On Saturday, NASA launched the Swift satellite - this is a new space observatory whose mission is to hunt for gamma ray bursts and thereby study the most powerful explosions seen in the universe since the Big Bang itself
On Saturday, NASA launched the Swift satellite - this is a new space observatory whose mission is to hunt for gamma ray bursts and thereby study the most powerful explosions seen in the universe since the Big Bang itself.
Gamma ray bursts are short but extremely powerful flashes of radiation. The scientists believe that they are the result of the creation of black holes, when massive stars collapse into their own gravity.
The Swift satellite, a joint project of the United States, Great Britain and Italy, was launched on a Delta rocket from Cape Canaveral, Florida on Saturday, November 21, 2004.
According to Dr. Niel Tanibar, the space observatory that costs 250 million dollars includes three instruments that will work in combination.
One of the devices is the Gamma Ray Burst Alert Telescope and it was built by NASA's Goddard Research Center in order to locate and locate gamma ray bursts in large parts of the sky. The information that the telescope will transmit will make it possible to direct the rest of the spacecraft's more delicate instruments that will conduct an analysis of the eruption at different wavelengths, to the exact location of the eruption.
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Following explosions in space
News Agencies, Cape Canaveral, Florida (Haaretz)
The space telescope rotating around its axis at the highest speed ever, was launched last Saturday. He was sent to scan the universe for violent explosions, which, according to one hypothesis, mark the moment of birth of black holes.
The telescope should begin searching for these explosions, known as gamma ray bursts, by January. His observations should solve part of the mystery surrounding gamma-ray bursts and black holes.
Gamma ray bursts are the most powerful events in the universe. The outbursts, which last a few seconds on average, appear suddenly out of nowhere. The explanation is that they indicate the formation of black holes.
Astronomers hypothesize that black holes, from which even light cannot escape, are formed during the collapse of massive stars. Apparently, one possibility is that the death of a star causes these violent outbursts, in which large amounts of gamma radiation are emitted.
The satellite, named "Swift", will scan one-sixth of the sky in any given period of time, and therefore will notice one-sixth of the bursts of gamma radiation. The observations will help scientists learn more about the nature of the eruptions and their quantity and how black holes are formed.
The data on gamma ray bursts and their exact locations will be quickly transmitted to astronomers around the world by the monitoring center, located at the University of Pennsylvania. This way it will be possible to direct additional observations from the ground, which will help in the analysis of the data.
After chasing gamma ray bursts for a year or two, Swift - a $250 million project, which is the result of a collaboration between NASA, Italy and Britain - will expand its repertoire to additional cosmic events, which occur frequently.
The Swift satellite, which will be launched in October, has arrived at the Kennedy Space Center
Dikla Oren, 2/8/2004
The Swift satellite arrived on July 29 at the Kennedy Space Center and will begin preparations for the launch in October 2004. The Swift will locate the location of distant and short explosions, which probably symbolize the moment of birth of black holes.
These mysterious flashes of light, called Gamma Ray Bursts (GRBs), are the most powerful explosions in the universe. They emit a hundred billion times more energy than our sun emits in a year. However, they last from a few milliseconds to a few minutes, and appear again and again in different places.
The Swift satellite is named after the swift bird (Sis in Hebrew), because it can aim its instruments at lightning speed to catch an eruption "hot" in order to study both the eruption itself and its subsequent glow. The afterglow phenomenon occurs after the initial burst of gamma rays in most bursts. It may last for weeks in the fields of X-ray radiation, visible light and radio waves and provide a wealth of information.
"Gamma-ray bursts have been among the greatest mysteries in the science of astronomy since their discovery more than 35 years ago," said Dr. Neil Gehrels, chief scientist of the Swift project at NASA's Goddard Space Center in Greenbelt, Maryland, United States. "Swift is exactly the tool needed to solve the mystery. One of Swift's instruments will detect the outburst, while two higher-resolution telescopes will zero in on the source of the outburst within a minute to get an in-depth look at it. In the meantime, Swift will 'email' other scientists and telescopes around the world to watch the outburst live."
The Burst Alert Telescope, built by NASA's Goddard Center, will detect and locate about two gamma-ray bursts per week and transmit their location to the ground with an accuracy of one arc minute to four arc minutes in about twenty seconds. The location it finds will be used to orient the satellite to the eruption, to study the afterglow with an X-ray telescope (XRT) and an ultraviolet and visible light telescope (UVOT).
These two longer-wavelength (and lower-energy) telescopes will determine the location of the outburst with arcsecond accuracy and also the spectrum of its trailing glow in the wavelength range from visible light to X-rays. For most of the eruptions, the Swift will detect, the data obtained in combination with data from telescopes on Earth will allow the measurement of the redshift, or the distance, to the origin of the eruption. The afterglow provides vital information about the dynamics of the outburst, but scientists need precise information about the outburst to detect the afterglow.
Swift will spread its message to the community, which includes both museums and the general public as well as scientists at respected observatories, through the Gamma-ray Burst Landmark Network (GCN), maintained by the Goddard Center. A whole network of special robotic telescopes for this mission, scattered around the Earth, will watch for messages from the Swift-CGN network.
A continuous stream of information about outbursts will flow through Swift's Mission Control Center, located at the University of Pennsylvania. The University of Pennsylvania, an important partner from the United States, built the XRT telescope in collaboration with the University of Leicester in England and the Brera Astronomical Observatory from Italy. The UVOT telescope was built by the University of Pennsylvania in collaboration with the Mullard Space Science Laboratory from England.
Besides new clues to what is known about the nature of gamma-ray bursts, Swift may provide us with a wealth of cosmological data.
"It is likely that some of the outbursts occurred in remote regions of the universe, and therefore also in ancient times," said Swift mission director John Nousek, a professor of astronomy and astrophysics at Pennsylvania State University. "The eruptions act like a beacon, illuminating everything in their path, including interstellar and bingalactic gas in the line of sight."
Various theorists claim that some eruptions may have their origin in the formation of the first generation of stars. Swift's unprecedented sensitivity will provide the first opportunity to test these theories.
With the help of NASA's 2-HETE (High Energy Transient Explorer) satellite, which is now operational, scientists have determined that at least some of the outbursts involved massive stellar explosions. Swift will sharpen this knowledge, meaning it will answer questions such as how massive are the stars, how far away are they, what types of galaxies are they in and why are some of the outbursts so different from the others?
While the association between some bursts and massive starbursts is solid, other bursts may be the signature of neutron stars or black holes orbiting each other in strange binaries. Swift will determine whether there are different types of gamma ray bursts associated with each of the scenarios mentioned. Furthermore, the Swift may be fast enough to detect afterglows from short bursts, if they are indeed accompanied by afterglows. So far, the afterglow phenomenon has only been observed in bursts lasting more than two seconds. "We may have only seen part of the picture so far," Gerles said.
The SWIFT team hopes to discover and analyze over 100 outbreaks a year. While SWIFT will not be making measurements of gamma-ray bursts, it will be making observations of the short wavelengths of X-rays. These observations will be twenty times more accurate than previous measurements. Scientists expect that Swift's increased sensitivity compared to previous studies will reveal over 400 new massive black holes.
SWIFT, a medium-sized research operation, is managed by NASA's Goddard Space Flight Center in Greenbelt, Maryland, United States. SWIFT was built in collaboration with national laboratories, universities and international partners, including Los Alamos National Laboratory, Pennsylvania State University, Sonoma State University in Italy and England.
