’s accumulated knowledge of the heavens. Many of these missions have achieved their prime science goals, but continue to produce spectacular results in their extended operations.

NASA-funded investigators also participate in observations, data analysis and developed instruments for the astrophysics missions of our international partners, including ESA’s XMM-Newton.

The near future will be dominated by several missions. Currently in development, with especially broad scientific utility, is the James Webb Space Telescope. Explorer mission TESS is also in development. TESS will provide an all-sky transit survey, identifying planets ranging from Earth-sized to gas giants, orbiting a wide range of stellar types and orbital distances.Also in work are detectors for ESA’s Euclid mission.

Completing the missions in development, supporting the operational missions, and funding the research and analysis programs will consume most of the Astrophysics Division resources.

In February 2016, NASA formally started the top Astro2010 decadal recommendation, the Wide Field Infrared Survey Telescope (WFIRST). WFIRST will aid researchers in their efforts to unravel the secrets of dark energy and dark matter, and explore the evolution of the cosmos. It will also discover new worlds outside our solar system and advance the search for worlds that could be suitable for life.

In January 2017, NASA selected the new Small Explorer (SMEX) mission IXPE (Imaging X-ray Polarimetry Explorer) which uses the polarization state of light from astrophysical sources to provide insight into our understanding of X-ray production in objects such as neutron stars and pulsar wind nebulae, as well as stellar and supermassive black holes.

In March 2017, NASA selected the Explorer Mission of Opportunity GUSTO (Galactic/Extragalactic ULDB Spectroscopic Terahertz Observatory) to measure emissions from the interstellar medium to help scientists determine the life cycle of interstellar gas in our Milky Way, witness the formation and destruction of star-forming clouds, and understand the dynamics and gas flow in the vicinity of the center of our galaxy.

Since the 2001 decadal survey, the way the universe is viewed has changed dramatically. More than 3400 planets have been discovered orbiting distant stars. Black holes are now known to be present at the center of most galaxies, including the Milky Way galaxy. The age, size and shape of the universe have been mapped based on the primordial radiation left by the big bang. And it has been learned that most of the matter in the universe is dark and invisible, and the universe is not only expanding, but accelerating in an unexpected way.

For the long term future, the Astrophysics goals will be guided based on the results of the 2010 Decadal survey New Worlds, New Horizons in Astronomy and Astrophysics. The priority science objectives chosen by the survey committee include: searching for the first stars, galaxies, and black holes; seeking nearby habitable planets; and advancing understanding of the fundamental physics of the universe.In 2016 the New Worlds, New Horizons: A Midterm Assessment was released.

In 2012 the Astrophysics Implementation Plan was released (updated in 2014 and again in 2016) which describes the activities currently being undertaken in response to the decadal survey recommendations within the current budgetary constraints.

The Astrophysics roadmap Enduring Quests, Daring Visions was developed by a task force of the Astrophysics Subcommittee (APS) in 2013. The Roadmap presents a 30-year vision for astrophysics using the most recent decadal survey as the starting point.

Work on the upcoming 2020 decadal survey has commenced. Please visit the “2020 Decadal Planning” page for additional information about the Large Mission and Probe Mission concept studies currently underway.

Continued here:

NASA Astrophysics | Science Mission Directorate

Company Seven | Astro-Optics Index Page

To learn more about how this site is arranged and how to navigate it, or for those new to Company Seven please Click Here. To learn more about the latest activities, web page changes, and developments at Company Seven then visit our News and Developments page. For those new to astronomy, we also provide Observing Plan Aids to help them learn the sky.

We fondly remember:

Bruce Roy Wrinkle (b. 7 August 1945, d. 28 April 2013) was the soul of our showroom; kind, witty, intelligent, and able to greet you with a funny joke. Bruce was was amazingly well read, able to hold conversations with doctors and scientists on matters from prions to dark matter. And he was our friend, a true friend in every sense of the word and every day without him lacks some luster.

And Robert Kim Carter (b. 18 Jan 1962, d. 23 April 2005) whose friendship and support originally brought this site on line in 1994. Robert founded one of the first Internet Service Providers of “Internet Valley”, Digital Gateway Systems, Inc. in Vienna, Virginia. DGS used to be to ISP’s, as Company Seven is to our industry.

Go here to see the original:

Company Seven | Astro-Optics Index Page

NASA Astrophysics | Science Mission Directorate

In the Science Mission Directorate (SMD), the Astrophysics division studies the universe.The science goals of the SMD Astrophysics Division are breathtaking: we seek to understand the universe and our place in it. We are starting to investigate the very moment of creation of the universe and are close to learning the full history of stars and galaxies. We are discovering how planetary systems form and how environments hospitable for life develop. And we will search for the signature of life on other worlds, perhaps to learn that we are not alone.

NASA’s goal in Astrophysics is to “Discover how the universe works, explore how it began and evolved, and search for life on planets around other stars.” Three broad scientific questions emanate from these goals.

Astrophysics comprises of three focused and two cross-cutting programs. These focused programs provide an intellectual framework for advancing science and conducting strategic planning. They include:

The Astrophysics current missions include three of the Great Observatories originally planned in the 1980s and launched over the past 27 years. The current suite of operational Great Observatories include the Hubble Space Telescope, the Chandra X-ray Observatory, and the Spitzer Space Telescope. Additionally, the Fermi Gamma-ray Space Telescope explores the high-energy end of the spectrum.Innovative Explorer missions, such as the Swift Gamma-ray Explorer and NuSTAR, as well as Mission of Opportunity NICER, complement the Astrophysics strategic missions. SOFIA, an airborne observatory for infrared astronomy, is in its operational phase and the Kepler mission is now actively engaged in K2 extended mission operations. All of the missions together account for much of humanity’s accumulated knowledge of the heavens. Many of these missions have achieved their prime science goals, but continue to produce spectacular results in their extended operations.

NASA-funded investigators also participate in observations, data analysis and developed instruments for the astrophysics missions of our international partners, including ESA’s XMM-Newton.

The near future will be dominated by several missions. Currently in development, with especially broad scientific utility, is the James Webb Space Telescope. Explorer mission TESS is also in development. TESS will provide an all-sky transit survey, identifying planets ranging from Earth-sized to gas giants, orbiting a wide range of stellar types and orbital distances.Also in work are detectors for ESA’s Euclid mission.

Completing the missions in development, supporting the operational missions, and funding the research and analysis programs will consume most of the Astrophysics Division resources.

In February 2016, NASA formally started the top Astro2010 decadal recommendation, the Wide Field Infrared Survey Telescope (WFIRST). WFIRST will aid researchers in their efforts to unravel the secrets of dark energy and dark matter, and explore the evolution of the cosmos. It will also discover new worlds outside our solar system and advance the search for worlds that could be suitable for life.

In January 2017, NASA selected the new Small Explorer (SMEX) mission IXPE (Imaging X-ray Polarimetry Explorer) which uses the polarization state of light from astrophysical sources to provide insight into our understanding of X-ray production in objects such as neutron stars and pulsar wind nebulae, as well as stellar and supermassive black holes.

In March 2017, NASA selected the Explorer Mission of Opportunity GUSTO (Galactic/Extragalactic ULDB Spectroscopic Terahertz Observatory) to measure emissions from the interstellar medium to help scientists determine the life cycle of interstellar gas in our Milky Way, witness the formation and destruction of star-forming clouds, and understand the dynamics and gas flow in the vicinity of the center of our galaxy.

Since the 2001 decadal survey, the way the universe is viewed has changed dramatically. More than 3400 planets have been discovered orbiting distant stars. Black holes are now known to be present at the center of most galaxies, including the Milky Way galaxy. The age, size and shape of the universe have been mapped based on the primordial radiation left by the big bang. And it has been learned that most of the matter in the universe is dark and invisible, and the universe is not only expanding, but accelerating in an unexpected way.

For the long term future, the Astrophysics goals will be guided based on the results of the 2010 Decadal survey New Worlds, New Horizons in Astronomy and Astrophysics. The priority science objectives chosen by the survey committee include: searching for the first stars, galaxies, and black holes; seeking nearby habitable planets; and advancing understanding of the fundamental physics of the universe.In 2016 the New Worlds, New Horizons: A Midterm Assessment was released.

In 2012 the Astrophysics Implementation Plan was released (updated in 2014 and again in 2016) which describes the activities currently being undertaken in response to the decadal survey recommendations within the current budgetary constraints.

The Astrophysics roadmap Enduring Quests, Daring Visions was developed by a task force of the Astrophysics Subcommittee (APS) in 2013. The Roadmap presents a 30-year vision for astrophysics using the most recent decadal survey as the starting point.

Work on the upcoming 2020 decadal survey has commenced. Please visit the “2020 Decadal Planning” page for additional information about the Large Mission and Probe Mission concept studies currently underway.

See original here:

NASA Astrophysics | Science Mission Directorate

Astro-Physics – Buy Telescopes

Astro-Physics products can be shipped to overseas destinations except for the following countries: Australia, France, Germany, Italy and Japan.

Astro-Physics is dedicated to the production and development of amateur telescopes and accessories. They strive to produce the highest possible quality telescope components at an affordable price. Astro-Physics builds optics, critical gears, circuit boards, and components including the knobs and fitting from scratch.

Astro-Physics offers a variety of telescope mounts andmount accessories, tube rings and photo / visual accessories.

The German Equatorial mounts Astro-Physics manufactures are: the Mach1GTO, 1100GTO, 1600GTOand 3600GTO. The Mach1GTO is compact, light-weight and portable. The 1100GTO German Equatorial Mount incorporates the design features of the 1600GTO in a smaller, more portable package.The 1600GTO can be used for basic configuration or with the optional Absolute Encoders it can go into demanding astro-imaging. The 3600GTO is the solution for imaging with large instruments or with a combined weight.

Mounting plates are another product of Astro-Physics. They produce an arrangement of dovetail mountings and fixed mountings. Astro-Physics also offer an array of accessories from counterweight shaft options, shaft extension and shaft safety parts, tripod, piers, power supplies and so much more. From the smallest accessory to the largest telescope mount you will find Astro-Physics products to be of the finest quality.

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Astro-Physics – Buy Telescopes

Astrophysics – Wikipedia

This article is about the use of physics and chemistry to determine the nature of astronomical objects. For the use of physics to determine their positions and motions, see Celestial mechanics. For the physical study of the largest-scale structures of the universe, see Physical cosmology. For the journal, see Astrophysics (journal).

Astrophysics is the branch of astronomy that employs the principles of physics and chemistry “to ascertain the nature of the heavenly bodies, rather than their positions or motions in space.”[1][2] Among the objects studied are the Sun, other stars, galaxies, extrasolar planets, the interstellar medium and the cosmic microwave background.[3][4] Their emissions are examined across all parts of the electromagnetic spectrum, and the properties examined include luminosity, density, temperature, and chemical composition. 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.

In practice, modern astronomical research often involves a substantial amount of work in the realms of theoretical and observational physics. Some areas of study for astrophysicists include their attempts to determine: the properties of dark matter, dark energy, and black holes; whether or not time travel is possible, wormholes can form, or the multiverse exists; and the origin and ultimate fate of the universe.[3] Topics also studied by theoretical astrophysicists include: Solar System formation and evolution; stellar dynamics and evolution; galaxy formation and evolution; magnetohydrodynamics; large-scale structure of matter in the universe; origin of cosmic rays; general relativity and physical cosmology, including string cosmology and astroparticle physics.

Although astronomy is as ancient as recorded history itself, it was long separated from the study of terrestrial physics. In the Aristotelian worldview, bodies in the sky appeared to be unchanging spheres whose only motion was uniform motion in a circle, while the earthly world was the realm which underwent growth and decay and in which natural motion was in a straight line and ended when the moving object reached its goal. Consequently, it was held that the celestial region was made of a fundamentally different kind of matter from that found in the terrestrial sphere; either Fire as maintained by Plato, or Aether as maintained by Aristotle.[5][6] During the 17th century, natural philosophers such as Galileo,[7] Descartes,[8] and Newton[9] began to maintain that the celestial and terrestrial regions were made of similar kinds of material and were subject to the same natural laws.[10] Their challenge was that the tools had not yet been invented with which to prove these assertions.[11]

For much of the nineteenth century, astronomical research was focused on the routine work of measuring the positions and computing the motions of astronomical objects.[12][13] A new astronomy, soon to be called astrophysics, began to emerge when William Hyde Wollaston and Joseph von Fraunhofer independently discovered that, when decomposing the light from the Sun, a multitude of dark lines (regions where there was less or no light) were observed in the spectrum.[14] By 1860 the physicist, Gustav Kirchhoff, and the chemist, Robert Bunsen, had demonstrated that the dark lines in the solar spectrum corresponded to bright lines in the spectra of known gases, specific lines corresponding to unique chemical elements.[15] Kirchhoff deduced that the dark lines in the solar spectrum are caused by absorption by chemical elements in the Solar atmosphere.[16] In this way it was proved that the chemical elements found in the Sun and stars were also found on Earth.

Among those who extended the study of solar and stellar spectra was Norman Lockyer, who in 1868 detected bright, as well as dark, lines in solar spectra. Working with the chemist, Edward Frankland, to investigate the spectra of elements at various temperatures and pressures, he could not associate a yellow line in the solar spectrum with any known elements. He thus claimed the line represented a new element, which was called helium, after the Greek Helios, the Sun personified.[17][18]

In 1885, Edward C. Pickering undertook an ambitious program of stellar spectral classification at Harvard College Observatory, in which a team of woman computers, notably Williamina Fleming, Antonia Maury, and Annie Jump Cannon, classified the spectra recorded on photographic plates. By 1890, a catalog of over 10,000 stars had been prepared that grouped them into thirteen spectral types. Following Pickering’s vision, by 1924 Cannon expanded the catalog to nine volumes and over a quarter of a million stars, developing the Harvard Classification Scheme which was accepted for worldwide use in 1922.[19]

In 1895, George Ellery Hale and James E. Keeler, along with a group of ten associate editors from Europe and the United States,[20] established The Astrophysical Journal: An International Review of Spectroscopy and Astronomical Physics.[21] It was intended that the journal would fill the gap between journals in astronomy and physics, providing a venue for publication of articles on astronomical applications of the spectroscope; on laboratory research closely allied to astronomical physics, including wavelength determinations of metallic and gaseous spectra and experiments on radiation and absorption; on theories of the Sun, Moon, planets, comets, meteors, and nebulae; and on instrumentation for telescopes and laboratories.[20]

Around 1920, following the discovery of the Hertsprung-Russell diagram still used as the basis for classifying stars and their evolution, Arthur Eddington anticipated the discovery and mechanism of nuclear fusion processes in stars, in his paper The Internal Constitution of the Stars.[22][23] At that time, the source of stellar energy was a complete mystery; Eddington correctly speculated that the source was fusion of hydrogen into helium, liberating enormous energy according to Einstein’s equation E = mc2. This was a particularly remarkable development since at that time fusion and thermonuclear energy, and even that stars are largely composed of hydrogen (see metallicity), had not yet been discovered.[non-primary source needed]

In 1925 Cecilia Helena Payne (later Cecilia Payne-Gaposchkin) wrote an influential doctoral dissertation at Radcliffe College, in which she applied ionization theory to stellar atmospheres to relate the spectral classes to the temperature of stars.[24] Most significantly, she discovered that hydrogen and helium were the principal components of stars. Despite Eddington’s suggestion, this discovery was so unexpected that her dissertation readers convinced her to modify the conclusion before publication. However, later research confirmed her discovery.[25]

By the end of the 20th century, studies of astronomical spectra had expanded to cover wavelengths extending from radio waves through optical, x-ray, and gamma wavelengths.[26] In the 21st century it further expanded to include observations based on gravitational waves.

Observational astronomy is a division of the astronomical science that is concerned with recording data, in contrast with theoretical astrophysics, which is mainly concerned with finding out the measurable implications of physical models. It is the practice of observing celestial objects by using telescopes and other astronomical apparatus.

The majority of astrophysical observations are made using the electromagnetic spectrum.

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. Neutrino observatories have also been built, primarily to study our Sun. Cosmic rays consisting of very high energy particles can be observed hitting the Earth’s atmosphere.

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. On the other hand, radio observations may look at events on a millisecond timescale (millisecond pulsars) or combine years of data (pulsar deceleration studies). The information obtained from these different timescales is very different.

The study of our very 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 HertzsprungRussell diagram, which can be viewed as representing the state of a stellar object, from birth to destruction.

Theoretical astrophysicists use a wide variety of tools which include analytical models (for example, polytropes to approximate the behaviors of a star) and computational numerical simulations. 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.[27][28]

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 dynamics and evolution; galaxy formation and evolution; magnetohydrodynamics; large-scale structure of matter in the universe; origin of cosmic rays; general relativity and physical cosmology, including string cosmology and astroparticle physics. 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)physics and the study of gravitational waves.

Some widely accepted and studied theories and models in astrophysics, now included in the Lambda-CDM model, are the Big Bang, cosmic inflation, dark matter, dark energy and fundamental theories of physics. Wormholes are examples of hypotheses which are yet to be proven (or disproven).

The roots of astrophysics can be found in the seventeenth century emergence of a unified physics, in which the same laws applied to the celestial and terrestrial realms.[10] There were scientists who were qualified in both physics and astronomy who laid the firm foundation for the current science of astrophysics. In modern times, students continue to be drawn to astrophysics due to its popularization by the Royal Astronomical Society and notable educators such as prominent professors Lawrence Krauss, Subrahmanyan Chandrasekhar, Stephen Hawking, Hubert Reeves, Carl Sagan and Neil deGrasse Tyson. The efforts of the early, late, and present scientists continue to attract young people to study the history and science of astrophysics.[29][30][31]

Read the rest here:

Astrophysics – Wikipedia

Company Seven | Astro-Optics Index Page

To learn more about how this site is arranged and how to navigate it, or for those new to Company Seven please Click Here. To learn more about the latest activities, web page changes, and developments at Company Seven then visit our News and Developments page. For those new to astronomy, we also provide Observing Plan Aids to help them learn the sky.

We fondly remember:

Bruce Roy Wrinkle (b. 7 August 1945, d. 28 April 2013) was the soul of our showroom; kind, witty, intelligent, and able to greet you with a funny joke. Bruce was was amazingly well read, able to hold conversations with doctors and scientists on matters from prions to dark matter. And he was our friend, a true friend in every sense of the word and every day without him lacks some luster.

And Robert Kim Carter (b. 18 Jan 1962, d. 23 April 2005) whose friendship and support originally brought this site on line in 1994. Robert founded one of the first Internet Service Providers of “Internet Valley”, Digital Gateway Systems, Inc. in Vienna, Virginia. DGS used to be to ISP’s, as Company Seven is to our industry.

Read the original:

Company Seven | Astro-Optics Index Page

Company Seven | Astro-Optics Index Page

To learn more about how this site is arranged and how to navigate it, or for those new to Company Seven please Click Here. To learn more about the latest activities, web page changes, and developments at Company Seven then visit our News and Developments page. For those new to astronomy, we also provide Observing Plan Aids to help them learn the sky.

We fondly remember:

Bruce Roy Wrinkle (b. 7 August 1945, d. 28 April 2013) was the soul of our showroom; kind, witty, intelligent, and able to greet you with a funny joke. Bruce was was amazingly well read, able to hold conversations with doctors and scientists on matters from prions to dark matter. And he was our friend, a true friend in every sense of the word and every day without him lacks some luster.

And Robert Kim Carter (b. 18 Jan 1962, d. 23 April 2005) whose friendship and support originally brought this site on line in 1994. Robert founded one of the first Internet Service Providers of “Internet Valley”, Digital Gateway Systems, Inc. in Vienna, Virginia. DGS used to be to ISP’s, as Company Seven is to our industry.

Read the original here:

Company Seven | Astro-Optics Index Page

Astrophysics – Wikipedia

This article is about the use of physics and chemistry to determine the nature of astronomical objects. For the use of physics to determine their positions and motions, see Celestial mechanics. For the physical study of the largest-scale structures of the universe, see Physical cosmology. For the journal, see Astrophysics (journal).

Astrophysics is the branch of astronomy that employs the principles of physics and chemistry “to ascertain the nature of the heavenly bodies, rather than their positions or motions in space.”[1][2] Among the objects studied are the Sun, other stars, galaxies, extrasolar planets, the interstellar medium and the cosmic microwave background.[3][4] Their emissions are examined across all parts of the electromagnetic spectrum, and the properties examined include luminosity, density, temperature, and chemical composition. 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.

In practice, modern astronomical research often involves a substantial amount of work in the realms of theoretical and observational physics. Some areas of study for astrophysicists include their attempts to determine: the properties of dark matter, dark energy, and black holes; whether or not time travel is possible, wormholes can form, or the multiverse exists; and the origin and ultimate fate of the universe.[3] Topics also studied by theoretical astrophysicists include: Solar System formation and evolution; stellar dynamics and evolution; galaxy formation and evolution; magnetohydrodynamics; large-scale structure of matter in the universe; origin of cosmic rays; general relativity and physical cosmology, including string cosmology and astroparticle physics.

Although astronomy is as ancient as recorded history itself, it was long separated from the study of terrestrial physics. In the Aristotelian worldview, bodies in the sky appeared to be unchanging spheres whose only motion was uniform motion in a circle, while the earthly world was the realm which underwent growth and decay and in which natural motion was in a straight line and ended when the moving object reached its goal. Consequently, it was held that the celestial region was made of a fundamentally different kind of matter from that found in the terrestrial sphere; either Fire as maintained by Plato, or Aether as maintained by Aristotle.[5][6] During the 17th century, natural philosophers such as Galileo,[7] Descartes,[8] and Newton[9] began to maintain that the celestial and terrestrial regions were made of similar kinds of material and were subject to the same natural laws.[10] Their challenge was that the tools had not yet been invented with which to prove these assertions.[11]

For much of the nineteenth century, astronomical research was focused on the routine work of measuring the positions and computing the motions of astronomical objects.[12][13] A new astronomy, soon to be called astrophysics, began to emerge when William Hyde Wollaston and Joseph von Fraunhofer independently discovered that, when decomposing the light from the Sun, a multitude of dark lines (regions where there was less or no light) were observed in the spectrum.[14] By 1860 the physicist, Gustav Kirchhoff, and the chemist, Robert Bunsen, had demonstrated that the dark lines in the solar spectrum corresponded to bright lines in the spectra of known gases, specific lines corresponding to unique chemical elements.[15] Kirchhoff deduced that the dark lines in the solar spectrum are caused by absorption by chemical elements in the Solar atmosphere.[16] In this way it was proved that the chemical elements found in the Sun and stars were also found on Earth.

Among those who extended the study of solar and stellar spectra was Norman Lockyer, who in 1868 detected bright, as well as dark, lines in solar spectra. Working with the chemist, Edward Frankland, to investigate the spectra of elements at various temperatures and pressures, he could not associate a yellow line in the solar spectrum with any known elements. He thus claimed the line represented a new element, which was called helium, after the Greek Helios, the Sun personified.[17][18]

In 1885, Edward C. Pickering undertook an ambitious program of stellar spectral classification at Harvard College Observatory, in which a team of woman computers, notably Williamina Fleming, Antonia Maury, and Annie Jump Cannon, classified the spectra recorded on photographic plates. By 1890, a catalog of over 10,000 stars had been prepared that grouped them into thirteen spectral types. Following Pickering’s vision, by 1924 Cannon expanded the catalog to nine volumes and over a quarter of a million stars, developing the Harvard Classification Scheme which was accepted for worldwide use in 1922.[19]

In 1895, George Ellery Hale and James E. Keeler, along with a group of ten associate editors from Europe and the United States,[20] established The Astrophysical Journal: An International Review of Spectroscopy and Astronomical Physics.[21] It was intended that the journal would fill the gap between journals in astronomy and physics, providing a venue for publication of articles on astronomical applications of the spectroscope; on laboratory research closely allied to astronomical physics, including wavelength determinations of metallic and gaseous spectra and experiments on radiation and absorption; on theories of the Sun, Moon, planets, comets, meteors, and nebulae; and on instrumentation for telescopes and laboratories.[20]

Around 1920, following the discovery of the Hertsprung-Russell diagram still used as the basis for classifying stars and their evolution, Arthur Eddington anticipated the discovery and mechanism of nuclear fusion processes in stars, in his paper The Internal Constitution of the Stars.[22][23] At that time, the source of stellar energy was a complete mystery; Eddington correctly speculated that the source was fusion of hydrogen into helium, liberating enormous energy according to Einstein’s equation E = mc2. This was a particularly remarkable development since at that time fusion and thermonuclear energy, and even that stars are largely composed of hydrogen (see metallicity), had not yet been discovered.[non-primary source needed]

In 1925 Cecilia Helena Payne (later Cecilia Payne-Gaposchkin) wrote an influential doctoral dissertation at Radcliffe College, in which she applied ionization theory to stellar atmospheres to relate the spectral classes to the temperature of stars.[24] Most significantly, she discovered that hydrogen and helium were the principal components of stars. Despite Eddington’s suggestion, this discovery was so unexpected that her dissertation readers convinced her to modify the conclusion before publication. However, later research confirmed her discovery.[25]

By the end of the 20th century, studies of astronomical spectra had expanded to cover wavelengths extending from radio waves through optical, x-ray, and gamma wavelengths.[26] In the 21st century it further expanded to include observations based on gravitational waves.

Observational astronomy is a division of the astronomical science that is concerned with recording data, in contrast with theoretical astrophysics, which is mainly concerned with finding out the measurable implications of physical models. It is the practice of observing celestial objects by using telescopes and other astronomical apparatus.

The majority of astrophysical observations are made using the electromagnetic spectrum.

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. Neutrino observatories have also been built, primarily to study our Sun. Cosmic rays consisting of very high energy particles can be observed hitting the Earth’s atmosphere.

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. On the other hand, radio observations may look at events on a millisecond timescale (millisecond pulsars) or combine years of data (pulsar deceleration studies). The information obtained from these different timescales is very different.

The study of our very 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 HertzsprungRussell diagram, which can be viewed as representing the state of a stellar object, from birth to destruction.

Theoretical astrophysicists use a wide variety of tools which include analytical models (for example, polytropes to approximate the behaviors of a star) and computational numerical simulations. 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.[27][28]

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 dynamics and evolution; galaxy formation and evolution; magnetohydrodynamics; large-scale structure of matter in the universe; origin of cosmic rays; general relativity and physical cosmology, including string cosmology and astroparticle physics. 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)physics and the study of gravitational waves.

Some widely accepted and studied theories and models in astrophysics, now included in the Lambda-CDM model, are the Big Bang, cosmic inflation, dark matter, dark energy and fundamental theories of physics. Wormholes are examples of hypotheses which are yet to be proven (or disproven).

The roots of astrophysics can be found in the seventeenth century emergence of a unified physics, in which the same laws applied to the celestial and terrestrial realms.[10] There were scientists who were qualified in both physics and astronomy who laid the firm foundation for the current science of astrophysics. In modern times, students continue to be drawn to astrophysics due to its popularization by the Royal Astronomical Society and notable educators such as prominent professors Lawrence Krauss, Subrahmanyan Chandrasekhar, Stephen Hawking, Hubert Reeves, Carl Sagan and Neil deGrasse Tyson. The efforts of the early, late, and present scientists continue to attract young people to study the history and science of astrophysics.[29][30][31]

Go here to see the original:

Astrophysics – Wikipedia

Company Seven | Astro-Optics Index Page

To learn more about how this site is arranged and how to navigate it, or for those new to Company Seven please Click Here. To learn more about the latest activities, web page changes, and developments at Company Seven then visit our News and Developments page. For those new to astronomy, we also provide Observing Plan Aids to help them learn the sky.

We fondly remember:

Bruce Roy Wrinkle (b. 7 August 1945, d. 28 April 2013) was the soul of our showroom; kind, witty, intelligent, and able to greet you with a funny joke. Bruce was was amazingly well read, able to hold conversations with doctors and scientists on matters from prions to dark matter. And he was our friend, a true friend in every sense of the word and every day without him lacks some luster.

And Robert Kim Carter (b. 18 Jan 1962, d. 23 April 2005) whose friendship and support originally brought this site on line in 1994. Robert founded one of the first Internet Service Providers of “Internet Valley”, Digital Gateway Systems, Inc. in Vienna, Virginia. DGS used to be to ISP’s, as Company Seven is to our industry.

View post:

Company Seven | Astro-Optics Index Page

Company Seven | Astro-Physics Tripods, Portable Piers

ASTRO-PHYSICS ADJUSTABLE HEIGHT WOOD FIELD TRIPOD, AND PORTABLE PIERS FOR MODEL400, 600, 800, 900, AND 1200 SERIES GERMAN EQUATORIAL MOUNTS

Astro-Physics German equatorial mounts employ either a portable tripod, or a portable or a fixed pier as a support stand. Theassembled portable piers are under stress to provide excellent rigidity. The portable piers are also a good choice for travelby air or cargo as they are very resistant to impact damage. Neither of these choices of stand requires any tools for assemblyin the field, although to install a Model 900 or 1200 head requires an Allen wrench that is provided with the mount head.

It is possible to have a metal pier fabricated locally, and then install it (into a foundation below the regional frost line)at a convenient observing location. Utilities for power and signal can be installed below ground and up through the pier.Those persons interested in such an effort should contact us for specific advice.

The selection of a field tripod or a portable pier will to some degree be a matter of personal preference. For those personswho intend to do astrophotography (film or CCD), or for those where economy and durability are a concern then we do suggest aportable or permanent pier. For those where the convenience of height adjustment, quicker set up and disassembly, oraesthetics are a concern then the wood or aluminum tripods may be a good choice.

Portable Piers:

These piersfeature a unique tension design that combines rugged construction with light weight, while also eliminating flexure andannoying vibrations. Legs and tension rods attach without the need for any tools thereby permitting assembly in a matter of afew minutes. The stainless steel tension rods do not interfere when the telescope is pointed at zenith as the rods are locateda reasonable distance below the mount head. Turnbuckles are used to adjust tension on the rods; these also allow limitedultra-fine adjustments when polar aligning. The tension system is the simple technology that results in the firm base ofsupport provided by the portable pier. The center post is constructed of aluminum tubing, the base and legs are of steel. Theconstruction materials and finish provide great resistance to the environmental elements.

Piers have no provisions for leveling nor is it necessary; the mount heads have adjustments to make polar alignment even onuneven terrain. For reasons of stability it is desirable to locate a pier (or a tripod) on as firm and level ground as ispossible. Sand bags may be installed within and or inside the piers to add rigidity and dampening in wind prone environments.

Astro-Physics Adjustable Height Wood Field Tripod (AWT000):

This tripod can easily be set up level with out the use of any tools. While this not necessary since the mount heads haveadjustment devices to polar align even on uneven terrain, leveling the tripod can minimize adjustment in elevation of themount head. For reasons of stability it is desirable to locate a tripod (or a pier) on as firm and level ground as ispossible. Sand bags may be installed at the feet of the tripod to add rigidity and dampening in wind prone environments.

Support Bar and Accessory Tray for Astro-Physics Piers:

For those who wish a convenient location for the placement of small accessories, Astro-Physics has produced a support bar andaccessory tray. In addition to serving as a storage shelf, when used as a pair the top tray will keep dew from forming onaccessories placed onto a lower accessory tray.

A Support Bar (TRAYSB) is attached to one of the holes at the top of a pier post. Each support bar can accept up to twoaccessory trays. Each accessory tray spans 120 degrees (1/3) of the pier so that you can construct a complete 360 degreecircular tray around the pier post with just three support bars and three trays. These trays slip into the support bars. Theavailable trays are:

It is possible to buy Astro-Physics support bar and accessory tray systems for installation onto any portable or permanentpier that complies with the Astro-Physics specifications for pier diameter and hole pattern.

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Company Seven | Astro-Physics Tripods, Portable Piers

Company Seven | Astro-Physics Tripods, Portable Piers

ASTRO-PHYSICS ADJUSTABLE HEIGHT WOOD FIELD TRIPOD, AND PORTABLE PIERS FOR MODEL400, 600, 800, 900, AND 1200 SERIES GERMAN EQUATORIAL MOUNTS

Astro-Physics German equatorial mounts employ either a portable tripod, or a portable or a fixed pier as a support stand. Theassembled portable piers are under stress to provide excellent rigidity. The portable piers are also a good choice for travelby air or cargo as they are very resistant to impact damage. Neither of these choices of stand requires any tools for assemblyin the field, although to install a Model 900 or 1200 head requires an Allen wrench that is provided with the mount head.

It is possible to have a metal pier fabricated locally, and then install it (into a foundation below the regional frost line)at a convenient observing location. Utilities for power and signal can be installed below ground and up through the pier.Those persons interested in such an effort should contact us for specific advice.

The selection of a field tripod or a portable pier will to some degree be a matter of personal preference. For those personswho intend to do astrophotography (film or CCD), or for those where economy and durability are a concern then we do suggest aportable or permanent pier. For those where the convenience of height adjustment, quicker set up and disassembly, oraesthetics are a concern then the wood or aluminum tripods may be a good choice.

Portable Piers:

These piersfeature a unique tension design that combines rugged construction with light weight, while also eliminating flexure andannoying vibrations. Legs and tension rods attach without the need for any tools thereby permitting assembly in a matter of afew minutes. The stainless steel tension rods do not interfere when the telescope is pointed at zenith as the rods are locateda reasonable distance below the mount head. Turnbuckles are used to adjust tension on the rods; these also allow limitedultra-fine adjustments when polar aligning. The tension system is the simple technology that results in the firm base ofsupport provided by the portable pier. The center post is constructed of aluminum tubing, the base and legs are of steel. Theconstruction materials and finish provide great resistance to the environmental elements.

Piers have no provisions for leveling nor is it necessary; the mount heads have adjustments to make polar alignment even onuneven terrain. For reasons of stability it is desirable to locate a pier (or a tripod) on as firm and level ground as ispossible. Sand bags may be installed within and or inside the piers to add rigidity and dampening in wind prone environments.

Astro-Physics Adjustable Height Wood Field Tripod (AWT000):

This tripod can easily be set up level with out the use of any tools. While this not necessary since the mount heads haveadjustment devices to polar align even on uneven terrain, leveling the tripod can minimize adjustment in elevation of themount head. For reasons of stability it is desirable to locate a tripod (or a pier) on as firm and level ground as ispossible. Sand bags may be installed at the feet of the tripod to add rigidity and dampening in wind prone environments.

Support Bar and Accessory Tray for Astro-Physics Piers:

For those who wish a convenient location for the placement of small accessories, Astro-Physics has produced a support bar andaccessory tray. In addition to serving as a storage shelf, when used as a pair the top tray will keep dew from forming onaccessories placed onto a lower accessory tray.

A Support Bar (TRAYSB) is attached to one of the holes at the top of a pier post. Each support bar can accept up to twoaccessory trays. Each accessory tray spans 120 degrees (1/3) of the pier so that you can construct a complete 360 degreecircular tray around the pier post with just three support bars and three trays. These trays slip into the support bars. Theavailable trays are:

It is possible to buy Astro-Physics support bar and accessory tray systems for installation onto any portable or permanentpier that complies with the Astro-Physics specifications for pier diameter and hole pattern.

See more here:

Company Seven | Astro-Physics Tripods, Portable Piers

Company Seven | Astro-Optics Index Page

To learn more about how this site is arranged and how to navigate it, or for those new to Company Seven please Click Here. To learn more about the latest activities, web page changes, and developments at Company Seven then visit our News and Developments page. For those new to astronomy, we also provide Observing Plan Aids to help them learn the sky.

We fondly remember:

Bruce Roy Wrinkle (b. 7 August 1945, d. 28 April 2013) was the soul of our showroom; kind, witty, intelligent, and able to greet you with a funny joke. Bruce was was amazingly well read, able to hold conversations with doctors and scientists on matters from prions to dark matter. And he was our friend, a true friend in every sense of the word and every day without him lacks some luster.

And Robert Kim Carter (b. 18 Jan 1962, d. 23 April 2005) whose friendship and support originally brought this site on line in 1994. Robert founded one of the first Internet Service Providers of “Internet Valley”, Digital Gateway Systems, Inc. in Vienna, Virginia. DGS used to be to ISP’s, as Company Seven is to our industry.

Read more from the original source:

Company Seven | Astro-Optics Index Page


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