Cepheids have a certain relationship between their period, and their absolute luminosity. Thus, their absolute luminosity can be determined. Comparing this with their apparent luminosity allows us to calculate their distance.
Cepheids have a certain relationship between their period, and their absolute luminosity. Thus, their absolute luminosity can be determined. Comparing this with their apparent luminosity allows us to calculate their distance.
Cepheids have a certain relationship between their period, and their absolute luminosity. Thus, their absolute luminosity can be determined. Comparing this with their apparent luminosity allows us to calculate their distance.
Cepheids have a certain relationship between their period, and their absolute luminosity. Thus, their absolute luminosity can be determined. Comparing this with their apparent luminosity allows us to calculate their distance.
You can calculate the distance to any star if you know its luminosity. Look at it and measure how bright it SEEMS to be, and you can calculate how far away it is. The trick is to know the absolute luminosity.
That's where the Cepheid variable stars come in. The period, or time between maximum brilliance points, is very nearly correlated with the absolute luminosity. It's difficult to know what the luminosity of a star is, if you don't know how far away it is, but the period is EASY to measure.
Cepheids have a certain relationship between their period, and their absolute luminosity. Thus, their absolute luminosity can be determined. Comparing this with their apparent luminosity allows us to calculate their distance.
The apparent brightness. Also, the period of the star, which is related to its real brightness.
what is the type of star used by the Hubble to measure the distance to other galaxies.
There are many ways to calculate distance at huge scales. One popular way is using a Cepheid within the nebula. A Cepheid is a very luminous variable star (a star that changes brightness). The changing of brightness tells us a lot about the distance by measuring the period (time) and the luminosity. See the related link for more methods.
No.
By unit of length and distance and conversion ,we can say that miles measure distance.
seh-fee-id or see-fee-id (most common pronunciations I think:) 'seh' as in seven or 'see' as in 'sea' Important variable star for distance calculations.
He applied the period-luminosity relation to Cepheid variables.
what is the type of star used by the Hubble to measure the distance to other galaxies.
Cepheid variables
A Cepheid is a member of a class of pulsating variable stars. The relationship between a Cepheid variable's luminosity and pulsation period is quite precise, securing Cepheids as viable standard candles and the foundation of the Extragalactic Distance Scale.
A Cepheid is a member of a particular class of variable stars. The relationship between a Cepheid variable's luminosity and pulsation period is quite precise, securing classical Cepheids as viable standard candles and the foundation of the Extragalactic Distance Scale. See related link for more information
The symbol for CEPHEID in NASDAQ is: CPHD.
There are many ways to calculate distance at huge scales. One popular way is using a Cepheid within the nebula. A Cepheid is a very luminous variable star (a star that changes brightness). The changing of brightness tells us a lot about the distance by measuring the period (time) and the luminosity. See the related link for more methods.
CEPHEID (CPHD) had its IPO in 2000.
As of July 2014, the market cap for CEPHEID (CPHD) is $2,827,322,635.80.
Nothing.Inches are a measure of distance, not weight.Nothing.Inches are a measure of distance, not weight.Nothing.Inches are a measure of distance, not weight.Nothing.Inches are a measure of distance, not weight.
"Lighthouses of the sky" are the Cepheid Variables. These are stars that periodically change in brightness, somewhat the way a rotating beam from a lighthouse would as it fell on an observer. The brightness of a Cepheid is proportional to the period of its variance. So if we know the period (how long it takes the beam to come around), we know how bright the star should be. Comparing that to the observed brightness tells us how far away it is (if it's one-quarter as bright as it would be at a standard distance - 32.6 light years - then it's twice as distant (65.2 light years).)
The Doppler effect is well known, and Fizeau observed the red-shift of the light from distant stars. So the effect was called Doppler-Fizeau. There are a class of astronomic objects called the Cepheid Variables in which it is observed that the rate of variation in the brightness of the star related to its absolute brightness, and therefore its mass. Thus these stars can be used as a measure of distance, as the period of their variability does not change with distance, but their apparent brightness and their red-shift does. Hubble made a number of observations of Cepheids in the Andromeda galaxy. The article on Cepheid Variables in wikipedia.org is well worth reading, as it illustrates scientific discovery and enquiry. He went on to reason that the Cepheids could be used as a standard measure of astronomical distance. And this formed the basis of the Expanding Universe. These observations are one of the foundations of cosmology.