A cepheid (which take their name from prototypical stars in constellation Cepheus) is a type of star which varies or pulses over time. They are important to astronomy as they help establish a "standard candle" which helps in measurement of distance. The variation in brightness, size and spectrum is proportional to the density and size of the star; thus, the absolute magnitude can be calculated and the distance of a cepheid of a given luminance can be inferred from how quickly it changes. Hubble used this method to show that the "spiral nebulae" were in fact not close objects inside our galaxy but instead were distant galaxies.
A Cepheid variable star is a type of pulsating star that changes in brightness over a set period of time. This change in brightness is directly related to the star's intrinsic luminosity, making Cepheids valuable for distance measurements in astronomy. They played a crucial role in determining the scale of the universe and are important for understanding the cosmos.
Variable stars, such as Cepheid variables, are important for determining distances to other galaxies. By studying the period-luminosity relationship of these stars, astronomers can accurately measure their distance from Earth. This helps in mapping the size and shape of our galaxy by providing reference points for the scale of the universe.
1 star - Brigadier General 2 star - Major General 3 star - Lieutenant General 4 star - General 5 star - General of the Army
The Sun is a star.
The planet Venus has at times been called the Morning Star or the Evening Star, although it is not a star.
A neutron star is a stellar remnant
The astronomer's observations proved that cephid variable stars would pulsate in a regular cycle
First [may be partial] is: A Cephid Variable Star. Quasars and other Gamma Ray sources [colliding Neutron Stars, and 'coalescing' Pairs of Black Holes for example] are also closely related.
"kpc" is the abbreviation for kilo-parsecs. One parsec is approximately equal to 3.26 light years, so one kpc would be about 3260 ly. In terms of the diameters of galaxies, we can at best come up with approximations. The distance to another galaxy is a matter of some conjecture, involving calculations of the relative brightness of "standard candle" stars, typically Cephid variable stars. As our understanding of the relationships between the mass, luminocity and the periodicity of a Cephid variable has evolved, our estimations of the distances has likewise changed.
For the Moon they bounce a laser off it and time the return. For space its the change in the light spectrum, I think discovered by Halley. This is similar to the sound of a siren coming and going. This shift lead to the expanding universe theory.___________________________________________For things that aren't too far away, we can measure the parallax by measuring the precise angle to a star at one time, and measure the angle to the star 6 months later when the Earth is on the opposite side of the Sun. That gives us a baseline 2AU long, so we can use geometry to calculate the distance.For things farther away, there is a measure of guesswork involved. By measuring the light spectrum of the star, we can come close to figuring out how hot the star is, and if we know how hot it is, we can calculate how bright it really is. Compare the star's absolute magnitude (how bright it really is) to its visual magnitude (how bright it appears to be) and we can make a good estimate of how far away the star is.This is where an interesting class of stars called "Cephid Variables" come in. They get periodically brighter and dimmer on a regular basis. Astronomers have calculated a relationship between how bright this particular type of star is with the time that it takes to vary in brightness, so we can use these stars as a measuring stick to compare other stars.
STAR G STAR, STAR F STAR, STAR E STAR, STAR D STAR, STAR GF STAR, STAR EF STAR, STAR FE STAR, STAR GFGF STAR
Variable stars, such as Cepheid variables, are important for determining distances to other galaxies. By studying the period-luminosity relationship of these stars, astronomers can accurately measure their distance from Earth. This helps in mapping the size and shape of our galaxy by providing reference points for the scale of the universe.
The Star , Star 80 , Star ! ,
Star! 1968 Star Wars 1977 Star Trek 1996 Lone Star 1996 A Star is Born 1954 Dark Star 1974 Star 80 1983 Porn Star 2001 Star Maps 1992 The North Star 1943 The Tin Star 1957 Rainbow Brite and Star Stealer 1985 Wish Upon A Star 1996 The Star Chamber 1983 The Star Packer 1934 Star Struck 1982 The Star 1952 Flaming Star 1960 Lone Star State Of Mind 2002 The Lucky Star 1980 Fist Of The North Star 1995 Star Spangled Rhythm 1942 Star Kid 1997 Dog Star Man 1962 Follow A Star 1959 Star-Crossed 2003 Deep Inside Clint Star 1999 Star In The Night 1945 Man Without A Star 1955 Five Star Final 1931 Star Spangled Death 2004 Star Tours 1987 The Yellow Star 1915 Une Star Internationale 2004 Tom's Little Star 1919 Throw A Saddle On A Star 1946 Tell It To A Star 1945 A Star Too Far 1993 Star Stuff 2005 A Star Shall Rise 1952 The Star Rover 1920 The Star Reporter 1921 The Star Reporter In Hollywood Number Two 1937 Star Quality 2002 The Star Prince 1918 Star Power 2007 Star Party 2005 Star Of The Circus 1938 The Star Of The Sea 1915 Star Of Texas 1953 The Star Of India 1916 A Star Is Shorn 1939 A Star Is Lost! 1974 Star Impersonations 1930 Star Gazing 1935 Star Garden 1974 A Star Fell From Heaven 1936 Star Dust Trail 1924 The Star Boarder 1920 Stairway For A Star 1947 Shooting Star 2000 The Rock Star 1999 Riders Of The Lone Star 1947 The Polar Star 1919 Ninja Star In The Eye 2006 My Lucky Star 1933 Mr. Hollywood Star 2002 Love Letters Of A Star 1937 Lone Star Vigilantes 1942 The Lone Star Ranger 1923 Lone Star Pioneers 1939 Lone Star Moonlight 1946 Lone Star Hate 1997 Lone Star Bar And Grill 1983 Hanging On A Star 1978 Follow Your Star 1938 The Baseball Star From Bingville 1911 Star Portal 1998 The Star Maker 1939 A Star For Two 1991 Star For A Night 1936 Rock Star 2004 Lone Star Trail 1943 He Found A Star 1941 The Cowboy Star 1936 The Broken Star 1956 Starforce 2000 Star Dust 1940 The Southern Star 1969 The Silver Star 1955 Pick A Star 1937 My Lucky Star 1938 Major Movie Star 2008 Invasion Of The Star Creatures 1963 Bright Star 2008 Star Crystal 1986 Lone Star 1952 Star time 1992 Star Of Midnight 1935 Lick The Star 1998 Star Spangled Girl 1971
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The magen star is the star of David - a star with 6 corners
Barnard's Star is a red dwarf star
the 2087 star known as the king star