http://www.spacedaily.com/reports/Most_Ext..._Found_999.html

The two white dwarf stars in binary HM-Cancri revolve around each other in only 5 minutes 24 seconds. This makes HM-Cancri by far the smallest and shortest known binary star orbital period. The binary system is no larger than a quarter the distance from Earth to the Moon.

White dwarfs are the burnt-out cinders of sun-like stars and contain highly condensed helium, carbon, and oxygen. An X-ray source first seen in 1999 showing a 5.4 minutes periodicity showed HM-Cancri. For a long time though it was unclear whether this period indicated the system orbital period. Astrophysicists were reluctant to accept the possibility because it was so short.

Astronomers used the world's largest telescope, Keck in Hawaii, to show that the 5.4-minute period is indeed the binary system period. They detected spectral line Doppler velocity variations in HM-Cancri’s light caused by the star’s orbital motion. The Doppler Effect causes the lines to shift from blue to red and back.

HM-Cancri observations were an ultimate challenge due to the extremely short period and the binary system faintness. At 16,000 light years from Earth, it is no more than one millionth as bright as the faintest stars visible to the naked eye.

This system intriguingly has an extremely short period with mass flowing from one star and crashing onto the equator of the other. This region that is the size of the English Midlands liberates more than the Sun's entire power in X-rays. It could also be a strong gravitational wave emitter, which we may one day detect in testing General Relativity.

These observations are at the limit of what is currently possible. Not only do we need the world’s biggest telescopes, but they also need the best available instruments. HM-Cancri challenges our stellar and binary evolution understanding. The system came from two normal stars that spiraled together in two earlier mass transfer episodes, but we do not know the physics of this process.

Interesting and small article

Money key to more shuttle flights





Sounds interesting-but is is workable

http://www.universetoday.com/2010/03/07/ta...rnova-ngc-4490/

In the Canes Constellation 50 million light years away the Venetici pair of interacting galaxies, “The Cocoon” have already made their closest approach to each other and are now separating. You see a trail of stars spanning 24,000 light-years between them showing numerous star-forming regions. Where there is life though, there is also death.

Interacting galaxies NGC-4485 and NGC-4490 have long interested astronomers to analyses the hot interstellar medium. Chandra reveals diffuse X-ray emission properties from these galaxies. Chandra’s high angular resolution removes discrete sources and resolves starburst regions and outflows. This shows the physical properties of the hot interstellar medium, hydrogen column density, and varying metal abundances.

An Ha filament emerging from NGC-4490 projects 10,000 light-years, which has both radio continuum and HI counterparts. The HI portion extends 100,000 light-years from NGC-4490, evidence that the giant HI envelope has its origins in star formation. Radio data constrains the distribution of dust around the star forming regions. The lack of an independent estimate limits this analysis of the dust temperature, something that both SIRTF and SOFIA will provide. However, some evidence shows that most obscuring dust is not in the HII regions themselves.

As far back as 1997, astronomers combed images made in different wavelengths and drew conclusions. They determined the tidal star-forming region ages, including a newly discovered faint tail east of NGC-4490. They distinguish this tail from the connecting bridge between the two galaxies from the “tidal arm” that spirals out from NGC-4485’s bright regions toward the bridge. Now astronomers are about to combine images again.

On March 4, 2008 Swift Ultraviolet/Optical Telescope (UVOT), X-Ray Telescope (XRT), and amateur astronomer Rick Johnson captured a supernova. One view though is not enough, so they combed data was from Dietmar Hager’s astrophotograph taken by prior to the supernova. They merged more data when combined it with weeks old RGB data taken by Torsten Grossmann. The result was nothing short of magic. An animated .Gif image at the website shows the Supernova blinking.

The Lick Observatory and astronomer Koichi Itagaki of Japan independently discovered neophyte Supernova 2008ax in galaxy NGC-4490. They thought it was a blue variable at its beginning pulse. Soon enough it went to a young Type II supernova and then escalated into a Type Ib. The pulse was faint but there and undeniable.

The nearby Sd galaxy NGC-4490 hosts one of the most numerous Ultraluminous X-ray Source, ULX, populations within 30 million light-years; only M-51 and M-82 have more. Astronomers detected all five previously identified ULX’s in NGC-4490 and those in NGC-4485’s tidal tail with one new transient ULX. The sources show a variety of long-term light curves; however, short-term temporal variability is conspicuous by its absence. ULX’s are point like, non-nuclear X-ray sources outside their host galaxy nucleus with X-ray luminosities in excess of 10^39 erg s-1.

 Galaxy_NGC_4490.jpg ( 48.53K ) Number of downloads: 1

http://www.spacetelescope.org/images/html/opo0825c.html
Friedrich August Theodor Winnecke discovered open star cluster NGC-6791 in 1853 in Constellation Lyra. It is 8 billion years old with a heavy metal Iron to Hydrogen abundance ratio more than twice that of our Sun. This makes it one of the oldest and most metal-rich clusters in the Milky Way. This is odd because typically older means metal-poor. It also has an unusually high star population, putting NGC-6791 among the most studied star clusters.

http://en.wikipedia.org/wiki/NGC_6791
The cluster has two groups of White Dwarfs, one 6 billion years old and the other 4 billion.

http://apod.nasa.gov/apod/ap000112.html
NGC-6791 is one of the oldest and largest open clusters known. Most contain a few hundred stars at most, which are all less than a billion years old. NGC-6791’s thousands are much older. Throw in their high metal content and they are confusing indeed.

http://www.youtube.com/watch?v=x57dxsoNCxk
This NASA movie takes a closer look at Hubble’s NGC-6791 image. At the end, it zeros in on the white dwarfs that vary in age.

 NGC_6791_1d_Hubble.jpg ( 722.45K ) Number of downloads: 3


A closer look at the image will show many background galaxies, not just the two large ones.

http://www.spacedaily.com/reports/First_Of...overed_999.html

A second-generation star from the early universe formed shortly after the Big Bang. This star is almost as old as the universe itself. The star in the dwarf galaxy Sculptor 290,000 light-years away has a remarkably similar chemical make-up to the oldest Milky Way stars. Its existence shows that our galaxy cannibalized other galaxies, growing by swallowing dwarf galaxies and other galactic building blocks.

Dwarf galaxies are small with just a few billion stars, compared to hundreds of billions in the Milky Way. In the “bottom-up model” galaxy formation, large galaxies absorb their smaller neighbors over billions of years to reach their size. A time-lapse movie of our galaxy would show a swarm of dwarf galaxies buzzing around it like bees around a hive. Over time, those galaxies smashed together, their stars mingling to make our Milky Way. If dwarf galaxies indeed build larger galaxies, then older metal poor stars should be in both kinds of galaxies.

Metals are chemical elements heavier than hydrogen or helium produced by stellar evolution and therefore rare in the early Universe. This means that old stars tend to be metal-poor. Old Milky Way halo stars are extremely metal-poor; our Sun has 100,000 times the metal abundance. Surveys over the past decade have failed to turn up any such extremely metal-poor stars in dwarf galaxies, however.

The Milky Way has some stars that are much more primitive than stars in any dwarf galaxy. If dwarf galaxies were Milky Way original components, then it is hard to understand why they would not have similar stars.

Methods to find metal-poor stars in dwarf galaxies were biased and missed the most metal-poor stars. A new method to estimate metal abundances in large numbers of stars at a time made it possible to search for metal-poor stars in dwarf galaxies. This was harder than finding a needle in a haystack; it was like looking for a needle in a stack of needles. It took hundreds of candidates dwarf galaxies to find the target stat.

Among stars in the Sculptor dwarf galaxy was one faint, 18th-magnitude speck designated S1020549. It had a metal abundance on part in 6,000 that of the Sun, or one part in five of any other dwarf galaxy star. Its total metal abundance from heavy elements resembles that of old Milky Way stars, supporting galactic stars originally forming in dwarf galaxies.

Researchers expect to discover additional metal-poor stars in other dwarf galaxies, although their distance and faintness pose a challenge for current optical telescopes. The next generation of extremely large optical telescopes will allow studying the growth of galaxies through their star’s chemistry. In the meantime, the extremely low metal abundance in S1020549 significantly aids in understanding our galaxy’s formation.

http://www.moondaily.com/reports/Deep_Crat...t_Moon_999.html

An asteroid struck the Moon’s southern hemisphere shortly after it formed. It gouged out a truly enormous South Pole-Aitken basin, almost 1,500 miles across and more than five miles deep. This biggest, deepest crater on the Moon could engulf the United States from the East Coast through Texas. The tremendous impact heat melted part of the crater floor, turning it into a sea of molten rock.

Asteroid bombardment over billions of years has pockmarked the lunar surface with craters of all sizes. It covered the surface with solidified lava, rubble, and dust. Any original surface, or crust, is rare, with views into the deep crust rarer still. The Apollo Basin on the edge of the South Pole-Aitken basin may provide such a view. Measuring a respectable 300 miles across, it is like digging a deeper hole in your basement.

The Apollo Basin center may expose some of the Moon’s lower crust. It is one of just a few places where we can see into the deep lunar crust. Volcanic material did not cover it did many other areas. Apollo teaches us early lunar history. The Moon Mineralogy Mapper (M3) board India's Chandrayaan-1 lunar-orbiting spacecraft discovered that portions of Apollo’s interior have a similar composition to the impact melt in the South Pole-Aitken (SPA) basin.

Going deeper into the Moon, crustal minerals have more iron. The Moon was molten when it first formed. Minerals with heavier elements like iron sank toward the core, while minerals with lighter elements like silicon, potassium, and sodium floated to the top. This formed the original lunar crust. The asteroid that created the SPA basin carved through this crust and perhaps into the upper mantle. The impact melt then solidified to form SPA’s central floor, making it a mixture of all those layers. It should have slightly more iron than the bottom of Apollo since it went deeper into the crust, what M3 found. However, this Apollo area also has more iron than the surrounding lunar highlands. This indicates Apollo uncovered a crustal layer between what we typically see on the surface and that in the deepest craters.

Apollo survived the impact that created SPA because it was on the edge of SPA, several hundred miles from the impact site. The large number of smaller craters superimposed on both SPA and Apollo say they are among the oldest lunar craters. As time passes, new craters cover old ones, so a crater count provides a relative age.

A crater riddled with additional craters is older than a relatively clean one with few craters overlying it. Craters break up the crust and form regolith, a layer of broken up rock and dust, like a soil on the Earth. Although the Apollo basin is ancient and covered with regolith, it still gives a useful view of the lower crust. The smaller meteorite impacts that create most of the regolith do not scatter material very far. Because 50% of the regolith is local, M3 still shows us some lower crust.

Earth did not escape the Moon’s abusive asteroid bombardment. Giant craters on other worlds such as Mercury and Mars show the widespread rain from the heavens. On Earth, crustal recycling and weathering erased the record of these events long ago. The Apollo and SPA basins give us a window into the Moon’s earliest history, and the Moon gives us a window into Earth’s violent youth.

http://www.marsdaily.com/reports/NASA_Mars...estone_999.html

The NASA Mars orbiter, days short of its fourth year on Mars, has now returned 100 terabits of information. That is more data than in 35 hours of uncompressed high-definition video. It is also more than three times the data from all other missions flown past the orbit of Earth’s moon combined. The orbiter pours data Earthward at up to 6 megabits per second. The data quality tells us how Mars’ environment diversity has changed over time.

The spacecraft launched from Florida on August 12, 2005 and entered orbit around Mars on March 10, 2006. Its primary science phase finished in 2008 and it continues investigations of Mars’ surface, subsurface, and atmosphere. The orbiter has found the surface water acted for hundreds of millions of years. This regional and possibly global extent was possibly intermittent. The spacecraft also observed signatures of watery environments. Some were acidic and some alkaline, increasing the possibility of past life. The orbiter instruments viewed half the planet at 20 feet per pixel, and nearly 1% of the planet at one foot per pixel, sharp enough to discern a desk. The radar has looked beneath the surface for half the planet.

So far everything it working well tonight. Attached is raw, unprocessed images of the Orion Nebula (1) and the Horsehead (2). Both are 10 minute exposures, no tracking issues tonight so far. (IMG:style_emoticons/default/greensmilie.gif)

Eight inch reflector with SBIG ST-7 ccd camera

http://www.space-travel.com/reports/ISRO_B...f_NASA_999.html

The article caught my eye because India has been conducting one space launch after another recently. It is amazing that they can do more with their space program than NASA can and yet NASA gets 30 times the money ISRO does.

Rather than make you go to the link to mouse around for the stellar names, I showed both images here.

 Deep_Auriga_1a_Tezel_Labeld.jpg ( 156.33K ) Number of downloads: 1

 Deep_Auriga_1a_Tezel.jpg ( 345.94K ) Number of downloads: 0