An Even More Massive Black Hole

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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

Station Solar Array Tears During Redeployment

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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

Tunguska Meteoroid’s Cousins Found?

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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 – in collaboration with the Observatoire de la Côte d’Azur in France – 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

Astronomy Cast Research

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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 audience’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)

Hundreds of Hidden Black Holes Discovered

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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

Tropical Storm Noel… from Space

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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

What’s Up this Week: October 29 – November 4, 2007

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Monday, October 29 – On this night in 1749, the French astronomer Le Gentil was at the eyepiece of an 18′ focal length telescope. His object of choice was the Andromeda Galaxy, which he believed to be a nebula. Little did he know at the time that his descriptive notes also included M32, a satellite galaxy of M31. It was the first small galaxy discovered, and it would be another 175 years before these were recognized as such by Edwin Hubble.

Tonight, take the time to view the Andromeda Galaxy for yourself. Located just about a degree west of Nu Andromeda, this ghost set against the starry night was known as far back as 905 AD, and was referred to as the “Little Cloud.” Located about 2.2 million light-years from our solar system, this expansive member of our Local Galaxy Group has delighted observers of all ages throughout the years. No matter if you view with just your eyes, a pair of binoculars or a large telescope, M31 still remains one of the most spectacular galaxies in the night.

“Boo” tiful…

Tuesday, October 30 – Today in 1981 Venera 13 was launched on its way toward Venus – did you catch the bright planet before dawn?

What Halloween celebration would be complete without a black cat? Tonight let’s cruise Draco “The Dragon” in search of the “Cat’s Eye”…

Located about halfway between Delta and Zeta Draconis is one of the brightest planetary nebulae in the night – 8.8 magnitude NGC 6543. Around three thousand light-years away, it was one of the first planetary nebulae to be studied spectroscopically and the resulting emission lines proved that the phenomenon was actually a shell of gas emitted from a dying star – a fate that awaits our own Sun.

While a small telescope will never reveal NGC 6543 as gloriously as a Hubble image, you can expect even in a small telescope or binoculars to make out a small, blue/green glowing object. Large aperture telescopes and good sky conditions are needed to reveal some of the braided structure seen within this bright object. No matter how you view it, the “Cat’s Eye” belongs on the list of spooky objects!

Wednesday, October 31 – Happy Halloween! Many cultures around the world celebrate this day with a custom known as “Trick or Treat.” Tonight instead of tricking your little ghouls and goblins, why not treat them to a sweet view through your telescope or binoculars?

So far we’ve collected a demon, a pumpkin, a galactic ghost, and the eye of the cat… And what Halloween would be complete without a witch! Easily found from a modestly dark site with the unaided eye, the Pleiades can be spotted well above the northeastern horizon within a couple of hours of nightfall. To average skies, many of the 7 bright components will resolve easily without the use of optical aid, but to telescopes and binoculars? M45 is stunning…

First let’s explore a bit of history. The recognition of the Pleiades dates back to antiquity and its stars are known by many names in many cultures. The Greeks and Romans referred to them as the “Starry Seven,” the “Net of Stars,” “The Seven Virgins,” “The Daughters of Pleione,” and even “The Children of Atlas.” The Egyptians referred to them as “The Stars of Athyr,” the Germans as “Siebengestiren” (the Seven Stars), the Russians as “Baba” after Baba Yaga, the witch who flew through the skies on her fiery broom. The Japanese call them “Subaru,” Norsemen saw them as packs of dogs and the Tonganese as “Matarii” (the Little Eyes). American Indians viewed the Pleiades as seven maidens placed high upon a tower to protect them from the claws of giant bears, and even Tolkien immortalized the stargroup in “The Hobbit” as “Remmirath.” The Pleiades have even been mentioned in the Bible! So, you see, no matter where we look in our “starry” history, this cluster of seven bright stars has been part of it. But, let’s have some Halloween fun!

The date of the Pleiades culmination (its highest point in the sky) has been celebrated through its rich history by being marked with various festivals and ancient rites – but there is one particular rite that really fits this occasion! What could be more spooky on this date than to imagine a group of Druids celebrating the Pleiades’ midnight “high” with Black Sabbath? This night of “unholy revelry” is still observed in the modern world as “All Hallow’s Eve” or more commonly as Halloween. Although the actual date of the Pleiades midnight culmination is now on November 21 instead of October 31, why break with tradition? Thanks to its nebulous regions, M45 looks wonderfully like a “ghost” haunting the starry skies.

Treat yourself and your loved ones to the “scariest” object in the night. Binoculars give an incredible view of the entire region, revealing far more stars than are visible with the naked eye. Small telescopes at lowest power will enjoy M45’s rich, icy-blue stars and fog-like nebulosity. Larger telescopes and higher power reveal many pairs of double stars buried within its silver folds. No matter what you choose, the Pleiades definitely rock!

Thursday, November 1 – On this day in 1977, Charles Kowal made a wild discovery – Chiron. This represented the first discovery of a multitude of tiny, icy bodies that lie in the outer reaches of our solar system. Collectively known as Centaurs, they reside in unstable orbits between Jupiter and Neptune and are almost certainly “refugees”” from the Kuiper Belt

Tonight let’s go for something small, but white-hot as we head for a dwarf star and planetary nebula, NGC 246. You’ll find it just a bit more than a fistwidth north-northeast of Beta Ceti (RA 00 47 03.34 Dec -11 52 18.9).

First discovered by Sir William Herschel and cataloged as object V.25, this 8th magnitude planetary nebula has a wonderful patchy, diffuse structure that envelops four stars. Around 1600 light-years away, the nebulosity you can see around the exterior edges was once the outer atmosphere of a star much like our own Sun. At the center of the nebula lies the responsible star – the fainter member of a binary system. While it is now in the process of becoming a white dwarf, we can still enjoy the product of this expanding shell of gas that is often called the “Skull Nebula.”

Friday, November 2 – Today celebrates the birth of an astronomy legend – Harlow Shapely. Born in 1885, the American-born Shapley paved the way in determining distances to stars, clusters, and the center of our Milky Way galaxy. Among his many achievements, Shapely was also the Harvard College Observatory director for many years. Today in 1917 also represents the night first light was seen through the Mt. Wilson 100″ telescope.

Of course, Dr. Shapley spent his fair share of time on the Hooker telescope as well. One of his many points of study was globular clusters, their distance, and their relationship to the halo structure of our galaxy. Tonight let’s have a look at a very unusual little globular located about a fistwidth south-southeast of Beta Ceti and just a couple of degrees north-northwest of Alpha Sculptor (RA 00:52:47.5 Dec -26:35:24), as we have a look at NGC 288.

Discovered by William Herschel on October 27, 1785, and cataloged by him as H VI.20, the class X globular cluster blew apart scientific thinking in the late 1980’s as a study of perimeter globulars showed it to be more than 3 million years older than similar globulars – thanks to the color magnitude diagrams of Hertzsprung and Russell. By identifying both its blue and red branches, it was shown that many of NGC 288’s stars are being stripped away by tidal forces and contributing to the formation of the Milky Way’s halo structure. In 1997, three additional variable stars were discovered in this cluster.
At magnitude 8, this small globular is easy for southern observers, but faint for northern ones. If you are using binoculars, be sure to look for the equally bright spiral galaxy NGC 253 to the globular’s north.

Saturday, November 3 – On this day in 1955, one of the few documented cases of a person being hit by a meteorite occurred. What are the odds on that?

1957 the Russian space program launched its first “live” astronaut into space – Laika. Carried on board Sputnik 2, our canine hero was the first living creature to reach orbit. The speedily developed Sputnik 2 was designed with sensors to transmit the ambient pressure, breathing patterns and heartbeat of its passenger, and also had a television camera on board to monitor its occupant. The craft also studied ultraviolet and x-ray radiation to further assess the impact of space flight upon live occupants. Unfortunately, the technology of the time offered no way to return Laika to Earth, so she perished in space. On April 14, 1958, Laika and Sputnik 2 returned to Earth in a fiery re-entry after 2,570 orbits.

Since we’ve got the scope out, let’s go have another look at that galaxy we spied last night!

Discovered by Caroline Herschel on September 23, 1783, NGC 253 (RA 00 47.6 Dec -25 17) is the brightest member of a concentration of galaxies known as the Sculptor Group, near to our own local group and the brightest of all outside it. Cataloged as both H V.1 and Bennett 4, this 7th magnitude beauty is also known as Caldwell 65, and due to both its brightness and oblique angle is often called the “Silver Dollar Galaxy.” As part of the SAC 110 best NGCs, you can even spot this one if you don’t live in the Southern Hemisphere. At around 10 million light-years away, this very dusty, star-forming Seyfert galaxy rocks in even a modest telescope!

Sunday, November 4 – This morning will be the peak of the Southern Taurid meteor shower. Already making headlines around the world for producing fireballs, the Taurids will be best visible in the early morning hours as soon as the Moon is far west.. The radiant for this shower is, of course, the constellation of Taurus and red giant Aldeberan, but did you know the Taurids are divided into two streams?

It is surmised that the original parent comet shattered as it passed our Sun around 20,000 to 30,000 years ago. The larger “chunk” continued orbiting and is known as periodic comet Encke. The remaining debris field turned into smaller asteroids, meteors and larger fragments that often pass through our atmosphere creating the astounding “fireballs” known as bolides. Although the fall rate for this particular shower is rather low at 7 per hour, these slow traveling meteors (27 km or 17 miles per second) are usually very bright and appear to almost “trundle” across the sky. With the chances high all week of seeing a bolide, this makes a bit of quiet contemplation under the stars worthy of a morning walk. Be sure to look at how close Saturn is to the Moon!

For unaided eye or binocular observers – or those who just wish something a bit “different” tonight – have a look at 19 Pisces. You’ll find it as the easternmost star in the small “circlet” just south of the Great Square of Pegasus.

Also known as TX, you’ll find this one quite delightful for its strong red color. TX is a cool giant star which varies slightly in magnitude on an irregular basis. This carbon star is located anywhere from 400 to 1000 light-years away and rivals even R Leporis’ crimson beauty.

Podcast: Questions on Inflation

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It’s about time for a question show again, so we’ll have one last interruption to our planetary tour, to deal with the questions that arose from our inflation show. So if you still don’t understand inflation, take a listen to this week’s show and as always, send us your questions.
Click here to download the episode

Questions on Inflation – Show notes and transcript

Or subscribe to: astronomycast.com/podcast.xml with your podcatching software.

Harmony Module Installed onto the Station, Damage Discovered

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NASA astronauts added the newest module to the International Space Station on Friday morning, clearing the way for several new laboratory modules and increasing the sleeping capacity. Astronauts Scott E. Parazynski and Col. Douglas H. Wheelock spent their morning on Friday, suspended above the planet, attaching the newly delivered Harmony module to the station. During the second spacewalk on Sunday, the astronauts discovered damage to one of the joints that orient the station’s solar arrays.

First Spacewalk – Friday
Once the shuttle docked on Thursday, the first scheduled spacewalk began early the next day. Parazynski and Wheelock went outside the station at 6 a.m. EDT, and prepared Harmony for its removal from the shuttle’s payload bay.

Inside the station, Stephanie D. Wilson and Daniel M. Tani operated the station’s robotic arm, to help remove the module from the shuttle’s cargo bay and transfer it over to the station.

The spacewalk itself went quickly, and mostly without incident. The astronauts struggled briefly to remove some of holding bolts and hose connectors. And there were a few situations where frozen ammonia drifted away from some of the hoses. This ammonia could contaminate the station’s atmosphere if it got back inside, so the astronauts carefully avoided coming into contact with any of the substance.

Second Spacewalk – Sunday
For the second spacewalk on Sunday, Scott Parazynski was joined by Daniel M. Tani. Their task was to unbuckle a solar array atop the station so that it can be relocated. They also began outfitting the exterior of the newly attached Harmony module.

After removing a protective cover, Tani discovered what appeared to be metallic shavings in one of the station’s rotating joint assemblies. He collected up some samples with tape so that engineers can study it, and figure out what could be going on. Station controllers had noticed that a joint on the right-hand side of the station was experiencing unusual vibrations as it rotated, so these two events could be connected.

The best theory right now is that the foil backing on an aluminum cover is rubbing against the mechanism that turns the station’s solar arrays to orient towards the Sun. This material is shredding off the cover and getting into the mechanism.

NASA is considering whether they’ll have the astronauts open up all 21 covers to see if any are the source of the damage. This could be done during a currently planned spacewalk, or it could become another spacewalk all on its own. Even if the source of the metal is discovered, it might be impossible to clean.

Original Source: NASA Station Coverage

Astrosphere for October 28th, 2007

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I hope you’re all enjoying this lazy Sunday. Sorry for the lack of updates, things have been busy for me. Of course, you’ll be wanting an image of Comet Holmes. This one was captured by Phil22 from the forum, but there are lots more there, so check them all out.

Lots of people are talking about Comet 17P/Holmes. Astroprof captured an image of the comet above his house. And here’s an image captured by Steve Tuttle. And here’s a cool series showing its evolution from Slacker Astronomy. And another nice one from Tom’s Astronomy Blog. And finally, here’s a sketch made by Bill Greer.

And everyone else is out at the X-Prize Cup. Jeff Foust uploaded a bunch of images. And here’s a video of Armadillo Aerospace’s unsuccessful attempt to win the first lunar prize. And here’s some coverage from Alan Boyle’s Cosmic Log. Finally, here’s Wired Science’s excellent coverage. Orbital Outfitters showed off their new prototype commercial pilot spacesuit.