Sentences with phrase «apparent brightness»

An interesting change in apparent brightness and to some degree form will result — what may be called a «here comes the sun» effect.

The huge concentration of mass bends light coming from more distant objects and can increase their total apparent brightness and make them visible.

Even though most of the visible radiation is concentrated in a few discrete emission lines, the total apparent brightness of the brightest is the equivalent of tens of thousands of solar luminosities.

By comparing this new diagram to the Hertzsprung - Russell diagram for the nearby stars, you will see that the ratio of the observed apparent brightness to the absolute brightness is the same for every kind of star - and this ratio gives you then the distance to the cluster.

«This was the first time that such behavior was seen in a gamma - ray burst,» says Kulkarni, an author of a report in Nature, «and it may help explain in part its enormous apparent brightness.»

Because all the stars in the Small Magellanic Cloud have approximately the same distance to us, the observed relationship between apparent brightness and period implies that there is an equivalent relationship between absolute brightness and oscillation period.

The astronomers compare the true and apparent brightness of distant supernovae to measure out to the distance where the expansion of the universe can be seen (shown at right).

For example, in dealing with the structural organization of the heavens, he assumed that all stars were equally bright, so that differences in apparent brightness are an index only of differences in distances.

We extract science by carefully modeling all the ways in which the spacecraft and the instruments themselves could have caused the apparent brightness of a planetary system to change over time... We are pretty sure we can trust our models of Spitzer down to about a part in 10,000; we are in uncharted territory as far as detector behavior is concerned.»

Over the past decade, researchers have carefully calibrated the intrinsic luminosity of type Ia supernovae, so the distance to one of these explosions can be determined from its apparent brightness.

Cepheid stars pulsate at rates that correspond to their true brightness, which can be compared with their apparent brightness as seen from Earth to accurately determine their distance.

The astronomers compare the calibrated true brightness values with the stars» apparent brightness, as seen from Earth, to determine accurate distances.

Type 1a supernova all seem to have the same intrinsic brightness, so their apparent brightness can be used to work out how far away they are.

You can then measure its apparent brightness and determine how far away it is.

Comparing this with the apparent brightness gives the distance to the supernova and therefore the parent galaxy.

The apparent brightnesses of distant type Ia supernovae then reveal the distances of their galaxies, which in turn give the Hubble constant.

This Leavitt Law enables astronomers to use cepheids as a cosmic ruler or «standard candle»: Just measure how fast they vary, find their average true luminosity from the Leavitt Law, compare this to the apparent brightness in the sky, and out pops the distance, since stars appear fainter when they're farther away.

Comparing this with the apparent brightness yields the distance to the star and galaxy.

This period - luminosity relationship can be used to deduce the distance of a star from its period of variation and its apparent brightness.

Then, as with the Cepheids, he could compare that luminosity with the galaxy's apparent brightness to figure out its true place in deep space.

Compare that with the apparent brightness and you know the distance, even at larger scales where parallax measurements are impossible.

If you moved Pluto twice as far from the sun, its apparent brightness would decrease by 2 to the 4th power — a factor of 16.

As they move, then, their distance from us changes and so does their apparent brightness.

Telescopes increase the apparent angular size of distant objects, as well as their apparent brightness.

This phenomenon increases the apparent brightness and angular size of the lensed objects, making it easier to study sources that would be otherwise too faint to probe.

More than 2000 years ago, the Greek astronomer Hipparchus devised a scale ranking the apparent brightness of different stars.

Kepler continuously tracks more than 150,000 stars; when a planet passes in front of one of them, in a kind of mini eclipse known as a transit, the spacecraft registers a slight dip in the star's apparent brightness.

This need only be compared with the star's apparent brightness to yield the distance (see «Starry signposts to the Universe», New Scientist, 6 June 1992).

Its actual brightness, which we can observe on earth, is called the apparent brightness.

You will get again a main sequence, some giants and some dwarfs - but this time, you don't have plotted their absolute brightnesses, but their apparent brightnesses.

By comparing this with the apparent brightness, one gets as usual the distance of the supernova - and thereby of the galaxy in which it was situated.

One method of determining the distance discussed above uses the period - luminosity relation of Cepheid variable stars to derive the distance from the apparent brightness of the Cepheids.

As such, their apparent brightness allows their distance to be easily estimated.

Note: Thanks to Andrew James for notifying us of updated orbit information for Stars A and B and to Aaron Freed for new calculations of the apparent brightness of Stars A and B on planets orbiting in the water zone of each star.

The luminosity of the galaxy is found from the width of the 21 - cm emission line and the distance is then derived using the apparent brightness and the inverse square law.

Cepheid stars pulsate at rates that correspond to their true brightness (power), which can be compared with their apparent brightness as seen from Earth to accurately determine their distance and thus the distance of the galaxy.

Scientists can measure the apparent brightness of a standard candle, compare it with the actual brightness, and then determine how far away the object is.

By measuring about 2,400 Cepheid stars in 19 nearby galaxies and comparing the apparent brightness of both types of stars, they accurately determined the true brightness of the Type Ia supernovae.

One technique for measuring the expansion rate is to observe the apparent brightness of objects of known luminosity like Type Ia supernovas.

A comparison with its apparent brightness then allows the use of the «standard candle» technique to determine its distance.

Because the luminosity = the energy / time, the apparent brightness will be reduced enough by the expansion to make the sky dark.

The Sunyaev - Zel «dovich effect (SZE) causes a change in the apparent brightness of the CMB towards a cluster of galaxies or any other reservoir of hot plasma.

When an input catalog is provided, the apparent brightness of each source needs to be specified in each filter; a future upgrade will allow spectral energy distributions to be specified instead.

An artistically pleasing brightness curve must instead be authored which follows the apparent brightness falloff your eyes would expect, and also be robust enough to handle dim Y class dwarf stars to super-bright Wolf - Rayets.