Instruct: Given a question, retrieve relevant documents that can help answer the question.
Query: What is the most common type of star?
Red dwarfs are by far the most common type of star in the Milky Way, at least in the neighborhood of the Sun, but because of their low luminosity, individual red dwarfs cannot be easily observed. From Earth, not one is visible to the naked eye.[1] Proxima Centauri, the nearest star to the Sun, is a red dwarf (Type M5, apparent magnitude 11.05), as are fifty of the sixty nearest stars. According to some estimates, red dwarfs make up three-quarters of the stars in the Milky Way.[2]
It is expected that the existence of dust drives the mass loss in cool stars, but it is unclear what type of dust can form in the atmosphere of an S star with most carbon and oxygen locked into CO gas. The stellar winds of S stars are comparable to oxygen-rich and carbon-rich stars with similar physical properties. There is about 300 times more gas than dust observed in the circumstellar material around S stars. It is believed to be made up of metallic iron, FeSi, silicon carbide, and forsterite. Without silicates and carbon, it is believed that nucleation is triggered by TiC, ZrC, and TiO.
The symptoms of dementia vary across types and stages of the diagnosis. The most common affected areas include memory, visual-spatial, language, attention and problem solving. Most types of dementia are slow and progressive. By the time the person shows signs of the disorder, the process in the brain has been happening for a long time. It is possible for a patient to have two types of dementia at the same time. About 10% of people with dementia have what is known as "mixed dementia", which is usually a combination of Alzheimer's disease and another type of dementia such as frontotemporal dementia or vascular dementia.
The spectral type is formed by the letter S and a number between zero and ten. This number corresponds to the temperature of the star and approximately follows the temperature scale used for class M giants. The most common types are S3 to S5. The non-standard designation S10 has only been used for the star Chi Cygni when at an extreme minimum.
Pulsational pair-instability supernovae are likely the most common pair-instability events and are probably common causes of supernova impostor events. Depending on the nature of the progenitor star they may take the appearance of either a type II, type Ib or type Ic supernova. . Like full scale pair-instability supernovae, pulsational pair-instability supernova are very bright and last for many months longer than a typical type II or type I supernova.
Conventional overhead, trolling or baitcasting type reels usually use one of two types of drags: star or lever. The most common and simplest mechanically is the star drag—so-called because the adjustor wheel looks like a star with rounded points. Star drags work by screw action to increase or decrease the pressure on the washer stack which is usually located on the main driving gear. Reels with star drags generally have a separate lever which allows the reel to go into "freespool" by disengaging the spool from the drive train completely and allowing it to spin freely with little resistance. The freespool position is used for casting, letting line out and/or allowing live bait to move freely.
There are several types of pancreatic cancer, involving both the endocrine and exocrine tissue. Pancreatic adenocarcinoma, which affects the exocrine part of the pancreas, is by far the most common form. The many types of pancreatic endocrine tumors are all uncommon or rare, and have varied outlooks. However the incidence of these cancers has been rising sharply; it is not clear to what extent this reflects increased detection, especially through medical imaging, of tumors that would be very slow to develop. Insulinomas (largely benign) and gastrinomas are the most common types. In the United States pancreatic cancer is the fourth most common cause of deaths due to cancer. The disease occurs more often in the developed world, which had 68% of new cases in 2012. Pancreatic adenocarcinoma typically has poor outcomes with the average percentage alive for at least one and five years after diagnosis being 25% and 5% respectively. In localized disease where the cancer is small (< 2 cm) the number alive at five years is approximately 20%. For those with neuroendocrine cancers the number alive after five years is much better at 65%, varying considerably with type.
Most type II supernova progenitors are thought to be red supergiants, while the less common type Ib/c supernovae are produced by hotter Wolf–Rayet stars that have completely lost more of their hydrogen atmosphere. Almost by definition, supergiants are destined to end their lives violently. Stars large enough to start fusing elements heavier than helium do not seem to have any way to lose enough mass to avoid catastrophic core collapse, although some may collapse, almost without trace, into their own central black holes.
To help with the classification of O-type stars, standard examples are listed for most of the defined types. The following table gives one of the standard stars for each spectral type. In some cases, a standard star has not been defined. For spectral types O2 to O5.5, supergiants are not split into Ia/Iab/Ib sub-types. Subgiant spectral types are not defined for types O2, O2.5, or O3. Bright giant luminosity classes are not defined for stars hotter than O6.
In the past scientists thought that planets would be unlikely to form around binary stars. However, recent simulations indicate that planets are just as likely to form around binary star systems as single-star systems. Of the 3457 exoplanets currently known, 146 actually orbit binary star systems (and 39 orbit multiple star systems with 3 or more stars). Specifically, they orbit what are known as "wide" binary star systems where the two stars are fairly far apart (several AU). Tatooine appears to be of the other type — a "close" binary, where the stars are very close, and the planets orbit their common center of mass.
About two-thirds of all variable stars appear to be pulsating. In the 1930s astronomer Arthur Stanley Eddington showed that the mathematical equations that describe the interior of a star may lead to instabilities that cause a star to pulsate. The most common type of instability is related to oscillations in the degree of ionization in outer, convective layers of the star.
The most massive and most luminous star currently known, R136a1, is also a Wolf–Rayet star of the WNh type that is still fusing hydrogen in its core. This type of star, which includes many of the most luminous and most massive stars, is very young and usually found only in the centre of the densest star clusters. Occasionally a runaway WNh star such as VFTS 682 is found outside such clusters, probably having been ejected from a multiple system or by interaction with other stars.
Only a minority of planetary nebulae have WR type central stars, but a considerable number of well-known planetary nebulae do have them.
OGLE-2003-BLG-235L/MOA-2003-BLG-53L is the designation given to the star in the lens system. In 2004, analysis of the light curve produced as it passed in front of the source star allowed detection of an exoplanet orbiting the star with a mass 0.0039 times that of the host star (this would put it in the jovian mass range). The star was originally assumed to be a red dwarf star, since they are the most common type of star in the galaxy.
Stars are given a single-letter classification according to their spectra, ranging from type "O", which are very hot, to "M", which are so cool that molecules may form in their atmospheres. The main classifications in order of decreasing surface temperature are: "O, B, A, F, G, K", and "M". A variety of rare spectral types are given special classifications. The most common of these are types "L" and "T", which classify the coldest low-mass stars and brown dwarfs. Each letter has 10 sub-divisions, numbered from 0 to 9, in order of decreasing temperature. However, this system breaks down at extreme high temperatures as classes "O0" and "O1" may not exist.
It has been estimated that there are around 20,000 massive O-type stars in the galaxy. The low-mass sdO and CSPNe O-type stars are probably more common, although less luminous and therefore harder to find. Despite their short lifetimes, they are thought to be normal stages in the evolution of common stars only a little more massive than the Sun.
Like the closely related bilimbi, there are two main types of carambola: the small sour (or tart) type and the larger sweet type. The sour varieties have a higher oxalic acid content than the sweet type. A number of cultivars have been developed in recent years. The most common cultivars grown commercially include the sweet types "Arkin" (Florida), "Dah Pon" (Taiwan), "Ma fueng" (Thailand), "Maha" (Malaysia), and "Demak" (Indonesia) and the sour types "Golden Star", "Newcomb", "Star King", and "Thayer" (all from Florida). Some of the sour varieties like "Golden Star" can become sweet if allowed to ripen.
The original diagram displayed the spectral type of stars on the horizontal axis and the absolute visual magnitude on the vertical axis. The spectral type is not a numerical quantity, but the sequence of spectral types is a monotonic series that reflects the stellar surface temperature. Modern observational versions of the chart replace spectral type by a color index (in diagrams made in the middle of the 20th Century, most often the B-V color) of the stars. This type of diagram is what is often called an observational Hertzsprung–Russell diagram, or specifically a color–magnitude diagram (CMD), and it is often used by observers. In cases where the stars are known to be at identical distances such as within a star cluster, a color–magnitude diagram is often used to describe the stars of the cluster with a plot in which the vertical axis is the apparent magnitude of the stars. For cluster members, by assumption there is a single additive constant difference between their apparent and absolute magnitudes, called the distance modulus, for all of that cluster of stars. Early studies of nearby open clusters (like the Hyades and Pleiades) by Hertzsprung and Rosenberg produced the first CMDs, antedating by a few years Russell's influential synthesis of the diagram collecting data for all stars for which absolute magnitudes could be determined.
Most of the work done on the behavioural basis of apostatic selection was done by A.B Bond. It has been suggested that for frequency dependent predation, the amount of encounters with the prey aids to shape the predators prey detection.These ideas are based on the assumption that when the predator is learning foraging behaviour, they are going to obtain the common form more frequently. Since the predator is going to learn what is most frequently and commonly captured, the most common morph is what is identified as prey. This concludes that their foraging behaviour is shaped by this learned preference, thus causing apostatic selection and a fitness benefit to the rare morphs. From this, it was concluded that this search image formation and adaption is the mechanism that drives the most common prey type to be more easily distinguished from the environment, and thus be eaten more frequently.
Wolf–Rayet stars form from massive stars, although the evolved population I stars have lost half or more of their initial masses by the time they show a WR appearance. For example, γ Velorum A currently has a mass around 9 times the Sun, but began with a mass at least 40 times the Sun. High-mass stars are very rare, both because they form less often and because they have short lives. This means that Wolf–Rayet stars themselves are extremely rare because they only form from the most massive main-sequence stars and because they are a relatively short-lived phase in the lives of those stars. This also explains why type Ibc supernovae are less common than type II, since they result from higher-mass stars.
Crosses are fairly common, although most of those found on traditional pysanky are not Ukrainian (Byzantine) crosses. The crosses most commonly depicted are of the simple "Greek" cross type, with arms of equal lengths. This type of cross predates Christianity, and is a sun symbol (an abstracted representation of the solar bird); it is sometimes combined with the star (ruzha) motif. The "cross crosslet" type of cross, one in which the ends of each arm are crossed, is frequently seen, particularly on Hutsul and Bukovynian pysanky.
Type Ib supernovae lack hydrogen lines in their spectra. The more common type Ic supernova lack both hydrogen and helium lines in their spectra. The expected progenitors for such supernova are massive stars that respectively lack hydrogen in their outer layers, or lack both hydrogen and helium. WR stars are just such objects. All WR stars lack hydrogen and in some WR stars, most notably the WO group, helium is also strongly depleted. WR stars are expected to experience core collapse when they have generated an iron core, and resulting supernova explosions would be of type Ib or Ic. In some cases it is possible that direct collapse of the core to a black hole would not produce a visible explosion.
What separates Brain typing from Jungian typology and its offshoots, such as the Myers–Briggs Type Indicator (MBTI) and Socionics, is its emphasis on motor skills. Each of the sixteen brain types is said to specialize in certain regions of the brain responsible for varying degrees of mental and motor skills. Niednagel believes the types are inherited, possessing a genetic basis. The brain types website and books also explain how it differs from the Myers-Briggs Type Indicator in that it believes the ENTP/FCIR type is by far the most common of the sixteen types, whereas some other types presumed as common in the Myers-Briggs Type Indicator, such as the ISTJ/BEIL, are actually only about 3% of the populace according to their estimates.
A simple progression of WR stars from low to hot temperatures, resulting finally in WO-type stars, is not supported by observation. WO-type stars are extremely rare and all the known examples are more luminous and more massive than the relatively common WC stars. Alternative theories suggest either that the WO-type stars are only formed from the most massive main-sequence stars, and/or that they form an extremely short-lived end stage of just a few thousand years before exploding, with the WC phase corresponding to the core helium burning phase and the WO phase to nuclear burning stages beyond. It is still unclear whether the WO spectrum is purely the result of ionisation effects at very high temperature, reflects an actual chemical abundance difference, or if both effects occur to varying degrees.
Within any giant luminosity class, the cooler stars (spectral class K, M, S, and C) are called red giants. Red giants include stars in a number of distinct evolutionary phases of their lives: a main red-giant branch (RGB); a red horizontal branch or red clump; the asymptotic giant branch (AGB), although AGB stars are often large enough and luminous enough to get classified as supergiants; and sometimes other large cool stars such as immediate post-AGB stars. The RGB stars are by far the most common type of giant star due to their moderate mass, relatively long stable lives, and luminosity. They are the most obvious grouping of stars after the main sequence on most HR diagrams, although white dwarfs are more numerous but far less luminous.
Flowcharts are used in designing and documenting simple processes or programs. Like other types of diagrams, they help visualize what is going on and thereby help understand a process, and perhaps also find less-obvious features within the process, like flaws and bottlenecks. There are different types of flowcharts: each type has its own set of boxes and notations. The two most common types of boxes in a flowchart are: