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BY Draconis Variables
BY Draconis variables are variable stars of stellar classification, late spectral types, usually K or M, and typically belong to the main sequence. The name comes from the archetype for this category of variable star system, BY Draconis. They exhibit variations in their luminosity due to rotation of the star coupled with starspots, and other chromosphere, chromospheric activity. Resultant brightness fluctuations are generally less than 0.5 Apparent magnitude, magnitudes. Light curves of BY Draconis variables are quasiperiodicity, quasiperiodic. The period is close to the star's mean rotational rate. The light curve is irregular over the duration of the period and it changes slightly in shape from one period to the next. For the star BY Draconis the shape of the light curve over a period remained similar for a month. Nearby K and M stars that are BY Draconis variables include Barnard's Star, Kapteyn's Star, 61 Cygni, Ross 248, Lacaille 8760, Lalande 21185, Epsilon Eridani and Luyten ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
V1297 Her TESS Light Curve
V1 can refer to the first version of anything. V1, V01 or V-1 may also refer to: In aircraft * V-1 flying bomb, a World War II German weapon * V1 speed, V1 speed, the maximum speed at which an aircraft pilot may abort a takeoff without causing a runway overrun * Vultee V-1, an American single-engine airliner of the 1930s * Fokker V.1, a German parasol monoplane experimental fighter prototype, built in 1916 * The first prototype/experimental ''(Versuchs)'' airframe of nearly List of RLM aircraft designations, any German WW II-era military aircraft Vessels * V1-class destroyer, a German World War I destroyer class * USS V-1, 1924–1931 designation of the USS Barracuda (SS-163), USS ''Barracuda'' (SS-163), first of the US "V-boat" series of submarines * V1, a rudderless single-paddler outrigger canoe * V1, the first prototype of the Panzer VIII Maus tank In medicine * V1, the Visual cortex#Primary visual cortex (V1), primary visual cortex * V1, the ophthalmic nerve, first division ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
61 Cygni
61 Cygni is a binary star system in the constellation Cygnus (constellation), Cygnus, consisting of a pair of K-type main-sequence star, K-type dwarf stars that orbit each other in a period of about 659 years. Of apparent magnitude 5.20 and 6.05, respectively, they can be seen with binoculars in city skies or with the naked eye in rural areas without light pollution. 61 Cygni first attracted the attention of astronomers when its large proper motion was first demonstrated by Giuseppe Piazzi in 1804. In 1838, Friedrich Bessel measured its distance from Earth at about 10.4 light-years, very close to the actual value of about 11.4 light-years; this was the first distance estimate for any star other than the Sun, and the first star to have its stellar parallax measured. Among all stars or stellar systems listed in the latest Gaia catalogues, 61 Cygni has the sixth-highest proper motion, and the highest among all visible stars or systems.By convention, limitin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RS Canum Venaticorum Variable
An RS Canum Venaticorum variable is a type of variable star. The variable type consists of close binary stars having active chromospheres which can cause large stellar spots. These spots are believed to cause variations in their observed luminosity. Systems can exhibit variations on timescales of years due to variation in the spot surface coverage fraction, as well as periodic variations which are, in general, close to the orbital period of the binary system. Some systems exhibit variations in luminosity due to their being eclipsing binaries. Typical brightness fluctuation is around 0.2 magnitudes. They take their name from the star RS Canum Venaticorum (abbreviated RS CVn). Otto Struve (1946) first called attention to the group, but it was Oliver (1974) who was the first to formally propose a set of observational characteristics to define the RS CVn criteria. The working definition, as it is used today, was that set down by Hall (1976). Berdyuginabr>2.4 RS CVn stars/ref> The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fraunhofer Lines
The Fraunhofer lines are a set of spectral absorption lines. They are dark absorption lines, seen in the optical spectrum of the Sun, and are formed when atoms in the solar atmosphere absorb light being emitted by the solar photosphere. The lines are named after German physicist Joseph von Fraunhofer, who observed them in 1814. Discovery In 1802, English chemist William Hyde WollastonMelvyn C. UsselmanWilliam Hyde WollastonEncyclopædia Britannica, retrieved 31 March 2013 was the first person to note the appearance of a number of dark features in the solar spectrum. In 1814, Joseph von Fraunhofer independently rediscovered the lines and began to systematically study and measure their wavelengths. He mapped over 570 lines, designating the most prominent with the letters A through K and weaker lines with other letters. Modern observations of sunlight can detect many thousands of lines. About 45 years later, Gustav Kirchhoff and Robert Bunsen noticed that several Fraunhofer li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flare Star
A flare star is a variable star that can undergo unpredictable dramatic increases in brightness for a few minutes. It is believed that the flares on flare stars are analogous to solar flares in that they are due to magnetic reconnection, the magnetic energy stored in the stars' atmospheres. The brightness increase is across the Electromagnetic spectrum, spectrum, from X-rays to radio waves. Flare activity among late-type stars was first reported by Adriaan van Maanen, A. van Maanen in 1945, for Gliese 412, WX Ursae Majoris and YZ Canis Minoris. However, the best-known flare star is UV Ceti, first observed to flare in 1948. Today similar flare stars are classified as UV Ceti type variable stars (using the abbreviation UV) in variable star catalogs such as the General Catalogue of Variable Stars. Most flare stars are dim red dwarfs, although recent research indicates that less massive brown dwarfs might also be capable of flaring. The more massive RS Canum Venaticorum variables (RS ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pavel Fedorovich Chugainov
Pavel ( Bulgarian, Russian, Serbian: Павел; Czech, Slovene, and (although Romanian also uses Paul); ; ; ) is a male given name. It is a Slavic cognate of the name Paul (derived from the Greek Pavlos). Pavel may refer to: People Given name * Pavel I of Russia (1754–1801), Emperor of Russia * Paweł Adamowicz (1965–2019), Polish politician * Paweł Brożek (born 1983), Polish footballer * Paweł Cibicki (born 1994), Swedish footballer * Paweł Deląg (born 1970), Polish actor *Pavel Durov (born 1984), Telegram founder *Paweł Fajdek (born 1989), Polish hammer thrower *Pavel Haas (1899-1944), Czech composer who was murdered during the Holocaust * Paweł Jasienica (1909–1970), Polish historian, journalist, essayist and soldier *Paweł Kisielow (born 1945), Polish immunologist *Pavel Kuzmich (born 1988), Russian luger *Paweł Łukaszewski (born 1968), Polish composer *Paweł Mąciwoda (born 1967), Polish bassist for the German rock band Scorpions *Paweł Mykietyn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gerald Kron
Gerald Kron (April 6, 1913 – April 9, 2012) was an American astronomer who was one of the pioneers of high-precision photometry with photoelectric instrumentation. He discovered the first starspot and made the first photometric observation of a stellar flare. A graduate of the University of Wisconsin-Madison, where he earned a Master of Science degree in mechanical engineering in 1934, Kron became interested in astronomy, which he studied under Joel Stebbins. Stebbins arranged for Kron to enter the University of California at Berkeley, where he received his doctorate in astronomy in 1938. During World War II, Kron served with the Radiation Laboratory at the Massachusetts Institute of Technology, and participated in the development of microwave radar. He later became the head of the Special Devices Group at the Naval Ordnance Test Station (NOTS) at Inyokern, California, where he conducted studies on solid fuel rockets, and developed radio transponders for the Manhattan Pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Luyten 726-8
Gliese 65, also known as Luyten 726-8, is a binary star system that is one of Earth's nearest neighbors, at from Earth in the constellation Cetus. The two component stars are both flare stars with the variable star designations BL Ceti and UV Ceti. Star system The star system was discovered in 1948 by Willem Jacob Luyten in the course of compiling a catalog of stars of high proper motion; he noted its exceptionally high proper motion of 3.37 arc seconds annually and cataloged it as Luyten . The two stars are of nearly equal brightness, with visual magnitudes of 12.7 and 13.2 as seen from Earth. They orbit one another every 26.5 years. The distance between the two stars varies from . The Gliese 65 system is approximately from Earth's Solar System, in the constellation Cetus, and is thus the seventh-closest star system to Earth. Its own nearest neighbor is Tau Ceti, away from it. If R_v=+29 km/s then approximately 28,700 years ago Gliese 65 was at its minimal dist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epsilon Eridani
Epsilon Eridani ( Latinized from ε Eridani), proper name Ran, is a star in the southern constellation of Eridanus. At a declination of −9.46°, it is visible from most of Earth's surface. Located at a distance from the Sun, it has an apparent magnitude of 3.73, making it the third-closest individual star (or star system) visible to the naked eye. The star is estimated to be less than a billion years old. This relative youth gives Epsilon Eridani a higher level of magnetic activity than the Sun, with a stellar wind 30 times as strong. The star's rotation period is 11.2 days at the equator. Epsilon Eridani is smaller and less massive than the Sun, and has a lower level of elements heavier than helium. It is a main-sequence star of spectral class K2, with an effective temperature of about , giving it an orange hue. It is a candidate member of the Ursa Major moving group of stars, which share a similar motion through the Milky Way, implying these stars shared a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lalande 21185
Lalande 21185 (also known as BD+36 2147, Gliese 411, and HD 95735) is a star in the south of Ursa Major. It is the apparent brightest red dwarf in the northern hemisphere.Only AX Microscopii and Lacaille 9352, in the southern hemisphere, are brighter Despite this, and being relatively close by, it is very dim (as are all red dwarfs), being only magnitude 7.5 in visible light and thus too faint to be seen with the unaided eye. The star is visible through a small telescope or binoculars. At away it is one of the stars nearest to the Solar System; only the Alpha Centauri system, Barnard's Star, Wolf 359, and the brown dwarfs Luhman 16 and WISE 0855−0714 are known to be closer. Because of its proximity it is a frequent subject for astronomical surveys and other research and thus is known by numerous other designations, most commonly Gliese 411 and HD 95735. In approximately 19,900 years it will be at its closest, about 4.65 ly (1.43 pc) from the Sun, just over ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lacaille 8760
Lacaille 8760 (AX Microscopii) is a red dwarf star in the constellation Microscopium. It is one of the List of nearest stars, nearest stars to the Sun at about 12.9 light-years' distance, and the brightest Stellar classification#Class M, M-class main-sequence star in Earth's night sky, although it is generally too faint to be seen without a telescope. At an apparent magnitude of +6.7, it may only be visible to the unaided eye under exceptionally good viewing conditions, under dark skies. This star was originally listed in a 1763 catalog that was published posthumously by the France, French Abbé Nicolas-Louis de Lacaille. He observed it in the southern sky while working from an observatory at the Cape of Good Hope. Number ''8760'' was assigned to this star in the 1847 edition of Lacaille's catalogue of 9,766 stars by Francis Baily.Francis Baily. ''A Catalogue of 9766 Stars'' (1847)Page 219/ref> In the past, Lacaille 8760 has been classified anywhere from spectral class ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ross 248
Ross 248, also called HH Andromedae or Gliese 905, is a small star approximately from Earth in the northern constellation of Andromeda (constellation), Andromeda. Despite its List of nearest stars, proximity it is too dim to be seen with the naked eye. It was first catalogued by Frank Elmore Ross in 1926 with his second list of Proper motion, proper-motion stars; on which count it ranks 261st in the SIMBAD database. It was too dim to be included in the Hipparcos survey. In about 40,000 years, Voyager 2 will pass 1.7 light-years (9.7 trillion miles) from the star. Within the next 80,000 years, Ross 248 is predicted to be the nearest star to the Sun for around 9,000 years, overtaking the current nearest star, the triple system Alpha Centauri. Characteristics This star has about 14% of the solar mass, Sun's mass and 19% of the solar radius, Sun's radius, but only 0.2% of the solar luminosity, Sun's luminosity. It has a stellar classification of M6 V, which indicate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
