v 0.99r 2008-05-15 (Protégé 3.4 build 130) corrections on keywords/annotations radio##metric##m Radio Metric Binaries, cataclysmic CV* Cataclysmic Variable CataclyV* cataclysmic##variable##star Variable stars showing outbursts caused by thermonuclear burst processes in their surface layers (novae) or deep in their interiors (supernovae). We use the term "novalike" for variables that show novalike outbursts caused by rapid energy release in the surrounding space (UG-type stars) and also for objects not displaying outbursts but resembling explosive variables at minimum light by their spectral (or other) characteristics. The majority of explosive and novalike variables are close binary systems, their components having strong mutual influence on the evolution of each star. It is often observed that the hot dwarf component of the system is surrounded by an accretion disk formed by matter lost by the other, cooler, and more extended component. Binaries:cataclysmic YSO yso##young##stellar##object YSOs YSOs Y*O YSO IR Infrared Source ir##infrared##source IR Infrared sources IV nebular##continuum Nebular Continuum Recombination thermal continuum Novae Nova nova##novae Novae Close binary systems with orbital periods from 0.05 to 230 days. One of the components of these systems is a hot dwarf star that suddenly, during a time interval from one to several dozen or several hundred days, increases its brightness by 7-19 mag in V, then returns gradually to its former brightness over several months, years, or decades. Small changes at minimum light may be present. Cool components may be giants, subgiants, or dwarfs of K-M type. The spectra of novae near maximum light resemble A-F absorption spectra of luminous stars at first. Then broad emission lines (bands) of hydrogen, helium, and other elements with absorption components indicating the presence of a rapidly expanding envelope appear in the spectrum. As the light decreases, the composite spectrum begins to show forbidden lines characteristic of the spectra of gas nebulae excited by hot stars. At minimum light, the spectra of novae are generally continuous or resemble the spectra of Wolf-Rayet stars. Only spectra of the most massive systems show traces of cool components. Some novae reveal pulsations of hot components with periods of approximately 100 s and amplitudes of about 0.05 mag in V after an outburst. Some novae eventually turn out to be eclipsing systems. According to the features of their light variations, novae are subdivided into fast, slow, very slow, and recurrent categories. N No* Nova emission synchrotron Synchrotron Emission Thermonuclear Supernova Explosion supernova##explosion##thermonuclear##thermo##nuclear Stellar Object in Association stellar##object##star##in##association *iA *inAssoc SB##SBa##SBb##SBc##SBd##SBab##SBbc##SBcd##SB0##SB0a Space velocities velocity Velocity Velocities eruption##explosion##process Explosion or Eruption process Explosion or Eruption process GinGroup group##galaxy##gal##galaxies##in GiG Galaxy in Group Emission Process emission##process radio##cm##centimetric Radio Centimetric type 1##type1##flat##spectrum##radio##quasar##qso Flat-Spectrum Radio Quasar B Star Star of Spectral Type B bstar##b##star Stars, B-type High-mass X-ray Binary HXB x##ray##xray##binary##binaries##high##mass##hmxb A high-mass X-ray binary (HMXB) is a binary star system where one of the components is a neutron star or a black hole. The other component is a massive star, usually a Be star or a blue supergiant. A fraction of the stellar wind of the companion star is captured by the compact star, and produces X-rays as it falls onto the compact object. In HMXB, the massive star dominates the emission of optical light. The compact object is the dominant source of X-rays. The massive stars are very luminous and therefore easily detected. One of the most famous HMXB is Cygnus X-1 which was the first stellar-mass black hole discovered. Soft-gamma rays emitters. HMXB High Mass X-Ray Binary Variable Star of gamma Dor type gD* Gamma Doradus variables are variable stars which display variations in luminosity due to non-radial pulsations of their surface. The stars are typically young, early F or late A type main sequence stars, and typical brightness fluctuations are 0.1 magnitudes with periods on the order of one day. This is a relatively new class of variable stars, having been first characterised in the second half of the 1990s, and details on the underlying physical cause of the variations remains under investigation. Gamma Doradus Variable gamma##doradus##variable##star gammaDor magnetic##field Magnetic_fields magnetic Field Magnetic fields UV UV Source uv##ultraviolet##ultra##violet##source UV dE HI hi##region##cold Cold HI Region HI Supernova type II SNII supernova##typeii##type2##type##2##ii LSB LSB_G Low Surface Brightness Galaxy low##surface##brightness##lsb##gal##galaxy##galaxies Lenticular Galaxy lenticular##gal##galaxy##galaxies F Far Infrared far##infrared Wavelength > 30 microns Blue blue Low-mass X-ray Binary Low Mass X-Ray Binary LXB LMXB Low-mass X-ray binaries (LMXBs) are binary stars where one of the components is either a black hole or neutron star. The other component (donor) is usually filling its Roche lobe and therefore transfers mass to the compact star. The donor is less massive than the compact object, and can be on the main sequence, a degenerate dwarf (white dwarf), or an evolved star (red giant). Found in the Milky Way, external galaxies, and in globular clusters. A typical LMXB emits almost all of its radiation in X-rays, and typically less than one percent in visible light, so they are among the brightest objects in the X-ray sky, but relatively faint in visible light. The apparent magnitude is typically around 15 to 20. The brightest part of the system is the accretion disk around the compact object. The orbital periods of LMXBs range from ten minutes to hundreds of days. Soft-gamma rays emitters. x##ray##xray##binary##binaries##low##mass##lmxb star Star neutron##star Neutron Star Effective Temperature effective##temperature Effective temperatures EUV Extreme UV sources EUV sources Blue Supergiant blue##super##giant##supergiant core##dominated##coredominated Core/Extented Flux Ratio >1 Core Dominated Stars, G-type Star of Spectral Type G G Star g##gstar##star Radio-loud AGN agn##radio##loud##active##galaxy##nucleus L Variable Star of delta sct type delta##scuti##deltascuti PulsV*delsct Variables of the Delta Scuti type. These are pulsating variables of spectral types A0-F5 III-V displaying light amplitudes from 0.003 to 0.9 mag in V (usually several hundredths of a magnitude) and periods from 0.01 to 0.2 days. The shapes of the light curves, periods, and amplitudes usually vary greatly. Radial as well as nonradial pulsations are observed. The variability of some members of this type appears sporadically and sometimes completely ceases, this being a consequence of strong amplitude modulation with the lower value of the amplitude not exceeding 0.001 mag in some cases. The maximum of the surface layer expansion does not lag behind the maximum light for more than 0.1 periods. Delta Sct stars are representatives of the galactic disk (flat component) and are phenomenologically close to the SX Phe variables. Sub-type: - Low amplitude group of Delta Sct variables (light amplitude <0.1 mag in V). The majority of this type's representatives are stars of luminosity class V; objects of this subtype generally are representative of the Delta Sct variables in open clusters. Delta Scuti Variable Star DSCT dS* early##type##star##earlytype Early-type Star Stars, OB Stars:early-type Star of the early spectral types Stellar Object in Double Star *i* *in** stellar##object##star##in##double A star that is part of a double star pm##proper##motion Proper_Motions Proper Motion Proper motions component of the spacevelocity Radio Radio Source radio##source Rad Radio sources Variable Star of RR Lyr type RR Lyrae Variable rr##lyrae##variable##star Variables of the RR Lyrae type, which are radially-pulsating giant A-F stars having amplitudes from 0.2 to 2 mag in V. Cases of variable light-curve shapes as well as variable periods are known. If these changes are periodic, they are called the "Blazhko effect." Traditionally, RR Lyrae stars are sometimes called short-period Cepheids or cluster-type variables. The majority of these stars belong to the spherical component of the Galaxy; they are present, sometimes in large numbers, in some globular clusters, where they are known as pulsating horizontal-branch stars. Like Cepheids, maximum expansion velocities of surface layers for these stars practically coincide with maximum light. Sub-types: - RR Lyrae variables showing two simultaneously operating pulsation modes, the fundamental tone with the period P0 and the first overtone, P1 (AQ Leo). The ratio P1/P0 is approximately 0.745; - RR Lyrae variables with asymmetric light curves (steep ascending branches), periods from 0.3 to 1.2 days, and amplitudes from 0.5 to 2 mag in V; - RR Lyrae variables with nearly symmetric, sometimes sinusoidal, light curves, periods from 0.2 to 0.5 days, and amplitudes not greater than 0.8 mag in V (SX UMa). RR RR* RRLyr Ultraviolet Spectra, ultraviolet Ultraviolet uv##ultraviolet##ultra##violet UV I Blue objects blu Blue_objects Blue Object Blue blue##object X X X-ray sources X-ray Source HI HI HI Region H I data hi##region HI (neutral) region high##power##radio##loud##agn##active##galaxy##nucleus## High-power Radio-loud AGN l##ltype##type##irregular##star L-type Irregular Star Galaxy in Cluster of Galaxies GinCl cluster##in##galaxy##gal##galaxies GiC Galaxy in Cluster asteroid Asteroid Minor planets Asteroids Red Giant red##redgiant##giant Association of Stars Associations AS* Associations, stellar Association of Stars association##star##stars Assoc* Galaxies, Seyfert SyG low##power##radio##quiet##agn##active##galaxy##nucleus##seyfert Seyfert Galaxy Seyfert Seyfert Galaxy Seyfert_Galaxies barred##spiral##galaxy##gal##galaxies Barred Spiral Galaxy BYDra by##draconis##variable##star BY BY* BY Draconis-type variables, which are emission-line dwarfs of dKe-dMe spectral type showing quasiperiodic light changes with periods from a fraction of a day to 120 days and amplitudes from several hundredths to 0.5 mag in V. The light variability is caused by axial rotation of a star with a variable degree of nonuniformity of the surface brightness (spots) and chromospheric activity. Some of these stars also show flares similar to those of UV Cet stars, and in those cases they also belong to the latter type and are simultaneously considered eruptive variables. BY Draconis Variable Varaible Star of BY Dra type Stars, distances Radio continuum Multiplet continuum Radio Lines Continuum Equivalent widths Range allowing the description of the existence of a (noticeable) continuum for a given object Balmer lines Line Profiles Space Velocity space##velocity BLLAC BL Lac-type Object BL Lac objects BLLac##BL##Lac##Object##Lacertae BLL BLLac BLLac BL_Lac_objects Irregular_V* Ir* Stars showing variations of irregular (non-periodic) type. Mostly (?) of eruptive type. Irregular Variable Star irregular##variable##star Variable Star of Irregular type High-velocity Cloud HVC high##velocity##cloud##nebula HVCld HVC (High Velocity Cloud) ch##envelope##type##star CH Envelope-type Star CH Envelope-type Star CH* CH* Flux flux line##width Line Width Starburst Process star##burst##starburst Polarization polarization Pu* PulsV* Pulsating variables are stars showing periodic expansion and contraction of their surface layers. The pulsations may be radial or nonradial. A radially pulsating star remains spherical in shape, while in the case of nonradial pulsations the star's shape periodically deviates from a sphere, and even neighboring zones of its surface may have opposite pulsation phases. Depending on the period value, on the mass and evolutionary status of the star, and on the scale of pulsational phenomena, different types of pulsating variables may be distinguished. Pulsating Variable Star Pulsating Star pulsating##variable##star EmG Emission-line galaxy EmG Emission-line Galaxy emission##line##galaxy##gal##galaxies Large Separation Lobes large##separation##lobes##radio Gamma-ray Source gamma gamma##ray##source gam pulsation##process Pulsation Process Seyfert 1 Galaxy Sy1 Seyfert_1 Seyfert 1 Galaxy seyfert##seyfert1##1##galaxy Stellar Remnant stellar##remnant High_z_G Galaxy with high redshift Galaxy with High Redshift HzG high##redshift##galaxy##gal##galaxies measure##measurement##measures##measurements Measurement Measured observational parameters/properties Stars:variable V* V* variable##star##stellar##object Stars, variable RS Eruptive variables of the RS Canum Venaticorum type. This type is ascribed to close binary systems with spectra showing Ca II H and K in emission, their components having enhanced chromospheric activity that causes quasi-periodic light variability. The period of variation is close to the orbital one, and the variability amplitude is usually as great as 0.2 mag in V (UX Ari). They are X-ray sources and rotating variables. RS CVn itself is also an eclipsing system. RS* rs##canum##venaticorum##cv Variable of RS CVn type RSCVn RS Canum Venaticorum Variable Star Stars * stellar##object Stellar Object Star O Galaxies, UV-excess Galaxies, optical Galaxies, IR galaxy##gal##galaxies Galaxy catalogs G Galaxy Galaxies, optical Galaxies, photometry Galaxies, spectra Galaxies, nearby Galaxies, rotation Galaxies, Markarian Galaxies Photosphere photosphere Millimetric/submm sources sub##millimetric##submillimetric##radio##source smm Sub-millimetric Radio Source Radio(sub-mm) Ages Stars, ages Rotation Process rotation##process Supernova type IIb supernova##typeiib##type2b##type##2##ii##b##typeii##type2 High-mass Star high##mass##star##highmass Surface Brightness s'applique aux objets étendus ( Gal/nebula) surface##brightness flux##amplitude##variation Flux Amplitude Variation AGN AGN Active Galaxy Nucleus AGN AGN Active gal. nuclei AGN##active##galaxy##nucleus##nuclei##galactic dust Dust Stars, pre-main sequence pre##main##sequence##star pr* Pre-main sequence star pMS* Pre-Main Sequence Star qso##2##quasar##qso2 QSO2 Rotation-powered Pulsar rotation##powered##pulsar Interacting Galaxy IG IG interacting##galaxy##galaxies galaxy in strong interaction with others (within a pair or a group) temperature Radio Millimetric radio##millimetric##mm Spectra, millimetric/submm MK spectral classification Spectral types Spectral_Classification Spectral Type spectral##type Any class in Morgan Keeman's spectral classification FU Orionis Variable Star Variable Star of FU Ori type FU* Orion variables (eruptive) of the FU Orionis type. Characterized by gradual increases in brightness by about 6 mag in several months, followed by either almost complete constancy at maximum that is sustained for long periods of time or slow decline by 1-2 mag. Spectral types at maximum are in the range Ae(alpha) - Gpe(alpha). After an outburst, a gradual development of an emission spectrum is observed and the spectral type becomes later. These variables probably mark one of the evolutionary stages of T Tauri-type Orion variables, as evidenced by an outburst of one member, V1057 Cyg, but its decline (2.5 mag in 11 years) commenced immediately after maximum brightness was attained. All presently known FU Ori variables are coupled with reflecting cometary nebulae. FU FUOr* fu##orionis##orion##variable##star X-Rays x##ray##xray##rays##xrays X-Ray Pulsating Alpha2 Canum Venaticorum pulsating##alpha##2##alpha2##cv##cvn##canum##venaticorum near##ir##infrared Near Infrared Wavelength < 10 microns gamma##rays##ray Gamma-ray Gamma Rays Gamma rays Stars, dwarfs dwarf Star of Luminosity Class V Dwarf B mR Radio(m) Metric Radio Source radio##source##metric 2 thing##top##anything TOP TOP concept PaG PairG pair##gal##galaxy##galaxies Galaxy Pair Rotationally Variable Object RotV* Variable stars with nonuniform surface brightness and/or ellipsoidal shapes, whose variability is caused by axial rotation with respect to the observer. The nonuniformity of surface brightness distributions may be caused by the presence of spots or by some thermal or chemical inhomogeneity of the atmosphere caused by a magnetic field whose axis is not coincident with the rotation axis. Rotationally Variable Star rotational##rotationally##variable##object##star Ro* Accretion-powered Pulsar accretion##powerred##pulsar Parallaxes Parallaxes, trigonometric *iN stellar##object##star##in##nebula *inNeb Stellar Object in Nebula emission##maser Maser Emission weak##line##t##tau##tauri##star Weak-line T Tauri starburst##gal##galaxy##galaxies StarburstG SBG Starburst Galaxy Pulsars PSR Pulsar Optically variable pulsars (CM Tau), which are rapidly rotating neutron stars with strong magnetic fields, radiating in the radio, optical, and X-ray regions. Pulsars emit narrow beams of radiation, and periods of their light changes coincide with rotational periods (from 0.004 to 4 s), while amplitudes of the light pulses reach 0.8 mag. pulsar Pulsar Pulsar Psr Pulsars Spectra, infrared IR ir##infrared Infrared super##cluster##supercluster##galaxies SCG Super Cluster Of Galaxies 3 SuperClG Super Cluster of Galaxies Pl? Planets planet Planet? Planet (Extra-solar) Planet Candidate Compact_Gr_G compact##galaxy##galaxies##group CGG Compact Group of Galaxies Millimetric Radio Source Millimetric/submm sources Radio(mm) mm millimetric##radio##source not##non##radial##pulsation Non-radial Pulsation Line Emission emission##line##lines LINER LINER AGN LIN liner##agn LINER-type Active Galaxy Nucleus LumX lumx accretion##disk Accretion Disk eruptive##variable##star Eruptive* Eruptive variables are stars varying in brightness because of violent processes and flares occurring in their chromospheres and coronae. The light changes are usually accompanied by shell events or mass outflow in the form of stellar winds of variable intensity and/or by interaction with the surrounding interstellar medium. Eruptive Variable Star Eruptive Variable Star Er* near IR emission, age around 10^6years INT,IT TT* T Tauri Star t##tauri##star##tau Alpha2 Canum Venaticorum Variable alpha##2##alpha2##cv##cvn##canum##venaticorum Variable Star of alpha2 CVn type Alpha2 Canum Venaticorum variables. These are main-sequence stars with spectral types B8p-A7p and displaying strong magnetic fields. Spectra show abnormally strong lines of Si, Sr, Cr, and rare earths whose intensities vary with rotation. They exhibit magnetic field and brightness changes (periods of 0.5-160 days or more). The amplitudes of the brightness changes are usually withine 0.01-0.1 mag in V. Sub-type: - Rapidly oscillating Alpha2 CVn variables. These are nonradially pulsating, rotating magnetic variables of Ap spectral type (DO Eri). Pulsation periods are in the range of 6-12 mmag (0.004-0.01 days), while amplitudes of light variation caused by the pulsation are about 0.01 mag in V. The pulsational variations are superposed on those caused by rotation. RotV*alf2CVn a2* ACV Diffuse clouds dwarf##nova##novae##u##geminorum Dwarf Nova (U Geminorum-type variable star) DN* DwarfNova UG U Geminorum-type variables, quite often called dwarf novae. They are close binary systems consisting of a dwarf or subgiant K-M star that fills the volume of its inner Roche lobe and a white dwarf surrounded by an accretion disk. Orbital periods are in the range 0.05-0.5 days. Usually only small, in some cases rapid, light fluctuations are observed, but from time to time the brightness of a system increases rapidly by several magnitudes and, after an interval of from several days to a month or more, returns to the original state. Intervals between two consecutive outbursts for a given star may vary greatly, but every star is characterized by a certain mean value of these intervals, i.e., a mean cycle that corresponds to the mean light amplitude. The longer the cycle, the greater the amplitude. These systems are frequently sources of X-ray emission. The spectrum of a system at minimum is continuous, with broad H and He emission lines. At maximum these lines almost disappear or become shallow absorption lines. Some of these systems are eclipsing, possibly indicating that the primary minimum is caused by the eclipse of a hot spot that originates in the accretion disk from the infall of a gaseous stream from the K-M star. According to the characteristics of the light changes, U Gem variables may be subdivided into three types: SS Cyg, SU UMa, and Z Cam. Dwarf Nova absolute##magnitude Absolute Magnitude Spectral Index spectral##index supernova##typeia##type1b##type##1b##ib##b##1##i Supernova type Ib V Type1.5-Seyfert1.5 Seyfert Seyfert 1.5 Galaxy seyfert##seyfert1.5##1.5##galaxy Power Radio Ghz power##radio##ghz##radioghz##powerradioghz Stars:Emission Emission-line Star Em* Em* Emission-line Star emission##line##emissionline##star Core Collapse Supernova Explosion supernova##explosion##core##collapse Eclipse eclipse flux##ratio##radio5ghz##radio##5Ghx##optical Flux Ration Radio5Ghz-Optical Elliptical Galaxy elliptical##galaxy##gal##galaxies open##cluster##star##stars OpCl OpC Open Cluster Open_clusters Clusters, open Stars, A-type Star of Spectral Type A A Star a##star##astar Or* Variable Star of Orion type Orion_V* IN Orion Variable Star Orion variables. Irregular, eruptive variables connected with bright or dark diffuse nebulae or observed in the regions of these nebulae. Some of them may show cyclic light variations caused by axial rotation. In the Spectrum-Luminosity diagram, they are found in the area of the main sequence and subgiants. They are probably young objects that, during the course of further evolution, will become light-constant stars on the zero-age main sequence (ZAMS). The range of brightness variations may reach several magnitudes. This type may be divided into the following subtypes: - Rapid light variations observed (up to 1 mag in 1-10 days), - Orion variables of early spectral types (B-A or Ae). They are often characterized by occasional abrupt Algol-like fadings (T Ori); - Orion variables of intermediate and late spectral types, F-M or Fe-Me (BH Cep, AH Ori). F-type stars may show Algol-like fadings; K-M stars may produce flares along with irregular light variations; - Orion variables of the T Tauri type. Stars are assigned to this type on the basis of the following (purely spectroscopic) criteria: spectral types are in the range Fe-Me. The spectra of most typical stars resemble the spectrum of the solar chromosphere. The feature specific to the type is the presence of the flourescent emission lines Fe II 4046, 4132 A (anomalously intense in the spectra of these stars), emission lines [Si II] and [O I], as well as the absorption line Li I 6707 A. These variables are usually observed only in diffuse nebulae. - Some Orion variables (YY Ori) show the presence of absorption components on the redward sides of emission lines, indicating the infall of matter toward the stars' surfaces. orion##variable##star dwarf##spiral##galaxy##gal##galaxies Dwarf Spiral Galaxy Mass mass Masses A planetary nebula is a nebula surrounding a stellar remnant (white dwarf) Planetary nebulae PN 2 Planetary_Nebulae Planetary Nebula PN planetary##nebula##nebulae QSO QSOs high##power##radio##quiet##agn##active##galaxy##nucleus## QSOs High-power Radio-quiet AGN QSO kstar##k##star K Star Star of Spectral Type K Stars, K-type Supernova type Ia supernova##typeia##type1a##type##1a##ia##a##1##i BlueCompG Blue Compact Galaxy BCG blue##compact##galaxy##gal##galaxies Blue Compact Galaxy Eclipse of Beta Lyrae Type eclipse##beta##lyrae lpv##long##period##variable Long-period Variable dwarf##barred##spiral##galaxy##gal##galaxies Dwarf Barred Spiral Galaxy 3 Clusters, galaxy ClG cluster##galaxy##galaxies ClG Clusters_of_galaxies Cluster of Galaxies Steep-spectrum Radio Quasar steep##spectrum##radio##quasar##qso Protostars Protostar protostar##proto##star Brilliant Giant Star of Luminosity Class II brilliant##giant f##fstar##star F Star Stars, F-type Star of Spectral Type F S Reflection of stellar light Reflection Process reflection##process S##Sa##Sb##Sc##Sd##Sab##Sbc##Scd## Halo halo eclipse##algol Eclipse of Algol Type Dark Nebula dark##cloud##nebula DNe Nebulae, dark DkNeb Luminosity Class luminosity##class brown##dwarf Brown Dwarf Planetary Nebula Central Star planetary##nebula##central##star white##dwarf##wd Stars, white dwarf WD* Stars:white_dwarf WD* White Dwarf A white dwarf or a stellar remnant These are the classical cepheids, or Delta Cep-type variables. Comparatively young objects that have left the main sequence and evolved into the instability strip of the Hertzsprung-Russell (H-R) diagram, they obey the well-known Cepheid period-luminosity relation and belong to the young disk population. Delta Cep stars are present in open clusters. They display a certain relation between the shapes of their light curves and their periods. Sub-type: - These are Delta Cep variables having light amplitudes <0.5 mag in V (<0.7 mag in B) and almost symmetrical light curves (M-m approx. 0.4 - 0.5 periods); as a rule, their periods do not exceed 7 days. They are probably first-overtone pulsators and/or are in the first transition across the instability strip after leaving the main sequence (SU Cas). Traditionally, both Delta Cep and W Vir stars are quite often called Cepheids because it is often impossible to discriminate between them on the basis of the light curves for periods in the range 3 - 10 days. However, these are distinct groups of entirely different objects in different evolutionary stages. One of the significant spectral differences between W Vir stars and Cepheids is the presence, during a certain phase interval, of hydrogen-line emission in the former and of Ca II H and K emission in the latter. Classical Cepheid (delta Cep type) Classical Cepheid delta##cepheid##classical##cep##cephei DCEP deltaCep cC* su* Substellar Object sub##substellar##object Sub-stellar low##power##radio##loud##agn##active##galaxy##nucleus Low-Power Radio-loud AGN Object of Unknown nature Unknown ? Object of unknown nature Variable Star of RV Tau type PulsV*RVTau Variables of the RV Tauri type. These are radially pulsating supergiants having spectral types F-G at maximum light and K-M at minimum. The light curves are characterized by the presence of double waves with alternating primary and secondary minima that can vary in depth so that primary minima may become secondary and vice versa. The complete light amplitude may reach 3-4 mag in V. Periods between two adjacent primary minima (usually called formal periods) lie in the range 30-150 days. Two subtypes are recognized: - RV Tauri variables that do not vary in mean magnitude (AC Her); - RV Tauri variables that periodically (with periods from 600 to 1500 days and amplitudes up to 2 mag in V) vary in mean magnitude (DF Cyg, RV Tau). RV* RV RV Tauri Variable Star rv##tau##tauri##rvtau##rvtauri##star##variable T H2G hii####galaxy##gal##galaxies HII Galaxy HII_G HII Galaxy Accretion Portion of Stellar Object any component of a stellar object portion##of##stellar##object Classical T Tauri classical##t##tauri##star##tau Binaries:spectroscopic binary##binaries##spectroscopic Binaries, spectroscopic Spectroscopic Binary SB* SB eclipse##wuma##w##ursae##majoris Eclipse of WUMa Type DQHer dq##herculis##variable##star DQ* Cataclysmic Variable Star DQ Her type DQ Herculis OH/IR oh##ir##envelope##star OH* OH/IR Envelope-type Star OH/IR Envelope-type Star IR<10µ NIR Near-IR Source near##ir##infrared##source Supernova Explosion supernova##explosion A system of two or more distinct stars Multiple_Stars Multiple Star Stars, double and multiple Double or multiple star ** multiple##star Rotating ellipsoidal variables (b Per, Alpha Vir). These are close binary systems with ellipsoidal components, which change combined brightnesses with periods equal to those of orbital motion because of changes in emitting areas toward an observer, but showing no eclipses. Light amplitudes do not exceed 0.1 mag in V. ELL ellipsoidal##variable##star RotV*Ell Ellipsoidal Variable Star El* Ellipsoidal Variable Star portion##of##galaxy Any component of a galaxy Portion of Galaxy ring##gal##galaxy##galaxies Ring Galaxy Galaxies, ring M Red Object red Red red##object HI HI Region Warm HI warm##hi##region dI ZZ* PulsWD* Pulsating White Dwarf Pulsating White Dwarf pulsating##white##dwarf##wd Star of Luminosity Class IV Subgiant sub##giant##subgiant EB* EB* E Eclipsing Binary Eclipsing Binary Binaries, eclipsing Binaries:eclipsing Binary systems with orbital planes so close to the observer's line of sight (the inclination i of the orbital plane to the plane orthogonal to the line of sight is close to 90 deg) that the components periodically eclipse each other. Consequently, the observer finds changes of the apparent combined brightness of the system with the period coincident with that of the components' orbital motion. eclipsing##binary##star Interstellar_Medium Interstellar medium Neb ISM Interstellar Medium Cld Cloud Neb inter##stellar##interstellar##medium rG Radio Galaxy Galaxies, radio RadioG radio##gal##galaxy##galaxies variable##object Object which main particularity is to feature a variability Variable Object Maser Mas Maser Masers Masers##Stars, masers maser red##super##giant##supergiant Red Supergiant component of the spacevelocity Radial Velocity radial##velocity Radial velocities value < 300000 asymptotic##giant##branch##star##agb AGB Star AG* AGB* Asymptotic Giant Branch Star radio##sub##millimetric##submillimetric Spectra, millimetric/submm Radio Submillimetric radial##pulsation Radial Pulsation fanaroff##riley##type##1 Fanaroff-Riley Type-1 Object Polar Ring Galaxy polar##ring##gal##galaxy##galaxies Compound Object Morphology compound##object##morphology Sy* ZAND Symbiotic* Symbiotic Star Symbiotic Star symbiotic##star Symbiotic variables of the Z Andromedae type. They are close binaries consisting of a hot star, a star of late type, and an extended envelope excited by the hot star's radiation. The combined brightness displays irregular variations with amplitudes up to 4 mag in V. A very inhomogeneous group of objects. IR>30µ Far-IR Source far##ir##infrared##source FIR cm centimetric##radio##source Radio(cm) Centimetric Radio Source HII_regions hii##region HII HII Region HII (inonized) region HII H II regions Proplyd Proplyd protoplanetary##proto##planetary##disk##proplyd Class class##type Carbon Star C* carbon##star##c Carbon Star C* Gravitational_lensing lensing##process Lensing Process Gravitational lensing WU* W Ursae Majoris-type eclipsing variables. These are eclipsers with periods shorter than 1 days, consisting of ellipsoidal components almost in contact and having light curves for which it is impossible to specify the exact times of onset and end of eclipses. The depths of the primary and secondary minima are almost equal or differ insignificantly. Light amplitudes are usually <0.8 mag in V. The components generally belong to spectral types F-G and later. EB*WUMa Eclipsing Binary of W UMa type WUMa Eclipsing Binary eclipsing##binary##star##wuma##w##ursae##majoris EW Comet Comets comet chromosphere Chromosphere qso##quasi##stellar##object##quasar##type1##type##1 QSO type 1 Core/Extended Flux Ratio < 1) Lobe Dominated lobe##dominated##lobedominated Supergiant Stars, supergiant Star of Luminosity Class I super##giant##supergiant RfNeb Reflexion Nebula RNe reflexion##nebula Mi* mira##ceti##omicron##variable##star Mira Variable Star of Mira Cet type M Mira Ceti Variable Mira (Omicron) Ceti-type variables. These are long-period variable giants with characteristic late-type emission spectra (Me, Ce, Se) and light amplitudes from 2.5 to 11 mag in V. Their periodicity is well pronounced, and the periods lie in the range between 80 and 1000 days. Infrared amplitudes are usually less than in the visible and may be <2.5 mag. For example, in the K band they usually do not exceed 0.9 mag. NL Nova-like Object Insufficiently studied objects resembling novae by the characteristics of their light changes or by spectral features. This type includes, in addition to variables showing novalike outbursts, objects with no bursts ever observed; the spectra of novalike variables resemble those of old novae, and small light changes resemble those typical for old novae at minimum light. However, quite often a detailed investigation makes it possible to reclassify some representatives of this highly inhomogeneous group of objects into other types. novalike##like##nova##object Nova-like NL* HB* Stars, horizontal branch hb##star##horizontal##branch Horizontal-branch Star Horizontal Branch Star HB* Optical optical optical Red red power##radio Power Radio portion##astroportion Portion of Astronomical Object Portion of an astronomical object which is not an astronomical object itself dwarf##irregular##galaxy##gal##galaxies Dwarf Irregular Galaxy Emission Nebula emission##nebula Spiral Galaxy spiral##gal##galaxy##galaxies Equivalent Width EquivalentWidth equivalent##width Stars, Am Pe* Stars:peculiar Pec* Stars, Ap Peculiar Stellar Object Peculiar Stellar Object peculiar##star##stellar##object Stars, peculiar Stars, barium Stars, Bp Stars, metal-deficient SNI supernova##typei##type1##type##1##i Supernova type I astrobject##astroobject##astronomical##object Any astronomical object Astronomical Object Post-AGB Star postagb##post##agb##asymptotic##giant##branch##star post-AGB* Post-AGB Star pA* III continuum##non##not##thermal Continuum Non-thermal Nebula Nebula in##pair##galaxy##gal##galaxies Galaxy in Pair GinPair GiP super##massive##supermasive##black##hole##blackhole Supermassive Black Hole spectrum Spectrum G electron##temperature Electron Temperature Supernovae supernova SN SN supernova##supernovae SN* SuperNovae SuperNova Rapid Irregular Variable Star Rapid_Irreg_V* rapid##irregular##variable##star Rapid irregular variables (class: eruptive) having no apparent connection with diffuse nebulae and showing light changes of about 0.5 - 1.0 mag within several hours or days. There is no strict boundary between rapid irregular and Orion variables. If a rapid irregular star is observed in the region of a diffuse nebula, it is considered an Orion variable. To attribute a variable to this type (R.I.), it is necessary to take much care to be certain that its light changes are really not periodic. Sub-types: - Rapid irregular variables of the early spectral types, B-A or Ae; - Rapid irregular variables of the intermediate and late spectral types, F-M and Fe-Me. Variable Star with rapid variations IS RI* I Stellar Object in Cluster stellar##object##star##in##cluster *iC An individual star located in a star cluster *inCl atomic##element Atomic Element Binaries, X-ray XB X-ray Binary X x##ray##xray##binary##binaries Close binary systems that are sources of strong, variable X-ray emission and which do not belong to or are not yet attributed to any other type of variable stars. One of the components of the system is a hot compact object (white dwarf, neutron star, or possibly a black hole). X-ray emission originates from the infall of matter onto the compact object or onto an accretion disk surrounding the compact object. In turn, the X-ray emission is incident upon the atmosphere of the cooler companion of the compact object and is reradiated in the form of optical high-temperature radiation (reflection effect), thus making that area of the cooler companion's surface an earlier spectral type. XB* galactic##galaxy##morphology Galaxy Morphology HV* highvelocity##high##velocity##star Stars, high-velocity HV* High-velocity Star High Velocity Star Stars, late-type Star of the late spectral types Stars, cyanogen late##type##star##latetype Late-type Star Stars:late-type Stars, S Stars, carbon Cataclysmic Variable Star AM Her type am##herculis##variable##star AMHer AM* AM AM Herculis Jet jet morphology##morphological##geometry##geometrical##feature##features Morphology Geometry or morphology of astronomical objects (including components which are not astronomical objects) Morphological Feature supernova##typeic##type1c##type##1c##ic##c##1##i Supernova type Ic period Period giant Star of Luminosity Class III Stars, giant Giant PulsV*semi-reg SR Semi-regular pulsating star sr* Semi-regular Pulsating Star semi##regular##semiregular##pulsating##star chromospheric##activity##chromosphere Corresponds to an important chromosperic activity, usually a source of emission Chromospheric Activity Supernova type IILP supernova##typeiilp##type2lp##type##2##iilpb##typeii##type2 rcb##r##coronae##borealis##variable RC* Variable Star of R CrB type R Coronae Borealis Variable Variables of the R Coronae Borealis type. These are hydrogen-poor, carbon- and helium-rich, high-luminosity stars belonging to the spectral types Bpe-R, which are simultaneously eruptive and pulsating variables. They show slow nonperiodic fadings by 1-9 mag in V lasting from a month or more to several hundred days. These changes are superposed on cyclic pulsations with amplitudes up to several tenths of a magnitude and periods in the range 30-100 days. RCB Erupt*RCrB Process process Phenomenon or associated process Set of ranges in the electromagnetic spectrum EM Spectrum Range em##electromagnetic##specrum##range K Envelope envelope bL* EB eclipsing##binary##star##beta##lyrae Beta Lyrae Eclipsing Binary Beta Lyrae-type eclipsing systems. These are eclipsing systems having ellipsoidal components and light curves for which it is impossible to specify the exact times of onset and end of eclipses because of a continuous change of a system's apparent combined brightness between eclipses; secondary minimum is observed in all cases, its depth usually being considerably smaller than that of the primary minimum; periods are mainly longer than 1 day. The components generally belong to early spectral types (B-A). Light amplitudes are usually <2 mag in V. Eclipsing Binary of Beta Lyr type EB*betLyr Abundances, peculiar Abundances, [Fe/H] Abundances Abundances Gravitationnaly Lensed Image of a Quasar lensed##quasar##qso##gravitationnaly Lensed Quasar LeQ LensedQ Optical Source optical##source Nonstellar objects Non-stellar Body Planets+Asteroids Nonstellar Supernova Remnant Shell SNR Supernova remnants supernova##shell##remnant SNR SuperNovae_Remnants Old Disk Galactic Sperical Component (old disk) old##disk##galactic##sperical##component Extended extended wolf##rayet##wolfrayet##star##wr Wolf-Rayet star Stars:WR WR* Wolf-Rayet Star Stars, Wolf-Rayet WR* Variability Time Scale time##scale##timescale##variability bok##globule Bok Globule Globules Bok globules roche##lobe##rochelobe Roche Lobe Thermal Continuum Black Body thermal continuum thermal##continuum molecules Molecules dwarf##elliptic##galaxy##gal##galaxies Dwarf Elliptical Galaxy PN planetary##nebula##shell Planetary Nebula Shell PN GrG Group of Galaxies group##galaxies##galaxy GroupG High-proper motion Star High Proper Motion Star PM* PM* high##proper##motion##star C MolCld molecular##cloud MoC Molecular Cloud Molecular clouds fanaroff##riley##type##2 Fanaroff-Riley type 2 Double Star A system of two stars ** 2 double##star Double or multiple star spiral##arm Spiral Arm Spiral Arm of a galaxy compact Compact Morphology Irregular Galaxy irregular##galaxy##gal##galaxies microlensing##micro##lensing Micro-lensing Ce* Cepheid cepheid##cep##cephei CEP Cepheids. Radially pulsating, high luminosity (classes Ib-II) variables with periods in the range of 1-135 days and amplitudes from several hundredths to 2 mag in V (in the B band, the amplitudes are greater). Spectral type at maximum light is F; at minimum, the types are G-K. The longer the period of light variation, the later is the spectral type. The maximum of the surface-layer expansion velocity almost coinciding with maximum light. Sub-type: - Cepheids (TU Cas, V 367 Sct) displaying the presence of two or more simultaneously operating pulsation modes (usually the fundamental tone with the period P0 and the first overtone P1). The periods P0 are in the range from 2 to 7 days, with the ratio P1/P0 approx. 0.71. Cepheid variable star Cepheid S-type Star S* S* S-type Star s##type##stype##star##sstar Optically Violently Variable Object OVV##Optically##Variable##Object OVV OVV Optically Violently Variable Object II Light Curve light##curve M Star m##star##mstar Star of Spectral Type M cosmological##lensing Cosmological Lensing E Giant Elliptical Galaxy giant##elliptical##galaxy##gal##galaxies non##not##periodic##process PartofG Part Of Galaxy Part of Galaxy part##of##galaxy PoG EM Source em##source##electromagnetic##electro##magnetic Neutral Gas neutral##gas flare##star##flarestar Flare Star Flare* Flare Star Stars, flare Eruptive variables varying in brightness because of flares occurring in their chromospheres and coronae. Sub-types: - Orion variables of late (K-M) spectral types - Eruptive variables of the UV Ceti type, these are K Ve-M Ve stars sometimes displaying flare activity with amplitudes from several tenths of a magnitude up to 6 mag in V. The amplitude is considerably greater in the ultraviolet spectral region. Maximum light is attained in several seconds or dozens of seconds after the beginning of a flare; the star returns to its normal brightness in several minutes or dozens of minutes. - Flaring Orion variables of spectral types Ke-Me. These are phenomenologically almost identical to UV Cet variables observed in the solar neighborhood. In addition to being related to nebulae, they are normally characterized by being of earlier spectral type and greater luminosity, with slower development of flares (V389 Ori). - BY Draconis-type (rotating) variables, which are emission-line dwarfs of dKe-dMe spectral type showing quasiperiodic light changes with periods from a fraction of a day to 120 days and amplitudes from several hundredths to 0.5 mag in V. The light variability is caused by axial rotation of a star with a variable degree of nonuniformity of the surface brightness (spots) and chromospheric activity. Some of these stars also show flares similar to those of UV Cet stars, and in those cases they also belong to the latter type and are simultaneously considered eruptive variables. Fl* Radio Radio radio radio##quiet##agn Radio-quiet AGN mul A composite object is made of at least two distinct astronomical objects Compound object multiple_object 2 compound##composite##object Sy2 Seyfert_2 Seyfert 2 Galaxy seyfert##seyfert2##2##galaxy Seyfert 2 Galaxy Blazar Blazar Bla Blazar Blazar GlC globular##cluster##star##stars Globular_Clusters GlCl Globular Cluster Clusters, globular stellar##black##hole Stellar Black Hole Galaxies, peculiar Peculiar Galaxy peculiar##gal##galaxy##galaxies small##separation##lobes##radio Close close Extremely Red Object Extremely Red Obejct ERO extremely##red##object RedExtreme A EUV magnetar##pulsar##magnetic##field Magnetar flux##ratio Flux Ratio Lensed Galaxy lensed##gravitationnal##gal##galaxy##galaxies LeG LensedG Gravitationnaly Lensed Image of a Galaxy Redshifts Redshift redshift##red##shift Redshifts -12 < value < 12 Cluster of Stars Cl* 3 Cl* cluster##star##stars bC* BCEP PulsV*bCep Beta Cephei Variable Variables of the Beta Cephei type (Beta Cep, Beta CMa), which are pulsating O8-B6 I-V stars with periods of light and radial-velocity variations in the range of 0.1 - 0.6 days and light amplitudes from 0.01 to 0.3 mag in V. The light curves are similar in shape to average radial-velocity curves but lag in phase by a quarter of the period, so that maximum brightness corresponds to maximum contraction, i.e., to minimum stellar radius. The majority of these stars probably show radial pulsations, but some (V649 Per) display nonradial pulsations; multiperiodicity is characteristic of many of these stars. Sub-type: - A short-period group of Beta Cep variables. The spectral types are B2-B3 IV-V; periods and light amplitudes are in the ranges 0.02 - 0.04 days and 0.015 - 0.025 days, respectively, i.e., an order of magnitude smaller than the normally observed ones. cephei##cep##beta##cepheid##cma Variable of the Beta Cep type Be Star Stars, Be Be* Be* Be Star be##star##bestar Velocity dispersion Eclipsing Binary of Algol type Algol Eclipsing Binary eclipsing##binary##star##algol##beta##persei Algol (Beta Persei)-type eclipsing systems. Binaries with spherical or slightly ellipsoidal components. It is possible to specify, for their light curves, the moments of the beginning and end of the eclipses. Between eclipses the light remains almost constant or varies insignificantly because of reflection effects, slight ellipsoidality of components, or physical variations. Secondary minima may be absent. An extremely wide range of periods is observed, from 0.2 to >= 10000 days. Light amplitudes are also quite different and may reach several magnitudes. EB*Algol Al* EA S0##S0a shockwave##shock##wave Shockwave The shockwave-generating process or the resulting Shockwave HH Herbig-Haro Object herbig##haro##herbigharo##object HH accreting##white##wd##dwarf Accreting White Dwarf O Star o##star##ostar Stars, O Star of Spectral Type O Power Radio Mhz power##radio##mhz##powerradiomhz##radiomhz Variables of the W Virginis type. These are pulsating variables of the galactic spherical component (old disk) population with periods of approximately 0.8 to 35 days and amplitudes from 0.3 to 1.2 mag in V. They obey a period-luminosity relation different from that for Delta Cep variables. For an equal period value, the W Vir variables are fainter than the Delta Cep stars by 0.7 - 2 mag. The light curves of W Vir variables for some period intervals differ from those of Delta Cep variables for corresponding periods either by amplitudes or by the presence of humps on their descending branches, sometimes turning into broad flat maxima. W Vir variables are present in globular clusters and at high galactic latitudes. Variable Star of W Vir type W Virginis Variable Star PulsV*WVir WV* CW w##virginis##wvirginis##type##variable##star part##of##cloud PartofCloud PoC Part Of Cloud is component of Indicates that the DOMAIN AstrObject is a direct physical component of the RANGE CompositeObject (not a component of a component of the RANGE CompositeObject) has among its portions Indicates that the RANGE AstroPortion can be found whithin the DOMAIN CompoundObject or AstroPortion Indicates that an astronomical object is the location of a Process/has an attached process has among its processes has among its measurements Indicates that the DOMAIN AstrObject has the RANGE Measurement among its (observational) measurements features an abundance of is class of is morphology of features absorption spectral line(s) for is a member of the class: features emission spectral line(s) for Indicates the Progenitor of a Supernova has for progenitor has among its (direct) components Indicates that the DOMAIN CompoundObject has the RANGE AstrObject among its direct physical components (the RANGE AstrObject cannot be a component of a component of the composite object) is portion of features a noticeable emission in Indicates what ionizes the gas of a given ISM is ionized by is measured for features high measurement(s) for Indicates that an astronomical object has a related (observational) measurement which value is considered as high has among its morphological features the unit associated with the value of an instance of measturement (this annotation should be used only if there actually is a unit) The operators and values for an instance (of measurement), format is either operator1##value1##operator2##value2, or operator##value if there is only one value Short code in Simbad's object classification Main part of the spectral type in SIMBAD (letters only, found at the beginning of SIMBAD's spectral type value) GCVS code(s) corresponding to a concept of the ontology tests that should be taken care of outside of the ontology (e.g. check that a value is within sensible boundaries) textual description/definition of a concept Standard name in Simbad's object classification morphological type for galaxies in SIMBAD name in natural language for display purposes VizieR keyword corresponding to an item of the ontology Main part of the luminosity class in SIMBAD (letters only, found within SIMBAD's spectral type value after said spectral type) keywords for (text) search purposes