http://hubblesite.org/newscenter/press_resources/workshop_archive.php
Tuesday, April 5, 2011
Top 10 Impacts from Hubble Telescope
http://hubblesite.org/newscenter/press_resources/hubble_science_impact.php
The accelerating universe and dark energy.Hubble's ability to detect faint supernovae contributed to the discovery that the expansion rate of the universe is accelerating, indicating the existence of mysterious “dark energy” in space.
The distance scale and age of the universe.Observations of Cepheid variable stars in nearby galaxies were used to establish the expansion rate of the universe to better than 10 percent accuracy.
The evolution of galaxies.The Hubble Deep Field provided our deepest view yet into the universe’s distant past, allowing us to reconstruct how galaxies evolve and grow by swallowing other galaxies.
The birth of stars and planets.Peering into nearby regions of star birth in the Milky Way galaxy, Hubble has revealed flattened disks of gas and dust that are the likely birthplaces of new planets.
Stellar death.When Sun-like stars end their lives, they eject spectacular nebulae. Hubble has revealed fantastic and enigmatic details of this process.
Stellar populations in nearby galaxies.Deep images that resolve individual stars in other galaxies reveal the history of star formation.
Planets around other stars.Hubble made detailed measurements of a Jupiter-sized planet orbiting a nearby star, including the first detection of the atmosphere of an extrasolar planet.
The impact of comet Shoemaker-Levy 9 on Jupiter.The explosive collision of the comet with Jupiter provided Earthlings with a cautionary tale of the danger posed by cometary impacts.
Black holes in galaxies.Hubble observations have shown that monster black holes, with masses millions to billions times the mass of our Sun, inhabit the centers of most galaxies.
Gamma-ray bursts.Hubble played a key role in determining the distances and energies of gamma-ray bursts, showing that they are the most powerful explosions in the universe other than the big bang itself.
he Hubble Space Telescope has had a major impact in every area of astronomy, from the solar system to objects at the edge of the universe. To date, more than 3,500 technical publications have reported HST Hubble results. Here is a “Top 10” summary of Hubble’s major scientific results.
The accelerating universe and dark energy.Hubble's ability to detect faint supernovae contributed to the discovery that the expansion rate of the universe is accelerating, indicating the existence of mysterious “dark energy” in space.The distance scale and age of the universe.Observations of Cepheid variable stars in nearby galaxies were used to establish the expansion rate of the universe to better than 10 percent accuracy.The evolution of galaxies.The Hubble Deep Field provided our deepest view yet into the universe’s distant past, allowing us to reconstruct how galaxies evolve and grow by swallowing other galaxies.The birth of stars and planets.Peering into nearby regions of star birth in the Milky Way galaxy, Hubble has revealed flattened disks of gas and dust that are the likely birthplaces of new planets.Stellar death.When Sun-like stars end their lives, they eject spectacular nebulae. Hubble has revealed fantastic and enigmatic details of this process.Stellar populations in nearby galaxies.Deep images that resolve individual stars in other galaxies reveal the history of star formation.Planets around other stars.Hubble made detailed measurements of a Jupiter-sized planet orbiting a nearby star, including the first detection of the atmosphere of an extrasolar planet.The impact of comet Shoemaker-Levy 9 on Jupiter.The explosive collision of the comet with Jupiter provided Earthlings with a cautionary tale of the danger posed by cometary impacts.Black holes in galaxies.Hubble observations have shown that monster black holes, with masses millions to billions times the mass of our Sun, inhabit the centers of most galaxies.Gamma-ray bursts.Hubble played a key role in determining the distances and energies of gamma-ray bursts, showing that they are the most powerful explosions in the universe other than the big bang itself.
Hubble Telescope Images Archive
Temperature and Lumunosity Relationship in Star Light Part 2
Temperature and Lumunosity Relationship in Star Light Part 2
Temperature and Lumunosity Relationship in Star Light
Temperature and Lumunosity Relationship in Star Light
Sunday, April 3, 2011
NASA's Hubble Rules Out One Alternative to Dark Energy
http://hubblesite.org/newscenter/archive/releases/2011/08
MARCH 14, 2011: Astronomers using NASA's Hubble Space Telescope have ruled out an alternate theory on the nature of dark energy after recalculating the expansion rate of the universe to unprecedented accuracy. The universe appears to be expanding at an ever-increasing rate, and one explanation is that the universe is filled with a dark energy that works in the opposite way of gravity. One alternative to that hypothesis is that an enormous bubble of relatively empty space eight billion light-years across surrounds our galactic neighborhood. If we lived near the center of this void, observations of galaxies being pushed away from each other at accelerating speeds would be an illusion. This hypothesis has been invalidated because astronomers have refined their current understanding of the universe's present expansion rate to an uncertainty of just 3.3 percent. The new measurement reduces the error margin by 30 percent over Hubble's previous best measurement in 2009. The results are reported in the April 1 issue of The Astrophysical Journal.
Amongst the myriad stars in spiral galaxy NGC 5584, imaged in visible light with Hubble's Wide Field Camera 3 between January and April 2010, are pulsating stars called Cepheid variables and one recent Type Ia supernova, a special class of exploding stars. Astronomers used Cepheid variables and Type Ia supernovae as reliable distance markers to measure the universe's expansion rate. NGC 5584 lies 72 million light-years away in the constellation Virgo and was one of the eight galaxies astronomers studied to measure the universe's expansion rate. In those galaxies, astronomers analyzed more than 600 Cepheid variables, including 250 in NGC 5584. Cepheid variables pulsate at a rate matched closely by their intrinsic brightness, making them ideal for measuring distances to relatively nearby galaxies. Type Ia supernovae flare with the same brightness and are brilliant enough to be seen from relatively longer distances. Astronomers search for Type Ia supernovae in nearby galaxies containing Cepheid variables so they can compare true brightness of both types of stars. That brightness information is used to calibrate the measurement of Type Ia supernova in far-flung galaxies and calculate their distance from Earth. Once astronomers know accurate distances to galaxies near and far, they can determine the universe's expansion rate.
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