University of Wyoming
The University of Wyoming is a land-grant university located in Laramie, situated on Wyoming's high Laramie Plains, at an elevation of 7,220 feet, between the Laramie and Snowy Range mountains. It is known as UW to people close to the university; the university was founded in March 1886, four years before the territory was admitted as the 44th state, opened in September 1887. The University of Wyoming is unusual in that its location within the state is written into the state's constitution; the university offers outreach education in communities throughout Wyoming and online. The University of Wyoming consists of seven colleges: agriculture and natural resources and sciences, education and applied sciences, health sciences, law; the university offers over 120 undergraduate and certificate programs including Doctor of Pharmacy and Juris Doctor. The University of Wyoming was featured in the 2011 Princeton Review Best 373 Colleges. In addition to on-campus classes in Laramie, the university's Outreach School offers more than 41 degree and endorsement programs to distance learners across the state and beyond.
These programs are delivered through the use of technology, such as online and video conferencing classes. The Outreach School has nine regional centers in the state, with several on community college campuses, to give Wyoming residents access to a university education without relocating to Laramie. On September 27, 1886, the cornerstone of Old Main was laid marking the beginning of the University of Wyoming; the stone is inscribed Domi Habuit Unde Disceret, translated, "He need not go away from home for instruction." The following year, the first class of women began their college education. For the next decade the building housed a library and administration offices; the style of Old Main set a precedent for all future University buildings. The main stone used is rough-cut sandstone from a quarry east of Laramie and the trim stone is smooth Potsdam Sandstone from a quarry near Rawlins. Old Main was designed to be a monumental structure and was designed to be a symmetrical building with a prominent central spire as the focal point.
The building was designed to reflect the character of Wyoming and the rough stone and smooth trim represented the progressing frontier. The design of Old Main had a lasting effect on university structures, most visible by the use of sandstone façade on nearly every building. In 1916, the central spire was removed due to structural concerns and the auditorium was reduced in size during a 1936 renovation. In 1949, the building was remodeled—the auditorium and exterior stairs were removed, it became known as Old Main and the name was carved above the east entrance. Old Main houses university administration including the President's Office and the board room where the Trustees meet. Prexy's Pasture is a large grassy area located within a ring of classroom and administrative buildings and serves as the center mall of the campus; the name is attributed to an obscure rule that the university president, or "prexy", is given exclusive use of the area for livestock grazing. During the administration of Arthur G. Crane the name, "Prexy's Pasture", was formally declared.
Prexy's, as it is called today, is known for the unique pattern formed by concrete pathways that students and faculty use to cross the pasture. When the University of Wyoming first opened its doors in 1887, Prexy's Pasture was nothing more than an actual pasture covered in native grasses; the football team played their games on the pasture until 1922, when Corbett Field opened at the southeast corner of campus. Over time, as the needs of the university has changed, the area has been redesigned; the original design was established in 1924 and in 1949 the area was landscaped with Blue Spruce and Mugo Pine. In February 1965, the Board of Trustees decided to construct the new science center on the west side of Prexy's Pasture; the board president, Harold F. Newton, concerned about the location, leaked the decision to the local press; the uproar that followed caused the board to decide on a new location for the science center and resulted in a new state statute making it necessary for any new structure built on the pasture to receive legislative approval.
The statue known as "University of Wyoming Family" was installed in 1983 by UW Professor Robert Russin in anticipation of the centennial celebration. In the summer of 2004, Prexy's Pasture was remodeled as the first step in a two part redesign project; this step involved removing the asphalt roadway that circled the pasture and replacing it with concrete walkways to make the area a walking campus, as recommended by the 1966 and 1991 Campus Master Plans. The grassy area was increased and new lampposts were installed for better lighting; the second phase of the project involves the construction of a plaza at each corner featuring trees and rocks styled after the rocky outcrops of nearby Vedauwoo. Two of the plazas, Simpson Plaza and Cheney Plaza, have been completed. Several exhibits from the exhibition Sculpture: A Wyoming Invitational are featured along the exterior walkway. Outside of its primary use by students travelling to and from classes or socializing, the area is host to campus barbecues and fall welcome events.
In September 1937, the university obtained a Public Works Administration loan during the Great Depression for $149,250 for construction of a student union. On March 3, 1938, ground was broken and construction began on what would become the Wyoming Union. Many students were involved in the construction and twenty-five students were trained to be stone-cutters. From the begin
University of Wyoming College of Law
The University of Wyoming College of Law is the law school of the University of Wyoming and the only law school located in Wyoming. It is situated in the rocky mountains in Laramie, Wyoming at 7,165 ft. between the Laramie Mountains and Snowy Range Mountains. It is referred to as "Law at its Highest Point". Established in 1920, the law school offers the J. D. degree in law, as well "a joint JD/MA in Environment and Natural Resources and joint degrees in JD/MPA and JD/MBA. Other electives include coverage of trial and appellate practice, business planning, estate planning and commercial law, administrative law, consumer law, international law, Indian law, health law, education law."The College is accredited by the American Bar Association and its graduates are eligible for admission to the bar in every state. In addition, the College is a member of the Association of American Law Schools; the University of Wyoming College of Law is specially recognized by being admitted as a member of the Order of the Coif.
According to Wyoming's official 2018 ABA-required disclosures, 71.4% of the Class of 2017 obtained full-time, long-term, JD-required employment within nine months of graduation. The University of Wyoming College of Law was founded in 1920. Classes were held on one floor of the University library building until the College of Law moved to a separate facility in 1953; because of increasing class size, the College of Law relocated to its current building in 1977. Considerable library space and a variety of other rooms were added to the building in 1993; the building contains three classrooms, a large moot courtroom, a small moot court room, two seminar rooms, a student lounge area, lockers for every student, the law library, faculty and staff offices. In 2009, the University of Wyoming College of Law finished construction on a large addition to the college of law that expanded the main lecture hall and added two technologically advanced moot court rooms; the main moot court room is the main lecture hall, but includes a retrieving class room wall that opens up into the large moot court room.
This court room has become so useful that since it was finished, the Wyoming Supreme Court and the U. S. Tenth Circuit Court of Appeals have both used it to hear oral arguments; the University of Wyoming College of Law is a public law school. It only has a full-time program. Tuition runs $33,125 for nonresidents. Statistics for 2018 show the median LSAT was a 152 and the median GPA was a 3.39. Those numbers along with all numbers have been on the rise since Dean Easton took his place at the school in 2009. However, Dean Easton resigned as dean in 2013 citing an inability to work with former President Sternberg of the university. President Sternberg resigned shortly after, Steve Easton remained on faculty as a professor; the average first-time bar passing rate for the class of 2017 was 74.17% with the majority of students taking the bar in Wyoming and Colorado. The reported average salary for the class of 2016 was $61,881 for graduates working in the private sector, $53,473 for graduates in the public sector.
The George W. Hopper Law Library at the University of Wyoming College of Law serves the students and staff of the College of Law, as well as the university community and the state; the library's collection includes 206,120 treatises, law reviews and state statutes, administrative decisions, looseleafs, encyclopedias and audio-visual resources. The library has access to many electronic legal databases, such as Westlaw. While many of the databases are only accessible to College of Law students and staff, some are accessible on public computers within the library; the library is open to the public, is used by attorneys throughout the state as well as self-represented litigants. The library, named for a 1956 graduate of the College of Law, includes multiple study rooms that can be reserved for student use, study carrels which are assigned to students through a lottery run by the Potter Law Club; the library is open seven days a week during the spring semesters. The Wyoming Law Review is the legal publication at the University of Wyoming College of Law.
Founded in 1946, the law review publishes semiannually on a variety of topics. The law review is managed by students of the University of Wyoming College of Law. According to Wyoming's official 2018 ABA-required disclosures, 71.4% of the Class of 2013 obtained full-time, long-term, JD-required employment within nine months of graduation. Wyoming's Law School Transparency under-employment score is 15.7%, indicating the percentage of the Class of 2017 unemployed, pursuing an additional degree, or working in a non-professional, short-term, or part-time job nine months after graduation. The total cost of attendance at Wyoming for the 2018-2019 academic year is $32,628 for residents and $49,483 for nonresidents; the Law School Transparency estimated debt-financed cost of attendance for three years is $122,909 for residents and $187,400 for nonresidents. The University of Wyoming College of Law has many alumni Wyoming Supreme Court Judges and 10th circuit judges. All of the Wyoming Supreme Court judges are graduates from the College of Law along with 4 10th circuit judges.
James Emmett Barrett, Wyoming Attorney General, Senior Judge United States Court of Appeals for the Tenth Circuit Wade Brorby, Senior Judge United States Court of Appeals for the Tenth Circuit Ken Buck, U. S. Representative from the 4th District of Colorado E. James Burke, Justice of the Wyomin
Infrared radiation, sometimes called infrared light, is electromagnetic radiation with longer wavelengths than those of visible light, is therefore invisible to the human eye, although IR at wavelengths up to 1050 nanometers s from specially pulsed lasers can be seen by humans under certain conditions. IR wavelengths extend from the nominal red edge of the visible spectrum at 700 nanometers, to 1 millimeter. Most of the thermal radiation emitted by objects near room temperature is infrared; as with all EMR, IR carries radiant energy and behaves both like a wave and like its quantum particle, the photon. Infrared radiation was discovered in 1800 by astronomer Sir William Herschel, who discovered a type of invisible radiation in the spectrum lower in energy than red light, by means of its effect on a thermometer. More than half of the total energy from the Sun was found to arrive on Earth in the form of infrared; the balance between absorbed and emitted infrared radiation has a critical effect on Earth's climate.
Infrared radiation is emitted or absorbed by molecules when they change their rotational-vibrational movements. It excites vibrational modes in a molecule through a change in the dipole moment, making it a useful frequency range for study of these energy states for molecules of the proper symmetry. Infrared spectroscopy examines transmission of photons in the infrared range. Infrared radiation is used in industrial, military, law enforcement, medical applications. Night-vision devices using active near-infrared illumination allow people or animals to be observed without the observer being detected. Infrared astronomy uses sensor-equipped telescopes to penetrate dusty regions of space such as molecular clouds, detect objects such as planets, to view red-shifted objects from the early days of the universe. Infrared thermal-imaging cameras are used to detect heat loss in insulated systems, to observe changing blood flow in the skin, to detect overheating of electrical apparatus. Extensive uses for military and civilian applications include target acquisition, night vision and tracking.
Humans at normal body temperature radiate chiefly at wavelengths around 10 μm. Non-military uses include thermal efficiency analysis, environmental monitoring, industrial facility inspections, detection of grow-ops, remote temperature sensing, short-range wireless communication and weather forecasting. Infrared radiation extends from the nominal red edge of the visible spectrum at 700 nanometers to 1 millimeter; this range of wavelengths corresponds to a frequency range of 430 THz down to 300 GHz. Below infrared is the microwave portion of the electromagnetic spectrum. Sunlight, at an effective temperature of 5,780 kelvins, is composed of near-thermal-spectrum radiation, more than half infrared. At zenith, sunlight provides an irradiance of just over 1 kilowatt per square meter at sea level. Of this energy, 527 watts is infrared radiation, 445 watts is visible light, 32 watts is ultraviolet radiation. Nearly all the infrared radiation in sunlight is shorter than 4 micrometers. On the surface of Earth, at far lower temperatures than the surface of the Sun, some thermal radiation consists of infrared in the mid-infrared region, much longer than in sunlight.
However, black body or thermal radiation is continuous: it gives off radiation at all wavelengths. Of these natural thermal radiation processes, only lightning and natural fires are hot enough to produce much visible energy, fires produce far more infrared than visible-light energy. In general, objects emit infrared radiation across a spectrum of wavelengths, but sometimes only a limited region of the spectrum is of interest because sensors collect radiation only within a specific bandwidth. Thermal infrared radiation has a maximum emission wavelength, inversely proportional to the absolute temperature of object, in accordance with Wien's displacement law. Therefore, the infrared band is subdivided into smaller sections. A used sub-division scheme is: NIR and SWIR is sometimes called "reflected infrared", whereas MWIR and LWIR is sometimes referred to as "thermal infrared". Due to the nature of the blackbody radiation curves, typical "hot" objects, such as exhaust pipes appear brighter in the MW compared to the same object viewed in the LW.
The International Commission on Illumination recommended the division of infrared radiation into the following three bands: ISO 20473 specifies the following scheme: Astronomers divide the infrared spectrum as follows: These divisions are not precise and can vary depending on the publication. The three regions are used for observation of different temperature ranges, hence different environments in space; the most common photometric system used in astronomy allocates capital letters to different spectral regions according to filters used. These letters are understood in reference to atmospheric windows and appear, for instance, in the titles of many papers. A third scheme divides up the band based on the response of various detectors: Near-infrared: from 0.7 to 1.0 µm. Short-wave infrared: 1.0 to 3 µm. InGaAs covers to about 1.8 µm. Mid-wave infrared: 3 to 5 µm (defined by the atmospheric window and covered by indium antimonide and mercury cadmium telluride and by lead
Wyoming Territorial Prison State Historic Site
The Wyoming Territorial Prison is a former federal government prison near Laramie, Wyoming. Built in 1872 it is one of the oldest buildings in Wyoming, it operated as a federal penitentiary from 1872 to 1890, as a state prison from 1890 to 1901. It was transferred to the University of Wyoming and was used as an agricultural experiment station until 1989. In 1991 the facility was opened to the public, in 2004 was designated as Wyoming Territorial Prison State Historic Site; the prison was built in 1872 and began accepting prisoners in early 1873. The facility had problems from the outset, with a fire in recurrent jailbreaks. Of the 44 prisoners accepted in the first two years of operation, 11 escaped. By 1877 the prison was overcrowded; as the prison filled its reputation worsened, it became less used, being considered more appropriate for those with light sentences. During the 1880s the prison was with as few as three prisoners at one time. However, in 1889 a second cellblock was constructed, a expanding capacity to 150 and providing a central kitchen, dining hall, guards' rooms and steam heat.
There were at least five cells for female inmates, several solitary confinement cells. In 1890 Wyoming became a state and the facility was transferred to the new state, which had planned a new facility in Rawlins. Butch Cassidy was incarcerated here in 1894-1896. Prisoners were transferred to Rawlins in 1901, The prison was closed in 1903 and given to the University of Wyoming; the university operated the property to conduct experiments in livestock breeding until 1989. In 1991 the property opened to the public. In 2004 it was established as Wyoming Territorial Prison State Historic Site, it was listed on the National Register of Historic Places on March 29, 1978. When it was built the Wyoming Territorial Penitentiary stood apart from Laramie on the west side of the town, surrounded by open land; the principal buildings are built of rough gray sandstone, embellished by brown sandstone quoining and arches. The original cellblock measured about 40 feet by 70 feet, a mansard roofed rectangular building with a prominent, steeply pitched cross gable.
Tall windows with dormers above illuminate the interior, where most of the cellblocks have been removed and the space adapted to house animals. The original plan consisted of three tiers of cells, each tier with 14 8-foot square cells, heated by fireplaces at either end of the cellblock; the prison was enclosed by a wooden fence, 12 feet high. The warden's residence was built in 1875 by convicts; the stucco-covered stone structure housed the superintendent of the stock farm. The interior, which once had 12-foot ceilings, has been much altered, it was connected to the main building by a tunnel for steam pipes. Wyoming Territorial Prison State Historic Site Wyoming Territorial Prison Wyoming State Parks, Historic Sites & Trails Wyoming Territorial Penitentiary Wyoming State Historic Preservation Office Wyoming Territorial Penitentiary Library of Congress Historic American Buildings Survey
An observatory is a location used for observing terrestrial or celestial events. Astronomy, climatology/meteorology, geophysical and volcanology are examples of disciplines for which observatories have been constructed. Observatories were as simple as containing an astronomical sextant or Stonehenge. Astronomical observatories are divided into four categories: space-based, ground-based, underground-based. Ground-based observatories, located on the surface of Earth, are used to make observations in the radio and visible light portions of the electromagnetic spectrum. Most optical telescopes are housed within a dome or similar structure, to protect the delicate instruments from the elements. Telescope domes have a slit or other opening in the roof that can be opened during observing, closed when the telescope is not in use. In most cases, the entire upper portion of the telescope dome can be rotated to allow the instrument to observe different sections of the night sky. Radio telescopes do not have domes.
For optical telescopes, most ground-based observatories are located far from major centers of population, to avoid the effects of light pollution. The ideal locations for modern observatories are sites that have dark skies, a large percentage of clear nights per year, dry air, are at high elevations. At high elevations, the Earth's atmosphere is thinner, thereby minimizing the effects of atmospheric turbulence and resulting in better astronomical "seeing". Sites that meet the above criteria for modern observatories include the southwestern United States, Canary Islands, the Andes, high mountains in Mexico such as Sierra Negra. A newly emerging site which should be added to this list is Mount Gargash. With an elevation of 3600 m above sea level, it is the home to the Iranian National Observatory and its 3.4m INO340 telescope. Major optical observatories include Mauna Kea Observatory and Kitt Peak National Observatory in the US, Roque de los Muchachos Observatory and Calar Alto Observatory in Spain, Paranal Observatory in Chile.
Specific research study performed in 2009 shows that the best possible location for ground-based observatory on Earth is Ridge A — a place in the central part of Eastern Antarctica. This location provides the least atmospheric disturbances and best visibility. Beginning in 1930s, radio telescopes have been built for use in the field of radio astronomy to observe the Universe in the radio portion of the electromagnetic spectrum; such an instrument, or collection of instruments, with supporting facilities such as control centres, visitor housing, data reduction centers, and/or maintenance facilities are called radio observatories. Radio observatories are located far from major population centers to avoid electromagnetic interference from radio, TV, other EMI emitting devices, but unlike optical observatories, radio observatories can be placed in valleys for further EMI shielding; some of the world's major radio observatories include the Socorro, in New Mexico, United States, Jodrell Bank in the UK, Arecibo in Puerto Rico, Parkes in New South Wales and Chajnantor in Chile.
Since the mid-20th century, a number of astronomical observatories have been constructed at high altitudes, above 4,000–5,000 m. The largest and most notable of these is the Mauna Kea Observatory, located near the summit of a 4,205 m volcano in Hawaiʻi; the Chacaltaya Astrophysical Observatory in Bolivia, at 5,230 m, was the world's highest permanent astronomical observatory from the time of its construction during the 1940s until 2009. It has now been surpassed by the new University of Tokyo Atacama Observatory, an optical-infrared telescope on a remote 5,640 m mountaintop in the Atacama Desert of Chile; the oldest proto-observatories, in the sense of a private observation post, Wurdi Youang, Australia Zorats Karer, Armenia Loughcrew, Ireland Newgrange, Ireland Stonehenge, Great Britain Quito Astronomical Observatory, located 12 minutes south of the Equator in Quito, Ecuador. Chankillo, Peru El Caracol, Mexico Abu Simbel, Egypt Kokino, Republic of Macedonia Observatory at Rhodes, Greece Goseck circle, Germany Ujjain, India Arkaim, Russia Cheomseongdae, South Korea Angkor Wat, CambodiaThe oldest true observatories, in the sense of a specialized research institute, include: 825 AD: Al-Shammisiyyah observatory, Iraq 869: Mahodayapuram Observatory, India 1259: Maragheh observatory, Iran 1276: Gaocheng Astronomical Observatory, China 1420: Ulugh Beg Observatory, Uzbekistan 1442: Beijing Ancient Observatory, China 1577: Constantinople Observatory of Taqi ad-Din, Turkey 1580: Uraniborg, Denmark 1581: Stjerneborg, Denmark 1642: Panzano Observatory, Italy 1642: Round Tower, Denmark 1633: Leiden Observatory, Netherlands 1667: Paris Observatory, France 1675: Royal Greenwich Observatory, England 1695: Sukharev Tower, Russia 1711: Berlin Observatory, Germany 1724: Jantar Mantar, India 1753: Stockholm Observatory, Sweden 1753: Vilnius University Observatory, Lithuania 1753: Navy Royal Institute and Observatory, Spain 1759: Trieste Observatory, Italy 1757: Macfarlane Observatory, Scotland 1759: Turin Observatory, Italy 1764: Brera Astronomical Observatory, Italy 1765: Mohr Observatory, Indonesia 1774: Vatican Observatory, Vatican 1785: Dunsink Observatory, Ireland 1786: Madras Observatory, India 1789: Armagh Observatory, Northern Ireland 1790: Real Observatorio de Madrid, Spain, 1803: National Astronomical Observatory, Bogotá, Colombia.
1811: Tartu Old Observatory, Estonia 1812: Astronomical Observatory of Capodimonte, Italy 1830/1842: Depot of Charts & Instruments
War Memorial Stadium (Laramie, Wyoming)
War Memorial Stadium known as Jonah Field at War Memorial Stadium, is an outdoor college football stadium on the campus of the University of Wyoming in Laramie. It is the home field of the Wyoming Cowboys of the Mountain West Conference; the field is named after a natural gas field at the Green River Basin in Sublette County. At an elevation of 7,215 feet above sea level, War Memorial Stadium is the highest Division I FBS college football stadium in the United States, followed by the Air Force Academy's Falcon Stadium at 6,621 feet. Lying between them in elevation is the Walkup Skydome of Division I FCS Northern Arizona University at 6,900 feet. Along with the War Memorial Fieldhouse, War Memorial Stadium was built 69 years ago in the spring and summer of 1950; the stadium replaced Corbett Field, a small field opened in 1922 and located southeast of Half Acre Gym in land now used by the Business School and the student union parking lot. It sat 20,000 in grandstands on the east and west sides of the field.
In 1970, the western upper deck, containing 5,500 seats and a new press box, was added and in 1978 the eastern press box and northern bleachers were added, bringing capacity up to 33,500. The playing field runs in the traditional north-south configuration. Below the new north end zone scoreboard is a 5 ft 2 in statue Cowboy Tough by Chris Navarro. Fanning a Twister, located to the north of the stadium at the main entrance to the athletic complex, is modeled after a photo of Guy Holt riding Steamboat, the 1909 winner of "Worst Horse" at Frontier Park in Cheyenne. In the 1920s, an equipment manager named. Thinking it embodied the spirit of the athletics program and the cowboy life, he stenciled an outline of the photograph, which became the iconic logo of the university. In 2001, a new video scoreboard was added and the bleachers in the north end zone were moved to the south end zone. In 2004, the western stands were refurbished and the press box expanded. In 2005, the natural grass at War Memorial Stadium was replaced by infilled artificial turf, similar to FieldTurf.
The new surface, known as "Desso Challenge Pro 60 Monofilament Synthetic Turf," was the first of its kind in Division I-A football. It was replaced in 2013 by FieldTurf with enhanced graphics; the field itself was renamed "Jonah Field" in honor of the Wyoming gas fields owned by the primary benefactors of the turf project, the Martin and McMurry families. Capacity was reduced in 2004 to 32,580 and in 2007 to 30,514. Before the 2010 season, the new Wildcatter Stadium Club and Suites opened and capacity was further reduced to 29,181; the Wildcatter features 12 individual suites along with a stadium-club area that contains 256 indoor seats. In addition to UW home games, the stadium hosted the WHSAA State Football Championships in 2009, 2010, in 2011. List of NCAA Division I FBS football stadiums Official website
A Cepheid variable is a type of star that pulsates radially, varying in both diameter and temperature and producing changes in brightness with a well-defined stable period and amplitude. A strong direct relationship between a Cepheid variable's luminosity and pulsation period established Cepheids as important indicators of cosmic benchmarks for scaling galactic and extragalactic distances; this robust characteristic of classical Cepheids was discovered in 1908 by Henrietta Swan Leavitt after studying thousands of variable stars in the Magellanic Clouds. This discovery allows one to know the true luminosity of a Cepheid by observing its pulsation period; this in turn allows one to determine the distance to the star, by comparing its known luminosity to its observed brightness. The term Cepheid originates from Delta Cephei in the constellation Cepheus, identified by John Goodricke in 1784, the first of its type to be so identified. Cepheid variables are divided into two subclasses which exhibit markedly different masses and evolutionary histories: classical Cepheids and type II Cepheids.
Delta Scuti variables are A class stars on or near the main sequence at the lower end of the instability strip and were referred to as dwarf Cepheids. RR Lyrae variables have short periods and lie on the instability strip where it crosses the horizontal branch. Delta Scuti variables and RR Lyrae variables are not treated with Cepheid variables although their pulsations originate with the same helium ionisation kappa mechanism. Classical Cepheids undergo pulsations with regular periods on the order of days to months. Classical Cepheids are Population I variable stars which are 4–20 times more massive than the Sun, up to 100,000 times more luminous; these Cepheids are yellow bright giants and supergiants of spectral class F6 – K2 and their radii change by millions of kilometers during a pulsation cycle. Classical Cepheids are used to determine distances to galaxies within the Local Group and beyond, are a means by which the Hubble constant can be established. Classical Cepheids have been used to clarify many characteristics of our galaxy, such as the Sun's height above the galactic plane and the Galaxy's local spiral structure.
A group of classical Cepheids with small amplitudes and sinusoidal light curves are separated out as Small Amplitude Cepheids or s-Cepheids, many of them pulsating in the first overtone. Type II Cepheids are population II variable stars which pulsate with periods between 1 and 50 days. Type II Cepheids are metal-poor, low mass objects. Type II Cepheids are divided into several subgroups by period. Stars with periods between 1 and 4 days are of the BL Her subclass, 10–20 days belong to the W Virginis subclass, stars with periods greater than 20 days belong to the RV Tauri subclass. Type II Cepheids are used to establish the distance to the Galactic Center, globular clusters, galaxies. A group of pulsating stars on the instability strip have periods of less than 2 days, similar to RR Lyrae variables but with higher luminosities. Anomalous Cepheid variables have masses higher than type II Cepheids, RR Lyrae variables, our sun, it is unclear whether they are young stars on a "turned-back" horizontal branch, blue stragglers formed through mass transfer in binary systems, or a mix of both.
A small proportion of Cepheid variables have been observed to pulsate in two modes at the same time the fundamental and first overtone the second overtone. A small number pulsate in three modes, or an unusual combination of modes including higher overtones. On September 10, 1784, Edward Pigott detected the variability of Eta Aquilae, the first known representative of the class of classical Cepheid variables. However, the eponymous star for classical Cepheids is Delta Cephei, discovered to be variable by John Goodricke a few months later. A relationship between the period and luminosity for classical Cepheids was discovered in 1908 by Henrietta Swan Leavitt in an investigation of thousands of variable stars in the Magellanic Clouds, she published it in 1912 with further evidence. In 1913, Ejnar Hertzsprung attempted to find distances to 13 Cepheids using the motion through the sky, his research would require revision, however. In 1915, Harlow Shapley used Cepheids to place initial constraints on the size and shape of the Milky Way, of the placement of our Sun within it.
In 1924, Edwin Hubble established the distance to classical Cepheid variables in the Andromeda Galaxy, until known as the Andromeda Nebula, showed that the variables were not members of the Milky Way. Hubble's finding settled the question raised in the "Great Debate" of whether the Milky Way represented the entire Universe or was one of numerous galaxies in the Universe. In 1929, Hubble and Milton L. Humason formulated what is now known as Hubble's Law by combining Cepheid distances to several galaxies with Vesto Slipher's measurements of the speed at which those galaxies recede from us, they discovered. However, the expansion of the Universe was posited several years before by Georges Lemaître. In the mid 20th century, significant problems with the astronomical distance scale were resolved by dividing the Cepheids into different classes with different properties. In the 1940s, Walter Baade recognized two separate populations of Cepheids. Classical Cepheids are younger and more massive population I stars, whereas type II Cepheids are older fainter Population II stars.
Classical Cepheids and type