Monday, February 20, 2012

NASA’s Hubble Space Telescope discovers Black Hole surrounded by Star Cluster


Astronomers know how massive stars collapse to form black holes but it is not clear how supermassive black holes, which can weigh billions of times the mass of our sun, form in the cores of galaxies. One idea is that supermassive black holes may build up through the merger of smaller black holes.

Sean Farrell of the Sydney Institute for Astronomy in Australia discovered a middleweight black hole in 2009 using the European Space Agency’s XMM-Newton X-ray space telescope. Known as HLX-1 (Hyper-Luminous X-ray source 1), the black hole has an estimated weight of about 20,000 solar masses. It lies towards the edge of the galaxy ESO 243-49, 290 million light-years from Earth.

Farrell then observed HLX-1 simultaneously with NASA’s Swift observatory in X-ray and Hubble in near infrared, optical and ultraviolet wavelengths. The intensity and the color of the light may indicate the presence of a young, massive cluster of blue stars, perhaps 250-light-years across, encircling the black hole. Hubble can’t resolve the stars individually because the suspected cluster is too far away. The brightness and color is consistent with other clusters of stars seen in other galaxies, but some of the light may be coming from the gaseous disk around the black hole.

“Before this latest discovery, we suspected that intermediate-mass black holes could exist, but now we understand where they may have come from,” Farrell said. “The fact that there seems to be a very young cluster of stars indicates that the intermediate-mass black hole may have originated as the central black hole in a very-low-mass dwarf galaxy. The dwarf galaxy might then have been swallowed by the more massive galaxy, just as happens in our Milky Way.”

From the signature of the X-rays, Farrell’s team knew there would be some blue light emitted from the high temperature of the hot gas in the disk swirling around the black hole. They couldn’t account for the red light coming from the disk. It would have to be produced by a much cooler gas, and they concluded this would most likely come from stars.


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Thursday, February 09, 2012

Infrared Sounder on NASA's Suomi NPP Starts its Mission


A powerful new infrared instrument, flying on NASA's newest polar-orbiting satellite, designed to give scientists more refined information about Earth's atmosphere and improve weather forecasts and our understanding of climate, has started sending its data back to Earth.

The Cross-track Infrared Sounder (CrIS) joins four other new instruments aboard the Suomi National Polar-orbiting Partnership (NPP) satellite, which NASA launched on Oct. 28, 2011 from Vandenberg Air Force Base in California. The Suomi NPP mission is the bridge between NOAA's Polar Operational Environmental Satellite (POES) and NASA's Earth Observing System satellites and the next-generation Joint Polar Satellite System (JPSS).

Since it reached orbit, Suomi NPP and its suite of five instruments are undergoing extensive checkouts before starting regular science observations. Suomi NPP is the result of a partnership between NASA, NOAA and the Department of Defense.

CrIS, an advanced spectrometer with 1,305 infrared spectral channels, is designed to provide high vertical resolution information on the atmosphere's three-dimensional structure of temperature and water vapor. The Atmospheric Infrared Sounder (AIRS) on the EOS Aqua mission, launched in 2002, demonstrated how useful this type of data could be for understanding the atmosphere. CrIS will continue this data record and provide data for use in NOAA's numerical weather prediction models to forecast severe weather days in advance.

"Significant overlap between AIRS and CrIS will provide the Earth science research community the ability to maintain the unprecedented accuracy and stability of the temperature and moisture data record initiated by AIRS," said Diane Wickland, Suomi NPP program scientist at NASA Headquarters.

"Having data from CrIS will only improve the quality, timeliness and accuracy of NOAA's weather and climate predictions, which directly affect everyone in America," said Mary Kicza, assistant administrator for NOAA's Satellite and Information Service (NESDIS).

"Over longer periods, data from CrIS will help NOAA to better understand climate phenomena such as El Niño and La Niña that impact global weather patterns," said Mitch Goldberg, NOAA's JPSS program scientist.

The Advanced Technology Microwave Sounder (ATMS), which measures temperature and humidity in both clear and cloudy conditions, was the first Suomi NPP instrument activated. ATMS and CrIS data together will be used operationally in weather forecasts beginning in the Spring of 2012.


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Wednesday, February 01, 2012

NASA Enhances Solar squall Forecasting


Space agency uses technology to generate up to 100 computerized forecasts to enhanced predict the path and effect of solar storms.

NASA is applying existing technology called "ensemble forecasting" that's been used to predict hurricanes in its observations of solar weather to better predict the trail and effect of solar storms.
The use of the computational predictive technique couldn't come as a better time, as the sun is entering its solar maximum, or period of maximum activity, which will spur an increase in space weather, according to the agency.

Researchers at the Space Weather Laboratory of Goddard Space Flight Research Center have begun to implement ensemble forecasting--which allows them to produce as many as 100 computerized forecasts at once--with full accomplishment in three years' time, according to NASA.

Support from NASA's Space Technology Program Game Changing Program is allowing for the use of the technology, which meteorologists already use to track the potential trail or impact of hurricanes and other forms of severe weather.

Indeed, solar flare and storm activity has increased in latest months as the sun begins to wake up from years of relative inactivity, according to NASA. To organize for it, the agency has been working for some time to improve its forecasting of solar weather.

The sun emitted two considerable corona mass ejections (CMEs)--or billion-ton clouds of solar plasma launched by sun explosions--in the last six months, one on Aug 4 and one in mid January, the latter of which caused some airlines to divert flights. And earlier this week, the most powerful solar flare so far this year erupted from the similar region that caused last week's CME.

As the sun enters its peak of activity, CMEs become more frequent and can affect planets or spacecrafts in their path, as well as disrupt satellite-based communications or power grids on earth.