Astronomy   View all facts   Glossary   Help

physical object > natural object > celestial body > star > variable > periodic variable > long-period variable

long-period variable (red variable, Mira variable)
subject			fact

long-period variable	has amplitude 9 magnitudes in the visible, but only 2 or 3 magnitudes in the integrated spectrum
	has period 100 to 1000 days
	has prototype Mira
	has spectral type M star, R star, or N star
	has synonym red variable
	has synonym Mira variable
	has definition Cyclic variable with cycles 100-500 days, and of spectral types K, M, S and C.
	has definition Pulsating red giant or supergiant. Population I typically have periods greater than 200 days; Population II, periods less than 200 days. Long-period variables emit most of their radiation in the infrared.
	is a kind of periodic variable
	is a part of disk
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
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
physical object	has location or center of gravity
	has angular momentum
	has momentum
	has temperature
	has volume
	has extent

Kinds of long-period variable :

• Mira (15 facts) (omicron Cet) - A red giant that varies in brightness as it pulsates. When brightest, Mira is visible to the naked eye; when dimmest, Mira can be viewed only with optical aid. Mira is the prototype of all pulsating red giants, which are called Miras in its honor., A irregular long-period intrinsic variable. It was named Mira ("wonderful") in 1596 by Fabricius, who made the first recorded observations of its brightness fluctuations. Mira is a double star with a faint B companion which is itself variable.

Next periodic variable: RR Lyrae star    Up: periodic variable    Previous periodic variable: eclipsing binary