Sentences with phrase «known luminosity»

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

That period of variation is directly related to their true luminosity, so if you measure the period, you'll know the luminosity.

Several methods are used, such as exploiting the known luminosities of old stars that are just beginning to burn Helium in their cores, and the relationship between the rotation speed of galaxies and the number of stars they possess.

Not exact matches

But how may the Christian know that this faith is not simply «a lurking luminosity, a cozy thought»?

Since Hubble's guess that every star has the same luminosity is not strictly true, to chart the universe's expansion astronomers needed more reliable cosmic candles — celestial objects that they could trust to burn with the same luminosity no matter how far from Earth.

To take advantage of this simple fact requires finding astronomical objects that have a known intrinsic luminosity — the amount of radiation per second produced by the object — and that can be seen across the universe.

But even more staggering is the energy released in the form of neutrinos, which can briefly exceed the luminosity of all stars in the known galaxies.

Astronomers don't yet know which particular conditions could have triggered such «extraordinary luminosity,» as the team that discovered the supernova writes in the 20 October issue of The Astrophysical Journal Letters.

But astronomers still don't know exactly what kinds of stars give rise to their extreme luminosity or what physical processes are involved.

The newly discovered quasar SDSS J0100 +2802 is the one with the most massive black hole and the highest luminosity among all known distant quasars.

In order to determine the luminosities and masses of the galaxies and the distribution of the mass inside the galaxies, you must first know the distances to them.

Why must the distance to a galaxy be known first before you can measure such basic properties of the galaxy such as its luminosity, mass, and size?

Supergiant luminosities are not as well known or uniform as the Type Ia supernovae, so astronomers prefer to use the Type Ia supernovae to derive the distances to the very distant galaxies.

If you know the distance to a star, you can determine its luminosity and mass.

On average, main sequence stars are known to follow an empirical mass - luminosity relationship.

The incredible luminosity of a black - hole system known as ULX - 1 may force a rethink of the leading theories that explain how some black holes radiate energy, researchers said.

This has become known as the Period - Luminosity relation.

Barnard's Star is of a variable category known as BY Draconis, stars that show starspots, variations in luminosity and other activity.

We find that, for optically thick disks, CO inner radii are strongly correlated with the total system luminosity (stell... ▽ More We present an analysis of CO emission lines from a sample of T Tauri, Herbig Ae / Be, and transitional disks with known inclinations, in order to study the structure of inner disk molecular gas.

The distances to very luminous objects can be derived using the inverse square law of light brightness if their luminosity is known.

The peak absolute luminosity appears to be about 50,000 times the luminosity of the Sun, but the largest percentage of known open clusters has a brightness equivalent to 500 solar luminosities.

As for most planetary nebulae, the distance of M27 (and thus true dimension and intrinsic luminosity) is not very well known.

Conversely, if you know a star's luminosity, you can calculate its distance.

A luminosity classification known as the Mount Wilson system was used to distinguish between stars of different luminosities.

Nominal luminosity class VII (and sometimes higher numerals) is now rarely used for white dwarf or «hot sub-dwarf» classes, since the temperature - letters of the main sequence and giant stars no longer apply to white dwarfs.

Joan Mitchell was an abstract expressionist known for the unrestrained use of color and pervasive luminosity of her large scaled and multiple - paneled works.

Best known as the man responsible for the massive Mark Rothko: The Works on Canvas: A Catalogue Raisonné, British art historian David Anfam has more recently been focusing on another mid-20th-century American artist, Clyfford Still, whose flame - like works that have their own luminosity.

Known for luminosity and depth, Custom Fiber is hand printed, and selenium toned for archival stability, a Sistan bath and spotted for a print longevity of 100 years or more.

[I'll just quickly add what I do know about why Hansen says that a runaway could potentially occur now while it hasn't in the past: One point he makes is that the sun has slowly gotten brighter, so CO2 levels back several hundred million years ago or more are not directly comparable to levels now with the current luminosity.

Further on there is the well known mass - luminosity relation for stars.