Clipmarks | Rustee's 'astronomy' clips

Here on Earth, Nature recycles rocks, dead plants and animals, and just about everything else. But out in the universe, it may recycle entire planets.

An example is a system known as PSR 1257+12 -- the first confirmed planets discovered outside our own solar system. The system contains three planets that are roughly comparable to Earth -- fairly small, and probably made of rock.

The original star was a supergiant -- much bigger, heavier, and hotter than the Sun. It lived a short but dazzling life, then blasted itself to bits as a supernova.

The star's core collapsed to form a neutron star -- an object that's several times as massive as the Sun, but no bigger than a city.

When the star exploded, any distant planets might have been hurled away at breakneck speeds. But planets at close range would have been pulverized. So the planets in the system today weren't always there. They probably formed from the debris left over from the blast -- a case of recycling on a gigantic scale.

Tags: science, astronomy

Magnetic Rain

Fri, 23 May 2008 05:46:20 GMT

clipped by: Rustee
clipper's remarks: Texas sized blobs eh? Whoa.

Clip Source: spaceweather.com

MAGNETIC RAIN: There's a rainstorm underway on the sun's eastern limb. You'd better bring your asbestos umbrella, though, because the "droplets" are Texas-sized blobs of hot plasma:

Prominences are clouds of hydrogen held above the surface of the sun by magnetic fields. While this particular cloud appears to be raining like a summer shower on Earth, the true situation is more complicated. Look carefully: Some of the plasma raindrops are falling "up." That's because the motions are controlled by not only gravity but also magnetism, a force of little importance in terrestrial rainstorms. The solar magnetic field is rooted below the sun's visible surface; roiling motions in the body of the sun itself cause magnetic fields high overhead to shift, wriggle, and "rain" in all directions. No wonder prominences are so much fun to watch.

Tags: science, astronomy, sun

Listen to the Aurora

Tue, 20 May 2008 05:49:55 GMT

clipped by: Rustee
clipper's remarks: Lots of samples at the source.

Clip Source: www-pw.physics.uiowa.edu

"Natural Radio" describes naturally-occurring electromagnetic (radio) signals emanating from lightning storms, aurora (The Northern and Southern Lights), and most importantly, the Earth's magnetic-field (the Magnetosphere).

This is a presentation of Earth's natural radio emissions that occur in the extremely-low-frequency to very-low-frequency (ELF-VLF) radio spectrum--specifically, at AUDIO frequencies between approximately 100 to 10,000 cycles-per second (0.1 - 10 kHz).

PUWHS2.WAV

Tags: science, physics, astronomy

Birth of Radio Astronomy

Sat, 03 May 2008 18:44:09 GMT

clipped by: Rustee
clipper's remarks: This now includes seeing some of it visually as "snow" on televisions. Yet with the new transition to digital tv coming next year (in the U.S. at least), I wonder if "snow" will be a thing of the past?

Clip Source: stardate.org

The Milky Way glows in just about every form of energy, from radio waves to X-rays. In fact, the discovery of radio waves from the Milky Way made headlines 75 years ago this month.

Bell Labs had assigned a young engineer named Karl Jansky to check out sources of static on the radio waves used for long-distance radio transmissions.

Jansky found that most of the static came from thunderstorms. But there was a “hiss” that he couldn’t explain. It peaked once a day, so he first thought it came from the Sun.

After tracking it for a few months, though, Jansky found that the signal peaked about four minutes earlier each day. Since the distant stars rise and set four minutes earlier each day, Jansky concluded that the static came from the stars. The strongest signal came from the Milky Way -- and particularly from the constellation Sagittarius, which is home to the galaxy’s heart.

Clip Source: antwrp.gsfc.nasa.gov

The Galactic Center Radio Arc

Tags: astronomy, science, energy

Dark Stars

Wed, 23 Apr 2008 01:29:11 GMT

clipped by: Rustee
clipper's remarks:

The study says that particles of dark matter may have interacted with each other, producing other particles that heated the collapsing clouds. The heat kept the clouds from shrinking enough to ignite nuclear fusion.

Clip Source: stardate.org

One thing that all stars have in common is that they are bright.

But it could have been quite different in the very early universe. In fact, a recent study says that the earliest stars could have been gigantic but invisible.

The study was led by Paolo Gondolo of the University of Utah. It found that the first stars in the universe might have been kept dark by dark matter -- matter that produces no energy, but that exerts a gravitational pull on the normal matter around it.

Stars are born when giant clouds of gas collapse. When the gas gets packed tightly enough, it ignites the fires of nuclear fusion, and the star shines brightly.

But conditions in the first few hundred million years after the Big Bang were quite different. The universe was much smaller, so everything was packed tighter. As stars began to form, they contained high concentrations of dark matter.

So instead of the glowing orbs we see today, this early process formed giant dark stars.

Tags: astronomy, science

2300 Year Old Model Airplane

Fri, 11 Apr 2008 03:03:50 GMT

clipped by: Rustee
clipper's remarks:

Did anyone actually build a large version of this thing? Well, no one could have come this close to the real shape of flight without working on a larger scale. This little wooden model could hardly exist unless someone had worked with large, light models, or even with man-carrying versions.

Archaeologists have looked in vain for a prototype. A large model light enough to fly would be too delicate to stand the ravages of 2300 years. The original -- if it ever was -- has long since joined the desert dust. Whatever form this Egyptian airplane might have taken, it has long since returned to the world of dreams and imagination from which it first came.

Clip Source: www.uh.edu

The ancient bird models in the Cairo Museum were all pretty similar. Only one in the set was wrong.

In 1969 Khalil Messiha, an Egyptian doctor and amateur student of bird models, noticed it.

This wasn't a bird at all. It was a model airplane, and that wasn't possible.

The other birds had legs. This had none. The other birds had painted feathers. This had none. The other birds had horizontal tail feathers like a real bird.

This strange wooden model tapered into a vertical rudder.

It was all aerodynamically correct. Too much about the model was beyond coincidence.

The model was dug up in Sakkara a hundred years ago. Sakkara is a site of ancient ruins, but this model is more recent. It's from the 3rd century BC, from an age of invention that followed the death of Alexander the Great. That so-called Hellenistic period gave us gears, screws, plumbing, control valves, Euclidian geometry, Archimedes, and Ptolemy's astronomy.

And so, it seems, it also produced a modern concept of flight.

Tags: history, egypt

Red Supergiant All Puffed Up

Fri, 11 Apr 2008 01:31:18 GMT

clipped by: Rustee

Clip Source: stardate.org

Sometimes astronomical numbers are so immense that they’re simply, well, astronomical.

Consider a star known as Pi Puppis. It’s classified as a red supergiant. It’s more than a dozen times as massive as the Sun, but it’s a good bit cooler, so its surface glows orange. The star’s already entering the last stages of life, and fairly soon, it may explode as a supernova.

If it took the Sun’s place in our own solar system, it would extend almost all the way out to the orbit of Mars.

Since stars are big balls, not disks, Pi Puppis would extend far above the plane of the solar system, too.

But remember that Pi Puppis is only around a dozen times more massive than the Sun. When you compare the size and mass, you realize that Pi Puppis is just a puffed-up gasbag. Its outer layers are so thin that they’re hardly more than a vacuum. With the right kind of shielding, you might be able to fly a spaceship fairly deep into the star and come back out again -- a journey through an astronomical giant.

Tags: astronomy, space, science

Suspected Medium-Sized Black Hole in Omega Centauri

Sat, 05 Apr 2008 05:14:20 GMT

clipped by: Rustee
clipper's remarks:

Although the presence of an intermediate-mass black hole is the most likely reason for the stellar speedway near the cluster’s center, the astronomers said they have not ruled out a couple of other possible causes.

Clip Source: www.randybrewer.net

Clip Source: mcdonaldobservatory.org

A well-known star cluster that glitters with the light of millions of stars may have a mysterious dark object tugging at its core, according to researchers at The University of Texas at Austin.

Astronomer Karl Gebhardt has teamed up with recent Ph.D. graduate Eva Noyola to find evidence for a medium-size black hole at the core of Omega Centauri, one of the largest and most massive globular star clusters orbiting the Milky Way galaxy. The finding will appear in the April 10 issue of The Astrophysical Journal.

The black hole in Omega Centauri is estimated to be about 40,000 times the mass of the Sun, falling in between the masses of supermassive black holes at the hearts of galaxies like the Milky Way and stellar-mass black holes that result when the most massive stars explode as supernovae.

Measuring the speed of the stars swirling near the cluster’s center with the Gemini Observatory, the astronomers found that the stars closer to the core are moving faster than the stars farther away.

Tags: astronomy, science

Geriatric Star Giving Birth

Wed, 02 Apr 2008 01:17:40 GMT

clipped by: Rustee
clipper's remarks:

There’s no evidence of planets around BP Piscium, but the disk could be giving birth to some — a new generation of planets for a geriatric star.

Clip Source: stardate.org

The Sun is moving through Pisces this month, so the constellation’s stars are hidden in the Sun’s glare. One of those hidden stars is known as BP Piscium, and it’s a bit of an oddball. It appears to be an old star that’s giving birth to new planets.

The star itself is about twice as massive as the Sun. Its composition and gravity indicate that it’s late in life, so it’s puffed up like a big balloon.

But a research team led by astronomers at UCLA found that most of the energy that we receive from BP Piscium appears to come from a giant disk of dust that encircles the star.

Disks like these are the birthplaces of planets. But planets should form around young stars — not old, bloated ones like BP Piscium.

The astronomers who studied BP Piscium and a similar star suggest that it started life with a small companion star in a close orbit. But as BP Piscium aged, it puffed up and engulfed its smaller sibling.

This material has since formed a disk, which is growing thicker.

Tags: astronomy, science

Most Massive Black Hole has a Companion?

Tue, 25 Mar 2008 04:20:38 GMT

clipped by: Rustee
clipper's remarks: The next outburst is due in about 8 years, and they'll be watching.

Clip Source: stardate.org

It’s hard to think of a black hole that’s a hundred million times as massive as the Sun as little. But in a distant quasar known as OJ 287, that may be the case. According to a team of astronomers that studied the system, the black hole appears to orbit another black hole that’s the most massive yet discovered — 18 billion times the mass of the Sun.

But twice every 12 years, it flares up. Each outburst lasts a few days.

Although many astronomers are skeptical, an international team says the flareups and other evidence suggest that the system consists of two giant black holes. The smaller one orbits its bigger cousin once every 12 years. Its orbit is stretched out, and it’s tilted. So twice during each orbit, it passes through the hot gas surrounding the bigger black hole, causing the flareups.

The team tested this model last year. It predicted that a flareup would occur on September 13th — and it came right on cue, bolstering the model of how OJ 287 works.

Tags: astronomy, space, science

Knotted Galactic Embrace

Sun, 23 Mar 2008 04:43:49 GMT

clipped by: Rustee
clipper's remarks: Est. to be 100 million light years away in the direction of Pisces.

Clip Source: www.gemini.edu

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NGC 520 has a unique shape that is the result of two galaxies colliding with each other. One galaxy’s dust lane can be seen easily in the foreground and a distinct tail is visible at bottom center. These features are a result of the gravitational interactions that have robbed both of the galaxies of their original shapes. Some astronomers speculate that each member of the pair was originally similar to the Milky Way and Andromeda Galaxy. This collision could be providing us a glimpse at what might happen to our own galaxy in about five billion years as the Andromeda Galaxy collides with our Milky Way.

Hints of star formation (faint red glowing areas above and beneath the middle of the image) may have become more pronounced during the course of the collision.

Many background galaxies also appear in this image. They represent galaxy evolution at an even earlier epoch in the history of the universe.

Tags: astronomy, science, space

Supernova Remnants in the LMC

Sun, 23 Mar 2008 04:38:08 GMT

clipped by: Rustee
clipper's remarks: The Large Magellanic Cloud is a sister satellite galaxy to our Milky Way and lies about 160,000 light-years away.

Clip Source: www.gemini.edu

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The Gemini South Multi-Object Spectograph (GMOS) recently captured a dramatic image of a vast cloud complex named DEM L316 located in the Large Magellanic Cloud. The peanut-shaped nebula appears to be a single object, but the latest research indicates that it is really comprised of two distinct gas and dust clouds formed by different types of supernova explosions.

The object was first recognized in the early 1970s as a supernova remnant, a type of object that is enriched with elements created in stellar explosions. The nebula was likely created a few tens of thousands of years ago by more than one type of supernova exploding in this region of the Large Magellanic Cloud.

The DEM L316 nebula is located within the LMC and its two bubbles extend over a distance of about 140 light-years (roughly 35 times larger than the distance between our Sun and its nearest stellar neighbor).

Tags: astronomy, science, space

N44 - Interstellar Cavern

Sun, 23 Mar 2008 04:26:06 GMT

clipped by: Rustee
clipper's remarks:

The image provides one of the most detailed views ever obtained of this relatively large region in the Large Magellanic Cloud, a satellite galaxy to the Milky Way, located some 150,000 light-years away and visible from the Southern Hemisphere.

Clip Source: www.gemini.edu

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Known as the N44 superbubble complex, this cloudy tempest is dominated by a vast bubble about 325 by 250 light-years across. A cluster of massive stars inside the cavern has cleared away gas to form a distinctive mouth-shaped hollow shell. While astronomers do not agree on exactly how this bubble has evolved for up to the past 10 million years, they do know that the central cluster of massive stars is responsible for the cloud's unusual appearance. It is likely that the explosive death of one or more of the cluster’s most massive and short-lived stars played a key role in the formation of the large bubble.

Multiple smaller bubbles appear in the image as bulbous growths clinging to the central superbubble.

Our view into this cavern could really be like looking through an elongated tube, which lends the object its monstrous mouth-like appearance.

Tags: astronomy, space, science

What Does a Gamma-Ray Burst Look Like?

Sun, 23 Mar 2008 03:40:17 GMT

clipped by: Rustee

Clip Source: www.popsci.com

The universe’s most powerful explosions are, without parallel, those of gamma-ray bursts. A single such burst releases as much energy as a ten million billion suns. Short gamma-ray bursts lasting only a fraction of a second occur when two neutron stars or black holes collide. Long gamma-ray bursts of more than two seconds happen in connection with very powerful supernovae. This picture shows a long gamma-ray burst—in the form of a jet of gamma radiation—10 seconds after it was ejected by a heavy star that collapsed into a supernova. The image was created by a supercomputer at Lawrence Berkeley National Laboratory. The blue, red and yellow colors represent gamma-ray density, with blue the lowest and yellow the highest.

Tags: astronomy, space, science