Posted on by Tammy Plotner

Shedding New Starlight On The Andromeda Galaxy

This image shows NASA/ESA Hubble Space Telescope images of a small part of the disc of the Andromeda Galaxy, the closest spiral galaxy to the Milky Way. Hubble’s position above the distorting effect of the atmosphere, combined with the galaxy’s relative proximity, means that the galaxy can be resolved into individual stars, rather than the cloudy white wisps usually seen in observations of galaxies. Credit: NASA, ESA and T.M. Brown (STScI)

Thanks to Hubble’s Advanced Camera for Surveys, we’re now able to take a deeper look into the Andromeda Galaxy than ever before. Four new images are giving us an unprecedented view of resolved stars – something that just doesn’t occur when looking at other galaxies. Although we can see M31 with unaided vision from a relatively dark sky site, there’s no way we can see the outer regions without a telescope. Now we’re resolving them…

Although astronomers are quite aware that spiral galaxies have great distances between their stellar members, it is one thing to know it and another to see it. High above our atmosphere, the Hubble has a clean view of one of our nearest galactic neighbors, and it’s not looking in a window – it is photographing the backyard. Not only are individual stars revealed, but even more distant galaxies can be seen in the background beyond Andromeda’s dense disc.

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But it’s not only there that other galaxies can be seen. Try looking through M31’s halo…

This image shows NASA/ESA Hubble Space Telescope images of a small part of the halo of the Andromeda Galaxy. Credit: NASA, ESA and T.M. Brown (STScI)

“The two images taken in M 31’s halo show the lowest density of stars. The halo is the huge and sparse sphere of stars that surrounds a galaxy.” says the team. “While there are relatively few stars in a galaxy’s halo, studies of the rotation rate of galaxies suggest that there is a great deal of invisible dark matter.”

This image shows NASA/ESA Hubble Space Telescope images of a small part of the halo of the Andromeda Galaxy. Credit: NASA, ESA and T.M. Brown (STScI)

But don’t forget the stellar stream. There the stars are more densely packed, causing light extinction – yet the Hubble is resolving them! Take a look at this multitude of stars which could be the remainder of a galaxy M31 absorbed in the past…

This image shows NASA/ESA Hubble Space Telescope images of a small part of the giant stellar stream of the Andromeda Galaxy. The stream is a long structure thought to be the remains of a companion galaxy torn apart by the Andromeda Galaxy’s gravity and engulfed in it. Credit: NASA, ESA and T.M. Brown (STScI)

“These observations were made in order to observe a wide variety of stars in Andromeda, ranging from faint main sequence stars like our own Sun, to the much brighter RR Lyrae stars, which are a type of variable star.” says the Hubble crew. “With these measurements, astronomers can determine the chemistry and ages of the stars in each part of the Andromeda Galaxy.”

And we can marvel at a look at galaxies which may have remained forever hidden if it weren’t for Hubble’s incredible eye.

Original News Source: ESA / Hubble News.

Posted on by Jason Rhian

Hoping Forward At The End Of The Shuttle Era

Space shuttle Atlantis wraps up the shuttle program with an early orning return to Kennedy Space Center in Florida. Photo Credit: Mike Deep for Universe Today

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CAPE CANAVERAL Fla. — The last space shuttle mission, STS-135, ended with the landing of the shuttle Atlantis at Kennedy Space Center’s Shuttle Landing Facility at 5:57 a.m. EDT. The air was thick with both humidity and mosquitoes. It was also a day thick with loss. The United States, for the foreseeable future, has lost the ability to launch massive payloads, such as the International Space Station’s Kibo module, into orbit. Lost the capabilities that a manned spacecraft with a robot manipulator system or RMS affords. Lost the ability to chase down wayward satellites, repair them on-orbit or return them to Earth for more intensive work. Lost, at least for the time being, its leadership position in terms of space flight – that position now belongs to Russia with its human-rated Soyuz Spacecraft and unmanned Progress Cargo vessels.

NASA is working to put a positive spin on this new era. The space agency hopes that small, commercial space firms will provide the nation with the capacity to send men and material to orbit as it works to travel beyond low-Earth-orbit (LEO) once again. Only time will tell how successful this direction will be, but there are positive signs that NASA might be on the right path. Following the space program for decades – you learn to hedge your bets. Today’s SpaceX is tomorrow’s Constellation Program.

After 30 years, the shuttle program came to a close Thursday July 21, 2011 at 5:58 a.m. EDT. Photo Credit: NASA

Twin sonic booms shake me out of my revelry as the shuttle announces its return home. Then, a couple minutes later, there is the roar of the approaching orbiter. This sound comes not from shuttle, but rather from the sound of air being forcibly moved out of the shuttle’s path. I had set up two mini-camcorders to capture the landing, but had decided not to take any pictures. I took a moment, for myself, to watch as the shuttle roared past and landed.

There were a number of events held later in the day to commemorate the occasion. It struck me as odd that folks, some of whom would be in the unemployment line the following day, were celebrating. I decided to skip these events – I’ll celebrate when this nation regains the ability to launch astronauts into LEO. NASA Administrator Charlie Bolden worked to reassure everyone that all was well, given that he mistakenly said that the crew of STS-134 returned today – his words were not that reassuring.

This image was taken from the International Space Station as shuttle Atlantis returned to Earth. Photo Credit: NASA

With luck, when the U.S. does return to space again, it will do so on a multitude of different craft, with a multitude of different abilities – and hopefully launch vehicles. If these spacecraft are as different from one another as Boeing’s CST-100 is from Sierra Nevada Corporation’s Dream Chaser – that will be a very good thing – it will mean that many of the capabilities lost today will be replaced, albeit on completely separate vehicles.

That said, we are now entering an undiscovered country, one that NASA has never delved into before. Near the end of Apollo, the shuttle program was approved. With the end of the shuttle program here – NASA has no established human space flight program, it has initiatives, but no umbrella program, no clear path. That said, there are some potentially amazing things on the horizon – but they exist primarily on paper or on PowerPoint. Until they are fleshed out, until they fulfill their promises – today was a day of loss. Like the shuttle program, today was a mixed bag. One filled with hope for what might come, but uncertainty with what the future holds.

These are my personal reflections on the end of the shuttle program. They do not represent the opinions of Universe Today. These thoughts come from following and covering the space program for the last two decades and are not in favor of any one group’s position. I do not work to tell people things I think they want to hear – but what I feel they need to hear. I appreciate and welcome a mature debate with respect given by all sides for everyone’s point of view.

Posted on by Nancy Atkinson

Hubble Telescope Spots Another Moon Around Pluto

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From a NASA press release:

Astronomers using the Hubble Space Telescope discovered a fourth moon orbiting the icy dwarf planet Pluto. The tiny, new satellite – temporarily designated P4 — was uncovered in a Hubble survey searching for rings around the dwarf planet.

The new moon is the smallest discovered around Pluto. It has an estimated diameter of 8 to 21 miles (13 to 34 km). By comparison, Charon, Pluto’s largest moon, is 648 miles (1,043 km) across, and the other moons, Nix and Hydra, are in the range of 20 to 70 miles in diameter (32 to 113 km).

“I find it remarkable that Hubble’s cameras enabled us to see such a tiny object so clearly from a distance of more than 3 billion miles (5 billion km),” said Mark Showalter of the SETI Institute in Mountain View, Calif., who led this observing program with Hubble.

The finding is a result of ongoing work to support NASA’s New Horizons mission, scheduled to fly through the Pluto system in 2015. The mission is designed to provide new insights about worlds at the edge of our solar system. Hubble’s mapping of Pluto’s surface and discovery of its satellites have been invaluable to planning for New Horizons’ close encounter.

“This is a fantastic discovery,” said New Horizons’ principal investigator Alan Stern of the Southwest Research Institute in Boulder, Colo. “Now that we know there’s another moon in the Pluto system, we can plan close-up observations of it during our flyby.”

The new moon is located between the orbits of Nix and Hydra, which Hubble discovered in 2005. Charon was discovered in 1978 at the U.S. Naval Observatory and first resolved using Hubble in 1990 as a separate body from Pluto.

Illustration of the Pluto Satellite System orbits with newly discovered moon P4 highlighted. Credit: NASA, ESA, and A. Feild (STScI)

The dwarf planet’s entire moon system is believed to have formed by a collision between Pluto and another planet-sized body early in the history of the solar system. The smashup flung material that coalesced into the family of satellites observed around Pluto.

Lunar rocks returned to Earth from the Apollo missions led to the theory that our moon was the result of a similar collision between Earth and a Mars-sized body 4.4 billion years ago. Scientists believe material blasted off Pluto’s moons by micrometeoroid impacts may form rings around the dwarf planet, but the Hubble photographs have not detected any so far.

“This surprising observation is a powerful reminder of Hubble’s ability as a general purpose astronomical observatory to make astounding, unintended discoveries,” said Jon Morse, astrophysics division director at NASA Headquarters in Washington.

P4 was first seen in a photo taken with Hubble’s Wide Field Camera 3 on June 28. It was confirmed in subsequent Hubble pictures taken on July 3 and July 18. The moon was not seen in earlier Hubble images because the exposure times were shorter. There is a chance it appeared as a very faint smudge in 2006 images, but was overlooked because it was obscured.

For more images and information, see the HubbleSite.

Posted on by Nancy Atkinson

Hubble’s New Views of Neptune

Four images of Neptune taken a few hours apart by the Hubble Space Telescope on June 25-26, 2011. Credit: NASA, ESA and the Hubble Heritage Team (STScI/AURA)

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To celebrate the first complete orbit of the planet Neptue since its discovery in 1846, the Hubble Space Telescope took a series of images with the Wide Field Camera 3, showing the different faces of the planet as it rotates on its axis. The images were take on June 25-26, 2011.

Even with a telescope as powerful as Hubble, the planet still appears fairly small, but some details are visible. While its blue color is the most distinctive feature, the turbulent conditions in the planet’s atmosphere also show up. Neptune’s thick atmosphere is largely made up of hydrogen and helium and is thought to host the Solar System’s most furious storms, with winds of up to 2000 km/h.

See more about Neptune and these images from ESA’s Hubble page (including access to wallpaper-sized images) and tead more about Neptune’s discovery and anniversary in our article by Tammy Plotner.

Posted on by Nancy Atkinson

Hubble: One in a Million

For those of you bummed that Hubble’s one millionth observation didn’t include an eye-popping image, Daniel Pendick from the Geeked on Goddard Blog has put together a video of over 200 classic Hubble images, with the funky music from the “Planets” album by the band One Ring Zero. “Planets” is a collection of new compositions to represent the solar system and beyond. Gustav Holst its not, but it is “an eclectic and quirky journey from Mercury to Pluto, with influences as diverse as gypsy violin, Pink Floyd and David Bowie, Electric Light Orchestra, and even klezmer,” said Pendick on the 365 Days of Astronomy podcast. Enjoy!

Posted on by Nancy Atkinson

One Million Observations Now in the Books for Hubble Telescope

Artist's impression of the transiting exoplanet HAT-P-7b. Credit: NASA/ESA

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After 21 years in orbit, the Hubble Space Telescope has reached an historic milestone: the venerable HST has made its millionth observation. The telescope was used to search for the chemical signature of water in the atmosphere of planet HAT-P-7b, a gas giant larger than Jupiter which orbits the star HAT-P-7, about 1,000 light-years away from Earth. The observation was led by Dr. Drake Deming, planetary scientist and astronomer from the University of Maryland and the Goddard Space Flight Center.

With this announcement, however, there is no stunning image or unprecedented view of an exoplanet. The millionth observation will show up as squiggly lines on a graph, since the observation was done with Hubble’s spectrograph.

Spectroscopy is the technique of splitting light into its component colors, and the gases present in a planet’s atmosphere leave a fingerprint in the form of the distinctive color patterns that different gases absorb. Analyzing this data can give precise measurements of which elements are present in the exoplanet’s atmosphere.

“We are looking for the spectral signature of water vapor. This is an extremely precise observation and it will take months of analysis before we have an answer,” said Deming. “Hubble has demonstrated that it is ideally suited for characterizing the atmospheres of exoplanets and we are excited to see what this latest targeted world will reveal.”

“With a million observations and many thousands of scientific papers to its name, Hubble is one of the most productive scientific instruments ever built,” said Alvaro Gimenez, head of science and robotic exploration for the European Space Agency. “As well as changing our view of the Universe with its stunning imagery, Hubble has revolutionized whole areas of science.”

Hubble’s on-orbit history began when it was launched on the space shuttle Discovery on April 24, 1990. The HST has collected over 50 terabytes of data, enough to fill more than 10,000 DVDs. While the the data collected in the one millionth observation is now proprietary for the scientists, within a year, it will be released to the public. The huge and varied library of data Hubble has produced is made freely available to scientists and the public through an online archive at his link:

http://hla.stsci.edu/

Hubble made the millionth observation using its Wide Field Camera 3, a visible- and infrared-light imager with an on-board spectrometer. It was installed by astronauts during the Hubble Servicing Mission 4 in May 2009.

More Hubble info and images can be found at the HubbleSite, and ESA’s Hubble website.

Posted on by Jason Major

A Four Cluster Pile-Up

Abell 2744, a.k.a. "Pandora's Cluster"

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Abell 2744, shown above in a composite of images from the Hubble Space Telescope, the ESO’s Very Large Telescope and NASA’s Chandra X-ray  Observatory, is one of the most complex and dramatic collisions ever seen between galaxy clusters.

X-ray image of Abell 2744

Dubbed “Pandora’s Cluster”, this is a region 5.9 million light-years across located 3.5 billion light-years away. Many different kinds of structures are found here, shown in the image as different colors. Data from Chandra are colored red, showing gas with temperatures in the millions of degrees. Dark matter is shown in blue based on data from Hubble, the European Southern Observatory’s VLT array and Japan’s Subaru telescope. Finally the optical images showing the individual galaxies have been added.

Even though there are many bright galaxies visible in the image, most of the mass in Pandora’s Cluster comes from the vast areas of dark matter and extremely hot gas. Researchers made the normally invisible dark matter “visible” by identifying its gravitational effects on light from distant galaxies. By carefully measuring the distortions in the light a map of the dark matter’s mass could be created.

Galaxy clusters are the largest known gravitationally-bound structures in the Universe, and Abell 2744 is where at least four clusters have collided together. The vast collision seems to have separated the gas from the dark matter and the galaxies themselves, creating strange effects which have never been seen together before. By studying the history of events like this astronomers hope to learn more about how dark matter behaves and how the different structures that make up the Universe interact with each other.

Check out this HD video tour of Pandora’s Cluster from the team at Chandra:

Read more on the Chandra web site or in the NASA news release.

Image credit: X-ray: NASA/CXC/ITA/INAF/J.Merten et al, Lensing: NASA/STScI; NAOJ/Subaru; ESO/VLT, Optical: NASA/STScI/R.Dupke.

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Jason Major is a graphic designer, photo enthusiast and space blogger. Visit his website Lights in the Dark and follow him on Twitter @JPMajor or on Facebook for the most up-to-date astronomy awesomeness!

 

Posted on by Tammy Plotner

Black Hole Devours Star and Hurls Energy Across 3.8 Billion Light Years

What University of Warwick researchers think the star may have looked like at the start of its disruption by a black hole at the center of a galaxy 3.8 billion light years distant resulting in the outburst known as Sw 1644+57. Credit: University of Warwick / Mark A. Garlick

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Engaging the Hubble Space Telescope, Swift satellite and the Chandra X-ray Observatory, astronomers at the University of Warwick were quick to pick up a signal from Swift’s Burst Alert Telescope on March 28, 2011. In a classic line from Easy Rider, Jack Nicholson says: “It’s a UFO beaming back at you.” But this time it isn’t a UFO… it’s the death scream of a star being consumed by a black hole. The alert was just the beginning of a series of x-ray blasts that turned out to be the largest and most luminous event so far recorded in a distant galaxy.

Originating 3.8 billion light years from Earth in the direction of the constellation of Draco, the beam consisting of high energy X-rays and gamma-rays remained brilliant for a period of weeks after the initial event. As more and more material from the doomed star crossed over the event horizon, bright flares erupted signaling its demise. Says Dr. Andrew Levan, lead researcher on the paper from the University of Warwick; “Despite the power of this the cataclysmic event we still only happen to see this event because our solar system happened to be looking right down the barrel of this jet of energy”.

Dr Andrew Levan is a researcher at the University of Warwick.
Dr. Levan’s findings were published today in the Journal Science in a paper entitled “An Extremely Luminous Panchromatic Outburst from the Nucleus of a Distant Galaxy”. His findings leave no doubt as to the origin of the event and it has been cataloged as Sw 1644+57.

“The only explanation that so far fits the size, intensity, time scale, and level of fluctuation of the observed event, is that a massive black at the very centre of that galaxy has pulled in a large star and ripped it apart by tidal disruption.” says Levan. “The spinning black hole then created the two jets one of which pointed straight to Earth.”

And straight into our eager eyes…

Original Story Source: Eurekalert.

Posted on by Nancy Atkinson

Hubble’s Stunning New View of Centaurus A

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From a HubbleSite press release:

Resembling looming rain clouds on a stormy day, dark lanes of dust crisscross the giant elliptical galaxy Centaurus A. Hubble’s panchromatic vision, stretching from ultraviolet through near-infrared wavelengths, reveals the vibrant glow of young, blue star clusters and a glimpse into regions normally obscured by the dust.

The warped shape of Centaurus A’s disk of gas and dust is evidence for a past collision and merger with another galaxy. The resulting shockwaves cause hydrogen gas clouds to compress, triggering a firestorm of new star formation. These are visible in the red patches in this Hubble close-up.

At a distance of just over 11 million light-years, Centaurus A contains the closest active galactic nucleus to Earth. The center is home for a supermassive black hole that ejects jets of high-speed gas into space, but neither the supermassive or the jets are visible in this image.

This image was taken in July 2010 with Hubble’s Wide Field Camera 3.

Posted on by Tammy Plotner

Globular Clusters Are Real Oddballs

M80 Image Credit: NASA, The Hubble Heritage Team, STScI, AURA

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Hanging onto the outskirts of our Milky Way galaxy like cockle burs on a shaggy dog’s coat, globular clusters contain over hundreds of thousands of stars. Estimated to be up to ten billion years old, these spherical stellar seed pods are gravitationally bound together and tend to be more dense towards their cores. We’ve long known all the stars contained within a globular cluster to be about the same age and the individual members most likely formed at the same time as the parent galaxy – but what we weren’t expecting was change.

“We thought we understood these clusters very well”, says Dr. Alison Sills, Associate Professor of Physics & Astronomy. She is presenting new findings at this week’s CASCA 2011 meeting in Ontario, Canada. “We taught our students that all the stars in these clusters were formed at the same time, from one giant cloud of gas. And since that time, the individual stars may have evolved and died, but no new stars were born in the cluster.”

In 1953, astronomer Allan Sandage was performing photometry of the stars in the globular cluster M3 when he made an incredible discovery – blue stragglers. No, it’s not a down-his-luck musician waiting for a coin in his instrument case… but a main sequence star more luminous and more blue than stars at the main sequence turn-off point for the cluster. They shouldn’t belong where they are, but with masses two to three times that of the rest of the main sequence cluster stars, blue stragglers seem to be exceptions to the rule. Maybe they are a product of interaction… grappling together… pulling material from one another… and eventually merging.

Image of NGC 6397 taken by the Hubble Space Telescope, with evidence of a number of blue stragglers.

“Astronomers expect that the stars get too close to each other because of the complicated dance that stars perform in these dense clusters, where thousands of stars are packed into a relatively small space, and each star is moving through this cluster under the influence of the gravity of all the other stars. Somewhat like a traffic system with no stop lights, there are a lot of close encounters and collisions,” explains Sills.

By taking a closer look at globular clusters, the Hubble Space Telescope has given us evidence for two generations of star formation. The first is our accepted rule, but the second generation isn’t like anything else found in our Galaxy. Instead of being created from an earlier generation of expended stars, the second generation in globular clusters appears to have formed from material sloughed off by the first generation of stars. An enigma? You bet.

“Studying the normal stars in clusters was instrumental in allowing astronomers to figure out how stars lived and died”, says Dr. Sills, “but now we can look even further back, to when they were born, by using the oddballs. It pays off to pay attention to the unusual individuals in any population. You never know what they’ll be able to tell you.”

At the CASCA conference, Dr. Sills is presenting her work – a link between these two unusual forms of globular clusters. Blue stragglers and the second generation of stars would appear to have identical properties, including where they are concentrated in the cluster, and that both are.. well.. a little more “blue” than we would expect. She is investigating how the close encounters and collisions could affect the formation of this strange second generation and link the two phenomena we see in these complicated systems.

Real oddballs…

Original story soucre at Physorg.com.