Universe Today Exclusive – Cygnus Nova V2491 Revealed for Readers

Clouds got you down? No chance of seeing V2491 Cyg because of the weather? Are you sleeping when Cygnus is up? One of the most beautiful facets of having an astronomer around is being able to share information with other observatories around the world and put them to work. This time the job was handed to our friends in Australia who were able to produce for us an exclusive look at an elusive nova.

In trial test on image acquisition utilizing the combined resources of Macedon Ranges Observatory and its resident astronomers, they were able to nab the nova in less than 30 minutes from notice being given. The image was then processed, labeled and returned again halfway around the world within hours for UT readers to enjoy.

On 15 April 2008 from 10.50 to 11.40 UT, Joseph Brimacombe from Cairns, Queensland, Australia was busy employing remote technology located at 32 degrees 54 minutes North; 15 degrees 32 min West and recording the nova with an SBIG ST-L-1001 CCD camera. Coupled with a 20″ Ritchey-Chretien Optical System, 8 separate exposures of 5 minutes duration were taken in white light, and the results speak for themselves.

By comparing the zoom map of the area presented in the original Cygnus Nova Alert it’s easy to see the identifying line of three stars which helps orient the viewer to the general area. As predicted, Cygnus Nova V2491 easily stands out amongst the background stars.

Says Observatory Director, Burt Candusio: “The exercise was primarily designed to test the imaging and response capabilities of M.R.O resident astronomers. If another similar event presents itself, we would now be confident in our capabilities of imaging a target effectively and quickly from any part of the globe. A most pleasing outcome for all concerned and especially for Joseph Brimacombe.”

But the thrill was nothing compared to Joe’s own success: “Trapped under the mostly cloudy Cairns skies, I was remotely imaging the running chicken nebula (NGC 2944) at the Macedon Range Observatory and the Pinwheel galaxy (M101) at New Mexico Skies, when my good mate Bert Candusio notified me of a new nova (V2491) in Cygnus. At the time, it was 60 degrees below the horizon at the MRO, but 50 degrees above the horizon at NMS, so I slewed my 20 inch RCOS at NMS to the co-ordinates Bert had provided. There was just sufficient time before dawn to snap 8 x 5 min luminance frames of a dense star field. Both Bert and I were delighted to find the nova near the middle of the frame. We estimate the magnitude at around 10. The beauty of NGC 2944 and M101 was not a match for the excitement of imaging an acute stellar explosion for the first time!”

In the case of V2491 Cyg, the only thing better than having the stars up above is having friends down under. Our thanks go to our friends at Macedon Ranges Observatory!

Cygnus Nova Alert!!

According to today’s April 11 IAU Circular 8934, issued by the Central Bureau for Astronomical Telegrams at the Smithsonian Astrophysical Observatory in Cambridge, Massachusetts a 7th-magnitude nova was discovered on April 10, 2008, by Koichi Nishiyama and Fujio Kabashima in Japan. It’s time to observe!

NASA

The event is located in Cygnus, about one-third of the way from Albireo (β Cygni) to Sadr (γ Cygni) – RA 19 43 0 Dec +32 19. From early reports, it may still be continuing to brighten. Ernesto Guido and Giovanni Sostero of Remanzacco, Italy confirmed the discovery before the IAU announcement was made and estimated the nova’s magnitude at 7.5 at approximate 09:00:00 UT, 11 April 2008.

This image above is a map of Cygnus where the dimmest star shown is magnitude 7.5. The target area is circled. Binoculars and small telescopes are very capable of seeing this event! The zoomed map you see here is slightly larger than a binocular field of view and features the target area. The magnitudes are also set to 7.5. Should the event brighten, any stars you see that are in the target area brighter than what is shown will be the nova event.

If any updates or corrections occur, I will post them immediately. Clear skies and good luck!

What’s Up – The Weekend SkyWatcher’s Forecast

Greetings, fellow SkyWatchers! If we’ve explored the Moon in “Astronomy For Kids”, then by all means let’s explore the Moon in Astronomy for BIG kids! This weekend would be an great opportunity to dust off your telescopes or binoculars and do a little moongazing, because… Here’s what’s up!

Friday, April 11 – Tonight we’ll begin our SkyWatcher’s Weekend by heading toward the lunar surface to view a very fine old crater on the northwest shore of Mare Nectaris – Theophilus. Slightly south of midpoint on the terminator, this crater contains an unusually large multiple-peaked central mountain which can be spotted in binoculars. Theophilus is an odd crater: it’s shaped like a parabola – with no area on the floor being flat. It stretches across a distance of 100 kilometers and dives down 440 meters below the surface. Viewable in binoculars, Theophilus tonight it will appear dark, shadowed by its massive west wall, but if you’re using a telescope, look for sunrise on its 1400 meter summit!

Wes HigginsSaturday, April 12 – Today marks the 1851 birth of Edward Maunder – a bank teller turned assistant Royal Astronomer. Assigned to photographing and cataloging sunspots, Maunder was the first to discover solar minimum times and equate these with climate change. Maunder was also the first to suggest that Mars had no “canals,” only delicate changes in surface features. Smart man!

On Saturday night, Mars will play a very important role in observing as it will be slightly more than a degree away from the Moon’s limb for many observers. As grand as observing can be when the planet is near, it doesn’t even come close to the details that can be seen on the Moon. An outstanding feature visible tonight will be crater Maurolycus just southwest of the three rings of Theophilus, Cyrillus and Catharina. This Lunar Club challenge spans 114 kilometers and goes below the lunar surface by 4730 meters. Be sure to look for Gemma Frisius just to its north.

Wes HigginsSunday, April 13 – Tonight, let’s have a look at the Moon as challenge craters Cassini and Cassini A have now come into view just south of the black slash of the Alpine Valley. For more advanced lunar observers, head a bit further south to the Haemus Mountains to look for the bright punctuation of a small crater. You’ll find it right on the southwest shore of Mare Serenitatis! Now power up and look for a curious feature with an even more curious name…Rima Sulpicius Gallus. It is nothing more than a lunar wrinkle which accompanies the crater of the same name – a long-gone Roman counselor. Can you trace its 90 kilometer length?

Wishing you clear skies!

This week’s awesome lunar images belong to noneother than Wes Higgins. Many thanks!

Moon for Kids

New Moon Schedules

Right now, while the sky still gets dark early, is a great time to enjoy looking at the Moon with your small children or grandchildren. Even if you don’t have a telescope or binoculars, there are lots of fun ways that you can both enjoy our mysterious Moon together. Each evening as it gets dark, go outside and take a look at where the Moon is. There are nights when it will be cloudy, so it makes the game even more fun!

Having the Moon in the sky is something that we noticed all our lives, but most of us don’t think very much about it. When was the last time you saw the Moon? What did it look like? If you went outside, where would you find it? By learning to keep a “Moon Journal” you will soon learn much more about Earth’s nearest neighbor.

Keeping a Moon Journal is easy. All you need is a pencil and paper, and to understand where the cardinal directions are outside. If you have a compass, that’s great. But if you do not, remember to watch where the Sun sets. Next you need to choose a place! Look for an area that you can see most of the southern sky. Use your compass to find south or keep your right shoulder to the direction the Sun set. Don’t worry if there are things in the way, because trees, houses and even power wires will help with what we’re going to do. Mark the spot you chose by drawing an X on the pavement with a piece of chalk, or poking a stick into the ground. You must remember to return to this same spot each time.

Simple sketches make for lunar fun!Now you are ready to begin observing! The most important part about keeping a Moon Journal is to look for the Moon the same time each night. Right now about 8:30 or 9:00 will do very well. Go outside and look for the Moon. Do you see it? Good! Make a very simple picture of where you see the Moon in the sky and be sure to include things like a house or tree in your picture. It doesn’t have to be any more difficult than what you see here. Try your observations for several nights and see if you can learn to predict where the Moon will appear and what it will look like!

Now, let’s experiment with why the Moon has phases. All it takes is a bright flashlight and a ball on a stick. (Even an apple on a fork makes a great Moon, and you can eat it, too!) Whoever is holding the flashlight becomes the Sun and the Earth is your head. If you hold the ball out at arm’s length just above the flashlight while facing the Sun, you can’t see it. This is New Moon. The Moon is still in the sky, but we can’t see it because of the bright sunlight. Now keep the ball at arm’s length and turn slowly counterclockwise and watch what happens. That’s right! You see the ball go through phases, just like our Moon. When your back is towards the Sun, you see the ball as whole, and it will be Full Moon. The Moon will rise on the opposite side of the Earth at the same time the Sun goes down. Keep turning and you’ll see the phases reverse as the Moon moves back towards the Sun again.

Ask your child if he or she has ever seen the Moon during the daytime. Where in the sky do they think the Sun and the Moon needs to be for this to happen? What would happen if the Moon was in front of the Sun? How about the Earth?

Simple experiments like this are a great way to teach children more about astronomy!

A Black Hole Observed in the Heart of Mysterious Omega Centauri

Omega Centauri is a strange thing. It’s been classified as a star, then a nebula, then a globular cluster and now it’s thought to be a dwarf galaxy missing its outer stars. Why is it in such a mess? How can this oddball galaxy be explained? New research suggests it has an intermediate-black hole living in its core, giving astronomers the best idea yet as to where supermassive black holes come from. Omega Centauri might hold one of the most profound secrets as to how the largest objects in the observable universe are born…

The stars within Omega Centauri (credit: ESA/NASA)
Two thousand years ago, Omega Centauri was classified as a single star by Ptolemy. Edmond Halley studied this “star” but thought it looked a bit diffuse and re-classified it as a nebula in 1677. Then, in the 1830s, John Herschel was the first astronomer to realize this “nebula” was actually a galaxy, a globular cluster galaxy. But now, new observations by the Hubble Space Telescope (HST) reveal that this “globular cluster” isn’t what it seems… it’s actually a dwarf galaxy, stripped of its outer stars, some 17,000 light years away.

See an observation video zooming into the location of Omega Centauri in the constellation of Centaurus.

So what led to astronomers thinking there was something strange about this cosmic collection of stars? It rotates faster than other globular clusters, it is strangely flat and it contains stars of many generations (globular clusters usually contain stars of one generation). These reasons plus the fact Omega Centauri is ten times bigger than the largest globular clusters have led scientists to believe that this was no ordinary galaxy.

The constellation of Centaurus, where the globular cluster Omega Centauri is located (credit: ESA/NASA)

The main theory is that this unlucky galaxy may have crashed into the Milky Way in the distant past, shedding its outermost stars during the collision. This explains the lack of stars in its outer region. But why is it rotating so quickly, especially in the center?

These stunning images were taken by the NASA/ESA Hubble Space Telescope, which continues to do amazing science after 18 years in orbit. Combined with ground-based observations by the Gemini South telescope in Chile, astronomers have been able to deduce that a black hole may be at the root of a lot of the anomalies seen in Omega Centauri.

The research carried out at the Max-Planck Institute for Extraterrestrial Physics (in Garching, Germany), headed by Eva Noyola, shows stars near the center of Omega Centauri orbiting something very fast. In fact, this something is invisible for a reason. Calculating this invisible object’s mass, it is most likely that the group are observing an intermediate-size black hole with the mass of 40,000 solar masses. They have investigated other possibilities, perhaps the fast-orbiting stars could be accelerated by the collective mass of small, weakly radiating bodies such as white dwarves, or the orbiting stars’ have highly elliptical orbits and the point of closest approach is currently being observed, giving the impression they are going faster. However, the intermediate-size black hole theory appears to fit the situation far better.

This is a highly significant discovery, as so far there has been little linking the smaller, stellar black holes with the supermassive ones that sit in the center of large galaxies such as our own. There have been many theories put forward about how these huge black holes may have formed, but to find an intermediate-sized black hole may be the missing link and will help astrophysicists understand how supermassive black holes are “seeded” in the first place.

This result shows that there is a continuous range of masses for black holes, from supermassive, to intermediate-mass, to small stellar mass types […] We may be on the verge of uncovering one possible mechanism for the formation of supermassive black holes. Intermediate-mass black holes like this could be the seeds of full-sized supermassive black holes.” – Eva Noyola.

Source: SpaceTelescope.org

Planet Formation Revealed?

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One of the biggest unresolved questions of planet formation is how a thick disc of debris and gas surrounding young stars eventually evolves into a thin, dusty region with planets. This entire process, of course, has never actually been observed. But recently, and for the first time, a group of astrophysicists produced an image of material surrounding a star which seems to be coalescing into a planet.

The image was produced from a coronagraph attached to a telescope in Hawaii. It shows a horseshoe-shaped void in the disc of materials surrounding the star AB Aurigae, with a bright point appearing as a dot in the void.

“The deficit of material could be due to a planet forming and sucking material onto it, coalescing into a small point in the image and clearing material in the immediate surroundings,” said researcher Ben Oppenheimer, an astrophysicist at the American Museum of Natural History in New York. “It seems to be indicative of the formation of a small body, either a planet or a brown dwarf.”

A brown dwarf is considered a star that’s not massive enough to generate the thermonuclear fusion to create an actual star.

From what we know about planet formation, planets seem to be natural by-product of stars. But how does all this happen? Stars form when clouds of gas and dust contract under gravity, and if there’s enough compression and heat, sooner or later a nuclear reaction is triggered, and voilà: a star. If there’s any left-over material surrounding the young star, eventually the disc of dust and/or gas may congeal into planets. But the details of this process are unknown.

AB Aurigae is a well-studied star. It’s young, between one and three million years old, and can provide information on how stars and objects that orbit them form. And scientists hope that by studying this star, we can learn more about how planets form from the initial thick, gas-rich disk of debris that surrounds young stars. The observation of stars slightly older than AB Aurigae shows that at some point the gas is removed, but no one knows how this happens. AB Aurigae could be in an intermediate stage, where the gas is being cleared out from the center, leaving mainly dust behind.

“More detailed observations of this star can help solve questions about how some planets form, and can possibly test competing theories,” says Oppenheimer. And if this object is a brown dwarf, our understanding of them must be revamped as brown dwarfs are not believed to form in circumstellar materials, Oppenheimer said.

Original New Source: National Science Foundation Press Release

13.73 Billion Years – The Most Precise Measurement of the Age of the Universe Yet

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NASA’s Wilkinson Microwave Anisotropy Probe (WMAP) has taken the best measurement of the age of the Universe to date. According to highly precise observations of microwave radiation observed all over the cosmos, WMAP scientists now have the best estimate yet on the age of the Universe: 13.73 billion years, plus or minus 120 million years (that’s an error margin of only 0.87%… not bad really…).

The WMAP mission was sent to the Sun-Earth second Lagrangian point (L2), located approximately 1.5 million km from the surface of the Earth on the night-side (i.e. WMAP is constantly in the shadow of the Earth) in 2001. The reason for this location is the nature of the gravitational stability in the region and the lack of electromagnetic interference from the Sun. Constantly looking out into space, WMAP scans the cosmos with its ultra sensitive microwave receiver, mapping any small variations in the background “temperature” (anisotropy) of the universe. It can detect microwave radiation in the wavelength range of 3.3-13.6 mm (with a corresponding frequency of 90-22 GHz). Warm and cool regions of space are therefore mapped, including the radiation polarity.

This microwave background radiation originates from a very early universe, just 400,000 years after the Big Bang, when the ambient temperature of the universe was about 3,000 K. At this temperature, neutral hydrogen atoms were possible, scattering photons. It is these photons WMAP observes today, only much cooler at 2.7 Kelvin (that’s only 2.7 degrees higher than absolute zero, -273.15°C). WMAP constantly observes this cosmic radiation, measuring tiny alterations in temperature and polarity. These measurements refine our understanding about the structure of our universe around the time of the Big Bang and also help us understand the nature of the period of “inflation”, in the very beginning of the expansion of the Universe.

It is a matter of exposure for the WMAP mission, the longer it observes the better refined the measurements. After seven years of results-taking, the WMAP mission has tightened the estimate on the age of the Universe down to an error margin of only 120 million years, that’s 0.87% of the 13.73 billion years since the Big Bang.

Everything is tightening up and giving us better and better precision all the time […] It’s actually significantly better than previous results. There is all kinds of richness in the data.” – Charles L. Bennett, Professor of Physics and Astronomy at Johns Hopkins University.

This will be exciting news to cosmologists as theories on the very beginning of the Universe are developed even further.

Source: New York Times

Light Echos from 400 Year Old Supernova Observed for the First Time (Time-lapse Video)

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Its observations like these that really give us an idea about how big the cosmos actually is. A star in a small galaxy called the Large Magellanic Cloud (LMC), some 160,000 light years from Earth, exploded as a massive supernova 400 years ago (Earth years that is). Combining the observations from an X-ray observatory and an optical telescope, scientists are currently observing the reflected light off galactic dust, only just reaching the Earth hundreds of years after the explosion…

Shakespeare’s first run the stage production, Hamlet, will have been in full-swing. Galileo might have been experimenting with his first telescope. Guy Fawkes could have been plotting to blow up the British parliament. These events all occurred around the beginning of the 17th Century when a bright point of light may have been seen in the night sky. This point of light, in the Large Magellanic Cloud (LMC), is a massive star exploding, ending its life in a powerful supernova.

Now, 400 years after the event, we can see a “supernova remnant” (SNR), and this particular remnant is known as SNR 0509-67.5 (not very romantic I know). The remnant of superheated gas slowly expands into space and still emits X-rays of various energies. The 400 year old explosion has even been imaged in great detail by the Chandra Observatory currently observing space in X-ray wavelengths. Analysis of the SNR indicates that it was most likely caused by a Type Ia supernova after analysis of the composition of the gases, in particular the quantities of silicon and iron, was carried out. It is understood that the supernova was caused when a white dwarf star in a binary system reached critical mass, became gravitationally unstable (due to fusion reactions in the core stopping) and exploded.

When SNR 0509-67.5 exploded all those years ago, it will have radiated optical electromagnetic radiation (optical light) in all directions of space. Now, for the first time, optical Blanco 4-meter telescope at Cerro Tololo Inter-American Observatory (Chile) has observed reflected light from within the LMC originating from the supernova, 400 years after the event. Using the (reflected) optical light and X-ray emissions directly from the supernova remnant, scientists have been able to learn just how much energy was generated by the explosion.

Astronomers have even assembled a time-lapse video from observations of the light “echo” from 2001 to 2006. Although there are only five frames to the video, you can see the location of the reflected light change shape as different volumes of galactic dust are illuminated by the flash of supernova light. In each progressive frame, the clouds of gas that become illuminated will be further and further away from us, we are effectively looking further back in time as the light “echoes” bounce off the galactic matter.

An amazing discovery.

Source: Chandra X-ray Observatory

Biggest Ever Cosmic Explosion Observed 7.5 Billion Light Years Away

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A record-breaking gamma ray burst was observed yesterday (March 19th) by NASA’s Swift satellite. After red-shift observations were analysed, astronomers realized they were looking at an explosion half-way across the Universe, some 7.5 billion light years away. This means that the burst occurred 7.5 billion years ago, when the Universe was only half the age it is now. This shatters the record for the most distant object that can be seen with the naked eye…

Gamma ray bursts (GRBs) are the most powerful explosions observed in the Universe, and the most powerful explosions to occur since the Big Bang. A GRB is generated during the collapse of a massive star into a black hole or neutron star. The physics behind a GRB is highly complex, but the most accepted model is that as a massive star collapses to form a black hole, the in falling material is energetically converted into a blast of high energy radiation. It is thought the burst is highly collimated from the poles of the collapsing star. Any local matter downstream of the burst will be vaporized. This has led to the thought that historic terrestrial extinctions over the last hundreds of millions of years could be down to the Earth being irradiated by gamma radiation from such a blast within the Milky Way. But for now, all GRBs are observed outside our galaxy, out of harms way.

An artists impression of gamma ray burst (credit: Stanford.edu)

This record-breaking GRB was observed by the Swift observatory (launched into Earth orbit in 2004) which surveys the sky for GRBs. Using its Burst Alert Telescope (BAT), the initiation of an event can be relayed to Earth within 20 seconds. Once located, the spacecraft turns all its instruments toward the burst to measure the spectrum of light emitted from the afterglow. This observatory is being used to understand how GRBs are initiated and how the hot gas and dust surrounding the event evolves.

“This burst was a whopper; it blows away every gamma ray burst we’ve seen so far.” – Neil Gehrels, Swift principal investigator, NASA Goddard Space Flight Center, Greenbelt, Md.

This particular GRB was observed in the constellation of Boötes at 2:12 a.m. (EDT), March 19th. Telescopes on the ground and in space quickly turned to Boötes to analyse the afterglow of the burst. Later in the day, the Very Large Telescope in Chile and the Hobby-Eberly Telescope in Texas measured the burst’s redshift at 0.94. From this measure, scientists were able to pinpoint our distance from the explosion. This red shift corresponds to a distance of 7.5 billion light years, signifying that this huge GRB happened 7.5 billion years ago, over half the distance across the observable universe.

Source: NASA

When Black Holes Explode: Measuring the Emission from the Fifth Dimension

Primordial black holes are remnants of the Big Bang and they are predicted to be knocking around in our universe right now. If they were 1012kg or bigger at the time of creation, they have enough mass to have survived constant evaporation from Hawking radiation over the 14 billion years since the beginning of the cosmos. But what happens when the tiny black hole evaporates so small that it becomes so tightly wrapped around the structure of a fifth dimension (other than the “normal” three spatial dimensions and one time dimension)? Well, the black hole will explosively show itself, much like an elastic band snapping, emitting energy. These final moments will signify that the primordial black hole has died. What makes this exciting is that researchers believe they can detect these events as spikes of radio wave emissions and the hunt has already begun…

Publications about primordial black holes have been very popular in recent years. There is the possibility that these ancient singularities are very common in the Universe, but as they are predicted to be quite small, their effect on local space isn’t likely to be very observable (unlike younger, super-massive black holes at the centre of galaxies or the stellar black holes remaining after supernovae). However, they could be quite mischievous. Some primordial black hole antics include kicking around asteroids if they pass through the solar system, blasting through the Earth at high velocity, or even getting stuck inside a planet, slowly eating up material like a planetary parasite.

But say if these big bang relics never come near the Earth and we never see their effect on Earth (a relief, we can do without a primordial black hole playing billiards with near Earth asteroids or the threat of a mini black hole punching through the planet!)? How are we ever going to observe these theoretical singularities?

Eight-meter-wavelength Transient Array (credit: Virginia Tech)

Now, the ultimate observatory has been realized, but it measures a fairly observable cosmic emission: radio waves. The Eight-meter-wavelength Transient Array (ETA) run by Virginia Tech Departments of Electrical & Computer Engineering and Physics, and the Pisgah Astronomical Research Institute (PARI), is currently taking high cadence radio wave observations and has been doing so for the past few months. This basic-looking antenna system, in fields in Montgomery County and North Carolina, could receive emissions in the 29-47 MHz frequencies, giving researchers a unique opportunity to see primordial black holes as they die.

Interestingly, if their predictions are correct, this could provide evidence for the existence of a fifth dimension, a dimension operating at scales of billionths of a nanometer. If this exotic emission can be received, and if it is corroborated by both antennae, this could be evidence of the string theory prediction that there are more dimensions than the four we currently understand.

The idea we’re exploring is that the universe has an imperceptibly small dimension (about one billionth of a nanometer) in addition to the four that we know currently. This extra dimension would be curled up, in a state similar to that of the entire universe at the time of the Big Bang.” – Michael Kavic, project investigator.

As black holes are wrapped around this predicted fifth dimension, as they slowly evaporate and lose mass, eventually primordial black holes will be so stressed and stretched around the fifth dimension that the black hole will die, blasting out emissions in radio wave frequencies.

String theory requires extra dimensions to be a consistent theory. String theory suggests a minimum of 10 dimensions, but we’re only considering models with one extra dimension.” – Kavic

When the Large Hadron Collider goes online in May, it is hoped that the high energies generated may produce mini-black holes (amongst other cool things) where research can be done to look for the string theory extra dimensions. But the Eight-meter-wavelength Transient Array looking for the death of “naturally occurring” primordial black holes is a far less costly endeavour and may achieve the same goal.

Here’s an article on a theory that there could be 10 dimensions.

Source: Nature