Fraser Cain, Author at Universe Today

October 23, 2007December 26, 2015 by Fraser Cain

Galaxy Caught Stealing Gas

Out there, in the darkness of space, a galaxy is committing a robbery. The robber, known as 3C 326 North is a galaxy the size of our Milky Way. Its victim contains about half the mass, and that’s going steadily down, because 3C 326 North is stealing some of its gas away.

The galactic interaction was revealed by NASA’s Spitzer Space Telescope. These kinds of interactions are common across the Universe; however, this is one of the clearest examples ever seen. The mass of more than a billion suns is being heated up and siphoned away, from the smaller galaxy to the larger one.

According to Patrick Ogle, a researcher at NASA’s Spitzer Space Center, “this could be an important phase in galaxy mergers that we are just now witnessing.”

Ogle and his collaborators were initially trying to study a set of distant objects called radio galaxies, located about a billion light-years away. These are named for the torrent of radio waves pouring out of the supermassive black holes at the centres of the galaxies. 3C 326 North was just the most extreme of the bunch.

When they studied the interacting pair further, they noticed it had a tail of stars, connecting the two objects together. Here’s Ogle again:

“The galaxy in question appears to be stripping a large quantity of molecular hydrogen from its neighbor and heating it up,” said Ogle. “The supermassive black hole at the center of the galaxy is digesting a small fraction of the gas and ejecting it in enormous, relativistic jets millions of light-years long.”

In the near future, the older, larger 3C 326 North will experience a second youth. The stolen gas will give it renewed pockets of star formation. The smaller 3C 326 South will have that youth stolen from it – it’ll no longer be able to form stars on its own. In the far future, the two galaxies may eventually merge, and then all will be forgiven.

Original Source: NASA/JPL/Spitzer News Release

October 23, 2007December 26, 2015 by Fraser Cain

Chandra Sees the Death of a Star in Detail

This absolutely beautiful object has a big of a bizarre name: G292.0+1.8. But don’t let that astronomical jargon throw you, you’re looking at a supernova remnant, captured by NASA’s Chandra X-Ray Observatory and ground-based observatories. It’s considered a textbook example of what remains after a massive star blows itself apart as a supernova. But it’s got a few surprises too.

Near the core of G292.0+1.8 is a pulsar wind nebula, revealed by the X-rays pouring out of it. This is the magnetized bubble of high energy particles that surround the rapidly spinning pulsar at the heart of the nebula. The pulsar is all that remains of the star before it detonated as a supernova.

Here’s one of the surprises. Instead of being right at the centre of the nebula, the pulsar is located slightly below and to the left. It possible that the supernova explosion was lopsided, and the recoil sent the pulsar shooting off to its current location. That would be a fine explanation, except the kick direction and pulsar spin direction aren’t aligned like you would expect.

Another interesting feature is that long white line running across the centre of the remnant called the equatorial belt. Imagine this is ring of material that unraveled from the star as it was coming apart. Once again, the orientation of this belt suggests that the parent star had the same spin axis before and after it exploded.

Astronomers find it puzzling that the remnant is missing thin filaments of high energy X-ray emission. These are thought to be a source of cosmic ray acceleration, and have been seen in many other well known supernova remnants. It’s possible that G292.0+1.8 is just too old now, and that stage only happens when the remnant is young.

Original Source: Chandra News Release

October 23, 2007December 26, 2015 by Fraser Cain

Liftoff for Discovery, STS-120 is Underway

NASA’s space shuttle Discovery blasted off from Florida’s Cape Canaveral today, beginning the next construction mission to the International Space Station: STS-120. This time around, the 7-astronaut crew will deliver and help install the new Italian-made Harmony module, which will serve as a sleeping area and provides connections to upcoming European and Japanese science laboratories.

Although today’s launch was on schedule – Discovery lifted off at 11:38 a.m. EDT – there were a few nagging concerns. A worrying amount of ice built up on the orange external fuel tank as it was being filled with liquid oxygen and hydrogen. Safety officials were worried that it could shed ice during the launch and hit the shuttle, but engineers eventually ruled it out as a risk.

There was also a concern about the shuttle’s heat shields. Once again, safety officials were worried that heat tiles on the shuttle’s wings were getting a little worn, and could pose a risk during re-entry. Engineers met and decided that it wouldn’t be a risk to shuttle or crew safety.

If all goes well, Discovery will spend a total of 14 days in space. The 7 astronauts on board the shuttle will meet up with the crew of the International Space Station. Over the course of the mission, they’ll perform 5 spacewalks. And installing the Harmony module is probably one of the easier tasks. The more complex task will be shuffling around the station’s P6 solar panel array.

Discovery is expected to reach the station on Thursday at 8:35 a.m. EDT.

Original Source: NASA Shuttle Site

October 17, 2007December 26, 2015 by Fraser Cain

Discovery Set to Launch October 23rd

NASA announced today that the space shuttle Discovery has been officially targeted for an October 23rd launch. If all goes well, the shuttle will blast off from Florida’s Cape Canaveral at 11:38 a.m. EDT, carrying 7 astronauts into space to meet up with the International Space Station – mission STS-120 will be on its way.

There was a slight safety concern that might have held back the launch. NASA’s Engineering and Safety Center had raised awareness that there might be a problem with the reinforced carbon on three of Discovery’s wing leading edge panels. Agency officials met to discuss the situation, and decided that the panels didn’t need to be replaced before the mission.

During their 14 days in space, the shuttle crew will install the new Harmony module onto the International Space Station. This will serve as a hub for future international laboratories.

The crew will have their work cut out for them, though. They’re scheduled to make 4 spacewalks, and the station crew will complete one as well.

Discovery is expected to return back to Earth on November 6th.

Original Source: NASA Shuttle News

October 17, 2007December 26, 2015 by Fraser Cain

Heaviest Stellar Mass Black Hole Discovered

Black holes come in two varieties: supermassive and stellar. The supermassive variety can have millions of times
the mass of a star, while the stellar varieties are usually just a few times the mass of a single sun. Using the Chandra X-Ray Observatory, astronomers have turned up the most massive stellar mass black hole ever seen, weighing in at 15.7 times the mass of the Sun, lurking in a nearby galaxy.

M33 is a relatively nearby galaxy, located only 3 million light years from Earth. This newly discovered black hole has been designated as M33 X-7.

Astronomers using NASA’s Chandra X-Ray Observatory and the Gemini telescope on Mauna Kea were able to precisely determine the black hole’s mass because it’s actually in a binary system. Its binary partner is unusual too; a star with 70 times the mass of the Sun.

M33 X-7 orbits its companion star every 3.5 days, briefly passing behind it. This blocks the torrent of X-rays streaming from the environment around the black hole, so that astronomers were able to calculate its orbit. Once they could calculate the orbits of the two binary objects, it’s relatively straightforward to calculate their respective masses.

The fate of the companion star will eventually match its partner. “This is a huge star that is partnered with a huge black hole,” said coauthor Jeffrey McClintock of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. “Eventually, the companion will also go supernova and then we’ll have a pair of black holes.”

Although the black hole has less mass today, it must have started out with more. With more mass in the original star, it would have consumed its fuel more quickly, and detonated as a supernova earlier.

Here’s a puzzle, though. Before the black hole formed, the two stars wouldn’t have been able to orbit so closely. In fact, they would have been orbiting inside each other. This means that they were once further apart, and the process of sharing their outer atmospheres brought their orbits closer together.

Original Source: Chandra News Release

October 16, 2007December 26, 2015 by Fraser Cain

Mars Rovers’ Mission Extended Yet Again

NASA originally expected they’d only last a few months, but the plucky Martian rovers are still crawling across the surface of Mars – more than 3 years later. So the agency has gone ahead and extended their missions… again. This is the fifth time NASA has extended their mission, keeping them operational potentially through 2009.

The twin rovers landed on the surface of Mars in January, 2004. Mission planners expected that it would only take a few months before dust coated the rovers’ solar panels so thickly that they wouldn’t be able to generate power any more. But the Martian weather had a trick; dust devils and wind gusts came by often enough to keep the solar panels relatively clear of dust. Without the loss of power looming, the rovers have been able to keep going, and going, and going.

Their accomplishments to date have been staggering. So far, Spirit has driven a total of 7.26 kilometers (4.51 miles) and has returned more than 102,000 images. Opportunity has driven 11.57 kilometers (7.19 miles) and has returned more than 94,000 images.

Opportunity turned up evidence of the planet’s watery past, when oceans affected rocks for long periods of time, and deposited layers of material. Spirit also found that water altered the mineral composition of the rocks and soil in its surroundings. The rovers have been instrumental in helping scientists understand the Martian dust devils. And both have discovered metallic meteorites sitting the surface of the Red Planet. One of these has a similar composition to the meteorite that reached Earth from Mars.

Original Source: NASA/JPL News Release

October 16, 2007December 26, 2015 by Fraser Cain

Maunder Crater on Mars

Seen one Martian crater and you’ve seen them all right? Well, check this one out. It’s an image of Maunder Crater on the surface of Mars, captured by ESA’s Mars Express. Although the crater is large, 90 km (56 miles) across, it’s very shallow – less than a kilometre. It used to be much deeper, but some geologic process has since filled it in.

The images of Maunder crater were captured in late 2005 by Mars Express at a resolution of roughly 15 metres per pixel. The crater, named after British astronomer Edward W. Maunder, is located about halfway between Argyre Planitia and Hellas Planitia on the southern Highlands of Mars.

It once looked like a more traditional crater, but then something happened on the west side to make it cave in. A large landslide pushed material from the crater wall to the inner portion. The edges of the crater that remain show gullies that could have been created when large amounts of material was flowing down into the crater.

One intriguing discovery: there are gullies along the upper side of the trough in the middle of the crater that have been caused by seeping water.

Original Source: ESA News Release

October 16, 2007December 26, 2015 by Fraser Cain

Nearby Galaxy is Older Than it Looks

Look at the picture associated with this story. It just looks like a pretty galaxy, right? Well, according to astronomers, it’s actually much older than it appears. This image, captured by the Hubble Space Telescope, provides one of the most detailed observations ever taken of I Zwicky 18 – a galaxy that looks younger than it should.

According to researcher, galaxies like I Zwicky 18 are much more common billions of light years away, at a time when the Universe was much younger than it is today. These baby galaxies still had large quantities of gas and dust they could use up to make new stars. Their young hot stars, composed largely of primordial hydrogen and helium manufactured during the Big Bang, burn brightly in the blue end of the visible light spectrum.

Older galaxies, like our own Milky Way have had plenty of time to use up those primordial elements, mixing in heavier elements with generation after generation of supernovae.

Astronomers used to think that I Zwicky 18 was a rare example of a nearby, newly forming galaxy. Located only 59 million light-years from Earth, this galaxy could be used as a sort of time machine, to see the stages that galaxies went through early on in their evolution.

Well, the new observations from Hubble have dashed those hopes. I Zwicky 18 is old, possibly as old as the Milky Way, forming its first stars up to 10 billion years ago. With its sensitive instruments, Hubble was able to spot previously hidden red, older stars, showing that the galaxy has been forming stars for billions of years.

So how is it possible that such an old galaxy still has large quantities of primordial hydrogen and helium, but we see rapid star formation today? It’s possible that the galaxy has just been going slowly, forming stars at a dramatically reduced rate in the past. But something kicked that rate of star formation into high gear in the recent past.

Original Source: Hubble News Release

October 15, 2007January 24, 2021 by Fraser Cain

Astrosphere for October 15th, 2007

For the photo, we’ve got this wonderful image of M31 (the Andromeda Galaxy) by John Chumack.

Now, before we get rolling with today’s episode, I’d like to encourage you to subscribe to Universe Today. Instead of coming here regularly, just subscribe so you find out when I’ve updated the site, automagically. There are two ways – both free, of course – to do this. One is to subscribe to the email subscription. Just put your email into the box on the right there, and you’ll get the latest stories by email every day. The second way is with a feed reader, such as Google Reader. Set up a Google Reader account, and then subscribe to the Universe Today feed. Here’s the URL: http://www.universetoday.com/universetoday.xml.

Once you get your news through a feed, you’ll never go back.

Centauri Dreams considers the controversy of whether we should try and signal extraterrestrial civilizations.

Now all your work on the Galaxy Zoo is starting to pay off. The Universe might be lopsided.

The Bad Astronomer explains how valuable contributions to astronomy come from amateurs.

We’re just 5 days away from the Space Elevator Games. I sure wish I could attend them.

The astropixie suggests you try and spot Mercury this week. It’s not an easy challenge.

Scientific American’s blog has posted computer desktop images of Iapetus, in a variety of convenient sizes.

Do you have a space-related blog? Email me your URL, and I’ll start watching you. Write something interesting, and I’ll link to it.

October 12, 2007January 24, 2021 by Fraser Cain

Astrosphere for October 12th, 2008

We’re rapidly approaching Mars, so it’s only appropriate to make that the astrophoto of the day. This image was captured by Kyle Edwards.

First, let me draw your attention to the Carnival of Space. This week it’s being held at Space for Commerce. No entry from me this week. I really need to get more organized about that.

From HobbySpace we learn that NASA is restarting its suborbital rocket and balloon programs. These are surprisingly cost-effective ways to gather science.

Remember that X-Wing model that came apart on launch? Here’s a theory about what might have brought it down.

Look out Moon, here comes another mission. This time, from China.

When Cassini’s mission comes to an end, it’ll probably be dropped down into Saturn to gather some final science. If you think the loonies are going to predict that this will somehow ignite Saturn, you don’t need to wait. They already think this.