Saturday, 31 January 2015
A NEAR-COLLISION STRETCHED THIS GALAXY LIKE A "TAFFY PULL"
Sunday, 25 January 2015
NASA unveils 100-millionth picture of the sun
An instrument onboard the Solar Dynamics Observatory captured NASA's 100-millionth image of the sun. Four telescopes work parallel to capture eight images of the sun and cycle through 10 different wavelengths every 12 seconds.
A National Aeronautics and Space Administration instrument aboard a sun-viewing spacecraft has captured its 100-millionth image of the sun.
The instrument, on the Solar Dynamics Observatory, is the Atmospheric Imaging Assembly and uses four telescopes. The photo was taken Jan.19, according to NASA.
https://www.youtube.com/watch?v=7VVxdN79QZY
In the nearly five years since its start in 2010, Solar Dynamics Observatory has captured images of the sun "to help scientists better understand how the roiling corona gets to temperatures some 1,000 times hotter than the sun's surface, what causes giant eruptions such as solar flares, and why the sun's magnetic fields are constantly on the move," NASA says.
Source : USA TODAY
Tuesday, 4 November 2014
NASA rocket to click 1,500 images of Sun in 5 minutes
This image provided by NASA shows the sun emitting a significant X3.2-class flare erupting from the lower half of the sun, peaking at 5:40 p.m. EDT on Oct. 24, 2014. NASA's Solar Dynamics Observatory, which watches the sun constantly and captured images of the event.
A sounding rocket fitted with technology to gather 1,500 images of the Sun in flat five minutes is set for launch on Monday.
Capturing five images per second, the Rapid Acquisition Imaging Spectrograph Experiment (RAISE) mission will focus in on the split-second changes that occur near active regions on the Sun.
These are areas of intense and complex magnetic fields that can give birth to giant eruptions on the Sun that shoot energy and particles out in all directions, the U.S. space agency said in a statement.
“Even on a five-minute flight, there are niche areas of science we can focus on well. There are areas of the Sun that need to be examined with the high-cadence observations we can provide,” said Don Hassler, solar scientist at the Southwest Research Institute in Boulder, Colorado.
RAISE will create a kind of data product called a spectrogram which separates the light from the sun into different wavelengths.
“The Sun has been extremely active recently, producing several X-class flares in the past few weeks. The team will aim their instrument at one of these active regions to try to understand better the dynamics that cause these regions to erupt,” Mr. Hassler explained.
The team hopes to see how heat and energy move through such active regions, which, in turn, helps scientist understand what creates the regions and perhaps even what catalyses the sun’s eruptions.
RAISE’s launch time is planned for 2.07 p.m. (EST) from the White Sands Missile Range near Las Cruces, New Mexico.
Monday, 3 November 2014
Success in the search for quiet, distant quasars
If quasars weren’t so luminous, we couldn’t see them so far away in space and time. But how about modest quasars, also far away? Astronomers say they’ve found some.
Astronomers at the Institute of Astrophysics of Andalusia (IAA-CSIC) in Spain say they have at last discovered a population of quiet, distant quasars. Nearly all the quasars we see at great distances are ultraluminous, and no wonder. They must be extremely luminous in order for us to glimpse them over the vastness of space. And yet astronomers have thought there must be, at those same vast distances, some quasars that were relatively quiet. Now, they say, they’ve found some and have been able to compare them both with the ultraluminous quasars in the early universe and also with closer quasars of moderate luminosity.
The farther away we look in space, the deeper we are looking into the past. Thus the ultraluminous quasars at great distances are showing us events taking place in the early universe: mergers of great galaxies containing gigantic black holes, with masses equivalent to billions of our suns, at their cores. These objects and events in the young universe are what we see as the distant quasars. The question has been, do the distant, tremendously high energy quasars have local relatives, in their same region of space and time, with much lower energy? And are those quiet quasars at great distances the dying versions of formerly ultraluminous quasars? Or are they something else entirely?
Jack W. Sulentic, astronomer at the Institute of Astrophysics of Andalusia (IAA-CSIC), who is leading the research, said:
Astronomers have always wanted to compare past and present, but it has been almost impossible because at great distances we can only see the brightest objects and nearby such objects no longer exist.
Until now we have compared very luminous distant quasars with weaker ones close by, which is tantamount to comparing household light bulbs with the lights in a football stadium.
Now, these astronomers say, they have detected the first distant, quiet quasars.
They say they employed the light-gathering power of the Gran Telescopio Canarias – known as GranTeCan or GTC telescope – located on the island of La Palma, in the Canary Islands in Spain. This telescope let Sulentic and his team obtain the first spectroscopic data from distant, low luminosity quasars similar to typical nearby ones.
They say their data are reliable enough to let them establish essential parameters of the quiet, distance quasars such as their chemical composition, and the mass of the central black hole or rate at which it absorbs surrounding gas and dust.
Quasars appear to evolve with distance. That is, the farther away they are in space, the brighter they are. This could indicate that quasars extinguish over time. Or it could be the result of anobservational bias masking a different reality: that gigantic quasars evolving very quickly, most of them already extinct, coexist with a quiet population that evolves more slowly, but which our technological limitations have not allowed astronomers to study. AscensiĆ³n del Olmo, another IAA-CSIC researcher who took part in this study, said:
We have been able to confirm that, indeed, apart from the highly energetic and rapidly evolving quasars, there is another population that evolves slowly. This population of quasars appears to follow the quasar main sequence … There does not even seem to be a strong relation between this type of quasars, which we see in our environment and those ‘monsters’ that started to glow more than 10 billion years ago.
Are there also differences between distant, quiet quasars and the moderate quasars closer to us in space? These astronomers say there are, and these differences are not surprising. Jack W. Sulentic said:
The local quasars present a higher proportion of heavy elements such as aluminum, iron or magnesium, than the distant relatives, which most likely reflects enrichment by the birth and death of successive generations of stars.
Bottom line: Astronomers in Spain have been able to identify a population of quiet quasars located in the distant universe, that is, in the early universe. They have compared them both to ultraluminous quasars in the early universe and also to quasars closer to us in space and time … and found differences in both cases.
Source : earth sky
Friday, 31 October 2014
NASA catches the sun celebrating Halloween
NASA's Solar Dynamics Observatory (SDO) captured quite a photo of the sun on October 8.
In the photo, hotspots of magnetic fields on the sun form what can appear to look like eyes, a nose and a grin reminiscent of a Jack-O-Lantern.
The image is a composite of two photos taken in ultraviolet light. The magnetic activity in the corona, or sun's atmosphere, is what creates the pattern.
The SDO, launch in 2010, monitors the sun's activity to provide accurate space weather forecasts, including to provide warning when solar flares may threaten the Earth.
Sunday, 26 October 2014
X-Class Solar Flare, 4th Major Eruption On The Sun This Week Detected
It’s been a busy week for earth’s star, with a partial solar eclipse delighting space watchers Thursday, and three earlier solar flares captured on NASA’s cameras.
The NOAA’s space weather tracking detected the X3.1 class flare Friday, beginning just after two in the afternoon, Pacific time, and lasting till after 3 p.m.
Flares of this strength can disrupt radios and navigational equipment, but harmful radiation is absorbed by the earth’s atmosphere.
One legendary solar flare in 1989 actually shut down power grids in the U.S. and Canada. That was an “X15″ class flare, exponentially more powerful than this week’s flares.
An X1.6 class flare erupted on Tuesday. X is the strongest class, and an X2 is twice as strong as an X1.
An M-class or mid-level solar flare peaked at 6:59 p.m. Tuesday night, as measured by NASA’s Solar Dynamics Observatory.
A third flare, an X1.1 on October 19th also sent radiation toward earth.
These solar eruptions can trigger larger than usual northern lights also known as the Aurora Borealis, sometimes making the glow visible as far south as Northern California.
NOAA Space Weather Scale descriptions can be found at
http://www.swpc.noaa.gov/NOAAscales
Source : CBS Local