Universe Today

October 31, 2007December 26, 2015 by Fraser Cain

Three New Jupiter-Sized Planets Discovered

You know the science of planet hunting is getting mainstream when there’s very little fanfare for the discovery of 3 new extrasolar planets with the size of Jupiter. 3 new planets people! They’re named WASP-3, WASP-4, WASP-5, and were discovered by a European team of astronomers using observatories in South Africa and the Canary Islands.

The new planets were discovered using the SuperWASP instruments. These are high speed cameras affixed to two telescopes: SuperWASP-North at Roque de los Muchachos Observatory on the island of La Palma in the Canaries and SuperWASP-South at the South African Astronomical Observatory, South Africa. Both instruments are equipped with a detailed CCD camera array capable of monitoring up to 400,000 stars every minute.

They’re watching to see if any of those stars vary in brightness. If a star does get brighter and dimmer over a regular period, the astronomers can then determine if a planet is passing in front – an event known as a transit (or eclipse). Just by measuring the dimming, astronomers can then determine the size of the planet, and even some of its chemical constituents.

With this latest discovery, the three new planets all contain roughly the mass of Jupiter, but orbit much closer into their parent stars. They complete an orbit every 2 two days.

According to one of the discoverers, Dr Don Pollacco of Queenâ€™s Astrophysics Research Centre, “these are among the shortest orbital periods yet discovered. Being so close to their star, the surface temperatures of the planets will be more than 2000 C, so it is unlikely that life as we know it could survive there. However, the finding of Jupiter-mass planets around other stars supports the idea that there are also many Earth-sized planets waiting to be discovered as the technology employed by astronomers improves.â€?

Even a relatively tiny planet the size of the Earth should visibly dim the light from a star as it passes in front. This is an exciting technique that should just get better and better over time.

Original Source: University of St. Andrews News Release

October 31, 2007December 26, 2015 by Fraser Cain

Detailed Images of Comet Holmes

Late last week, the normally dim Comet 17P/Holmes suddenly blazed into view, increasing in brightness by a factor of a million. Before the eruption you needed a large telescope to see it, and now you can make it out with the unaided eye – even in the light-polluted city skies.

There are now many amateur and professional astronomers turning their gaze towards the newly brightened comet.

Eric Allen has been capturing images for several days, and stitched them together into an animation that shows the expanding coma. Even cooler, he compares it to Jupiter visually, so you can see just how big and bright it has gotten.

UK astronomers tuned in with the powerful Isaac Newton Telescope in La Palma, showing the fuzzy coma. They also tucked in an image of the Earth in the bottom corner, for scale.

Astronomers from the University of Montreal captured this image that seems to show that the comet has an actual tail.

Probably the best image I’ve seen was captured by Mario Motta from the Amateur Telescope Makers in Boston. His image shows what clearly looks like a jet, blasting off one side of the comet.

Still want more images? Space Weather has this enormous photo gallery of images of Comet 17P/Holmes.

Over the next few days/weeks, I’m sure some even bigger telescopes will be joining the fray, so stay tuned.

October 31, 2007December 26, 2015 by Fraser Cain

Better View of the Damaged Panel

With all that fancy camera equipment, the NASA astronauts took more detailed images of the damaged solar panels on the International Space Station. These are the images NASA engineers will use to figure out what kind of risk the panel faces if it’s fully deployed, and what kinds of repairs could be done to minimize the damage. Oh, and the next spacewalk has been delayed to Friday.

Because of the damaged panel, managers at NASA decided to change up their plans for the next few days. Instead of their originally scheduled spacewalk, to demonstrate tile repair techniques, the astronauts will now be focusing on damage assessment and repair.

They’ve got to have another look at the malfunctioning rotary joint on the right-hand side of the station. The joint is currently parked because the mechanism was vibrating too much, and consuming energy. When astronaut Daniel Tani looked inside, he found evidence that the mechanism was grinding together, shedding tiny metal shavings. During the latest spacewalk, the astronauts looked at the right-hand side and found that it was working fine.

The tear in the solar array happened during the latest spacewalk on Tuesday. The astronauts had just completed the redeployment of the solar array to its new home, and were extending the panels. A portion of the panels were invisible in the glare of the Sun, so the astronauts didn’t notice its damage until it was too late.

The 80 cm tear in the array was probably caused when a guide wire snagged one of the hinges that allow the panels to fold up tight. As the panel was extended, one flap hooked onto this guide wire and tore along the fold.

NASA is now in a bit of a bind. Although they’re generating power now, they’ll work best when fully extended. There are also structural problems with having the array not fully extended. For the time being, both rotary joints have been locked shut, protecting the panels, but reducing the station’s ability to generate power.

Original Source: NASA News Release

October 30, 2007December 26, 2015 by Fraser Cain

Hubble Sees Beautiful Carnage

Ahh, another beautiful photograph captured by the Hubble Space Telescope. This time we’re looking at two big, beautiful spiral galaxies… tearing each other apart. The large, face-on spiral is NGC 3808, while its dueling partner is the smaller, edge-on NGC 3808A. And between the two is a long today tail of stars, gas and dust, transferring from one to the other.

The two galaxies are collectively known as Arp 87; just one of the hundreds of interacting galaxies seen by astronomers. It was cataloged by the famous Halton Arp in the 1960’s, who maintained his Atlas of Peculiar Galaxies. And this collision is plenty peculiar, thanks to Hubble’s optics and resolution of fine details.

A stream of gas, stars and dust is flowing from NGC 3808 to its companion, enveloping it in a starry embrace. Because the NGC 3808A is seen nearly edge-on, you can make out the twisting trail of stars wrapping around it. Both galaxies have been distorted by their gravitational interaction.

When galaxies interact, stars are born. And this is the case for Arp 87. The colour of the stars and the intensity of heated interstellar dust show that both galaxies are undergoing furious rates of star formation.

Original Source: Hubble News Release

October 30, 2007December 26, 2015 by Fraser Cain

An Even More Massive Black Hole

Wait, stop the internet! Remember when I said the most massive black hole had been discovered? Sorry, that record has been broken by an even more “most massive black hole”. 16 times the mass of the Sun? Please. This new one raises the bar with a mass of 24 to 33 times the mass of our Sun.

As with the previous black hole, located in the nearby galaxy M33, this newly announced black hole is in a binary system. It’s located in the nearby dwarf galaxy IC 10, 1.8 million light-years from Earth in the constellation Cassiopeia. Since it’s orbiting another star, astronomers were able to calculate its mass – 24-33 solar masses.

The discovering team, led by Andrea Prestwich of the Harvard-Smithsonian Center for Astrophysics used NASA’s Chandra X-ray Observatory to study IC 10. They observed that the galaxy’s brightest X-ray source, IC 10 X-1, varied in brightness. This led them to believe that a star was periodically passing in front of a black hole, briefly obscuring it from view.

Follow up observations with NASA’s Swift satellite confirmed that the black hole was being eclipsed by the companion star, and gathered enough data that astronomers could work out the orbital period, and thus the masses of both objects.

A black hole this massive is surprising. Astronomers calculate that massive stars should throw off most of their gas before detonating as supernovae. No black hole should be able to exceed 15 times the mass of the Sun.

In the case of IC 10 X-1; however, it’s blown past that theoretical limit. Of course, it could have detonated as its largest size, and then consumed material from its companion article. But according to their calculations, it could only have gained 1 or 2 solar masses over the years.

So how did it get so large?

It probably started life with about 60 times the mass of the Sun. Since its host galaxy is deficient in any heavier elements, it was probably composed largely of hydrogen and helium. The heavier elements are actually easier to blow away from the star on the solar wind, so it maintained most of its mass right up until the end.

Original Source: CfA News Release

October 30, 2007December 26, 2015 by Fraser Cain

Station Solar Array Tears During Redeployment

The third spacewalk of STS-120 involved moving a large solar array panel to a new position on the International Space Station. Just as the supposedly successful spacewalk was coming to a close, the astronauts noticed that at least one panel on the array has torn. The astronauts halted extending the array, took a bunch of photographs, and now NASA engineers are working to figure out what to do next.

They were so close. Astronauts Scott Parazynski and Doug Wheelock had just finished installing the P6 truss with the help of the station and shuttle’s robotic arms. Completing this task had been done over the course of three different spacewalks – over 7 hours of work on today’s walk alone.

As the solar array was almost completely unfurled, the astronauts noticed that a section about 80 cm (2.5 feet) in length had torn. They didn’t notice the damage earlier, because sunlight was obscuring the view to the torn section.

Once they noticed the damage, the astronauts halted the operation, and reported the problem to NASA. Then they took a series of photographs so that engineers can study the damage and determine what will happen if they try to continue opening up the panels.

NASA has already decided to add an extra day to Discovery’s mission, giving the astronauts an extra spacewalk can be performed on Thursday. During this trip outside the station, the astronauts will study the troublesome joint that was found damaged during the second spacewalk of the mission.

Mike Suffredini, NASA’s International Space Station, isn’t worried about the power generating capacity of the panels, “if we get the array down and we cut the snag and we figure out how to reinforce it, we’ll redeploy the array. It’s giving all the power we need. It doesn’t have to look good; it’s not about style points.”

During today’s spacewalk, the astronauts also examined the port rotary joint, and didn’t find the same evidence of metal filings that were discovered in the starboard joint. Scott Parazynski described the joint’s race rings as “nice and clean.”

Discovery is now due to undock from the space station on Monday, and return to Earth on November 7th.

Original Source: NASA News Release

October 29, 2007December 26, 2015 by Nicholos Wethington

Tunguska Meteoroid’s Cousins Found?

It’s a cosmic whodunit: a meteorite exploded in the air near a remote part of Russia called Tunguska in 1908, and the meteorite that caused the event all but disappeared. Where did it come from? Was it an asteroid or part of a comet? Astronomers have taken up the case, using mathematical simulations to track down the perpetrator. They even think they might even know a few of its siblings.

Tadeusz J. Jopek and his team at the Astronomical Observatory UAM in Poland â€“ in collaboration with the Observatoire de la CÃ´te d’Azur in France â€“ looked for the possible origins of the Tunguska meteor by essentially running the explosion backwards, and mathematically simulating where the parent object of the event would have been before the impact.

By taking the existing forensic evidence of the impact to estimate the velocity and impact angle of the Tunguska meteorite, the team was able to simulate the possible orbit and speed of the object before it hit the earth. In doing this, they created 3311 virtual “particles” as possible origins of the object.

They then analyzed the orbits of near-earth objects that lie in the most likely region for the past 20,000 years to find possible matches with their simulated particles. It is still unclear exactly where the Tunguska meteor came from, and there are over 130 suspects.

“We believe that TCB originated as the result of a breakup of a single body : a comet or an asteroid. In our study we concluded that it is more probable that it was an asteroid. We cannot point to which one; instead we have found several candidates for the Tunguska parent, and the asteroid 2000 WK63 is an example of it,” Dr. Tadeusz said.

This is a hard case to solve indeed, as there remains little physical evidence of the original object near Tunguska, and the only tools astronomers have to work with are mathematical and statistical simulations. The question still remains whether the parent was a comet or asteroid, and indeed if the near-earth object it came from has been discovered yet.

“Such statistical conclusion gives no absolute sure [sic] that one of the presently known asteroids was indeed the Tunguska cosmic body parent. Therefore it is possible that still, the real Tunguska parent body is undiscovered.” Dr. Tadeusz said.

Source: Earth, Moon, and Planets Journal

October 29, 2007December 26, 2015 by Fraser Cain

Astronomy Cast Research

Thanks to everyone who responded to our listener survey a few months ago. As promised, the results of the survey are now available, and have actually been published in a research journal. So if you’re interested in learning about who’s listening to Astronomy Cast, check out the premier issue of Communicating Astronomy with the Public, published by the International Astronomical Union.

Our article is called, Astronomy Cast: Evaluation of a podcast audienceâ€™s content needs and listening habits. I guess the title sort of explains it all.

So once again, thanks to everyone who participated, you’ve given us great feedback, and helped us make some really pretty bar charts.

If I had to take away one piece of information, that really makes the whole podcasting thing worth while, it’s the change in interest towards astronomy. Check this out.

We found that 25% of our listener respondents had no interest or a passive interest in astronomy prior to listening to astronomy-related podcasts. After listening to astronomy-related podcasts, 70% of these individuals had begun to actively seek astronomy content or had become amateur astronomers.

You can download our specific article here.

Fraser Cain
Publisher, Universe Today (and co-host of Astronomy Cast)

October 29, 2007December 26, 2015 by Fraser Cain

Hundreds of Hidden Black Holes Discovered

Astronomers now believe there are supermassive black holes at the heart of every galaxy. When these black holes are actively feeding on material, they blaze with radiation, visible across the Universe. These active galaxies are known as quasars, and they were thought to be very common in the early Universe. But astronomers were having trouble finding almost any of them. It turns out, they were just hiding.

Supermassive black holes live at the very centre of galaxies, regions that can be thick with gas and dust. As the supermassive black hole goes into its actively feeding stage, the torrents of radiation that pour out collide with the dust. Instead of shining across the Universe, the radiation is smothered by dust.

These black holes are hidden, but they’re not entirely undetectable. Astronomers used NASA’s Spitzer Space Telescope to study 1,000 dusty, massive galaxies known to be furiously making stars. With all this gas and dust tearing around, you would think the supermassive black holes would be actively feeding, and blazing as quasars. But no quasars were seen.

Spitzer’s infrared view, however, allowed astronomers to pierce through the dusty veil surrounding the supermassive black hole, and see that 200 of the galaxies were producing an unusual amount of infrared light. The quasars heat up the dust in the surrounding doughnut cloud, and this cloud gives off the radiation detected by Spitzer.

These quasars are between 9 and 11 billion light-years away. In other words, we see the light they gave off when they were only 2.5 – 4.5 billion years old. Before now, only the rare, extremely energetic quasar was visible – after they had cleared away the surrounding gas and dust. This expanded population gives astronomers a much better understanding of galaxy evolution in the early Universe.

This discovery also downplays the role that galaxy collisions might have had in the early Universe, “theorists thought that mergers between galaxies were required to initiate this quasar activity, but we now see that quasars can be active in unharassed galaxies,” said co-author David Alexander of Durham University, United Kingdom.

The observations were made as part of the Great Observatories Origins Deep Survey, the most sensitive survey to date of the distant universe at multiple wavelengths.

Original Source: NASA News Release

October 29, 2007December 26, 2015 by Fraser Cain

Tropical Storm Noel… from Space

I don’t usually talk about the weather, but look at this picture… wow. It’s an image of tropical storm Noel, currently moving westward across the Caribbean Sea, and captured by ESA’s Envisat environmental monitoring satellite. When the image was taken, it was still just a depression, but it was upgraded to a tropical storm on Sunday. Noel is the 14th storm of the Atlantic hurricane season, and has tropical storm force winds stretch out 225 km from its centre.

Original Source: ESA News Release