|
Kepler-70
Kepler-70, also known as KIC 5807616 and formerly as KOI-55, is a star in the constellation Cygnus with an apparent visual magnitude of 14.87, and is 4200 light-years away. This is too faint to be seen with the naked eye; viewing it requires a telescope with an aperture of or more. A subdwarf B star, Kepler-70 passed through the red giant stage some 18.4 million years ago. In its present-day state, it is fusing helium in its core. Once it runs out of helium it will contract to form a white dwarf. It has a relatively small radius of about 0.2 times the Sun's radius; white dwarfs are generally much smaller. The star may be host to a planetary system with two planets, although later research indicates that this is not in fact the case. If they are confirmed to exist, then the innermost planet has the highest temperature of any known planet. Properties Kepler-70 is an sdB (B-type subdwarf star with a temperature of 27,730 K, equivalent to that of a B0-type star. It has ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kepler-70
Kepler-70, also known as KIC 5807616 and formerly as KOI-55, is a star in the constellation Cygnus with an apparent visual magnitude of 14.87, and is 4200 light-years away. This is too faint to be seen with the naked eye; viewing it requires a telescope with an aperture of or more. A subdwarf B star, Kepler-70 passed through the red giant stage some 18.4 million years ago. In its present-day state, it is fusing helium in its core. Once it runs out of helium it will contract to form a white dwarf. It has a relatively small radius of about 0.2 times the Sun's radius; white dwarfs are generally much smaller. The star may be host to a planetary system with two planets, although later research indicates that this is not in fact the case. If they are confirmed to exist, then the innermost planet has the highest temperature of any known planet. Properties Kepler-70 is an sdB (B-type subdwarf star with a temperature of 27,730 K, equivalent to that of a B0-type star. It has ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kepler-70b
Kepler-70b (formerly known as its Kepler Object of Interest designation ''KOI-55.01''; sometimes listed as KOI-55 b) is one of two postulated exoplanets orbiting the subdwarf B star (sdB) Kepler-70. The other planet is Kepler-70c, and both planets (if they exist) orbit very close to their host star. However, later research suggests that the two exoplanets probably do not exist, and that "pulsation modes visible beyond the cut-off frequency of the star" were a more likely explanation for the signals believed to indicate exoplanets. This has not been proven with certainty one way or the other. If it exists, Kepler-70b completes one orbit around its star in just 5.76 hours, so is an ultra-short period planet. It is also the hottest known exoplanet as of mid-2017, with a surface temperature of several thousand Kelvin. Its density is 5500 kg/m3 which is not much different from Earth. Characteristics Mass, radius and temperature Kepler-70b is likely a rocky exoplanet with a mass of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kepler-70c
Kepler-70c (formerly called KOI-55.02; sometimes listed as KOI-55 c) is one of two postulated exoplanets orbiting the sdB star Kepler-70. Their discovery was announced in 2011. However, later research suggests that the two exoplanets probably do not exist, and that "pulsation modes visible beyond the cut-off frequency of the star" were a more likely explanation for the signals believed to indicate exoplanets. This is not proven with certainty one way or the other. If it exists, Kepler-70c orbits its host along with another planet, Kepler-70b. Both of these planets orbit very close to their host star. Kepler-70c completes one orbit around its star in just 8.232 hours. It is also one of the hottest exoplanets as of mid-2013. It has a high density, suggesting that it is largely composed of metals. Kepler-70b passes 240,000 km away from Kepler-70c during their closest approach. This is currently the closest recorded approach between planets. Such orbital configuration is relativ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subdwarf B Star
A B-type subdwarf (sdB) is a kind of subdwarf star with spectral type B. They differ from the typical subdwarf by being much hotter and brighter. They are situated at the "extreme horizontal branch" of the Hertzsprung–Russell diagram. Masses of these stars are around 0.5 solar masses, and they contain only about 1% hydrogen, with the rest being helium. Their radius is from 0.15 to 0.25 solar radii, and their temperature is from 20,000 to 40,000K. These stars represent a late stage in the evolution of some stars, caused when a red giant star loses its outer hydrogen layers before the core begins to fuse helium. The reasons why this premature mass loss occurs are unclear, but the interaction of stars in a binary star system is thought to be one of the main mechanisms. Single subdwarfs may be the result of a merger of two white dwarfs. The sdB stars are expected to become white dwarfs without going through any more giant stages. Subdwarf B stars, being more luminous than white ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kepler-70 System
Kepler-7 is a star located in the constellation Lyra in the field of view of the Kepler Mission, a NASA operation in search of Earth-like planets. It is home to the fourth of the first five planets that Kepler discovered; this planet, a Jupiter-size gas giant named Kepler-7b, is as light as styrofoam. The star itself is more massive than the Sun, and is nearly twice the Sun's radius. It is also slightly metal-rich, a major factor in the formation of planetary systems. Kepler-7's planet was presented on January 4, 2010 at a meeting of the American Astronomical Society. Nomenclature and discovery Kepler-7 received its name because it was the home to the seventh planetary system discovered by the NASA-led Kepler Mission, a project aimed at detecting terrestrial planets that transit, or pass in front of, their host stars as seen from Earth. The planet orbiting Kepler-7 was the fourth planet to be discovered by the Kepler spacecraft; the first three planets combed from Kepler ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Universe Today
Universe Today (U.T.) is a popular North American-based non-commercial space and astronomy news website. The domain was registered on December 30, 1998, and the website went live in March 1999, founded by Canadian Fraser Cain. The ''Universe Today'' assumed its current form on July 24, 2003, featuring astronomy news and space-related issues. By early September 2005, the forum section merged with ''Bad Astronomy'' as a combined site with the BAUT forum. During April 2011, the Association of British Science Writers noted that ''Universe Today'' decided not to make preparations for reporting on embargoed stories until they are public knowledge. Emily Lakdawalla said that she relies on ''Universe Today'' and ''Bad Astronomy'' to "give ... an independent look at big news stories". Publications ''Universe Today'' has published two books, which are available both as e-books and on physical media: * * See also * ''Astronomy Cast'' * ''Space.com'' * ''The Space Show ''The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypothetical Planetary Systems
A hypothesis (plural hypotheses) is a proposed explanation for a phenomenon. For a hypothesis to be a scientific hypothesis, the scientific method requires that one can testable, test it. Scientists generally base scientific hypotheses on previous observations that cannot satisfactorily be explained with the available scientific theories. Even though the words "hypothesis" and "theory" are often used interchangeably, a scientific hypothesis is not the same as a scientific theory. A working hypothesis is a provisionally accepted hypothesis proposed for further research in a process beginning with an educated guess or thought. A different meaning of the term ''hypothesis'' is used in formal logic, to denote the antecedent (logic), antecedent of a proposition; thus in the proposition "If ''P'', then ''Q''", ''P'' denotes the hypothesis (or antecedent); ''Q'' can be called a consequent. ''P'' is the :wikt:assumption, assumption in a (possibly Counterfactual conditional, counterfac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kepler Objects Of Interest
Johannes Kepler (; ; 27 December 1571 – 15 November 1630) was a German astronomer, mathematician, astrologer, natural philosopher and writer on music. He is a key figure in the 17th-century Scientific Revolution, best known for his laws of planetary motion, and his books ''Astronomia nova'', ''Harmonice Mundi'', and ''Epitome Astronomiae Copernicanae''. These works also provided one of the foundations for Newton's theory of universal gravitation. Kepler was a mathematics teacher at a seminary school in Graz, where he became an associate of Prince Hans Ulrich von Eggenberg. Later he became an assistant to the astronomer Tycho Brahe in Prague, and eventually the imperial mathematician to Emperor Rudolf II and his two successors Matthias and Ferdinand II. He also taught mathematics in Linz, and was an adviser to General Wallenstein. Additionally, he did fundamental work in the field of optics, invented an improved version of the refracting (or Keplerian) telescope, and w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Courier Dover Publications
Dover Publications, also known as Dover Books, is an American book publisher founded in 1941 by Hayward and Blanche Cirker. It primarily reissues books that are out of print from their original publishers. These are often, but not always, books in the public domain. The original published editions may be scarce or historically significant. Dover republishes these books, making them available at a significantly reduced cost. Classic reprints Dover reprints classic works of literature, classical sheet music, and public-domain images from the 18th and 19th centuries. Dover also publishes an extensive collection of mathematical, scientific, and engineering texts. It often targets its reprints at a niche market, such as woodworking. Starting in 2015, the company branched out into graphic novel reprints, overseen by Dover acquisitions editor and former comics writer and editor Drew Ford. Most Dover reprints are photo facsimiles of the originals, retaining the original pagination and t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
F-type Main-sequence Star
An F-type main-sequence star (F V) is a main-sequence, hydrogen-fusing star of spectral type F and luminosity class V. These stars have from 1.0 to 1.4 times the mass of the Sun and surface temperatures between 6,000 and 7,600 K.Tables VII and VIII. This temperature range gives the F-type stars a whitish hue when observed by the atmosphere. Because a main-sequence star is referred to as a dwarf star, this class of star may also be termed a yellow-white dwarf (not to be confused with white dwarfs, remnant stars that are a possible final stage of stellar evolution). Notable examples include Procyon A, Gamma Virginis A and B, and KIC 8462852. Spectral standard stars The revised Yerkes Atlas system (Johnson & Morgan 1953) listed a dense grid of F-type dwarf spectral standard stars; however, not all of these have survived to this day as stable standards. The ''anchor points'' of the MK spectral classification system among the F-type main-sequence dwarf stars, i.e. those standa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asymptotic Giant Branch
The asymptotic giant branch (AGB) is a region of the Hertzsprung–Russell diagram populated by evolved cool luminous stars. This is a period of stellar evolution undertaken by all low- to intermediate-mass stars (about 0.5 to 8 solar masses) late in their lives. Observationally, an asymptotic-giant-branch star will appear as a bright red giant with a luminosity ranging up to thousands of times greater than the Sun. Its interior structure is characterized by a central and largely inert core of carbon and oxygen, a shell where helium is undergoing fusion to form carbon (known as helium burning), another shell where hydrogen is undergoing fusion forming helium (known as hydrogen burning), and a very large envelope of material of composition similar to main-sequence stars (except in the case of carbon stars). Stellar evolution When a star exhausts the supply of hydrogen by nuclear fusion processes in its core, the core contracts and its temperature increases, causing the outer l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
B-type Main-sequence Star
A B-type main-sequence star (B V) is a main-sequence (hydrogen-burning) star of spectral type B and luminosity class V. These stars have from 2 to 16 times the mass of the Sun and surface temperatures between 10,000 and 30,000 K. B-type stars are extremely luminous and blue. Their spectra have neutral helium, which are most prominent at the B2 subclass, and moderate hydrogen lines. Examples include Regulus and Algol A. This class of stars was introduced with the Harvard sequence of stellar spectra and published in the ''Revised Harvard photometry'' catalogue. The definition of type B-type stars was the presence of non-ionized helium lines with the absence of singly ionized helium in the blue-violet portion of the spectrum. All of the spectral classes, including the B type, were subdivided with a numerical suffix that indicated the degree to which they approached the next classification. Thus B2 is 1/5 of the way from type B (or B0) to type A. Later, however, more refined s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
