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Kappa1 Ceti
Kappa1 Ceti, Latinized from κ1 Ceti, is a variable yellow dwarf star approximately 30 light-years away in the equatorial constellation of Cetus. Bayer used the designations κ Ceti and g Tauri for the same star. g Tauri is now no longer used. The star was discovered to have a rapid rotation, roughly once every nine days. Though there are no extrasolar planets confirmed to be orbiting the star, Kappa1 Ceti is considered a good candidate to contain terrestrial planets, like the Earth. The system is a candidate binary star, but has not been confirmed. Description Kappa1 Ceti has a spectrm of G5Vv, classifying it as a G dwarf that fuses hydrogen into helium on its core. Since 1943, the spectrum of this star has served as one of the stable anchor points by which other stars are classified. The star has roughly the same mass as the Sun, with 95% of the Sun's radius and 88 percent of the luminosity. Its brightness varies by a few hundredths of a magnitude over a peri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cetus
Cetus () is a constellation, sometimes called 'the whale' in English. The Cetus (mythology), Cetus was a sea monster in Greek mythology which both Perseus and Heracles needed to slay. Cetus is in the region of the sky that contains other water-related constellations: Aquarius (constellation), Aquarius, Pisces (constellation), Pisces and Eridanus (constellation), Eridanus. Features Ecliptic Cetus is not among the 12 true zodiac constellations in the Epoch (astronomy), J2000 epoch, nor classical 12-part zodiac. The ecliptic passes less than 0.25° from one of its corners. Thus the Moon and planets will enter Cetus (occulting any stars as a foreground object) in 50% of their successive orbits briefly, and the southern part of the Sun appears in Cetus for about 14 hours each year on March 27 to 28. Many asteroids in belts have longer phases occulting the north-western part of Cetus, those with a slightly greater inclination to the ecliptic than the Moon and planets. Astronomy on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sunspot
Sunspots are temporary spots on the Sun's surface that are darker than the surrounding area. They are one of the most recognizable Solar phenomena and despite the fact that they are mostly visible in the solar photosphere they usually affect the entire solar atmosphere. They are regions of reduced surface temperature caused by concentrations of magnetic flux that inhibit convection. Sunspots appear within active regions, usually in pairs of opposite magnetic polarity. Their number varies according to the approximately 11-year solar cycle. Individual sunspots or groups of sunspots may last anywhere from a few days to a few months, but eventually decay. Sunspots expand and contract as they move across the surface of the Sun, with diameters ranging from to . Larger sunspots can be visible from Earth without the aid of a telescope. They may travel at relative speeds, or proper motions, of a few hundred meters per second when they first emerge. Indicating intense magneti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
G-type Main-sequence Stars
A G-type main-sequence star (spectral type: G-V), also often, and imprecisely, called a yellow dwarf, or G star, is a main sequence, main-sequence star (luminosity class V) of stellar classification, spectral type G. Such a star has about 0.9 to 1.1 solar masses and an effective temperature between about . Like other main-sequence stars, a G-type main-sequence star converts the Chemical element, element hydrogen to helium in its core by means of nuclear fusion. The Sun, the star in the center of the Solar System to which the Earth is gravitationally bound, is an example of a G-type main-sequence star (G2V type). Each second, the Sun fuses approximately 600 million tons of hydrogen into helium in a process known as the proton–proton chain (4 hydrogens form 1 helium), Mass–energy equivalence, converting about 4 million tons of matter to energy. Besides the Sun, other well-known examples of G-type main-sequence stars include Alpha Centauri, Tau Ceti, and 51 Pegasi. Description Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Illinois
The University of Illinois Urbana-Champaign (UIUC, U of I, Illinois, or University of Illinois) is a public university, public land-grant university, land-grant research university in the Champaign–Urbana metropolitan area, Illinois, United States. Established in 1867, it is the founding campus and Flagship#Colleges and universities in the United States, flagship institution of the University of Illinois System. With over 59,000 students, the University of Illinois is one of the List of United States public university campuses by enrollment, largest public universities by enrollment in the United States. The university contains 16 schools and colleges and offers more than 150 undergraduate and over 100 graduate programs of study. The university holds 651 buildings on and its annual operating budget in 2016 was over $2 billion. The University of Illinois Urbana-Champaign also operates Research Park at the University of Illinois Urbana-Champaign, a research park home to innova ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Astronomical Journal
''The Astronomical Journal'' (often abbreviated ''AJ'' in scientific papers and references) is a peer-reviewed monthly scientific journal owned by the American Astronomical Society (AAS) and currently published by IOP Publishing. It is one of the premier journals for astronomy in the world. Until 2008, the journal was published by the University of Chicago Press on behalf of the AAS. The reasons for the change to the IOP were given by the society as the desire of the University of Chicago Press to revise its financial arrangement and their plans to change from the particular software that had been developed in-house. The other two publications of the society, the ''Astrophysical Journal'' and its supplement series, followed in January 2009. The journal was established in 1849 by Benjamin A. Gould. It ceased publication in 1861 due to the American Civil War, but resumed in 1885. Between 1909 and 1941 the journal was edited in Albany, New York. In 1941, editor Benjamin Boss arranged ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VizieR
A vizier (; ; ) is a high-ranking political advisor or Minister (government), minister in the Near East. The Abbasids, Abbasid caliphs gave the title ''wazir'' to a minister formerly called ''katib'' (secretary), who was at first merely a helper but afterwards became the representative and successor of the ''dapir'' (official scribe or secretary) of the Sasanian Empire, Sassanian kings. In modern usage, the term has been used for government Minister (government), ministers in much of the Middle East and beyond. Several alternative spellings are used in English, such as ''vizir'', ''wazir'', and ''vezir''. Etymology Vizier may be derived from the Arabic ''wazara'' (), from the Semitic root ''W-Z-R''. The word is mentioned in the Quran, where Aaron is described as the ''wazir'' (helper) of Moses, as well as the word ''wizr'' (burden) which is also derived from the same root. It was later adopted as a title, in the form of ''wazīr āl Muḥammad'' () by the proto-Shi'a leaders ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Astronomical Union
The International Astronomical Union (IAU; , UAI) is an international non-governmental organization (INGO) with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreach, education, and development through global cooperation. It was founded on 28 July 1919 in Brussels, Belgium and is based in Paris, France. The IAU is composed of individual members, who include both professional astronomers and junior scientists, and national members, such as professional associations, national societies, or academic institutions. Individual members are organised into divisions, committees, and working groups centered on particular subdisciplines, subjects, or initiatives. the Union had 85 national members and 12,734 individual members, spanning 90 countries and territories. Among the key activities of the IAU is serving as a forum for scientific conferences. It sponsors nine annual symposia and holds a triannual General Assembly that sets policy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Nearest Stars By Spectral Type
Below there are lists the nearest stars separated by spectral type. The scope of the list is still restricted to the main sequence spectral types: M-type star, M, K-type star, K, F-type star, F, G-type star, G, A-type star, A, B-type star, B and O-type star, O. It may be later expanded to other types, such as S-type star, S, White dwarf, D or Carbon star, C. List of nearest M-type stars This is a list of M-type stars within 13 light years. List of nearest K-type stars This is a list of K-type stars within 30 light years. List of nearest G-type stars This is a list of G type stars, G-type stars within 40 light years. List of nearest F-type stars This is a list of F-type stars within 50 light years. List of nearest A-type stars This is a list of A type stars, A-type stars within 70 light years. } , 2.067 , , 1.444 , Part of a binary star system , - , colspan="2" , Iota Centauri , , A2V , 1.90 = 1.9\ R_\odot. , 2.03 ± 0.03 , , 1.47 , , - , colspan="2" , ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Star Systems Within 25–30 Light-years
This is a list of star systems within 25–30 light-years of Earth. List See also * List of nearest stars * List of star systems within 20–25 light-years * List of star systems within 30–35 light-years * Lists of stars * List of nearest bright stars The following nearest bright stars are found within of the closest star, the Sun, and have an absolute magnitude of +8.5 or brighter, which is approximately comparable to a listing of stars more luminous than a red dwarf. Right ascension and ... * Spherical shell References {{DEFAULTSORT:Star systems within 25-30 light-years Lists of stars Star systems Lists by distance ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moving Group
In astronomy, stellar kinematics is the observational study or measurement of the kinematics or motions of stars through space. Stellar kinematics encompasses the measurement of stellar velocities in the Milky Way and its satellites as well as the internal kinematics of more distant galaxies. Measurement of the kinematics of stars in different subcomponents of the Milky Way including the thin disk, the thick disk, the bulge, and the stellar halo provides important information about the formation and evolutionary history of our Galaxy. Kinematic measurements can also identify exotic phenomena such as hypervelocity stars escaping from the Milky Way, which are interpreted as the result of gravitational encounters of binary stars with the supermassive black hole at the Galactic Center. Stellar kinematics is related to but distinct from the subject of stellar dynamics, which involves the theoretical study or modeling of the motions of stars under the influence of gravity. Stella ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Space Velocity (astronomy)
In astronomy, stellar kinematics is the Observational astronomy, observational study or measurement of the kinematics or motions of stars through space. Stellar kinematics encompasses the measurement of stellar Velocity, velocities in the Milky Way and its Satellite galaxies of the Milky Way, satellites as well as the internal kinematics of more distant Galaxy, galaxies. Measurement of the kinematics of stars in different subcomponents of the Milky Way including the thin disk, the thick disk, the Bulge (astronomy), bulge, and the stellar halo provides important information about the formation and evolutionary history of our Galaxy. Kinematic measurements can also identify exotic phenomena such as hypervelocity stars escaping from the Milky Way, which are interpreted as the result of gravitational encounters of binary stars with the Sagittarius A*, supermassive black hole at the Galactic Center. Stellar kinematics is related to but distinct from the subject of stellar dynamics, wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
