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SN 2011dh
SN 2011dh was a supernova in the Whirlpool Galaxy (M51). It was discovered on 31 May 2011, with an apparent magnitude 13.5. and confirmed by several sources, including the Palomar Transient Factory. A candidate progenitor was detected in Hubble Space Telescope images. The progenitor may have been a highly luminous yellow supergiant with an initial mass of 18-24 solar masses. The supernova peaked near apparent magnitude 12.1 on 19 June 2011. Emission spectra indicated that the explosion was a type II supernova, in which a massive star collapses once nuclear fusion has ceased in its core. SN2011dh was the third supernova to be recorded in the Whirlpool galaxy since 1994 (following SN 1994I and SN 2005cs). The supernova frequency in the Milky Way The Milky Way is the galaxy that includes our Solar System, with the name describing the galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars that cannot be individually distinguished by the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
J2000
In astronomy, an epoch or reference epoch is a instant, moment in time used as a reference point for some time-varying astronomical quantity. It is useful for the celestial coordinates or orbital elements of a Astronomical object, celestial body, as they are subject to Perturbation (astronomy), perturbations and vary with time. These time-varying astronomical quantities might include, for example, the mean longitude or mean anomaly of a body, the node of its orbit relative to a reference plane, the direction of the apogee or Perihelion and aphelion, aphelion of its orbit, or the size of the major axis of its orbit. The main use of astronomical quantities specified in this way is to calculate other relevant parameters of motion, in order to predict future positions and velocities. The applied tools of the disciplines of celestial mechanics or its subfield orbital mechanics (for predicting orbital paths and positions for bodies in motion under the gravitational effects of other bodi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hubble Space Telescope
The Hubble Space Telescope (often referred to as HST or Hubble) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the first space telescope, but it is one of the largest and most versatile, renowned both as a vital research tool and as a public relations boon for astronomy. The Hubble telescope is named after astronomer Edwin Hubble and is one of NASA's Great Observatories. The Space Telescope Science Institute (STScI) selects Hubble's targets and processes the resulting data, while the Goddard Space Flight Center (GSFC) controls the spacecraft. Hubble features a mirror, and its five main instruments observe in the ultraviolet, visible, and near-infrared regions of the electromagnetic spectrum. Hubble's orbit outside the distortion of Earth's atmosphere allows it to capture extremely high-resolution images with substantially lower background light than ground-based telescopes. It has recorded some of the most detaile ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomical Objects Discovered In 2011
Astronomy () is a natural science that studies celestial objects and phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and evolution. Objects of interest include planets, moons, stars, nebulae, galaxies, and comets. Relevant phenomena include supernova explosions, gamma ray bursts, quasars, blazars, pulsars, and cosmic microwave background radiation. More generally, astronomy studies everything that originates beyond Earth's atmosphere. Cosmology is a branch of astronomy that studies the universe as a whole. Astronomy is one of the oldest natural sciences. The early civilizations in recorded history made methodical observations of the night sky. These include the Babylonians, Greeks, Indians, Egyptians, Chinese, Maya, and many ancient indigenous peoples of the Americas. In the past, astronomy included disciplines as diverse as astrometry, celestial navigation, observational astronomy, and the making of calendars. Nowadays, professional a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Milky Way
The Milky Way is the galaxy that includes our Solar System, with the name describing the galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars that cannot be individually distinguished by the naked eye. The term ''Milky Way'' is a translation of the Latin ', from the Greek ('), meaning "milky circle". From Earth, the Milky Way appears as a band because its disk-shaped structure is viewed from within. Galileo Galilei first resolved the band of light into individual stars with his telescope in 1610. Until the early 1920s, most astronomers thought that the Milky Way contained all the stars in the Universe. Following the 1920 Great Debate between the astronomers Harlow Shapley and Heber Curtis, observations by Edwin Hubble showed that the Milky Way is just one of many galaxies. The Milky Way is a barred spiral galaxy with an estimated D25 isophotal diameter of , but only about 1,000 light years thick at the spiral arms (more at the bulg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SN 2005cs
SN 2005cs was a supernova in the spiral galaxy M51, known as the Whirlpool Galaxy. It was a type II-P core-collapse supernova, discovered June 28, 2005 by Wolfgang Kloehr, a German amateur astronomer. The event was positioned at an offset of west and south of the galactic nucleus of M51. Based on the data, the explosion was inferred to occur 2.8 days before discovery. It was considered under-luminous for a supernova of its type, releasing an estimated in energy. The progenitor star was identified from a Hubble Space Telescope image taken January 20–21, 2005. It was a red supergiant with a spectral type in the mid- K to late- M type range and an estimated initial (ZAMS Zams is a municipality in the district of Landeck in the Austrian state of Tyrol. Geography The Inn River runs through Zams, which is situated in the river's basin together with its neighbour town Landeck. The geographical location is . Here, th ...) mass of . A higher mass star enshrouded in a cocoon of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SN 1994I
SN 1994I is a Type Ic supernova discovered on April 2, 1994 in the Whirlpool Galaxy by amateur astronomers Tim Puckett and Jerry Armstrong of the Atlanta Astronomy Club. Type Ic supernova are a rare type of supernova that result from the explosion of a very massive star that has shed its outer layers of hydrogen and helium. The explosion results in a highly luminous burst of radiation that then dims over the course of weeks or months. SN 1994I was a relatively nearby supernova, and provided an important addition to the then small collection of known Type Ic supernova. Very early images were captured of SN 1994I, as two high school students in Oil City, Pennsylvania serendipitously took images of the Whirlpool Galaxy using the 30-inch telescope at Leuschner Observatory on March 31, 1994, which included SN 1994I just after it began to brighten. Discovery and observations SN 1994I was independently discovered by multiple observers, with the first reports from amateur astronomers T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Fusion
Nuclear fusion is a reaction in which two or more atomic nuclei are combined to form one or more different atomic nuclei and subatomic particles ( neutrons or protons). The difference in mass between the reactants and products is manifested as either the release or absorption of energy. This difference in mass arises due to the difference in nuclear binding energy between the atomic nuclei before and after the reaction. Nuclear fusion is the process that powers active or main-sequence stars and other high-magnitude stars, where large amounts of energy are released. A nuclear fusion process that produces atomic nuclei lighter than iron-56 or nickel-62 will generally release energy. These elements have a relatively small mass and a relatively large binding energy per nucleon. Fusion of nuclei lighter than these releases energy (an exothermic process), while the fusion of heavier nuclei results in energy retained by the product nucleons, and the resulting reaction is endo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Type II Supernova
A Type II supernova (plural: ''supernovae'' or ''supernovas'') results from the rapid collapse and violent explosion of a massive star. A star must have at least 8 times, but no more than 40 to 50 times, the mass of the Sun () to undergo this type of explosion. Type II supernovae are distinguished from other types of supernovae by the presence of hydrogen in their spectra. They are usually observed in the spiral arms of galaxies and in H II regions, but not in elliptical galaxies; those are generally composed of older, low-mass stars, with few of the young, very massive stars necessary to cause a supernova. Stars generate energy by the nuclear fusion of elements. Unlike the Sun, massive stars possess the mass needed to fuse elements that have an atomic mass greater than hydrogen and helium, albeit at increasingly higher temperatures and pressures, causing correspondingly shorter stellar life spans. The degeneracy pressure of electrons and the energy generated by th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Emission Spectrum
The emission spectrum of a chemical element or chemical compound is the spectrum of frequencies of electromagnetic radiation emitted due to an electron making a atomic electron transition, transition from a high energy state to a lower energy state. The photon energy of the emitted photon is equal to the energy difference between the two states. There are many possible electron transitions for each atom, and each transition has a specific energy difference. This collection of different transitions, leading to different radiated wavelengths, make up an emission spectrum. Each element's emission spectrum is unique. Therefore, spectroscopy can be used to identify elements in matter of unknown composition. Similarly, the emission spectra of molecules can be used in chemical analysis of substances. Emission In physics, emission is the process by which a higher energy quantum mechanical state of a particle becomes converted to a lower one through the emission of a photon, resulting in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Mass
The solar mass () is a standard unit of mass in astronomy, equal to approximately . It is often used to indicate the masses of other stars, as well as stellar clusters, nebulae, galaxies and black holes. It is approximately equal to the mass of the Sun. This equates to about two nonillion (short scale), two quintillion (long scale) kilograms or 2000 quettagrams: The solar mass is about times the mass of Earth (), or times the mass of Jupiter (). History of measurement The value of the gravitational constant was first derived from measurements that were made by Henry Cavendish in 1798 with a torsion balance. The value he obtained differs by only 1% from the modern value, but was not as precise. The diurnal parallax of the Sun was accurately measured during the transits of Venus in 1761 and 1769, yielding a value of (9 arcseconds, compared to the present value of ). From the value of the diurnal parallax, one can determine the distance to the Sun from the geometry o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palomar Transient Factory
The Palomar Transient Factory (PTF, obs. code: I41), was an astronomical survey using a wide-field survey camera designed to search for optical transient and variable sources such as variable stars, supernovae, asteroids and comets. The project completed commissioning in summer 2009, and continued until December 2012. It has since been succeeded by the Intermediate Palomar Transient Factory (iPTF), which itself transitioned to the Zwicky Transient Facility in 2017/18. All three surveys are registered at the MPC under the same observatory code for their astrometric observations. Description The fully automated system included an automated realtime data reduction pipeline, a dedicated photometric follow-up telescope, and a full archive of all detected astronomical sources. The survey was performed with a 12K × 8K, 7.8 square degree CCD array camera re-engineered for the 1.2-meter Samuel Oschin Telescope at Palomar Observatory. The survey camera achieved firs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Type II Supernova
A Type II supernova (plural: ''supernovae'' or ''supernovas'') results from the rapid collapse and violent explosion of a massive star. A star must have at least 8 times, but no more than 40 to 50 times, the mass of the Sun () to undergo this type of explosion. Type II supernovae are distinguished from other types of supernovae by the presence of hydrogen in their spectra. They are usually observed in the spiral arms of galaxies and in H II regions, but not in elliptical galaxies; those are generally composed of older, low-mass stars, with few of the young, very massive stars necessary to cause a supernova. Stars generate energy by the nuclear fusion of elements. Unlike the Sun, massive stars possess the mass needed to fuse elements that have an atomic mass greater than hydrogen and helium, albeit at increasingly higher temperatures and pressures, causing correspondingly shorter stellar life spans. The degeneracy pressure of electrons and the energy generated by th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
