30
Dec 09

Galactic building blocks

Source: Universe Today

The current view of galactic formation is that galaxies form from a "bottom-up" method. In this picture, small dwarf galaxies, full of metal poor stars, were attracted by dark matter halos in the early universe which merged into larger galaxies. Many of those metal poor stars can still be seen today in the halo of the galaxy, but it was thought that the building blocks from which the galaxies were constructed were long gone or had evolved on their own and would no longer resemble the primordial building blocks.

However, earlier this year, an extremely metal poor star with only 0.00025% of the iron in the Sun was discovered in the Sculptor dwarf galaxy. If confirmed, this would show a strong link to further support the notion that metal poor dwarf galaxies were related to the metal poor stars that still populate our halo. Confirming this was the subject of a recent paper. (read more)

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29
Dec 09

Cassini Holiday Movies Showcase Dance of Saturn's Moons

Source: NASA/JPL

Like sugar plum fairies in "The Nutcracker," the moons of Saturn performed a celestial ballet before the eyes of NASA's Cassini spacecraft. New movies frame the moons' silent dance against the majestic sweep of the planet's rings and show as many as four moons gliding around one another. (read more)

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28
Dec 09

Voyager Makes an Interstellar Discovery

Source: NASA Science

The solar system is passing through an interstellar cloud that physics says should not exist. In the Dec. 24th issue of Nature, a team of scientists revealed how NASA's Voyager spacecraft have solved the mystery.

"Using data from Voyager, we have discovered a strong magnetic field just outside the solar system," explains lead author Merav Opher, a NASA Heliophysics Guest Investigator from George Mason University. "This magnetic field holds the interstellar cloud together and solves the long-standing puzzle of how it can exist at all." (read more)

Links:
NASA Science
Nature (Requires subscription)
SPACE.com

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27
Dec 09

365 Days of Astronomy goes into 2010!

Source: Astrosphere New Media Association

The award-winning 365 Days of Astronomy podcast is proud to announce that the project will continue for another 365 days and is now accepting sign-ups for participants for 2010. This is a legacy project of the International Year of Astronomy (IYA) and is being managed by Astrosphere New Media Association.

In 2009, the 365 Days of Astronomy podcast was a major project of the IYA, publishing one podcast for every day of the year. The podcast episodes are written, recorded, and produced by people all around the world. “This podcast gives a voice to everyone in astronomy – professionals, amateurs, and those who just enjoy the amazing
discoveries and images of our Universe,” said Dr. Pamela Gay, chair for the IYA’s New Media Group. The continuation of the project was officially announced at the .Astronomy (“dot Astronomy”) conference in Leiden, The Netherlands, on Friday. (read more)

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26
Dec 09

Cassini Spacecraft to Monitor North Pole on Titan

Source: NASA / Jet Propulsion Laboratory

Though there are no plans to investigate whether Saturn's moon Titan has a Santa Claus, NASA's Cassini will zoom close to Titan's north pole this weekend.

The flyby, which brings Cassini to within about 960 kilometers (600 miles) of the Titan surface at 82 degrees north latitude, will take place the evening of Dec. 27 Pacific time, or shortly after midnight Universal Time on Dec. 28. (read more)

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24
Dec 09

A Quarter Century of Infrared Astronomy

Source: NASA/Spitzer-Caltech

This composite graphic encompasses a quarter century of infrared astronomy from space, a world away from Galileo Galilei's eight-power telescope that was the cutting edge of astronomy 400 years ago. The composite recognizes the International Year of Astronomy and celebrates the dramatic progress in our understanding of the universe derived from infrared observations.  It also illustrates some of the contributions from the Infrared Processing and Analysis Center (IPAC) to this progress by way of astronomical data processing, analysis, archiving and dissemination. (read more)

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23
Dec 09

How old is the Universe?

Source: German Aerospace Center

In the field of archaeology the age of finds or the time of events can sometimes be determined relatively easily, for example via the number of tree rings or the rate of decomposition of radioactive elements. However, there is unfortunately no direct and absolute indicator for the age of the Universe. Astronomers have, however, found two ways to arrive at a good estimate.

Astronomers have ultimately calculated that the Universe is 13.7 billion years old. (read more)

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20
Dec 09

A Flash of Light from Titan

Credit: NASA

Titan_cassini20091217

The image above, obtained using Cassini's Visual and Infrared Mapping Spectrometer (VIMS),
shows the first observed flash of sunlight reflected off a lake on Saturn's moon Titan.
Credit: NASA/JPL/University of Arizona/DLR.

NASA's Cassini Spacecraft has captured the first flash of sunlight reflected off a lake on Saturn's moon Titan, confirming the presence of liquid on the part of the moon dotted with many large, lake-shaped basins. (read more)

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17
Dec 09

Colliding Auroras Produce Explosions of Light

Source: NASA

aurora_boreal

A continent-wide network of all-sky cameras has photographed a never-before-seen phenomenon: colliding auroras that produce explosions of light. The must-see images have solved a long-standing mystery of Northern Lights. (read more)

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16
Dec 09

Close-up Photos of Dying Star Show Our Sun's Fate

Credit: Harvard-Smithsonian Center for Astrophysics

RedGiant
Chi Cygni, a red giant star as shown in this artist's
conception of Betelgeuse, is nearing the end of its life.
Credit: ESO/L. Calçada

One day our Sun will eventually die. But it won't be tomorrow ... in fact, it will only happen in 5000 million years.

PulseChiCygni

Chi Cygni changes brightness dramatically and regularly
every 408 days due to in-and-out pulsations.
Credit: Sylvestre Lacour, Observatoire de Paris

About 550 light-years from Earth, a star like our Sun is writhing in its death throes. Chi Cygni has swollen in size to become a red giant star so large that it would swallow every planet out to Mars in our solar system. Moreover, it has begun to pulse dramatically in and out, beating like a giant heart. New close-up photos of the surface of this distant star show its throbbing motions in unprecedented detail. (read more)

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14
Dec 09

Zooniverse - A new contribution to Science Education

zooniverse

Galaxy Zoo team has launched Zooniverse. Galaxy Zoo has been an enormous success where professional astronomers, amateur astronomers, and scientists from other disciplines, have work to make discoveries about the Universe. The new website will be a platform for science projects where the public can take their pick of where and how they can make meaningful contributions to new scientific discoveries.

Link: Zooniverse

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13
Dec 09

First pictures from the new VISTA

Source: ESO 49/09 - Organisation Release

The new infrared southern sky survey telescope VISTA (Visible and Infrared Survey Telescope for Astronomy) right here on Earth has gone online and released its first few wonderful pictures of the Universe.

FlameNebula
Flame Nebula, or NGC 2024, in the constellation of Orion (the Hunter). Credit: ESO/VISTA.

VISTA is the latest telescope to be added to ESO’s Paranal Observatory in the Atacama Desert of northern Chile. It is housed on the peak adjacent to the one hosting the ESO Very Large Telescope (VLT) and shares the same exceptional observing conditions. VISTA’s main mirror is 4.1 metres across and is the most highly curved mirror of this size and quality ever made — its deviations from a perfect surface are less than a few thousandths of the thickness of a human hair — and its construction and polishing presented formidable challenges. (read more)

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12
Dec 09

Magnetic Dance of Titan and Saturn To Be Main Attraction during Flyby

Source: NASA

cassini20091211-browse

Artists impression of the rendez-vous. Credit: NASA.

When it flies by Saturn's largest moon, Titan, this weekend, NASA's Cassini spacecraft will study the interactions between the magnetic field of Saturn and Titan. The flyby will take place the evening of Dec. 11 California time, or shortly after midnight Universal Time on Dec. 12.

As Titan plows through the magnetic bubble, or magnetosphere around Saturn, it creates a wake in the magnetic field lines coming away from the planet. This flyby will allow Cassini's fields and particles instruments to study that wake about 5,200 kilometers (3,200 miles) away from the moon, a relatively unexamined region. Other instruments will also be taking a closer look at Titan's clouds.

At closest approach to Titan, Cassini will swing to within about 4,900 kilometers (3,000 miles) of the surface of the moon. (read more)

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12
Dec 09

ESA’s Tigers on prowl for solar corona’s secrets

Source: ESA

Proba3-3bis_medium,0

Two-spacecraft coronagraph. Credit: ESA.

Bring together a small group of highly motivated researchers, grant them full access to laboratory and production facilities, remove all administrative distractions, and let them work intensively for four to six months. That’s what ‘StarTiger’ is all about!

Within this initiative, ESA is running a six-month crash effort to design an instrument to operate between a pair of satellites flying in formation. One will cast a precisely-controlled shadow across the other to produce a perpetual solar eclipse, revealing parts of the Sun’s corona usually hidden in sunlight. (read more)

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11
Dec 09

IC 4970 and NGC 6872: Galaxy Collision Switches on Black Hole

Source: Chandra X-Ray Observatory
ngc6872_w1

This composite image of data from three different telescopes shows an ongoing collision between two galaxies, NGC 6872 and IC 4970 (roll your mouse over the image above). X-ray data from NASA's Chandra X-ray Observatory is shown in purple, while Spitzer Space Telescope's infrared data is red and optical data from ESO's Very Large Telescope (VLT) is colored red, green and blue. Credit NASA/ESO.

Astronomers think that supermassive black holes exist at the center of most galaxies. Not only do the galaxies and black holes seem to co-exist, they are apparently inextricably linked in their evolution. To better understand this symbiotic relationship, scientists have turned to rapidly growing black holes - so-called active galactic nucleus (AGN) - to study how they are affected by their galactic environments.

The latest data from Chandra and Spitzer show that IC 4970, the small galaxy at the top of the image, contains an AGN, but one that is heavily cocooned in gas and dust. This means in optical light telescopes, like the VLT, there is little to see. X-rays and infrared light , however, can penetrate this veil of material and reveal the light show that is generated as material heats up before falling onto the black hole (seen as a bright point-like source).

Despite this obscuring gas and dust around IC 4970, the Chandra data suggest that there is not enough hot gas in IC 4970 to fuel the growth of the AGN. Where, then, does the food supply for this black hole come from? The answer lies with its partner galaxy, NGC 6872. These two galaxies are in the process of undergoing a collision, and the gravitational attraction from IC 4970 has likely pulled over some of NGC 6872's deep reservoir of cold gas (seen prominently in the Spitzer data), providing a new fuel supply to power the giant black hole. (read more)

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10
Dec 09

Newly discovered star one of hottest in Galaxy

Source: Jodrell Bank Centre for Astrophysics

bugnebula-hst-annotated

Despite numerous attempts by astronomers across the world, the mysterious dying star at the heart of the Bug nebula - one of the brightest and most beautiful of the planetary nebulae - has never been seen before. The first image of the star at the center of the Bug Nebula (NGC 6302) has now been taken by a team of astronomers at the Jodrell Bank Centre for Astrophysics, using the newly refurbished Hubble Space Telescope. This star, one of the hottest in the galaxy, has a temperature of about 200,000 Kelvin – 33 times hotter than the Sun – and is at the center of one of the most beautiful planetary nebula in the galaxy.

(read more)

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10
Dec 09

Extra Star Found in the Big Dipper

Source: EurekAlert

big-dipper

Astronomers have found an additional star located in the Dipper's gripper that is invisible to the unaided eye. Alcor, one of the stars that makes the bend in the Big Dipper's handle has a smaller red dwarf companion orbiting it. Now known as "Alcor B," the star was found with an innovative technique called "common parallactic motion," and was found by members of Project 1640, an international collaborative team that gives a nod to the insight of Galileo Gallilei.

(read more)

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9
Dec 09

XMM-Newton celebrates decade of discovery

Source: ESA

XMM-Newton(1)
An artist's impression of XMM-Newton.
Credits: ESA (Image by C. Carreau)

ESA's XMM-Newton X-ray observatory is celebrating its 10th anniversary. During its decade of operation, this remarkable space observatory has supplied new data for every aspect of astronomy. From our cosmic backyard to the further reaches of the Universe, XMM-Newton has changed the way we think of space. (read more)

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9
Dec 09

365 Days of Astronomy Podcast continues for another year

Source:365-days-logo2365 Days of Astronomy Podcast

The award-winning 365 Days of Astronomy Podcast has announced that the project will continue for another 365 days, and is now accepting sign-ups for participants for 2010. Whether you're a seasoned podcaster or if you have never picked up a microphone before, anyone with a love of space exploration and astronomy is welcome to sign up to do a podcast.

Link:
365 Days of Astronomy Podcast

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8
Dec 09

The renewed Hubble reveals most distant galaxies yet

Source: Royal Astronomical Society

Using the recently updated Hubble Space Telescope (HST) two teams of UK astronomers have identified galaxies which are likely to be the most distant yet seen. The UK teams, one led by Andrew Bunker and Stephen Wilkins at the University of Oxford and the other by Ross McLure and Jim Dunlop at the University of Edinburgh, share their results in forthcoming papers in Monthly Notices of the Royal Astronomical Society.Read more

Universe-origin
Image shows a portion of the Hubble Deep Field, with a potentially very distant galaxy marked by the cross-hairs.
(Credit: NASA, ESA, STScI)

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