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Hubble Captures Strobe Flashes From A Young Star

February 13, 2013 Leave a comment

Image credit: NASA, ESA, J. Muzerolle (STScI)

Image credit: NASA, ESA, J. Muzerolle (STScI)

The NASA/ESA Hubble Space Telescope has produced a time-lapse movie of a mysterious protostar that behaves like a flashing light. Every 25.34 days, the object, designated LRLL 54361, unleashes a burst of light which propagates through the surrounding dust and gas. This is only the third time this phenomenon has been observed, and it is the most powerful such beacon seen to date. It is also the first to be seen associated with a light echo.

The cause of the fireworks seen in this Hubble image and video is hidden behind a dense disc and envelope of dust. However, astronomers think that the strobe effect is due to periodic interactions between two newly-formed stars that are gravitationally bound to each other.

These two stars drag material inwards from a surrounding disc of gas and dust. Astronomers propose that the light flashes seen in this video are due to this material suddenly being dumped onto the growing stars as they near one another in their orbits, unleashing a blast of radiation.

Full Story: http://www.spacetelescope.org/news/heic1303/
Also: http://hubblesite.org/newscenter/archive/releases/2013/04/full/

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NASA’s Deep Impact Spacecraft Eyes Comet ISON

February 13, 2013 Leave a comment

NASA’s Deep Impact spacecraft has acquired its first images of comet C/2012 S1 (ISON). The images were taken by the spacecraft’s Medium-Resolution Imager over a 36-hour period on Jan. 17 and 18, 2013, from a distance of 493 million miles (793 million kilometers). Many scientists anticipate a bright future for comet ISON; the spaceborne conglomeration of dust and ice may put on quite a show as it passes through the inner solar system this fall.

“This is the fourth comet on which we have performed science observations and the farthest point from Earth from which we’ve tried to transmit data on a comet,” said Tim Larson, project manager for the Deep Impact spacecraft at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “The distance limits our bandwidth, so it’s a little like communicating through a modem after being used to DSL. But we’re going to coordinate our science collection and playback so we maximize our return on this potentially spectacular comet.”

Full Story: http://www.jpl.nasa.gov/news/news.php?release=2013-047

Direct Infrared Image Of An Arm In Disk Demonstrates Transition to Planet Formation

February 13, 2013 Leave a comment

An international team of astronomers led by Satoshi Mayama (The Graduate University for Advanced Studies, Japan) and Ruobing Dong (Princeton University, U.S.A.) has made observations with the Subaru Telescope and captured the first vivid infrared image of a curved arm of dust extending over a hole on a disk around a young star–2MASS J16042165-2130284 (J 1604). This feature indicates the probable existence of unseen planets within the hole. The image shows the dynamic environment in which planets may be born and gives information about constraints on the distance at which planets can form from a central star.

Research over the past two decades has confirmed that new stars are often surrounded by disks of dense gas and dust (“protoplanetary disks”) from which planets form. A central star enters an active phase of planet building when it is a few million years old. During this period, newborn planets may deplete some of the gas and dust in the disk, producing a hole within it, although the outer ring remains. However, the debatable origins of the hole require direct observation to confirm this process. Direct imaging of the structures that indicate planet building inside of the hole have rarely occurred—until now.

Full Story: http://naoj.org/Pressrelease/2013/02/07/index.html

WISE Feels The Heat From Orion’s Sword

February 13, 2013 Leave a comment

Image Credit: NASA/JPL-Caltech/UCLA

Image Credit: NASA/JPL-Caltech/UCLA

The tangle of clouds and stars that lie in Orion’s sword is showcased in a new, expansive view from NASA’s Wide-field Infrared Survey Explorer, or WISE.

WISE scanned the whole sky in infrared light, capturing this vast view of the dynamic region, called the Orion nebula. The telescope picked up the infrared glow from dust heated by newborn stars. The colors green and red highlight this warmed dust, while the white regions are the hottest. Massive stars burned through the dust, carving out cavities, the largest of which is seen at the center of the picture.

Astronomers think that our sun was probably born in a similar cloud some five billion years ago. Over time, the cloud would have dispersed and the stars would have drifted apart, leaving us more isolated in space. The crowded newborn stars in the Orion nebula are less than 10 million years old — billions of years from now, they will likely spread out.

Full Story: http://www.jpl.nasa.gov/news/news.php?release=2013-046

Earth-Like Planets Are Right Next Door

February 13, 2013 Leave a comment

Using publicly available data from NASA’s Kepler space telescope, astronomers at the Harvard-Smithsonian Center for Astrophysics (CfA) have found that six percent of red dwarf stars have habitable, Earth-sized planets. Since red dwarfs are the most common stars in our galaxy, the closest Earth-like planet could be just 13 light-years away.

“We thought we would have to search vast distances to find an Earth-like planet. Now we realize another Earth is probably in our own backyard, waiting to be spotted,” said Harvard astronomer and lead author Courtney Dressing (CfA).

Red dwarf stars are smaller, cooler, and fainter than our Sun. An average red dwarf is only one-third as large and one-thousandth as bright as the Sun. From Earth, no red dwarf is visible to the naked eye.

Despite their dimness, these stars are good places to look for Earth-like planets. Red dwarfs make up three out of every four stars in our galaxy for a total of at least 75 billion. The signal of a transiting planet is larger since the star itself is smaller, so an Earth-sized world blocks more of the star’s disk. And since a planet has to orbit a cool star closer in order to be in the habitable zone, it’s more likely to transit from our point of view.

Full Story: http://www.cfa.harvard.edu/news/2013/pr201305.html

A Spiral Galaxy With A Secret

February 13, 2013 Leave a comment

Credit: NASA, ESA, the Hubble Heritage Team (STScI/AURA), and R. Gendler (for the Hubble Heritage Team). Acknowledgment: J. GaBany

Credit: NASA, ESA, the Hubble Heritage Team (STScI/AURA), and R. Gendler (for the Hubble Heritage Team). Acknowledgment: J. GaBany

Despite its appearance, which looks much like countless other galaxies, Messier 106 hides a number of secrets. Thanks to this image, which combines data from Hubble with observations by amateur astronomers Robert Gendler and Jay GaBany, they are revealed as never before.

At its heart, as in most spiral galaxies, is a supermassive black hole, but this one is particularly active. Unlike the black hole at the centre of the Milky Way, which pulls in wisps of gas only occasionally, Messier 106’s black hole is actively gobbling up material. As the gas spirals towards the black hole, it heats up and emits powerful radiation. Part of the emission from the centre of Messier 106 is produced by a process that is somewhat similar to that in a laser – although here the process produces bright microwave radiation.

As well as this microwave emission from Messier 106’s heart, the galaxy has another startling feature – instead of two spiral arms, it appears to have four. Although the second pair of arms can be seen in visible light images as ghostly wisps of gas, as in this image, they are even more prominent in observations made outside of the visible spectrum, such as those using X-ray or radio waves.

Full Story: http://www.spacetelescope.org/news/heic1302/
Also: http://heritage.stsci.edu/2013/06/caption.html

New “Retention Model” Explains Enigmatic Ribbon At Edge Of Solar System

February 13, 2013 Leave a comment

Since its October 2008 launch, NASA’s Interstellar Boundary Explorer (IBEX) has provided images of the invisible interactions between our home in the galaxy and interstellar space. Particles emanating from this boundary produce a striking, narrow ribbon, which had yet to be explained despite more than a dozen possible theories. In a new “retention model,” researchers from the University of New Hampshire and Southwest Research Institute suggest that charged particles trapped in this region create the ribbon as they escape as neutral atoms.

The Sun continually sends out a solar wind of charged particles or ions traveling in all directions at supersonic speeds. IBEX cameras measure energetic neutral atoms (ENAs) that form when charged particles become neutralized.

As solar wind ENAs leave the solar system, the majority move out in various directions, never to re-enter. However, some ENAs leave the solar system and impact other neutral atoms, becoming charges particles again. These newly formed pickup ions begin to gyrate around the local interstellar magnetic field just outside the solar system. In the regions where the magnetic field is perpendicular to their initial motion, they scatter rapidly and pile up. From those regions, some of those particles return to the solar system as secondary ENAs — ENAs that leave the solar system and become charged and then re-neutralized, only to travel back into the solar system as ENAs a second time.

“The syrup you pour on a pancake piles up before slowly oozing out to the sides,” says Dr. David McComas, IBEX principal investigator and assistant vice president of the SwRI Space Science and Engineering Division. “The secondary ENAs coming into the solar system after having been temporarily trapped in a region just outside the solar system do the same thing. As they pile up and get trapped or retained, they produce higher fluxes of ENAs from this region and form the bright ribbon seen by IBEX.”

Full Story: http://www.swri.org/9what/releases/2013/ribbon.htm
Also: http://www.eos.sr.unh.edu/news/indiv_news.shtml?NEWS_ID=1370