
	Where results make sense

Topic: Luminosity class

Related Topics

middle class

working class

Spectral class

social class

Bathurst class corvette

her class

Ohio class submarines

class computer science

equivalence class

Oliver Hazard Perry class frigate

Bathurst class

Attack class patrol boat

In the News (Sat 19 Dec 09)

Northern Trust

Marvin Harrison

Peter Chernin

Gary Locke

Match Play

Penelope Cruz

Mickey Rourke

AR Rahman

Danny Boyle

Hugh Jackman

	luminosity class
		A classification of stellar spectra according to luminosity for a given spectral type; it was introduced as part of the Morgan-Keenan classification.
		The luminosity class broadly indicates whether a star is a dwarf (that is, a main sequence star), a giant, or a supergiant, since luminosity is directly related to surface area.
		Luminosity class is expressed as a Roman numeral, from I to V, and appears after the spectral type; for example, Tau Ceti, with spectral type G8, is listed as a G8V object.
	www.daviddarling.info /encyclopedia/L/luminosity_class.html (156 words)

	Stellar classification - Wikipedia, the free encyclopedia
		Class L stars contain lithium which is rapidly destroyed in hotter stars.
		Class W is subdivided into subclasses WN and WC according to the dominance of nitrogen or carbon in their spectra (and outer layers).
		Class R and N stars are carbon stars (red giants thought to reach the end of their life) which run parallel to the normal classification system from roughly mid G to late M. These have more recently been remapped into a unified carbon classifier C, with N0 starting at roughly C6.
	en.wikipedia.org /wiki/Stellar_classification (2571 words)

	Spectra
		Decimal subdivisions of the spectral classes go toward lower temperature, for example, A0 lies at the hot end of class A near a temperature of 10,000 K, while A9 is at the cool end near 7200 K. The Sun, with a temperature of 5800 K, is class G2.
		Class L is a mixture of real dwarfs and brown dwarfs, while class T consists entirely of brown dwarfs.
		R and N are now lumped together under class "C" for "carbon." The exception to the "giant-star rule" is a rare class of main-sequence carbon stars that have been contaminated by evolving companions.
	www.astro.uiuc.edu /~kaler/sow/spectra.html (5857 words)

	Types of galaxies
		Those that are the most luminous are given a luminosity class of I, and the intrinsically faintest members of a class are assigned a V or VI, recalling the general approach of the luminosity class scheme used for stellar spectra.
		To assign a luminosity class, a galaxy's image has to be compared with a set of standard images of galaxies for which distances are known and for which luminosity classes have been established by van den Bergh.
		Here, a class is coded with a letter that indicates the spectral type of the galaxy in the blue (either as measured or as determined from the galaxy's bulge morphology, which correlates with the spectral type): e.g., a, af, f, fg, g, gk, k, for increasing dominance by cooler stars.
	www.wiedenhoff.nu /galaxy/galax2.htm (2704 words)

	[No title]
		A consequence of this is that if you know a star's luminosity, and you know how bright it appears (its apparent magnitude), you can tell how far away it is. luminosity class A star's luminosity is a measure of how much energy it generates.
		Luminosity classes are expressed as Roman numerals from I to V, with V being the least luminous and I being the most luminous.
		Depending on where they are on the graph of spectrum vs. luminosity, they may be red giants or supergiants (cool stars with high luminosity), white dwarfs (extremely compressed stars no larger than the Earth, with high temperatures and low luminosity), or other types.
	www.projectpluto.com /gloss/help_12.htm (3387 words)

	Spectral Classification
		For the standard spectral types, the spectra are sorted into luminosity classes, and displayed in increasing sub-type (decreasing temperature) for each luminosity class.
		Luminosity classes are determined from spectral features and photometric measurements, coupled with information regarding the distance to the star and theamount of extinction of the starlight from interstellar material.
		The luminosity class designation describes the size (gravitational acceleration in photosphere) of a star from the atmospheric pressure.
	cfa-www.harvard.edu /~pberlind/atlas/htmls/note.html (337 words)

	Definitions of lumen, luminosity, luminosity class, lux - Etacude.com
		A luminosity classification scheme is used to compare the brightness of stars with the same temperature or spectral class.
		Luminosity class V stars are also known as main-sequence stars because most of the stars fall on this category.
		A star's luminosity is roughly equal to the cube of a star's mass.
	dictionary.etacude.com /l/LS_LV.php (271 words)

	CLASS - HEASARC Object Classifications
		This section describes the `class` parameter, which is included in most of the database tables and can be used to select objects according to their classifications.
		As another example, all AGN have class codes that lie between 7000 and 7999; a search by class for AGN would thus be made by doing a search of the class parameter with the range set from 7000 to 7999.
		It should be emphasized that the class assignments of the same source found in different databases may not always be identical, and, for any given database, the class codes may not always be present, correct, or complete: see the database help for the particular database in question to determine how the class codes were constructed.
	heasarc.gsfc.nasa.gov /W3Browse/class_help.html (284 words)

	Stars
		With one known exception, class L is a mixture of low mass dwarfs and brown dwarfs, while T stars are all
		Carbon stars, class C, for which carbon exceeds oxygen in abundance, and class S, for which they are about equal, are listed at the end of the main table.
		MKK class, which consists of its decimalized letter class (in which the broad classes are subdivided 0 [zero] through 9 from warmest to coolest) followed by a Roman numeral that gives the luminosity: I through V for supergiant, bright giant, giant, subgiant, and dwarf.
	www.astro.uiuc.edu /~kaler/sow/class.html (553 words)

	[No title]
		Luminosity classes II III and IV are giants.
		Luminosity class V is the main sequence stars.
		The widths of a star's spectral absorption lines are dependent on luminosity class, with broader lines in the higher classes.
	www.gpc.edu /~fbuls/ast1403/revs/tt2rev5.html (1996 words)

	[No title] (Site not responding. Last check: 2007-10-26)
		class, is related to the temperature of the star's atmosphere.
		The luminosity classes are loci in the H-R diagram as shown below in Fig.
		The luminosity class is discerned by examining the absorption
	www.tcnj.edu /~pfeiffer/AST261SpClass.html (1115 words)

	Hemenway Ast 301 Spring 2000
		The sun is one solar luminosity and sets the standard for other stars.
		Luminosity includes ALL radiation emitted by the star, while absolute magnitude is just the magnitude is one wavelength range.
		Luminosity Class-- giant versus Main Sequence stars -- determined from the width of the spectral lines for two stars of the same temperature
	outreach.as.utexas.edu /marykay/notes3.html (1508 words)

	RedShift / Features - Stars - Filter by...
		Within a given spectral class a bright star will be larger than a faint star and its outer layers will be at a reduced pressure.
		The luminosity class is denoted by a roman numeral.
		A star with a class of F5 is roughly half-way between a class of F0 and G5.
	www.redshift.de /us/hb/help605307200.htm (230 words)

	Untitled Page (Site not responding. Last check: 2007-10-26)
		In class and in the spectroscopy lab, you’ve seen that the surface temperatures of the stars mostly control the stellar spectra: O stars are the hottest and bluest, M stars the coolest and reddest, with stars such as the Sun (a G star), at intermediate temperature.
		The luminosity also depends on the radius of a star: a type M star could be as bright as a type O because it is bigger than the type O star.
		The class will break into four groups, and you’ll use information about the luminosity classes of stars to predict where the disk of the Milky Way is located.
	www.astro.lsa.umich.edu /Course/Labs/BrightStars/BrightStarsShort.html (786 words)

	[No title]
		The luminosity of a star is a measure of the rate at which energy is being generated in its core.
		So stars that have different apparent brightness may have the same intrinsic luminosity, and stars that look to have the same apparent brightness may have very different intrinsic luminosities - depending on how far away the stars are.
		The intrinsic luminosity of a star follows from the Stefan-Boltzmann law and depends on the area of the surface of the star, and the fourth power of the temperature.
	www.astro.psu.edu /users/steinn/Astro1/lec20.html (1590 words)

	[No title]
		All spectra are grouped by spectral type, luminosity class and metallicity (see the file tbl3_types.txt).
		The flux library is intended to be amenable to improvement and extension in wavelength coverage, spectral type and luminosity class, by incorporation of additional digital spectral data as they become available.
		Spectra cover types O-M, luminosity classes, I, III & V. Continuum definition is poor: generally renormalised to SVID or GS SED.
	www.ifa.hawaii.edu /faculty/pickles/AJP/README.HILIB (1946 words)

	[No title] (Site not responding. Last check: 2007-10-26)
		Since this is a measure of brightness and the luminosity is higher at the top of the diagram (or a more negative Mabs), the brighter stars are at the top and consequently, dimmer stars are on the bottom.
		Also, you could use the mass-luminosity relationship to answer: the luminosity increases up the diagram, so the mass does too.
		The closest spectral class to G2 is epsilon Leo.
	jade.ccccd.edu /jwilson/docs/hrlabk.txt (765 words)

	Ast 110: Study Guide
		Luminosity and Sizes of stars [15.2](class 15): definition of luminosity and relation of luminosity, size and temperature from Stefan-Boltzmann law.
		Interior of the Sun [14.1,14.2] (class 17): gravitational collapse and hydrostatic equilibrium in the Sun, gravitational and thermal energy in the Sun, thermal equilibrium, the perfect gas law, central temperature and density of the Sun
		The Hubble Law [19.2,19.3] (class 23,24): galaxy redshifts and the redshift-distance relation, the Hubble constant, distances from standard candles, the value of the Hubble constant, the expansion of the Universe, the Big Bang as cosmic origin, the age of the Universe
	www.ifa.hawaii.edu /~acowie/class99b/study_guide_final.html (1049 words)

	Mean Values for Spectral Classes
		The table below indicates the mean values of temperature, luminosity, mass, and radius for any particular type of star.
		Luminosity, Mass, and Radius figures are mean comparitive figures in relation to G2 type stars.
		Stars are grouped into seven classes, designated by a roman numeral after the spectral classification.
	members.aol.com /usgoju/spectral.html (92 words)

	Virtual Eclipse - Science Fiction - Encyclopedia - L (Site not responding. Last check: 2007-10-26)
		Interstellar commerce has meant a need to return to a common time system, with the AI calendar now being used by most colonies.
		The luminosity class of a star indicates the brightness of a star.
		Luminosity class is related to the absolute magnitude (true brightness) of a star and not the apparent magnitude (which can vary depending on how far away you are when you observe it).
	virtualeclipse.aboho.com /scifi/pedia/l.htm (1624 words)

	Distances to Stars in Leo
		Finding the distances to stars based upon their spectral type and luminosity is known as spectroscopic parallax (even though no parallax determination is involved).
		The first part of this method involves determining the star's spectral type and luminosity class.
		Here is an example of the luminosity effect for spectral type A0 stars, from A0 Ia to A0 V, and a white dwarf.
	www.astro.washington.edu /labs/clearinghouse/labs/Leo/distleo.html (697 words)

	[28.03] Fundamental Transformation Equations Between the $u'g'r'i'z'$ and $UBVR_CI_C$ Filter Systems (Site not responding. Last check: 2007-10-26)
		That study developed transformation equations for luminosity class V (main sequence) stars using Landolt (1992) identified equatorial standards with spectroscopically confirmed luminosity classes.
		Here, we present new data for both luminosity class V and III bright standard stars with known metallicities.
		These data will be used to develop robust transformation equations for stars of these two luminosity classes.
	www.aas.org /publications/baas/v37n4/aas207/522.htm (117 words)

	Trans
		Luminosity Class is a categorization of stars by brightness (Luminosity)
		Luminosity Class I stars (Super-giants) are larger than Luminosity Class III stars (Giants)
		Luminosity Class III stars (Giants) are larger than Luminosity Class V stars (Dwarfs)
	cosserv3.fau.edu /~cis/AST2002/Lectures/C11/Trans/Trans.html (3922 words)

	Field 32: Spectral type and luminosity class
		For luminosity class, the following designations are used: Ia0, Ia, Iab, Ib for supergiants, II for bright giants, III for giants, IV for sub-giants, V for dwarfs.
		The sub-dwarfs are either noted sd followed by the spectral type, or class VI.
		: ] between two spectral types or luminosity classes indicates that the parameter is intermediate between those given; [
	wwwhip.obspm.fr /hipparcos/introsp1136/node47.html (451 words)

Try your search on: Qwika (all wikis)