Show Please allow the whole page to load before you start searching for an entry. Otherwise, errors will occur. [A B C D E F G H I J K L M N O P Q R S T U V W X Y Z] (Note - Greek letters are written out by name - alpha, beta etc.) Aabsorption absorption line spectrum accretion accretion disk active galactic nuclei (AGN) Tell me about AGN! angstrom angular momentum apastron aphelion apoapsis apogee arc minute arc second Ariel V Tell me more about Ariel V. ASCA Tell me more about ASCA. ASD ASM Astro-E/Astro-E2 Tell me more about Astro-E. astronomical unit (AU) astronomy astrophysics atmosphere AXAF Tell me more about AXAF. BBalmer lines (J. Balmer) baryon BATSE BBXRT Tell me more about BBXRT. Be star BeppoSAX Tell me more about BeppoSAX. Big Bang binary stars Tell me about X-ray binary stars. black dwarf black hole Tell me about X-rays from black holes. black-hole dynamic laws; laws of black-hole dynamics
blackbody radiation I(E,T) = 2 E3[h2c2(eE/kT - 1)]-1 where h is Planck's constant, k is Boltzmann's constant, and c is the the speed of light. blackbody temperature blueshift bolometric luminosity Boltzmann constant; k (L. Boltzmann) Brahe, Tycho (1546 - 1601) Show me a picture of Tycho Brahe! bremsstrahlung Ccalibration calorimeter cataclysmic variable (CV) Tell me more about Cataclysmic Variables. Cepheid Variable Tell me more about Cepheid Variables. CGRO Tell me more about CGRO. Chandra X-ray Observatory (CXO) Chandrasekhar, S. (1910 - 1995) Chandrasekhar limit cluster of galaxies collecting area Compton effect (A.H. Compton; 1923) Tell me how gamma-ray astronomers use the Compton effect. Copernicus Tell me more about the Copernicus mission. Copernicus, Nicolaus (1473 - 1543) Show me a picture of Nicholas Copernicus! corona (plural: coronae) Tell me about X-rays from the Sun's corona. COS-B Tell me more about COS-B. cosmic background radiation; primal glow cosmic rays cosmological constant; Lambda cosmological distance cosmological redshift cosmology CXO Tell me more about CXO. Ddark matter de Broglie wavelength (L. de Broglie; 1924) Declination deconvolution density Dewar disk Doppler effect (C.J. Doppler) dust dust tail Eeccentric eccentricity eclipse ecliptic Eddington limit (Sir A. Eddington) Einstein, Albert (1879 - 1955) Show me a picture of Albert Einstein! Einstein Observatory Tell me more about HEAO-2 (Einstein Observatory). ejecta electromagnetic spectrum Introduce me to the electromagnetic spectrum. electromagnetic waves (radiation) electron electron volt elements ellipse emission emission line spectrum erg/sec EUD event horizon evolved star EXOSAT Tell me more about EXOSAT. FFast Fourier Transformation (FFT) Fermi acceleration Bell (1978) and Blandford and Ostriker (1978) independently showed that Fermi acceleration by supernova remnant (SNR) shocks is particularly efficient, because the motions are not random. A charged particle ahead of the shock front can pass through the shock and then be scattered by magnetic inhomogeneities behind the shock. The particle gains energy from this "bounce" and flies back across the shock, where it can be scattered by magnetic inhomogeneities ahead of the shock. This enables the particle to bounce back and forth again and again, gaining energy each time. This process is now called 1st order Fermi acceleration, because the mean energy gain is dependent on the shock velocity only to the first power. Fermi Gamma-ray Telescope Tell me more about Fermi. flux frequency FTP fusion Ggalactic halo galaxy Galilei, Galileo (1564 - 1642) Show me a picture of Galileo! gamma ray Gamma-Ray Burst (GRB) Tell me about Gamma-Ray Bursts. Gamma-ray Large Area Space Telescope (GLAST) Tell me more about GLAST. Gamma Ray Imaging Platform (GRIP) Gamma Ray Imaging Spectrometer (GRIS) Tell me more about GRIS. gas general relativity Giant Molecular Cloud (GMC) Ginga Tell me more about Ginga. globular cluster gravitational collapse gravitational radius gravitational waves gravitationally bound gravity Gravity and Extreme Magnetism SMEX (GEMS) GSFC guest star Hhard x-ray Hawking radiation (S.W. Hawking; 1973) Hawking temperature HEAO Tell me more about HEAO-1. HEASARC helium Herschel, Sir William (1738 - 1822) Hertz, Heinrich (1857 - 1894) hertz; Hz (after H. Hertz, 1857 - 1894) HST Hubble, Edwin P. (1889 - 1953) Show me a picture of Edwin Hubble! Hubble constant; Ho (E.P. Hubble; 1925) Hubble's law (E.P. Hubble; 1925) Huygens, Christiaan (1629 - 1695) Show me a picture of Christian Huygens! hydrogen IIKI image Tell me about how astronomers use images. implosion infrared inclination INTEGRAL International X-ray Observatory (IXO) interstellar medium ions ionic (or ionized) gas IUE Tell me more about IUE. Jjets Kkelvin (after Lord Kelvin, 1824 - 1907) Kepler, Johannes (1571 - 1630) Kepler's laws (J. Kepler) Kepler's first law A planet orbits the Sun in an ellipse with the Sun at one focus. kilogram (kg) kinematics Kirchhoff's law of radiation (G.R. Kirchhoff) Kirchhoff's laws (G.R. Kirchhoff) LL0 Lagrange, Joseph (1736 - 1813) Show me a picture of Joseph Lagrange! Lagrange points L1 through L3 are points of unstable equilibrium; any disturbance will move a test particle there out of the Lagrange point. L4 and L5 are points of stable equilibrium, provided that the mass of the secondary is less than about 1/24.96 the mass of the primary. These points are stable because centrifugal pseudo-forces work against gravity to cancel it out. laser LHEA light light curve Tell me about light curves light year limb LISA (Laser Interferometer Space Antenna) Tell me more about LISA luminosity MM0 magnetic field magnetic pole magnetosphere magnetotail magnitude mass matter mega-ton 1 mega-ton = 4 x 1022 ergs = 4 x 1015 joules. Messier, Charles (1730 - 1817) meter; m metric system microquasar microwave NNASA nebula (pl. nebulae) neutrino neutron neutron star Tell me about X-rays from neutron stars Newton, Isaac 1642 - 1727 Show me a picture of Isaac Newton! Newton's law of universal gravitation (Sir I. Newton) Newton's laws of motion (Sir I. Newton) noise nova (plural: novae) nuclear fusion NuSTAR OOAO 3 Tell me more aboutOAO 3. occultation opacity orbit OSO 3 Tell me more about OSO 3 OSO 8 Tell me more about OSO 8 Ppair production Tell me how astronomers use pair production parallax parsec periapsis periastron perigee perihelion photoabsorption photoelectric effect The reason is that a photon has energy in proportion to its wavelength, and the constant of proportionality is the Planck constant. Below a certain frequency -- and thus below a certain energy -- the incident photons do not have enough energy to knock the photoelectrons out of the metal. Above that threshold energy, called the work function, photons will knock the photoelectrons out of the metal, in proportion to the number of photons (the intensity of the light). At higher frequencies and energies, the photoelectrons ejected obtain a kinetic energy corresponding to the difference between the photon's energy and the work function. photon pi Planck constant; h Planck equation The quantum mechanical equation relating the energy of a photon E to its frequency nu: E = h x nu planetary nebula plasma pointing polarization positron proton protostar Ptolemy (ca. 100-ca. 170) Show me a picture of Ptolemy! pulsar Tell me about pulsars! PVO Tell me more about PVO Qquasar quasi-stellar source (QSS) Rradial velocity radian; rad radiation radiation belt radio Rayleigh criterion; resolving power 1.22 x lambda/d Rayleigh-Taylor instabilities
red giant redshift reflection law relativity principle relativity, theory of resolution (spatial) resolution (spectral or frequency) resonance retrograde revolution Right Ascension Ritter, Johann Wilhelm (1776 - 1810) Roche limit Roche lobe Röntgen, Wilhelm Conrad (1845 - 1923) Tell me more about Wilhelm Röntgen ROSAT Tell me more about ROSAT rotation SSAS-2 Tell me more about SAS-2 SAS-3 Tell me more about SAS-3 satellite Schwarzschild black hole Schwarzschild radius scientific notation second; s semimajor axis rp = a(1-e) and ra = a(1+e) sensitivity Seyfert galaxy shock wave singularity soft x-ray solar flares solar mass 1 solar mass = 1 Msun = 2 x 1033 grams special relativity spectral line spectrometer A Dispersive Spectrometer is like a prism. It scatters light of different energies to different places. We measure the energy by noting where the X-rays go. A Non-Dispersive Spectrometer measures the energy directly. spectroscopy spectrum (plural: spectra) Tell me more about spectra speed of light (in vacuum) star star cluster Stefan-Boltzmann constant; sigma (Stefan, L. Boltzmann) Stefan-Boltzmann law (Stefan, L. Boltzmann) stellar classification stellar wind steradian; sr supernova (plural: supernovae) (a)The death explosion of a massive star, resulting in a sharp increase in brightness followed by a gradual fading. At peak light output, these type of supernova explosions (called Type II supernovae) can outshine a galaxy. The outer layers of the exploding star are blasted out in a radioactive cloud. This expanding cloud, visible long after the initial explosion fades from view, forms a supernova remnant (SNR). (b) The explosion of a white dwarf which has accumulated enough material from a companion star to achieve a mass equal to the Chandrasekhar limit. These types of supernovae (called Type Ia) have approximate the same intrinsic brightness, and can be used to determine distances. Tell me about X-rays from supernovae and their remnants sunspots Suzaku Tell me more about Suzaku SXG Swift Tell me more about Swift synchronous rotation synchrotron radiation Systéme Internationale d'Unités (SI) TTenma Tell me more about Tenma Thomson, William 1824 - 1907 Show me a picture of Lord Kelvin! time dilation UUhuru Tell me more about Uhuru ultraviolet universal constant of gravitation; G Universe VVela 5B Tell me more about Vela 5B The Venera satellite series Tell me more about Venera 11 & 12 visible Wwave-particle duality wavelength white dwarf Tell me more about white dwarfs Wien's displacement law WIMP (weakly interacting massive particle) WMAP (Wilkinson Microwave Anisotropy Probe) Tell me more about WMAP WWW XXMM-Newton X-ray Tell me more about XMM-Newton XSELECT XTE Tell me more about RXTE YZZ z = (delta-lambda)/lambda = (sqrt(1+v/c) / sqrt(1-v/c)) - 1. If the velocity of the object is small compared to the speed of light, then z = (delta-lambda)/lambda = v/c Objects at the furthest reaches of the known universe have values of z = 5 or slightly greater. [A B C D E F G H I J K L M N O P Q R S T U V W X Y Z] |