Stunning Hubble Silver Anniversary Picture Unveiled
Hubble anniversary tributes kicked off on Thursday with the unveiling a spectacular new image taken by the telescope.
NASA kicked off a series of Hubble anniversary tributes Thursday by unveiling a new image taken by the telescope, which was launched into orbit on April 24, 1990.
Managers chose a display of celestial fireworks in a giant cluster of stars known as Westerlund 2, located about 20,000 light-years away in the constellation Carina. The cluster, comprised of about 3,000 stars, is very young by astronomical standards, just about 2 million years old.
"This spectacular image shows a cloud of dense gas and dust, the gas is collapsing forming new stars," said NASA's chief scientist John Grunsfeld, an astronomer and former astronaut who was part of three different Hubble repair and servicing crews.
"It's a very vigorous breeding ground for new stars ... and it contains some of the galaxy's hottest, brightest and most massive stars that we know of," added Hubble project scientist Jennifer Wiseman, with NASA's Goddard Space Flight Center in Greenbelt, Md.
"What's great about Hubble's sharp resolution, is that we can differentiate star from star even in crowded regions like this cluster. This helps us scientifically to be able to understand what kinds of stars are in this cluster, how they're different from one another, how the population may have formed in the first place. We can study the characteristics because of Hubble's exquisite sensitivity and resolution," Wiseman said.
The image blends visible-light and near-infrared wavelengths. In the surrounding dust clouds, red represents hydrogen and the bluish-green hues are mostly oxygen.
"This is really an exciting a week for astronomers and people who love astronomy all over the world," Wiseman said.
"As we celebrate Hubble's 25th anniversary, we're celebrating some of the forefront science and the forefront discovery we've made about the universe through all those years and hopefully for years to come. This is an example of one of these spectacular images that we can get from Hubble."
A new star-forming region in the cluster Westerlund 2 in the Gum 29 interstellar cloud nebula.
Astronomers using the Hubble Space Telescope recently completed the largest and most sensitive survey of dust surrounding young star systems. The survey zoomed-in on stars that are between 10 million to 1 billion years old and the source of the dust is thought to be the left-over debris from planet, asteroid and comet collisions after systems of planets have formed.
The research is akin to looking far back into the history of our solar system, seeing the inevitable dusty mess left over after the Earth and other planets evolved. "It's like looking back in time to see the kinds of destructive events that once routinely happened in our solar system after the planets formed," said Glenn Schneider, of the University of Arizona's Steward Observatory and lead scientist on the survey team.
Read on to see some of the beautiful variety of circumstellar disks observed by Hubble.
One of the major findings to come from this survey is the stunning diversity of dust surrounding these young stars. Traditionally, circumstellar dust is thought to settle into an orderly disk-like shape -- but it turns out that the opposite is true.
"We find that the systems are not simply flat with uniform surfaces," said Schneider. "These are actually pretty complicated three-dimensional debris systems, often with embedded smaller structures. Some of the substructures could be signposts of unseen planets."
One stunning observation of the star HD 181327 exhibits a bright ring of dust containing irregularities, potential evidence of a massive collision that has scattered debris far and wide. "This spray of material is fairly distant from its host star — roughly twice the distance that Pluto is from the Sun," said Christopher Stark of NASA's Goddard Space Flight Center, Greenbelt, Md., and co-investigator in the survey team. "Catastrophically destroying an object that massive at such a large distance is difficult to explain, and it should be very rare. If we are in fact seeing the recent aftermath of a massive collision, the unseen planetary system may be quite chaotic."
Another interpretation for the irregularities could be some kind of interaction with unseen interstellar material. "Our team is currently analyzing follow-up observations that will help reveal the true cause of the irregularity," added Schneider.
Like the diversity of exoplanetary systems astronomers have discovered, it appears the accompanying dust disks also share this characteristic, possibly indicative of gravitational interactions with planets orbiting the stars surveyed by Hubble.
"How are the planets affecting the disks, and how are the disks affecting the planets? There is some sort of interdependence between a planet and the accompanying debris that might affect the evolution of these exoplanetary debris systems," said Schneider.
Since 1995, thousands of exoplanets have been discovered orbiting stars in our galaxy. Over the same period, however, only a couple of dozen circumstellar disks have been imaged directly. This is down to the fact that the scattered light off these disks is extremely faint (around 100,000 times fainter than the parent star's light). The technology and techniques are only recently becoming available for scientists to not only block the star's blinding light, but to also boost the sensitivity of observations to pick out this scattered light that would otherwise be obscured from view. Fortunately, Hubble's high-contrast imaging has been key in making this survey a success.
By studying these disks of dust and their surprising variety of morphologies may help astronomers better understand how the Earth-moon and Pluto-Charon systems formed. Through planetary collisions, the debris from the early solar system may have coalesced to create many of the natural satellites we see today, 4.6 billion years later. The results of this survey have been published in The Astrophysical Journal.