The Astronomy Thread

[American Horse]

There are two critical things which affect our ability to see astronomical events. They are timing (day lit sky versus night) and weather or cloud cover, (not to mention local light pollution. And both of those are determined by location.

At about 6:45 this evening EST (7:45 EDT), there will be a naked eye occultation of a 2.9 magnitude star (Mu Geminorum aka TEJAT aka ZC976).

Even an ordinary event in which the star disappears behind the dark limb of the moon is worth watching, but those events in which your view is along the “grazing path” are thrilling. A view along the grazing path will show the star blinking and reappearing from behind hills and mountains on the moon. In the more ordinary event, as this one will be, the bright star will disappear behind the dark edge of the moon, and an hour and some 20 minutes later it reappears on the other side.

The disappearance in Baltimore, Md. as an example on the east coast, will begin with disappearance at (23h 54m 36s UT) 7:54 pm EDT, and end with Tejat’s reappearance at (01h 16m 39s UT) 9:16 pm EDT.
Here’s Website called The International Occultation Timing Association with a CHART giving times at locations in the US which can observe this evening’s occultation.

Further west in Chicago, it will begin in daylight, with Tejat’s disappearance at 6:33 pm CDT, with reappearance at 7:58 pm CDT, an hour after local sunset.

These are always more fun to watch with a good set of binoculars. The moon will be just east of it’s highest point or the zenith.

Below is a map of the viewing path of the occultation

 

[jasonmorston]

like the neat solar system model. i say we add the solar plasma though. the body of the heliosphere.
ever notice all depictions of the solar system portray balls spinning in empty space? not very accurate. that space is full of high energy hydrogen and helium particles, gamma rays, xrays and plasma here is a cool link with info on taking power from the solar wind (you can use magnetohydrodynamics!)
Cosmic Electrodynamics

 

[American Horse]

like the neat solar system model. i say we add the solar plasma though. the body of the heliosphere.
ever notice all depictions of the solar system portray balls spinning in empty space? not very accurate. that space is full of high energy hydrogen and helium particles, gamma rays, xrays and plasma here is a cool link with info on taking power from the solar wind (you can use magnetohydrodynamics!)
Cosmic Electrodynamics

There's a lot of stuff out there we can't see "visually" so when we make visual representations if makes sense we would not show stuff we can't see. I don't doubt that our scientists do visualize those forces and radiation.

Space, even out in interstellar space is a lot more crowded and risky for space travel than we have been led to believe. To reflect on the fact that two galaxies can collide and no two stars within those colliding galaxies will likewise collide is to miss the extent of the dangers.

A large part of the matter in the universe or more specifically our own galaxy is already coalesced into unified objects like stars, planets, planetesimals, comets, etc. But the remainder, that which has not coalesced into those large easily seen objects (some not so easily seen) is spread out, and can be anywhere.

We see dark areas in front of fields of stars that diminish the starlight measurably and those are the denser areas that we can see. Giant molecular clouds are compressed by gravity waves on the leading edges of galactic spiral arms, and show up as glowing brilliantly from the star formation. That's a lot of previously "dark matter" being pushed, pulled, and compressed into gravitational collapse to form those stars. Consider how much interstellar “material" goes into forming a single star, and then all of it that is still at large.

Because of that space travel at velocities approaching large fractions of the speed of light are going to be very dangerous. I remember that the first interstellar space craft theorized were prudently designed to have "dusters" out in front (way away out in front) to neutralize any dust or gas before it was impacted by the craft.

Maybe our cosmologists and astronomers can come up with a Grand Unified Theory (of everything) that will provide us with the answers that will make space travel possible between the stars.

 

[xsited1]

House-Sized Asteroid Buzzes By Earth

It passed the planet at a distance of about 203,000 miles at about 5:49 pm.

NASA announced the flyby on Twitter.

Although large, the rock in space would have burned up in the atmosphere before doing damage.

House-Sized Asteroid Buzzes By Earth | Gather

 

[American Horse]

Mercury will reach it's greatest eastern elongation in the sky March 22, which happens to be today's date.

Mercury never gets far enough away from the sun to be seen in a totally dark sky. Being at its greatest eastern elongation means that it is visually as far from the sun as we can usually expect to see.
Look in the southwest just after sunset. At magnitude –0.3 Mercury will be the brightest object in this region of the sky, since Jupiter will have sunk deep into the twilight glow from the sun since the middle of the month.

It will be a little less than half lit as seen through a good set of binoculars.

 

[pAr]

The Crab Supernova was recorded by Korean, Chinese, Japanese, Native Americans, and Persian/Arab astronomers as being bright enough to see in daylight for 23 days in 1054 AD.

SN 1054 - Wikipedia, the free encyclopedia

 

[American Horse]

<<THE SUMMER SKY>> A FULL PANORAMIC VIEW OF THE NIGHT SKY as seen from Utah (of all places I personally like to see it from!)


Theres a tool for showing the constellations and cardinal directions.

Before you click on it you might want to press F-11 to clear your screen of tool-bars (hit again when done to undo)

 

[xsited1]

Technology News: Space: Brown Dwarf Star Is as Cool as They Come

A brown dwarf star about 75 light years from Earth has been identified as the coldest star ever observed. It runs at a temperature of about 100 degrees Celsius -- just enough to boil water but far colder than the blazing temperature of a normal star. It's not an example of a star that burned bright for some time before running out of gas; astronomers say it was never very hot to begin with.

Now that's cool!

 

[xsited1]

Here's a picture of Comet Hyakutake that I took with a basic 35mm camera at the Grand Canyon in April of 1996. Bright comets likes these don't come around too often.



(click image for bigger picture)

Comet Hyakutake Home Page (JPL)
Comet Hyakutake - Wikipedia, the free encyclopedia

 

[xsited1]

--> Historic Photos Reveal a Mercury Never Seen Before

NASA's MESSENGER spacecraft on Tuesday and Wednesday captured and delivered to Earth the first photographs of Mercury ever taken from within the planet's orbit.

 

[xsited1]

Boeing 747-based observatory studies star formation | Boeing and Aerospace News - seattlepi.com

The Stratospheric Observatory for Infrared Astronomy, or SOFIA, is the world’s only operational airborne observatory, flying at 39,000 to 45,000 feet to get above atmospheric water vapor that blocks most infrared radiation from celestial sources.

NASA - SOFIA

Pictures --> NASA - SOFIA Image Gallery

 

[Ernie S.]

Both Venus and Jupiter can be seen in daylight with the naked eye, at least for an hour or so after sunrise if they are high in the sky or to the west.
Get to your observing site before dawn and follow your object's movement. It's easier if you sit under a tree in winter when there are no leaves so you can use a branch as reference as the sky brightens. I've managed seeing Jupiter for a little over an hour after dawn.
I've found both Venus and Jupiter at mid day with 10x50 binolulars

The OP mentions the 24" Clark at Lowell. I've been fortunate to use the 20" Clark at Van Vleck. I actually owned a 4" Clark for a few days maybe 20 years ago. I gave $200 for it at a tag sale in New Cannan CT. I sold it to a fellow Astronomical Society member for 4 grand

 

[xsited1]

Both Venus and Jupiter can be seen in daylight with the naked eye, at least for an hour or so after sunrise if they are high in the sky or to the west.
Get to your observing site before dawn and follow your object's movement. It's easier if you sit under a tree in winter when there are no leaves so you can use a branch as reference as the sky brightens. I've managed seeing Jupiter for a little over an hour after dawn.
I've found both Venus and Jupiter at mid day with 10x50 binolulars

The OP mentions the 24" Clark at Lowell. I've been fortunate to use the 20" Clark at Van Vleck. I actually owned a 4" Clark for a few days maybe 20 years ago. I gave $200 for it at a tag sale in New Cannan CT. I sold it to a fellow Astronomical Society member for 4 grand

Now this is an amazing story. Somebody was selling a Clark Refractor in CT for $200? That just blows my mind. For more information about them, check this out:

Alvan Clark and Sons

The Clark family built their first telescope in 1844 when the eldest son George brought home a broken dinner bell from school, and melted the metal down to create a mirror for a reflecting telescope. His father, Alvan, became so interested in the project that telescope creation became a hobby that within two years evolved into a family business that endurd for nearly a hundred years.

Clark refractors

 

[Old Rocks]

An interesting site to explore;

Zooniverse - Real Science Online

 

[waltky]

Mebbe the good Lord sewed the universe together...

Did the universe begin as a slender thread?
April 22, 2011 - A new framework for the universe's formation suggests that it began as a single thready line, then evolved into a plane, and only then the three-dimensional space we now inhabit. This could simplify sticky cosmological questions, including dark matter and gravity waves.

A universe expanding faster than it ought to be? What's up with that? To Dejan Stojkovic, the phenomenon astrophysicists discovered in 1998 and labeled "dark energy" may not be as complicated a puzzle as many scientists make it out to be. Instead, he suggests, it's the signal that a fourth dimension – beyond the height, width, and depth humans are geared to experience – has opened up in a universe that is adding physical dimensions as it evolves. This possible explanation for dark energy results from applying a new "framework" for looking at the evolution of the universe that he and colleagues have developed over the past two years. Working backwards in time, the concept also implies that the universe did not begin its existence in a three-dimensional form, but as a one-dimensional structure that added dimensions as it evolved.

Some support for this may be found in high-energy cosmic rays, according to Dr. Stojkovic, a physicist at the State University of New York at Buffalo, who along with colleagues first proposed the idea last year. In a paper published recently in Physics Review Letters, Stojkcovic and colleague Jonas Mureika of Loyola Marymount University in Los Angeles write that further tests of the framework's validity could come from the Large Hadron Collider in Geneva as well as from planned space missions to detect gravity waves thought to be rippling through the cosmos.

If he and his colleagues are correct, Stojkovic says, their work could help break a 30-year logjam in efforts to demonstrate that the four fundamental forces in nature – electromagnetism, the weak force (governing radioactive decay), the strong force (binding atomic nuclei), and gravity – are low-energy relics of one unified force that briefly held sway over the cosmos during the first, tiniest fractions of a second after the big bang. The big bang is a sudden release of an enormous amount of energy that physicists and cosmologists credit with giving birth to the universe some 13.8 billion years ago.

Gravity remains the stubborn hold-out in this grand-unification effort. It's the only one of the four forces that has defied an explanation within the so-called standard model of physics. As the decades have passed, many researchers have developed ever more complicated ideas to fit gravity into the quantum-physics world inhabited by the rest of the forces and their associated subatomic particles. Scientists' calculations suggest that the solution may lie in "new physics" – beyond the standard model. Stojkovic is part of a subgroup of physicists collectively tapping their "new physics" colleagues on the shoulder and saying: The solution many not require new physics at all, but merely a new way of looking at the standard model.

MORE

 

[Mr. H.]

Six Planets Now Aligned in the Dawn Sky - Yahoo! News

If you get up any morning for the next few weeks, you&#8217;ll be treated to the sight of all the planets except Saturn arrayed along the ecliptic, the path of the sun through the sky.

For the last two months, almost all the planets have been hiding behind the sun, but this week they all emerge and are arrayed in a grand line above the rising sun. Mercury, Venus, Mars, and Jupiter are visible, and you can add Uranus and Neptune to your count if you have binoculars or a small telescope.

 

[asterism]

Saturn tonight.

It's blue because my version of Avidemux does that sometimes. Not sure why.

Reprocessed without Avidemux.

 

[waltky]

Looks like a cowpie to Granny...

4.5 billion-year-old meteorite yields new mineral
5/6/2011 : Krotite was formed when solar system was in its infancy, scientists say

A 4.5 billion-year-old meteorite from northwest Africa has yielded one of the earliest minerals of the solar system. Officially called krotite, the mineral had never been found in nature before, though it is a human-made constituent of some high-temperature concrete, according to study researcher Anthony Kampf, curator of Mineral Sciences at the Natural History Museum of Los Angeles County. "This is one that simply was not known in nature until we found it here," Kampf told LiveScience. "That's pretty dramatic."

The meteorite containing krotite is called NWA 1934 CV3 carbonaceous chondrite. Chondrites are primitive meteorites that scientists think were remnants shed from the original building blocks of planets. Most meteorites found on Earth fit into this group. The mineral, a compound of calcium, aluminum and oxygen, needs temperatures of 2,732 degrees Fahrenheit (1,500 degrees Celsius) to form, supporting the idea that it was created as the solar nebula condensed and the planets, including Earth, were formed, the researchers say. The tiny mineral sample — just 0.2 inches (4 millimeters) long — came from a grain in the meteorite dubbed "cracked egg" for its appearance. In addition to krotite, the cracked egg grain contains at least eight other minerals, one of which is new to science, the researchers say.

Studying this mineral and other components of the ancient meteorite is essential for understanding the origins of the solar system, the scientists say. When meteors hit the ground they are called meteorites. Most are fragments of asteroids (space rocks that travel through the solar system), and others are mere cosmic dust shed by comets. Rare meteorites are impact debris from the surfaces of the moon and Mars.

Another ancient meteorite, this one discovered in Antarctica, also recently yielded a new mineral called Wassonite. The fact that krotite forms at such high temperatures and low pressure make it likely it is one of the first minerals formed in the solar system. The mineral is named after Alexander N. Krot, a cosmochemist at the University of Hawaii, in recognition of his significant contributions to the understanding of early solar-system processes. The finding is detailed in the May-June issue of the journal American Mineralogist.

4.5 billion-year-old meteorite yields new mineral - Technology & science - Science - LiveScience - msnbc.com

 

[waltky]

Cosmic wind blows galaxies apart...

Cosmic Storm Gives Astronomers New Insight Into Galaxy Formation
May 10, 2011 - The European Space Agency (ESA) says it has observed fast-moving cosmic storms of star-forming gases that will help scientists unravel some of the mysteries of how galaxies and stars form and continue to evolve.

ESA’s Herschel space telescope detected the unique galactic phenomenon.

Scientists working on the project say the fastest gas and dust outflows gust at an estimated 1,000 kilometers per second, 10,000 times faster than the winds in a hurricane on earth. The storms could rob a galaxy of its star-forming matter in less than 10 million years.

The Herschel telescope observation is important because it is the first time scientists have witnessed high-velocity storms clearing out the molecular raw materials from which stars form.

Source

 

[waltky]

Granny says it gonna wreck havoc with the tides anna mighty Mississippi gonna be flowin' backwards...

Six Planets Will Be Aligning, but the Earth Will Not End
11 May`11 - Good thing President Obama released his long-form birth certificate. Now we can all go back to worrying about an even greater threat than the possibility that the President is a Kenyan double agent: the much buzzed-about reports that the world is going to end in 2012.

It was the Mayans - or maybe the Romans or the Greeks or the Sumerians - who called the shot this time, evidently on a day Nostradamus phoned in sick. Apparently, a rogue planet named Nibiru (which frankly sounds more like a new Honda than a new world) is headed our way, with a cosmic crack-up set for next year. No matter who's behind the current prediction, there are enough people ready to spread and believe in this kind of end-of-the-world hooey that you have to wonder if the earth isn't starting to take things personally.

Regrettably, the Nibiru yarn got a boost in recent days with the very real announcement that an alignment of several of the very real planets will be taking place this month, offering a fleeting treat for stargazers willing to get up before sunrise and take a look. Even this genuine cosmic phenomenon, however, may be a bit less than it appears.

Beginning today and lasting for a few weeks, Mercury, Venus, Jupiter and Mars will be visible in the early morning sky, aligned roughly along the ecliptic - or the path the sun travels throughout the day. Uranus and Neptune, much fainter but there all the same, should be visible through binoculars. What gives the end-of-the-worlders shivers is that just such a configuration is supposed to occur on Dec. 21, 2012, and contribute in some unspecified way to the demolition of the planet. But what makes that especially nonsensical - apart from the fact that it's, you know, nonsense - is that astronomers say no remotely similar alignment will occur next year.

"Nothing bad will happen to the earth in 2012," NASA explains patiently - if wearily - on its website. "Our planet has been getting along just fine for more than 4 billion years, and credible scientists worldwide know of no threat associated with 2012."

MORE

See also:

Crab Nebula's gamma-ray flare mystifies astronomers
11 May 2011 : The Crab Nebula has shocked astronomers by emitting an unprecedented blast of gamma rays, the highest-energy light in the Universe.

The cause of the 12 April gamma-ray flare, described at the Third Fermi Symposium in Rome, is a total mystery. It seems to have come from a small area of the famous nebula, which is the wreckage from an exploded star. The object has long been considered a steady source of light, but the Fermi telescope hints at greater activity. The gamma-ray emission lasted for some six days, hitting levels 30 times higher than normal and varying at times from hour to hour.

While the sky abounds with light across all parts of the spectrum, Nasa's Fermi space observatory is designed to measure only the most energetic light: gamma rays. These emanate from the Universe's most extreme environments and violent processes. The Crab Nebula is composed mainly of the remnant of a supernova, which was seen on Earth to rip itself apart in the year 1054. At the heart of the brilliantly coloured gas cloud we can see in visible light, there is a pulsar - a rapidly spinning neutron star that emits radio waves which sweep past the Earth 30 times per second.

But so far none of the nebula's known components can explain the signal Fermi sees, said Roger Blandford, director of the Kavli Institute for Particle Astrophysics and Cosmology, US. "The origin of these high-energy gamma rays has to be some other source," he told BBC News. "It takes about six years for light to cross the nebula, so it must be a very compact region in comparison to the size of the nebula that's producing these outbursts on the time scales of hours."

Since its launch nearly three years ago, Fermi has spotted three such outbursts, with the first two reported earlier this year at the American Astronomical Society meeting. These events are unleashing gamma rays with energies of more than 100 million electron-volts - that is, each packet of light, or photon, carries tens of millions of times more energy than the light we can see. But the Crab's recent outburst is more than five times more intense than any yet observed.

'Big puzzle'