NASA Jet Propulsion
Laboratory reported that the astronomers who work with the Space Telescope,
"Spitzer", were able to conduct a more accurate calculation of the
rate of increase in the history of astronomy. In other words, this swiftness is
called the Hubble constant.
We live on a small
planet Earth, but this does not preclude our interest in the rest of the world.
But to know the size of this huge, compared to us, the world, to find out what
the age and expansion rate of the universe has. More recently, you can also add
the concept of "acceleration of the expansion." But the accelerated
expansion of the universe, you can still stick to the linear Hubble law.
Even in the 20's of
last century, Edwin Hubble, the American astronomer, was able to prove that the
universe since its inception (about 13.7 billion years ago) is expanding at a
certain rate, which is constant. This constant velocity was named after the
astronomer. Only in the late 90's of the XX century has been found that this
rate is, in fact, increases with time. Previously, the value of this rate to
clarify, for example, the age of the universe, scientists can assess with a
telescope "Hubble", writes "Birzhevyo leader" in the
"U.S. News".
It is reported that the
"Spitzer" was able to improve the result of "Hubble" almost
three times and reduced uncertainty of 3%. To date, this is a huge leap in the
precision cosmological measurements.
New data show that the
Hubble constant is set to 74,3 ± 2,1 km per second per Mpc. These data indicate
that the two galaxies that are separated by a distance of about 3 million light
years (ie one Mpc), fly at nearly 74.3 kilometers per second, according to
"Market Leader". Recall that a parsec is about 3.3 light years. One
million parsecs means Mpc.
In a paper published in
the Astrophysical Journal, the researchers explain that we were able to take
advantage of the infrared "Spitzer" before "Hubble", which
only works in the visible range. In total, "Spitzer" Observe for
about 90 Cepheids in the Milky Way and the Large Magellanic Cloud.
As you know, Cepheids -
this pulsating variable stars are a separate class with a rather precise
relation between "period" and "luminosity". They are named
in honor of the star Cepheus. One of the best known Cepheids is, of course, the
North Star.
The period of light
variation of these variable stars are directly related to their luminosity.
When comparing the brightness of the Cepheids observable with "real"
brightness, which is calculated based on the period, the scientists may well
calculate the distance to a star, serving, so some "beacon".
Wendy Freedman,
professor of astronomy, and the band is so specified distance of about 90
stars, Cepheids.
Consequently, the
"Spitzer" gave scientists the ability to assess more accurately the
observed brightness of Cepheids, and hence also the distance to them.
"Spitzer" also helped clarify how the same is the value of the Hubble
constant.
It is reported that ten
years ago it was impossible to reconcile the concept of "cosmology"
and "accuracy." But now we can talk about the accuracy of a few
percent, which is really surprising fact.
Thanks to the new
updates on the 3% of the Hubble constant, scientists will be able to figure out
what and how can affect the expansion of the universe. In addition, scientists
are now able to more accurately calculate the forces of dark energy,
counteracting gravity, which inexplicably stretches our universe.
But what would all the
same dark energy might be, scientists by clarifying the value of the Hubble
constant, can use it to study the data on the CMB that are derived probe WMAP.
Thus, scientists have some independent assessment of the force with which the
dark energy and counteracts gravity, pushing, so the universe more and more
widely.
It is important to note
that in the previous week space telescope "Hubble" was an image very
distant galaxies that formed after the Big Bang, after which, by assumption,
and there was our universe.
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