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physical object > natural object > celestial body > star > Delta Del star > dwarf Cepheid

dwarf Cepheid (delta Scuti star, ultrashort-period Cepheid)
subject			fact

dwarf Cepheid	has period 1 to 3 hours
	has spectral type A star to F star
	has synonym delta Scuti star
	has synonym ultrashort-period Cepheid
	has definition Type I Cepheids ( <Mv> +4 to +2).
	has definition A group of pulsating variable stars with small variations in amplitude. They lie in the lower part of the Cepheid instability strip.
	is a kind of Delta Del star
	is a kind of Cepheid
Cepheid	has prototype delta Cephei
star	has star surface temperature
	has V magnitude
	has B magnitude
	has U magnitude
	has position on celestial sphere from the point of view of Earth
	has parallax from the point of view of Earth's orbit
	has proper motion
	has radiation at surface which is diffused out from the hotter core
	has energy source gravitational contraction and or fusion
	has energy production which takes place primarily within the core
	has surface density which depends on luminosity class
	has surface temperature greater than 1000 Kelvin
	has apparent magnitude
	has absolute magnitude
	has age
	has catalog star catalog
	has material hydrogen, helium
	has velocity determined from proper motion and radial velocity
	has mass greater than 0.08 the sun's mass
celestial body	has spectra
variable	has name designated with R, S, T, U, V, W, X, Y, or Z and the genitive of the latin constellation name RR, RS, RT, RU, RV, RW, RX, RY, or RZ and the genitive of the latin constellation name when the single letter designations are exhausted AA...AZ, BB...BZ, etc. (omitting J), which ends with QQ...QZ and the genitive of the latin constellation namewhen the RR...RZ designations are exhausted V 335, V 336, etc., when the double letter designations are exhausted
	has observational problem some difficulty in distinguishing between various kinds
	has observable variation time scale within a period of decades
	has light curve
	has optical brightness variation 0.2 magnitudes or greater
	has amplitude
physical object	has location or center of gravity
	has angular momentum
	has momentum
	has temperature
	has volume
	has extent

Kinds of dwarf Cepheid :

• AI Velorum star (2 facts) - A class of dwarf Cepheids. They are all RR Lyrae stars with periods shorter than 0.25 days.
• beat Cepheid (2 facts) - Dwarf Cepheid in which two or more almost identical periods exist which cause periodic amplitude fluctuations in their light curves. The "beat" period averages about 2 to 2^1/2 hours.
• SX Phoenicis (3 facts) - A dwarf Cepheid (spectral type A) with the shortest known period (1^h19^m).

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