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List Of Coolest Stars
This is a list of coolest stars discovered, arranged by decreasing temperature. The stars with temperatures lower than 2,000 Kelvin, K are included. List See also *List of most massive stars *List of hottest stars *List of largest stars References Lists of stars, coolest stars, list of Lists of superlatives in astronomy, Stars, coolest {{list-stub, date=December 2016 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Temperature
Temperature is a physical quantity that expresses quantitatively the perceptions of hotness and coldness. Temperature is measured with a thermometer. Thermometers are calibrated in various temperature scales that historically have relied on various reference points and thermometric substances for definition. The most common scales are the Celsius scale with the unit symbol °C (formerly called ''centigrade''), the Fahrenheit scale (°F), and the Kelvin scale (K), the latter being used predominantly for scientific purposes. The kelvin is one of the seven base units in the International System of Units (SI). Absolute zero, i.e., zero kelvin or −273.15 °C, is the lowest point in the thermodynamic temperature scale. Experimentally, it can be approached very closely but not actually reached, as recognized in the third law of thermodynamics. It would be impossible to extract energy as heat from a body at that temperature. Temperature is important in all fields of natur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epsilon Indi
Epsilon Indi, Latinized from ε Indi, is a star system located at a distance of approximately 12 light-years from Earth in the southern constellation of Indus. The star has an orange hue and is faintly visible to the naked eye with an apparent visual magnitude of 4.83. It consists of a K-type main-sequence star, ε Indi A, and two brown dwarfs, ε Indi Ba and ε Indi Bb, in a wide orbit around it. The brown dwarfs were discovered in 2003. ε Indi Ba is an early T dwarf (T1) and ε Indi Bb a late T dwarf (T6) separated by 0.6 arcseconds, with a projected distance of 1460 AU from their primary star. ε Indi A has one known planet, ε Indi Ab, with a mass of 3.3 Jupiter masses in a nearly circular orbit with a period of about 45 years. ε Indi Ab is the second-closest Jovian exoplanet, after ε Eridani b. The ε Indi system provides a benchmark case for the study of the formation of gas giants and brown dwarfs. Observation The constellation Indus (the Indian) first appea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Largest Stars
Below are lists of the largest stars currently known, ordered by radius and separated into categories by galaxy. The unit of measurement used is the Solar radius, radius of the Sun (approximately ). The angular diameters of stars can be measured directly using Astronomical optical interferometry, stellar interferometry. Other methods can use lunar occultations or from eclipsing binaries, which can be used to test indirect methods of finding stellar radii. Only a few useful supergiant stars can be occulted by the Moon, including Antares A (Alpha Scorpii A). Examples of eclipsing binaries are Epsilon Aurigae (Almaaz), VV Cephei, and V766 Centauri (HR 5171). Angular diameter measurements can be inconsistent because the boundary of the very tenuous atmosphere (Opacity (optics), opacity) differs depending on the wavelength of light in which the star is observed. Uncertainties remain with the membership and order of the lists, especially when deriving various parameters used in calcu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Hottest Stars
This is a list of hottest stars so far discovered (excluding degenerate stars), arranged by decreasing temperature. The stars with temperatures higher than 60,000 K are included. List See also *List of most massive stars *List of most luminous stars *List of least massive stars This is a list of brown dwarfs. These are objects that have masses between heavy gas giants and low-mass stars. The first isolated brown dwarf discovered was Teide 1 in 1995. The first brown dwarf discovered orbiting a star was Gliese 229 B, ... * List of coolest stars References {{Portal bar, Astronomy, Spaceflight, Outer space, Solar System hottest stars, list of Stars, hottest stars, hottest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Most Massive Stars
This is a list of the most massive stars that have been discovered, in solar masses (). Uncertainties and caveats Most of the masses listed below are contested and, being the subject of current research, remain under review and subject to constant revision of their masses and other characteristics. Indeed, many of the masses listed in the table below are inferred from theory, using difficult measurements of the stars' temperatures and absolute brightnesses. All the masses listed below are uncertain: Both the theory and the measurements are pushing the limits of current knowledge and technology. Both theories and measurements could be incorrect. For example, VV Cephei could be between , or , depending on which property of the star is examined. Complications with distance and obscuring clouds Since massive stars are rare, astronomers must look very far from Earth to find them. All the listed stars are many thousands of light years away, which makes measurements difficult. In addi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
V1426 Cygni
V14 may refer to: * V14 engine, a class of engine * V14, a grade in bouldering * V14, a personal history of allergy to medicinal agents, in the ICD-9 V codes (E000) External cause status * External cause status ** Civilian activity done for income or pay ** Military activity ** Volunteer activity ** Other external cause status ** Unspecified external cause status (E001–E030) Activity * Activ ... * Fokker V.14, an experimental aircraft {{Letter-NumberCombDisambig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
S Aurigae
S, or s, is the nineteenth letter in the Latin alphabet, used in the modern English alphabet, the alphabets of other western European languages and others worldwide. Its name in English is ''ess'' (pronounced ), plural ''esses''. History Origin Northwest Semitic šîn represented a voiceless postalveolar fricative (as in 'ip'). It originated most likely as a pictogram of a tooth () and represented the phoneme via the acrophonic principle. Ancient Greek did not have a phoneme, so the derived Greek letter sigma () came to represent the voiceless alveolar sibilant . While the letter shape Σ continues Phoenician ''šîn'', its name ''sigma'' is taken from the letter ''samekh'', while the shape and position of ''samekh'' but name of ''šîn'' is continued in the '' xi''. Within Greek, the name of ''sigma'' was influenced by its association with the Greek word (earlier ) "to hiss". The original name of the letter "sigma" may have been ''san'', but due to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
T Draconis
T, or t, is the twentieth letter in the Latin alphabet, used in the modern English alphabet, the alphabets of other western European languages and others worldwide. Its name in English is ''tee'' (pronounced ), plural ''tees''. It is derived from the Semitic Taw 𐤕 of the Phoenician and Paleo-Hebrew script ( Aramaic and Hebrew Taw ת/𐡕/, Syriac Taw ܬ, and Arabic ت Tāʼ) via the Greek letter τ ( tau). In English, it is most commonly used to represent the voiceless alveolar plosive, a sound it also denotes in the International Phonetic Alphabet. It is the most commonly used consonant and the second most commonly used letter in English-language texts. History ''Taw'' was the last letter of the Western Semitic and Hebrew alphabets. The sound value of Semitic ''Taw'', Greek alphabet Tαυ (''Tau''), Old Italic and Latin T has remained fairly constant, representing in each of these; and it has also kept its original basic shape in most of these alphabets. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
S Cassiopeiae
S Cassiopeiae (S Cas, HD 7769) is a Mira variable and S-type star in the constellation Cassiopeia. It is an unusually cool star, rapidly losing mass and surrounded by dense gas and dust producing masers. Distance In the absence of a measurement of its parallax by the Hipparcos satellite, its distance from the Solar System was estimated between 1,860 and 2,770 light-years. Gaia Data Release 2 published a parallax of , indicating a distance around , but the observations have a very high noise level and are considered unreliable. A distance of is preferred. Spectral type With a spectral type of S3,4e-S5,8e, S Cassiopeiae is an S-type star similar to χ Cygni; these are asymptotic giant branch (AGB) stars similar to those of class M except that the dominant spectral bands of metal oxides are formed by metals of the fifth period of the periodic table as zirconium or yttrium. Another feature of this class of stars is the high mass loss; in the case of S Cassiopeiae ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
OTS 44
OTS 44 is a free-floating planetary-mass object or brown dwarf located at in the constellation Chamaeleon near the reflection nebula IC 2631. It is among the lowest-mass free-floating substellar objects, with approximately 11.5 times the mass of Jupiter, or approximately 1.1% that of the Sun. Its radius is not very well known and is estimated to be 23–57% that of the Sun. OTS 44 was discovered in 1998 by Oasa, Tamura, and Sugitani as a member of the star-forming region Chamaeleon I. Based upon infrared observations with the Spitzer Space Telescope and the Herschel Space Observatory, OTS 44 emits an excess of infrared radiation for an object of its type, suggesting it has a circumstellar disk of dust and particles of rock and ice. This disk has a mass of at least 10 Earth masses. Observations with the SINFONI spectrograph at the Very Large Telescope show that the disk is accreting matter at the rate of approximately 10−11 of the mass of the Sun per year. It could e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
