The Annual Review of Astronomy and Astrophysics is an annual peer reviewed scientific journal published by Annual Reviews. The editors-in-chief are Sandra M. Faber (University of California, Santa Cruz) and Ewine van Dishoeck (Sterrewacht Leiden). The journal reviews scientific literature pertaining to local and distant celestial entities throughout the observable universe, as well as cosmology, instrumentation, techniques, and the history of developments. It was established in 1963.
|Annual Review of Astronomy and Astrophysics|
|Edited by||Sandra M. Faber and Ewine F. van Dishoeck|
|Annu. Rev. Astron. Astrophys.|
Alexander Dalgarno FRS (5 January 1928 – 9 April 2015) was a British physicist who was a Phillips Professor of Astronomy at Harvard University.Armin Joseph Deutsch
Armin Joseph Deutsch (A. J. Deutsch, 1918–1969), was an American astronomer and a science fiction writer.
He received a doctorate in astronomy from the University of Chicago in 1946; his undergrad was from the University of Arizona in 1940. He is noted for the concept of Doppler tomography, which he presented at a symposium at Mount Wilson Observatory in 1958. He served as associate editor for the Annual Review of Astronomy and Astrophysics prior to 1966. From 1964 until 1967 he served as a councillor for the American Astronomical Society.Babcock Model
The Babcock Model describes a mechanism which can explain magnetic and sunspot patterns observed on the Sun.Galaxy group
A galaxy group or group of galaxies (GrG) is an aggregation of galaxies comprising about 50 or fewer gravitationally bound members, each at least as luminous as the Milky Way (about 1010 times the luminosity of the Sun); collections of galaxies larger than groups that are first-order clustering are called galaxy clusters. The groups and clusters of galaxies can themselves be clustered, into superclusters of galaxies.
The Milky Way galaxy is part of a group of galaxies called the Local Group.Geoffrey Burbidge
Geoffrey Ronald Burbidge FRS (24 September 1925 – 26 January 2010) was an English astronomy professor and theoretical astrophysicist, most recently at the University of California, San Diego. He was married to astrophysicist Margaret Burbidge.Georgeanne R. Caughlan
Georgeanne (Jan) Caughlan (née Robertson; 25 October 1916 – 3 January 1994) was an American astrophysicist known for her work on stellar energy generation. Her compilation of experimental data of the rates of nuclear reactions was instrumental in establishing the theory of nucleosynthesis that led to a Nobel Prize for William A. Fowler.Herbig–Haro object
Herbig–Haro (HH) objects are turbulent looking patches of nebulosity associated with newborn stars. They are formed when narrow jets of partially ionized gas ejected by said stars collide with nearby clouds of gas and dust at speeds of several hundred kilometres per second. Herbig–Haro objects are ubiquitous in star-forming regions, and several are often seen around a single star, aligned with its rotational axis. Most of them lie within about one parsec of the source, although some have been observed several parsecs away. HH objects are transient phenomena that last around a few tens of thousand years. They can change visibly over quite short timescales of a few years as they move rapidly away from their parent star into the gas clouds of interstellar space (the interstellar medium or ISM). Hubble Space Telescope observations have revealed the complex evolution of HH objects over the period of a few years, as parts of the nebula fade while others brighten as they collide with the clumpy material of the interstellar medium.
First observed in the late 19th century by Sherburne Wesley Burnham, Herbig–Haro objects were not recognised as being a distinct type of emission nebula until the 1940s. The first astronomers to study them in detail were George Herbig and Guillermo Haro, after whom they have been named. Herbig and Haro were working independently on studies of star formation when they first analysed the objects, and recognised that they were a by-product of the star formation process.
Although HH objects are a visible wavelength phenomena, many remain invisible at these wavelengths due to dust and gas envelope and are only visible at infrared wavelengths. Such objects, when observed in near infrared, are called MHOs.Main sequence
In astronomy, the main sequence is a continuous and distinctive band of stars that appears on plots of stellar color versus brightness. These color-magnitude plots are known as Hertzsprung–Russell diagrams after their co-developers, Ejnar Hertzsprung and Henry Norris Russell. Stars on this band are known as main-sequence stars or dwarf stars. These are the most numerous true stars in the universe, and include the Earth's Sun.
After condensation and ignition of a star, it generates thermal energy in its dense core region through nuclear fusion of hydrogen into helium. During this stage of the star's lifetime, it is located on the main sequence at a position determined primarily by its mass, but also based upon its chemical composition and age. The cores of main-sequence stars are in hydrostatic equilibrium, where outward thermal pressure from the hot core is balanced by the inward pressure of gravitational collapse from the overlying layers. The strong dependence of the rate of energy generation on temperature and pressure helps to sustain this balance. Energy generated at the core makes its way to the surface and is radiated away at the photosphere. The energy is carried by either radiation or convection, with the latter occurring in regions with steeper temperature gradients, higher opacity or both.
The main sequence is sometimes divided into upper and lower parts, based on the dominant process that a star uses to generate energy. Stars below about 1.5 times the mass of the Sun (1.5 M☉) primarily fuse hydrogen atoms together in a series of stages to form helium, a sequence called the proton–proton chain. Above this mass, in the upper main sequence, the nuclear fusion process mainly uses atoms of carbon, nitrogen and oxygen as intermediaries in the CNO cycle that produces helium from hydrogen atoms. Main-sequence stars with more than two solar masses undergo convection in their core regions, which acts to stir up the newly created helium and maintain the proportion of fuel needed for fusion to occur. Below this mass, stars have cores that are entirely radiative with convective zones near the surface. With decreasing stellar mass, the proportion of the star forming a convective envelope steadily increases. Main-sequence stars below 0.4 M☉ undergo convection throughout their mass. When core convection does not occur, a helium-rich core develops surrounded by an outer layer of hydrogen.
In general, the more massive a star is, the shorter its lifespan on the main sequence. After the hydrogen fuel at the core has been consumed, the star evolves away from the main sequence on the HR diagram, into a supergiant, red giant, or directly to a white dwarf.OGLE-TR-123
OGLE-TR-123 is a binary stellar system containing one of the smallest main-sequence stars whose radius has been measured. It was discovered when the Optical Gravitational Lensing Experiment (OGLE) survey observed the smaller star eclipsing the larger primary. The orbital period is approximately 1.80 days.The smaller star, OGLE-TR-123b, is estimated to have a radius around 0.13 solar radii, and a mass of around 0.085 solar masses (M☉), or approximately 90 times Jupiter's. OGLE-TR-123b's mass is close to the lowest possible mass, estimated to be around 0.07 or 0.08 M☉, for a hydrogen-fusing star. OGLE-TR-123b is the second star with mass less than 0.1 M☉ whose radius has been directly measured; the first such star was the similar OGLE-TR-122b.Paul W. Hodge
Paul W. Hodge (born 1934) is an American astronomer whose principal area of research is the stellar populations of galaxies.Photodissociation region
Photodissociation regions (or photon-dominated regions, or PDRs) are predominantly neutral regions of the interstellar medium in which far ultraviolet photons strongly influence the gas chemistry and act as the most important source of heat. They occur in any region of interstellar gas that is dense and cold enough to remain neutral, but that has too low a column density to prevent the penetration of far-UV photons from distant, massive stars. A typical and well-studied example is the gas at the boundary of a giant molecular cloud. PDRs are also associated with HII regions, reflection nebulae, active galactic nuclei, and Planetary nebulae. All the atomic gas and most of the molecular gas in the galaxy is found in PDRs.Photometric system
In astronomy, a photometric system is a set of well-defined passbands (or filters), with a known sensitivity to incident radiation. The sensitivity usually depends on the optical system, detectors and filters used. For each photometric system a set of primary standard stars is provided.
The first known standardized photometric system is the Johnson-Morgan or UBV photometric system (1953). At present, there are more than 200 photometric systems.
Photometric systems are usually characterized according to the widths of their passbands:
broadband (passbands wider than 30 nm, of which the most widely used is Johnson-Morgan UBV system)
intermediate band (passbands between 10 and 30 nm wide)
narrow band (passbands less than 10 nm wide)Protoplanetary disk
A protoplanetary disk is a rotating circumstellar disk of dense gas and dust surrounding a young newly formed star, a T Tauri star, or Herbig Ae/Be star. The protoplanetary disk may also be considered an accretion disk for the star itself, because gases or other material may be falling from the inner edge of the disk onto the surface of the star. This process should not be confused with the accretion process thought to build up the planets themselves. Externally illuminated photo-evaporating protoplanetary disks are called proplyds.
In July 2018, the first confirmed image of such a disk, containing a nascent exoplanet, named PDS 70b, was reported.Robert Kraft (astronomer)
Robert Paul "Bob" Kraft (June 16, 1927 – May 26, 2015) was an American astronomer. He performed pioneering work on Cepheid variables, stellar rotation, novae, and the chemical evolution of the Milky Way. His name is also associated with the Kraft break: the abrupt change in the average rotation rate of main sequence stars around spectral type F8.Scott Jay Kenyon
Scott Jay Kenyon (born 1956) is an American astrophysicist. His work has included advances in symbiotic and other types of interacting binary stars, the formation and evolution of stars, and the formation of planetary systems.Superbubble
A superbubble or supershell is a cavity which is hundreds of light years across and is populated with hot (106 K) gas atoms, less dense than the surrounding interstellar medium, blown against that medium and carved out by multiple supernovae and stellar winds. The winds, passage and gravity of newly born stars strip superbubbles of any other dust or gas. The Solar System lies near the center of an old superbubble, known as the Local Bubble, whose boundaries can be traced by a sudden rise in dust extinction of exterior stars at distances greater than a few hundred light years.Synchronous orbit
A synchronous orbit is an orbit in which an orbiting body (usually a satellite) has a period equal to the average rotational period of the body being orbited (usually a planet), and in the same direction of rotation as that body.Tidal circularization
Tidal circularization is an effect of the tidal forces between an orbiting body and the primary object that it orbits, whereby the eccentricity of the orbit is reduced over time so that the orbit becomes less and less elliptical.Virginia Louise Trimble
Virginia Louise Trimble (born 1943) is an American astronomer specializing in the structure and evolution of stars and galaxies, and the history of astronomy. She has published more than 600 works in Astrophysics, and dozens of other works in the history of other sciences. She received the NAS Award for Scientific Reviewing in 1986, "for informing and enlightening the astronomical community by her numerous, comprehensive, scholarly, and literate reviews, which have elucidated many complex astrophysical questions," the Klopsteg Memorial Award from the American Association of Physics Teachers in 2001, and the George Van Biesbroeck Prize in 2010, for "many years of dedicated service to the national and international communities of astronomers, including her expert assessments of progress in all fields of astrophysics and her significant roles in supporting organizations, boards, committees and foundations in the cause of astronomy." She is famous for an annual review of astronomy and astrophysics research that was published in the Publications of the Astronomical Society of the Pacific, and often gives summary reviews at astrophysical conferences. In 2018, she was elected a Patron of the American Astronomical Society, for her many years of intellectual, organizational, and financial contributions to the society.