Wednesday, October 27, 2010

Indian toothpaste recipe theft

http://www.colgate.co.in/Colgate/IN/OralCare/Toothpowder/tooth_powder.gif

Colgate accused of toothpaste recipe theft

October 21, 2010 7:12PM

A LEGAL dispute between the US and India over a herbal toothpaste is leaving a bitter aftertaste between the two countries, with Colgate Palmolive accused of filing a bogus patent.

Colgate, the world's largest producer of toothpaste, patented a toothcleaning powder in the hope that it would take the multibillion-dollar Indian oral hygiene market by storm.

However, Indian activists claim that the patent is bogus because the ingredients - including clove oil, camphor, black pepper and spearmint - have been used for the same purpose for hundreds, "if not thousands", of years on the subcontinent.

The dispute is likely to become a test case for who owns India's folk medicines - a repository potentially worth billions.

The American household goods giant was granted the patent in the US in June for what it claimed was a groundbreaking "red herbal dentifrice."

The patent, the Indian activists allege, is the latest act of "biopiracy" - whereby Western corporations plunder techniques, plants or genes used in the emerging world for centuries, for commercial profit.

http://www.healthjockey.com/images/neem-toothpaste.jpg

"This toothpowder is classical in origin," said Devender Triguna, the president of the Association of Manufactures of Ayurvedic Medicines, an Indian body that promotes traditional remedies. It is demanding that the Indian government take legal action against Colgate.

http://www.ntpd.lacors.gov.uk/lacors/aio/163815

"The ingredients date back to antiquity. They have been used by the common Indian man for thousands of years. So how can it possibly be patented?" Triguna asked.

Colgate did not respond to a request for comment. However, its patent filing argues that the use of red iron oxide, which is less abrasive than ingredients in traditional toothpaste, is new.

http://www.jasontopia.com/wp-content/uploads/2009/11/india2009-0271v2blog.jpg

The case is the latest to anger India as it becomes increasingly vocal over the alleged pillaging of its ancient knowledge for commercial gain. It is one of 17 nations to form the Group of Like-Minded Megadiverse Countries, an alliance that has accused richer countries of tapping the emerging world's natural resources for medicines and cosmetics without paying royalties.

India is in the process of creating 34 million webpages to document its ancient medicinal techniques to stop them from being claimed by foreign profiteers.



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posted by u2r2h at Wednesday, October 27, 2010 0 comments

stuxnet virus removal tool instructions



how the STUXNET VIRUS SPREADS VIA USB STICKS  .. Dangerous Flash Drives

And here it comes again. You thoughT, that turning the "auto-run" feature for removable drives off is sufficient and no "Worm/Autorun" can harm you again. And I bet you are pretty sure about it. I'm sorry, you are wrong.


Few days ago, a very strange sample appeared here in our lab. In fact, it was so interesting, it deserved these lines. At the moment, both samples – two drivers which use the rootkit technology for hiding themselves – are detected by AVG. These are quite "standard" rootkits, except, one of them is signed with valid certificate of Realtek Semicondutor Corp. In fact, the certificate is not valid right now, but it _was_ and that's a bit scary as this could confuse a lot of antivirus products. Valid certificate is still kind of "quality mark".


But while this is very unusual, the biggest surprise is the method of distribution. This malware uses completely new technique and, unfortunately, still opened vulnerability in MS Windows where the main role plays the ".lnk"  file – yes, the well known Windows Shortcut File. In this particular case, following files are placed on the infected USB Flash Drive:


   Clipboard01
WARNING: You probably won't see these files..


Do you have Total Commander, or Windows Explorer? Or any other file manager which supports icons? You've got a problem – of course, only in case you plug in the infected flash drive and open it with one of those file managers. The process of infection starts immediately, two files are dropped to your computer:

 

  %system%\Drivers\mrxcls.sys

  %system%\Drivers\mrxnet.sys

 

Two services are created to start them:

 

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MRxCls]

"Description"="MRXCLS"

"DisplayName"="MRXCLS"

"Group"="Network"

"ImagePath"="\\??\\C:\\WINDOWS\\system32\\Drivers\\mrxcls.sys"

"Start"=dword:00000001

"Type"=dword:00000001

 

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MRxNet]

"Description"="MRXNET"

"DisplayName"="MRXNET"

"Group"="Network"

"ImagePath"="\\??\\C:\\WINDOWS\\system32\\Drivers\\mrxnet.sys"

"Start"=dword:00000001

"Type"=dword:00000001

 

Finally, all the malware files (.lnk and .tmp) are hidden, so the victim probably won't even notice there are some other files on the flash drive.

 

After this, common rootkit behavior follows including "process injection", "API hooking", etc.. The driver injects the malware code into following processes:"

 

  lsass.exe

  svchost.exe

  services.exe

 

Maybe, this is the only single threat that uses this vulnerability, but we can probably expect many others – until the vulnerability is closed. Microsoft knows about it and, hopefully, they'll do something about it soon. Until that time, you should, once again, care about your Flash Drives and the source they came from (remember the good old times with all the infected floppy disc?). And, of course, you should stay protected..

 

Thanks to Peter Gramantik and Arek Kupka


http://greatis.com/security/stuxnet_remover.html

http://greatis.com/security/pics/StuxnetRemover.jpg

How Stuxnet Remover works?

Stuxnet Remover is able to detect and remove the active infecton.
It can find the Rootkit drivers and other files made by Stuxnet Rootkit.

  1. C:\WINDOWS\system32\drivers\mrxcls.sys
  2. C:\WINDOWS\system32\drivers\mrxnet.sys
  3. C:\WINDOWS\inf\mdmcpq3.PNF
  4. C:\WINDOWS\inf\mdmeric3.PNF
  5. C:\WINDOWS\inf\oem6C.PNF
  6. C:\WINDOWS\inf\oem7A.PNF

In addition the Stuxnet Remover is able to detect and remove malicious "lnk" and "tmp" files stored on the removable media.

  1. ~WTR4132.tmp
  2. "Copy of Copy of Copy of Copy of Shortcut to.lnk"
  3. "Copy of Copy of Copy of Shortcut to.lnk"
  4. "Copy of Copy of Shortcut to.lnk"
  5. "Copy of Shortcut to.lnk"
  6. ~WTR4141.tmp
Stuxnet Remover is simple in using and free.



KB2347290
kb2286198   << still


Stuxnet Virus, or also known as Winsta, devouring all the vacant land on the hard disk until full. According to Alfons Tanujaya, antivirus analysts from Vaksincom, to detikINET, Friday (07/30/2010), Indonesia is the country with the second largest Stuxnet victims in the world after Iran.
The virus initially spread from various adult sites, pirated programs and content 'gray' other was quite disturbing. Here are the steps to eradicate the virus, as manifested by antivirus analysts Vaksincom Adi Saputra:

1. Using Dr. Web CureIt

Adi suggested that the victim Winsta Stuxnet alias to download a virus removal software. Removal Tools called Dr.Web CureIt can be downloaded from the site FreeDrWeb.com

2. Registry Fix

Then, Adi registry suggest improvements in Windows that has been modified by a virus. How, first of all, copy the script below into WordPad file.

[Version]
Signature="$Chicago$"
Provider=Vaksincom Oyee
[DefaultInstall]
AddReg=UnhookRegKey
DelReg=del

[UnhookRegKey]
HKCU, Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced, ShowSuperHidden,0x00010001,1
HKCU, Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced, SuperHidden,0x00010001,1
HKCU, Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced, HideFileExt,0x00010001,0
HKLM, SOFTWARE\CLASSES\batfile\shell\open\command,,,"""%1"" %*"
HKLM, SOFTWARE\CLASSES\comfile\shell\open\command,,,"""%1"" %*"
HKLM, SOFTWARE\CLASSES\exefile\shell\open\command,,,"""%1"" %*"
HKLM, SOFTWARE\CLASSES\piffile\shell\open\command,,,"""%1"" %*"
HKLM, SOFTWARE\CLASSES\regfile\shell\open\command,,,"regedit.exe "%1""
HKLM, SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon, Shell,0, "Explorer.exe"

[del]
HKLM, SYSTEM\CurrentControlSet\Services\MRxCls
HKLM, SYSTEM\CurrentControlSet\Services\MRxNet
HKLM, SYSTEM\ControlSet001\Services\MRxCls
HKLM, SYSTEM\ControlSet002\Services\MRxNet
HKLM, SYSTEM\CurrentControlSet\Services\Enum\Root\LEGACY_MRXClS
HKLM, SYSTEM\CurrentControlSet\Services\Enum\Root\LEGACY_MRXNET
HKLM, SYSTEM\ControlSet001\Services\Enum\Root\LEGACY_MRXClS
HKLM, SYSTEM\ControlSet002\Services\Enum\Root\LEGACY_MRXNET

Then, save the file with the name 'repair.inf'. Use the Save as type option to Text Document in order to avoid mistakes. Then, right click the file 'repair.inf', select 'Install' and restart the computer.

"Clean up temporary files, this in order to prevent the rest of the trojan is trying to become active again. Use tools such as ATF Cleaner or use the features of Windows that is the Disk Clean-Up," wrote Adi.

3. Emergency Solutions

In addition, the following is a script that can be used in emergencies to prevent re-infecting Winsta not. Save the following script with the name Winsta.bat (file type: Text)

@echo off
del /f c:\windows\system32\winsta.exe
rem rd c:\windows\system32\winsta.exe
md c:\windows\system32\winsta.exe
del /f c:\windows\system32\drivers\mrxnet.sys
rem rd c:\windows\system32\drivers\mrxnet.sys
md c:\windows\system32\drivers\mrxnet.sys
del /f c:\windows\system32\drivers\mrxcls.sys
rem rd c:\windows\system32\drivers\mrxcls.sys
md c:\windows\system32\drivers\mrxcls.sys
attrib +r +h +s c:\windows\system32\winsta.exe
attrib +r +h +s c:\windows\system32\drivers\mrxnet.sys
attrib +r +h +s c:\windows\system32\drivers\mrxnet.sys

Once completed, double-click the resulting file Winsta.bat. For optimal cleaning and prevent re-infection, re-use antivirus software that scans an updated and properly recognize this virus.




information from October 21, 2010:

Manufacturers of virus scan software have reported massive Stuxnet infections in some countries, with no distinction being made as to whether office PCs or industrial systems are affected. In none of the cases known to Siemens from the industrial environment was a plant's control system affected.

In the three months since Stuxnet appeared for the first time, a total of 19 Siemens customers worldwide from an industrial environment have reported an infection with the Trojan (as of October 21, 2010).

In all cases Stuxnet exploited security gaps in Windows-based operating systems. The virus could be removed in every case without any adverse effects on plant processes. In none of the cases did Stuxnet influence control software or even attempt to do so.

This behavior corresponds to the insights gained from the analysis that Siemens carried out on the virus. Stuxnet searches systematically for a very specific plant configuration. If it does not find such a configuration, the virus is not activated.


Product Information dated October 01, 2010:
  • Latest news on the infected computers::
    To date, we know of 15 systems infected worldwide. In all cases the malware could be removed. In none of these cases did the infection cause an adverse impact to the automation system. Since the end of August no new infections were registered.

Recommended procedure for detecting and removing "stuxnet" (updated August 04, 2010)

We recommend examining the following computer types:

  1. Embedded systems (e.g. Microbox)
  2. Other computers
    • Infrastructure computers (file servers, domain controllers, other servers...)
    • Computers with and without WinCC installed
    • Virtual machines (e.g. VMWARE installations))

The individual activities should be carried out based on the following procedure:
 

Important note:

Product Information dated September 17, 2010:

Analysis of virus and status of investigations

  1. The virus has been isolated on a test system in order to carry out more extensive investigations. Previously analyzed properties and the behavior of the virus in the software environment of the test system suggest that we are not dealing with the random development of one hacker, but with the product of a team of experts who must have IT expertise as well as specific know-how about industrial controls, their deployment in industrial production processes and corresponding engineering knowledge.
  2. As far as we know at the moment, industrial controls from Siemens are affected. The Trojan is activated whenever WinCC or PCS7 software from Siemens is installed.
  3. Further investigations have shown that the virus can theoretically influence specific processes and operations in a very specific automation environment or plant configuration in addition to passing on data. This means that the malware is able, under certain boundary conditions, to influence the processing of operations in the control system . However, this behavior has not yet been verified in tests or in practice.
  4. The behavioral pattern of Stuxnet suggests that the virus is apparently only activated in plants with a specific configuration. It deliberately searches for a certain technical constellation with certain modules and certain program patterns which apply to a specific production process. This pattern can, for example, be localized by one specific data block and two code blocks.
  5. This means that Stuxnet is obviously targeting a specific process or a plant and not a particular brand or process technology and not the majority of industrial applications.
  6. This conclusion also coincides with the number of cases known to Siemens where the virus was detected but had not been activated, and could be removed without any damage being done up to now. · This kind of specific plant was not among the cases that we know about.


How is it possible to say whether an automation system corresponds to the specific program pattern and what counter-measures recommended are?

  • The malware carries its own blocks (for example, DB890, FC1865,1874) and tries to load them into the CPU and integrate them into the program sequence. If the above-mentioned blocks are already present, the malware does not infiltrate the user program.
  • If the above-mentioned blocks were not present in the original program and are now detected, the virus has infected the system. In this case Siemens urgently recommends restoring the plant control system to its original state.


Is the current Microsoft Patch compatible with SIMATIC Software

Product Information dated September 07, 2010:

  • Latest news on the infected computers:
    To date, we know of 15 systems infected worldwide. In none of these cases did the infection cause an adverse impact to the automation system.

Product Information dated August 24, 2010:

  • Latest news on the infected computers:
    To date, we know of 12 systems infected worldwide. In none of these cases did the infection cause an adverse impact to the automation system.
     

Product Information dated August 13, 2010:

  • We continue to recommend to customers that they utilize the Siemens-approved virus scanner and make sure that they have sufficient IT security standards in place (e.g. network security, no active USB connections in the production environment, etc.). Operating systems must be checked continuously to ensure that they are up-to-date.
     
  • To the best of our knowledge right now, the malware is active only when very specific project structures in the automation system are present..
     
  • To date, we know of nine systems infected worldwide. In none of these cases did the infection cause an adverse impact to the automation system.
     

Product Information dated August 03, 2010:

  • Important note on the Microsoft Patch
    The Microsoft Patch only prevents that the trojan from being installed automatically on the system. If a user with admin-rights opens an infected LNK-file by mouse click on a computer on which the Microsoft Patch is installed, the computer will become infected - if no virus scanner has been installed. To avoid such an infection, it is strongly recommended that users only log in with power user rights. Power users do not have the necessary permissions to start code from another drive. For additional security use an approved virus scanner.

     

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posted by u2r2h at Wednesday, October 27, 2010 0 comments

Gamma Ray Bursts - 2do VLF GRB detector

2do  VLF GRB detector

http://solar-center.stanford.edu/SID/pictures.html
http://solar-center.stanford.edu/SID/Distribution/SuperSID/supersid_v1_1/Doc/SuperSIDManual_v1.pdf



http://upload.wikimedia.org/wikipedia/commons/thumb/b/b9/Egret_allsky_above100Mev.png/220px-Egret_allsky_above100Mev.png


Swift primarily studies gamma-ray bursts (GRBs) -- the biggest and most mysterious explosions in the cosmos. On April 13, the spacecraft's "burst-o-meter" cataloged its 500th GRB.

"On the one hand, it's just a number, but on the other it is a remarkable milestone," said Neil Gehrels, Swift's lead researcher at Goddard Space Flight Center in Greenbelt, Md. "Each burst has turned over a new piece of the puzzle and a clearer picture is emerging."

"Over five years and 500 bursts, Swift has fulfilled every significant promise of its mission and, in addition, brought a wealth of surprises," noted Derek Fox, a Swift team member at Penn State in University Park, Pa.

Burst 500, officially known as GRB 100413B, exploded in constellation Cassiopeia as a long burst, a type usually associated with the death of a massive star. It wasn't detected in on-board analysis of data from the spacecraft's Burst Alert Telescope (BAT), which was interrupted 18 seconds after the burst as Swift slewed to a pre-planned target.

Instead, GRB 100413B came to light when David Palmer, an astrophysicist at Los Alamos National Laboratory in New Mexico, later analyzed the data. "The BAT team regularly digs through the data once it comes to the ground and finds weak bursts like this one that take a bit of special care," said Goddard's Judith Racusin, who coordinated burst observations that day.

Summaries of other notable bursts in Swift's storied career are listed below.

Swift's main job is to quickly localize each gamma-ray burst, report its position so that others can immediately conduct follow-up observations, and then study the burst using its X-ray and Ultraviolet/Optical telescopes. But it does much more, including ultraviolet studies of exploding stars, monitoring black holes and neutron stars for surges of high-energy radiation, and carrying out a long-term X-ray survey of the entire sky.

The spacecraft rocketed into orbit in November 2004. Managed by NASA's Goddard Space Flight Center, Swift was built and is operated in collaboration with Penn State, the Los Alamos National Laboratory in New Mexico, and General Dynamics of Gilbert, Ariz. Other partners include the University of Leicester and Mullard Space Science Laboratory in the United Kingdom, Brera Observatory and the Italian Space Agency in Italy, with additional collaborators in Germany and Japan.

http://upload.wikimedia.org/wikipedia/commons/thumb/3/3a/Cosmicrayshower.png/600px-Cosmicrayshower.png

Origins

Because gamma rays are the highest-energy form of light, the brief but brilliant blasts represent a colossal energy release. Gamma-ray bursts were discovered in 1967 by unclassified military satellites designed to look for clandestine nuclear tests. The first observations required extensive analysis to be sure that the bursts were truly originating beyond the solar system, and they weren't published until 1973.

Over the following years, astronomers learned that sufficiently sensitive instruments could detect about two bursts per day, on average, somewhere in the sky. Of those twice-daily GRBs, Swift's Burst Alert Telescope snares about one in eight for detailed study.

According to Lorella Angelini, a Goddard astrophysicist now developing a comprehensive burst database, the number of recorded GRBs is approaching 6,000. Yet if one considers only bursts with measured distances, Swift's share of the total is a whopping 75 percent.

An earlier NASA satellite, the Compton Gamma Ray Observatory, showed that bursts come in long and short varieties, with long bursts (those lasting longer than two seconds) outnumbering short bursts three to one. Compton also showed that bursts occur randomly and evenly over the sky. Maps of GRB distribution bear no hint of our galaxy's structure. This means that they are extremely far away -- and all the more powerful.

Across the universe

A key breakthrough in understanding GRBs came from the Italian-Dutch satellite Beppo-SAX, which in 1997 provided the first precise burst positions. It later discovered lingering X-ray emission -- dubbed "afterglows" -- at burst locations. Observatories on the ground quickly discovered afterglows in visible light, which provided information that confirmed the burst's enormous distances. Astronomers now regularly study afterglows across the electromagnetic spectrum.

Most of the time, the hard task of measuring burst distances falls to ground-based observatories, which can target a burst's location with telescopes far larger than the Ultraviolet/Optical Telescope aboard Swift.

"Getting on the afterglows quickly with large ground-based telescopes remains a key element in understanding GRBs," said Fox, whose research focuses on follow-up observations. "It's this synergy between Swift and ground observatories that has really moved the ball forward, especially for short bursts."

And the farther the burst, the more important rapid ground follow-up becomes. At distances greater than about 12 billion light-years, gas clouds block ultraviolet wavelengths before they can reach Earth, and all optical light becomes shifted into infrared wavelengths only detectable by specially-equipped ground-based telescopes. Astronomers scramble to detect afterglow from new bursts as soon as they can.

"Thanks to such efforts, we know Swift has seen GRBs as close as about 100 million light-years and as far away as 13 billion light-years," adds Gehrels. Put another way, Swift sees gamma-ray bursts over a span of time equivalent to about 95 percent of the universe's age.

The long and the short of GRBs

By the time Swift launched, mounting evidence already pointed to the deaths of massive stars as the source of most long GRBs -- a scenario that still stands. When such a star runs out of fuel, its core collapses and likely forms a black hole surrounded by a dense hot disk of gas called an accretion disk. Somehow, the black hole diverts part of the infalling matter into a pair of high-energy jets that tear through the collapsing star.

The jets move so fast -- upwards of 99.9 percent the speed of light -- that collisions within them produce gamma rays. As the jet breaches the star's surface, a gamma-ray burst is born. The jet continues on, later striking gas beyond the star to produce afterglows.

Short bursts, however, proved much harder to pin down. "We didn't know their most basic properties," notes Ehud Nakar, an astrophysicist at Tel Aviv University in Israel. "We knew so little we weren't even sure that short GRBs were a unique astrophysical phenomenon."

It turns out they are. "Long GRBs originate from the collapse of stars just millions of years old, but the objects that give rise to some short GRBs reach ages of billions of years before exploding," Nakar adds.

The emerging picture is that short GRBs arise when two compact objects -- either a pair of neutron stars or a neutron star and a black hole -- collide and merge. These objects, which are the crushed cores of exploded stars, pack more mass than the sun into volumes just a few miles across. For those bound in a binary system, Einstein's relativity seals their fate.

According to Einstein, massive orbiting objects give off a type of energy called gravitational radiation. Although no one has yet detected these waves, astronomers have observed an effect predicted by this energy loss -- the slowly shrinking orbits of binary neutron stars. Over billions of years, the stellar cinders grow ever closer and finally merge in an event that unleashes titanic energies and creates a short GRB.

But Nakar thinks the full picture still eludes astronomers. "So far, the data favor merging neutron stars, and that is certainly the most popular idea, but other scenarios remain possible. We still do not know the origin of short GRBs."

Thanks mainly to burst identifications from Swift and the afterglow observations they make possible, scientists now have details on dozens of short bursts and their afterglows. "We're now beginning to understand the home galaxies of short GRBs," Fox said.

Over the past five years, Swift has delivered a great deal of revolutionary science. But its career isn't over yet -- and with a little luck, there will be much more to come.

Swift GRB highlights

April 13, 2010: NASA's Swift discovers its 500th burst. GRB 100413B is a long burst in the constellation Cassiopeia.

April 23, 2009: GRB 090423 in Leo holds the record for the farthest burst yet known -- 13.04 billion light-years away. "The burst is beyond the farthest confirmed galaxies and quasars, making it the most distant object we know in the universe today," Fox said. This find validates models suggesting that galaxy and star formation were well under way in the universe's first billion years and that some early stars died as bursts.

March 19, 2008: GRB 080319B, in Boötes, is truly extraordinary. It produces enough light to be seen briefly with the unaided eye, cresting at visual magnitude 5.3 despite occurring 7.5 billion light-years away -- or more than halfway across the visible universe. Scientists conclude that one of its particle jets appears to have been aimed squarely at Earth.

July 14, 2007: GRB 070714B explodes in Taurus. Afterglow observations indicate a distance of 7.3 billion light-years, making this one of the farthest short bursts to date.

Feb. 18, 2006: GRB 060218 explodes in Aries 450 million light-years away -- in our back yard, cosmically speaking. Although faint, the burst emits detectable gamma rays for more than 40 minutes and detectable optical and X-ray emission lasts more than 10 days. The event is a hybrid, showing characteristics of both a GRB and a supernova, and leads to the best observations yet exploring connections between these phenomena.

Sept. 4, 2005: At a distance of 12.77 billion light-years, GRB 050904, located in Pisces, is the farthest-known GRB at the time, the first of many such Swift records.

May 9, 2005: GRB 050509B, in Coma Berenices, erupts with a flash of gamma-rays that lasts just 0.03 second. Swift turns to the burst fast enough to detect 11 X-ray photons, making this the first short burst with a detected afterglow.

Dec. 17, 2004: Swift's first burst, in Crater, is eight-second-long GRB 041217.


Gamma-Ray Bursts
:

Energy Release with Human Experience
------------------------------------
1 ergs = energy to make a mosiquito jump
10^3 ergs = ball drop
10^10 ergs = hit by truck
10^15 ergs = smart bomb
10^20 ergs = H bomb
10^26 ergs = killer asteroid
10^40 ergs = Death Star

Energy Release with Astronomical Experience
-------------------------------------------
10^33 ergs/s = Sun
10^39 ergs/s = nova
10^41 ergs/s = SN
10^45 ergs/s = galaxy

10^52 ergs/s = GRB
The Vela-5A nuclear test detection satellite was part of a program run jointly by the Advanced Research Projects of the U.S. Department of Defense and the U.S. Atomic Energy Commission, managed by the U.S. Air Force, to verfy the Atmospheric Test Ban Treaty.

It and its twin, Vela-5B, were placed 180 degrees apart in nearly circular orbits at a geocentric distance of 118,000 km on 23 May 1969; the orbital period was 112 hours. The x-ray and gamma-ray detector was located 90 degrees from the spin axis, and so covered the celestial sphere twice per satellite orbit. Data were telemetered in 1-sec count accumulations.

In 1973, the Vela satellites discovered brief bursts of gamma-rays of cosmic origin coming from random directions on the sky. Networks of satellites carrying gamma-ray burst detectors were established in the inner solar system in the 1970's and 1980's (every space probe was mounted with a small gamma-ray detector) to produce source locations for these transients using a method analogous to triangulation of ships at sea. However, inspection of the relatively small locations produced no obvious counterparts to the gamma-ray bursts at any other wavelength.

The mystery of gamma-ray bursts has been prolonged by the impracticality of building and launching a gamma-ray telescope with focusing optics that could maneuver and point to the unknown direction of a burst while it is still in progress. This was partially resolved by the launch of the Compton Gamma-Ray Observatory (CGRO) in the late 1980's.

One of CGRO's experiments is EGRET which produced an all-sky map at gamma-ray energies above 100 MeV in galactic coordinates. The diffuse emission, which appears brightest along the galactic plane, is primarily due to cosmic ray interactions with the interstellar medium. The Vela, Geminga, and Crab pulsars are clearly visible as bright knots of emission in the galactic plane in the right portion of the image.

The burst-monitoring experiment on CGRO, BATSE (Burst And Transient Source Experiment), localizes bursts by comparing the burst's different intensities as measured by its eight detectors pointing to the eight octants of the sky.

The resulting coarse localizations have uncertainties of several degrees in radius, making positive identification of the corresponding object at optical or X-ray wavelengths very difficult: literally millions of candidate objects appear within the probable gamma-ray error region, and only one (or none) is related to the gamma-ray burst.

As can be seen from the uniform distribution of burst positions in this recent figure, no preferred direction for the burst sources is apparent. If the burst sources were associated with our own Milky Way Galaxy, then a distribution concentrated toward the Galactic plane (represented by the central horizontal line in the figure -- the "galactic equator"), like that seen by CGRO's EGRET instrument. Such reasoning led some gamma-ray astrophysicists to believe that bursts are coming either from very local sources (just outside the Solar System) or the very distant reaches of the Universe. In the later case, these brief events would be, momentarily, much brighter than entire galaxies.

In the late 1990's, a promising CGRO project takes advantage of real-time telemetry acquisition and calculation of burst source directions. The coarse BATSE, and other orbiting x-ray telescopes, positions are quickly relayed the burst's approximate location to fast-slewing, ground-based cameras primed to search for an elusive optical flash. Larger telescopes too captured the burster's optical counterpart and at right is an image identifying the candidate from the 60 inch Palomar reflector. At left is a prior sky survey image of the region which astonishingly shows a discernible smudge near the same position, likely the burster's host galaxy.

The galaxy and bright burst suggest that this is the closest yet localized gamma-ray burst.

Do the powerful explosions known as gamma-ray bursts (GRBs) originate in galaxies? This subject took on new light with the release of a Hubble Space Telescope image of the sky surrounding GRB 990123. This burst was cataloged as one of the most powerful GRBs ever. The optical transient (OT) counterpart to the GRB can be seen as the bright spot just below center. Once so bright it was briefly visible with just binoculars, this OT has since become four million times dimmer and continues to fade. Now, it can be seen easily with only a large telescope. The diffuse object above is of particular interest because it appears to be the host galaxy of GRB 990123. This distant galaxy seems to have a normal brightness but an irregular shape. This discovery increases the evidence that most OTs do occur in galaxies.

The big, unsolved mystery concerning gamma-ray bursts is their source of energy. The output of a GRB exceeds the total output from over 100 billion supernova's and a billion times the output of an entire galaxy of stars. This would require a black hole the size of a cluster of galaxies (hard to miss) or the collision of a matter and anti-matter about the mass of a star (there are no anti-matter stars). We are left with the possiblity that our knowledge of physics is incomplete to explain this phenomenon.


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posted by u2r2h at Wednesday, October 27, 2010 1 comments