Hubble’s images might look flat, but this one shows a remarkable depth of field that lets us see more than halfway to the edge of the observable Universe. Credit: NASA/ESA.
While this image isn’t as deep as the Hubble Deep Field, this 14-hour exposure by the Hubble Space Telescope shows objects around a billion times fainter than what can be seen with the human eyes alone. Astronomers say this image also offers a remarkable depth of field that lets us see more than halfway to the edge of the observable Universe.
As well, this image also provides an extraordinary cross-section of the Universe in both distance and age, showing objects at different distances and stages in cosmic history, and ranges from some of our nearest neighbors to objects seen in the early years of the Universe.
Annotated image of the field around CLASS B1608+656. Credit: NASA/ESA.
Most of the galaxies visible here are members of a huge cluster called CLASS B1608+656, which lies about five billion light-years away. But the field also contains other objects, both significantly closer and far more distant, including quasar QSO-160913+653228 which is so distant its light has taken nine billion years to reach us, two thirds of the time that has elapsed since the Big Bang.
Since the Hubble Deep Field combined 10 days of exposure and the eXtreme Deep Field, or XDF was assembled by combining ten years of observations (with over 2 million seconds of exposure time), this image at 14 hours of exposure may seem “small.” But it shows the power of the Hubble Space Telescope.
Also of note is that this image was “found” in the Hubble Hidden Treasures vault — where members of the public are able to search Hubble’s science for the best overlooked images that have never been seen by a general audience. This image of CLASS B1608+656 has been well-studied by scientists over the years, but this is the first time it has been published in full online.
Take a zooming view through the image in the video below and read more about this image here.
A grouping of galaxies, known as J0717 (center) is visible in this Spitzer Space Telescope image. Credit: NASA/JPL-Caltech/P. Capak (Caltech)
Talk about turning back time. Three NASA observatories — the Hubble Space Telescope, the Chandra X-Ray Observatory and the Spitzer Space Telescope — are all working together to look for the universe’s first galaxies. The project is called “Frontier Fields” and aims to examine these galaxies through a technique called gravitational lensing, which allows astronomers to peer at more distant objects when massive objects in front bend their light.
“Our overall science goal with the Frontier Fields is to understand how the first galaxies in the universe assembled,” stated Peter Capak, a research scientist with the NASA/JPL Spitzer Science Center at the California Institute of Technology and the Spitzer lead for the Frontier Fields.
“This pursuit is made possible by how massive galaxy clusters warp space around them, kind of like when you look through the bottom of a wine glass.”
Using the three observatories allows investigators to peer at the galaxies in different light wavelengths (namely, infrared for Spitzer, shorter infrared and optical for Hubble, and X-rays for Chandra). The teams also plan to learn more about how the foreground clusters influence the “warping” of the galaxies behind.
The Hubble and Spitzer telescopes are designed to locate where the galaxies are (and if they are indeed early galaxies) while Chandra can map out the X-ray emissions to better determine the galaxies’ masses. An early example of this project at work was examination of Abell 2744, which yielded a distant find: Abell2744 Y1, one of the earliest known galaxies, which was born about 650 million years after the Big Bang.
This series of images shows the asteroid P/2013 R3 breaking apart, as viewed by the NASA/ESA Hubble Space Telescope in 2013. This is the first time that such a body has been seen to undergo this kind of break-up. Credit: NASA, ESA, D. Jewitt (UCLA).
Asteroid P/2013 R3 appears to be crumbling apart in space, and astronomers using the Hubble Space Telescope recently saw the asteroid breaking into as many as 10 smaller pieces. The best explanation for the break-up is the Yarkovsky–O’Keefe–Radzievskii–Paddack (YORP) effect, a subtle effect from sunlight that can change the asteroid’s rotation rate and basically cause a rubbly-type asteroid to spin apart.
“This is a really bizarre thing to observe — we’ve never seen anything like it before,” said co-author Jessica Agarwal of the Max Planck Institute for Solar System Research, Germany. “The break-up could have many different causes, but the Hubble observations are detailed enough that we can actually pinpoint the process responsible.”
Astronomers first noticed this asteroid on September 15, 2013 and it appeared as a weird, fuzzy-looking object, as seen by the Catalina and Pan-STARRS sky-survey telescopes. A follow-up observation on Oct. 1 with the W.M. Keck telescope on Hawaii’s Mauna Kea revealed three co-moving bodies embedded in a dusty envelope that is nearly the diameter of Earth.
Then on October 29, 2013, astronomers used the Hubble Space Telescope to observe the object and saw there were actually 10 embedded objects, each with comet-like dust tails. The four largest rocky fragments are up to 200 meters/yards in radius, about twice the length of a football field.
The Hubble data showed that the fragments are drifting away from each other at a leisurely pace of 1.6 km/hr (one mile per hour), which would be slower than a strolling human.
“Seeing this rock fall apart before our eyes is pretty amazing,” said David Jewitt, from UCLA’s Department of Physics and Astronomy, who led the investigation.
The slowness of the speed at which the pieces are coming apart makes it unlikely that the asteroid is disintegrating because of a collision. That would be instantaneous and violent, with the pieces traveling away from each other at much higher speeds.
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Jewitt also said the asteroid is not coming unglued due to the pressure of interior ices warming and vaporizing, like comets do as they approach the Sun. The asteroid is too cold for ices to significantly sublimate, and it has presumably maintained its nearly 480 million-km (300 million–mile) distance from the Sun for much of its life.
Jewitt described the YORP torque effect as like grapes on a stem being gently pulled apart due to centrifugal force of an unusually shaped asteroid as it speeds up in its spin. This effect occurs when light from the Sun is absorbed by a body and then re-emitted as heat. When the shape of the emitting body is not perfectly regular, more heat is emitted from some regions than others. This creates a small imbalance that causes a small but constant torque on the body, which changes its spin rate. This effect has been discussed by scientists for several years but, so far, never reliably observed.
For the break-up to happen, P/2013 R3 must have a weak, fractured interior, probably as the result of previous but ancient collisions with other asteroids. Most small asteroids, in fact, are thought to have been severely damaged in this way, giving them a “rubble pile” internal structure. P/2013 R3 itself is probably the product of collisional shattering of a bigger body some time in the last billion years.
With Hubble’s recent discovery of an a different active asteroid spouting six tails (P/2013 P5), astronomers are seeing more circumstantial evidence that the pressure of sunlight may be the primary force that disintegrates small asteroids (less than a mile across) in the Solar System.
The asteroid’s remnant debris, estimated at weighing in at 200,000 tons, in the future will provide a rich source of meteoroids, Jewitt said. Most will eventually plunge into the sun, but a small fraction of the debris may one day enter the Earth’s atmosphere to blaze across the sky as meteors, he said.
The discovery is published online March 6 in Astrophysical Journal Letters. A preprint of the paper can be found here.
Massive stars can devastate their surroundings, unleashing hot winds and blasting radiation. With a mass over 100 times heavier than the Sun and a luminosity a million times brighter than the Sun, Eta Carinae clocks in as one of the biggest and brightest stars in our galaxy.
The enigmatic object walks a thin line between stellar stability and tumultuous explosions. But now a team of international astronomers is growing concerned that it’s leaning toward instability and eruption.
In the 19th Century the star mysteriously threw off unusually bright light for two decades in an event that became known as the “Great Eruption,” the causes of which are still up for debate. John Herschel and others watched as Eta Carinae’s brightness oscillated around that of Vega — rivaling a supernova explosion.
We now know the star ejected material in the form of two big globes. “During the eruption the star threw off more than 10 solar masses, which can now be observed as the surrounding bipolar nebula,” said lead author Dr. Andrea Mehner from the European Southern Observatory. Miraculously the star survived, but the nebula has been expanding into space ever since.
Eta Carinae has been observed at the South African Astronomical Observatory — a 0.75m telescope outside of Cape Town — for more than 40 years, providing a wealth of data. From the start of observations in 1976 until 1998, astronomers saw an increase across the J, H, K and L bands — filters, which allow certain wavelength ranges of infrared light to pass through.
“This data set is unique for its consistency over a timespan of more than 40 years,” Mehner told Universe Today. “It provides us with the opportunity to analyze long-term changes in the system as Eta Carinae still recovers from its Great Eruption.”
In order to understand the longterm overall increase in light we have to look at a more recent discovery noted in 2005 when scientists discovered that Eta Carinae is actually two stars: a massive blue star and a smaller companion. The temperature increased for 15 years until the companion came very close to the massive star, reaching periastron.
This increase in brightness is likely due to an overall increase in temperature of some component of the Eta Carinae system (which includes the massive blue star, its smaller companion, and the shells of gas and dust that now enshroud the system).
After 1998, however, the linear trend changed significantly and the star’s brightness increased much more rapidly in the J and H bands. It’s getting bluer, which in astronomy, typically means it’s getting hotter.
However, it’s unlikely the star itself is getting hotter. Instead we are seeing the effect of dust around the star being destroyed rapidly. Dust absorbs blue light. So if the dust is getting destroyed, more blue light will be able to pass through the nebulous globes surrounding the system. If this is the case, then we’re really seeing the star as it truly is, without dust absorbing certain wavelengths of its light.
While the nebula is slowly expanding and the dust is therefore dissipating, the authors do not think it’s enough to account for the recent brightening. Instead Eta Carinae is likely rotating at a different speed or losing mass at a different rate. “The changes observed may imply that the star is becoming more unstable and may head towards another eruptive phase,” Mehner told Universe Today.
Perhaps Eta Carinae is heading toward another “Great Eruption.” Only time will tell. But in a field where most events occur on a timescale of millions of years, it’s a great opportunity to watch the system evolve on a human time scale. And when Eta Carinae reaches periastron in the middle of this year, tens of telescopes will be collecting its light, hoping to see a sudden turn of events that may help us explain this exotic system.
The paper has been accepted for publication in Astronomy & Astrophysics and is available for download here.
Arp 147 contains a spiral galaxy (right) that collided with an elliptical galaxy (left), triggering a wave of star formation. Credit: X-ray: NASA/CXC/MIT/S.Rappaport et al, Optical: NASA/STScI
Like millionaires that burn through their cash too quickly, astronomers have found one factor behind why compact elliptical galaxies stopped growing stars about 11 billion years ago: they ate through their gas reserves.
The revelation comes as researchers released a new evolutionary track for compact elliptical galaxies that stopped their star formation when the universe was just three billion years old. When these galaxies ran out of gas, some of them cannibalized smaller galaxies to create giant elliptical galaxies. The “burned-out”galaxies have stars crowding 10 to 100 times more densely than elliptical galaxies formed more recently through a different evolutionary track.
“We at last show how these compact galaxies can form, how it happened, and when it happened. This basically is the missing piece in the understanding of how the most massive galaxies formed, and how they evolved into the giant ellipticals of today,” stated Sune Toft, who led the study and is a researcher at the Dark Cosmology Center at the Niels Bohr Institute in Copenhagen.
“This had been a great mystery for many years, because just three billion years after the Big Bang we see that half of the most massive galaxies have already completed their star formation.”
How massive elliptical galaxies evolved in about 13 billion years. Credit: NASA, ESA, S. Toft (Niels Bohr Institute), and A. Feild (STScI)
The team got a snapshot of these galaxies’ evolution by looking at a representative sample with the Hubble Space Telescope, specifically through the Cosmic Assembly Near-Infrared Deep Extragalactic Legacy Survey (CANDELS) and a spectroscopic survey called 3D-HST. To find out how old the stars were, they combined the Hubble work with data gathered from the Spitzer Space Telescope and the Subaru Telescope in Hawaii.
Next, they examined ancient, fast-star-forming submillimeter galaxies with data gathered from a range of space and ground-based telescopes.
The Hubble Space Telescope. image credit: NASA, tweaked by D. Majaess.
“This multi-spectral information, stretching from optical light through submillimeter wavelengths, yielded a full suite of information about the sizes, stellar masses, star-formation rates, dust content, and precise distances of the dust-enshrouded galaxies that were present early in the universe,” Hubble’s news center stated.
The group found that that the submillimeter galaxies were likely “progenitors” of compact elliptical galaxies, as they share predicted characteristics of the ancestors. Further, researchers calculated that starbursts in submillimeter galaxies only went on for about 40 million years before the galaxies ran out of gas.
The rotation of the Earth captured in the trails of the stars over Cape Canaveral Air Force Station on Jan 23, 2014. NASA's latest Tracking & Data Relay Satellite, TDRS-L, is seen here hitching a fiery ride to orbit atop an Atlas-V rocket, as viewed from the Turn Basin on Kennedy Space Center just a few miles away. Credit: Mike Killian/www.MikeKillianPhotography.com/AmericaSpace
The rotation of the Earth captured in the trails of the stars over Cape Canaveral Air Force Station on Jan 23, 2014. NASA’s latest Tracking & Data Relay Satellite, TDRS-L, is seen here hitching a fiery ride to orbit atop an Atlas-V rocket, as viewed from the Turn Basin on Kennedy Space Center just a few miles away. Credit: Mike Killian/www.MikeKillianPhotography.com/AmericaSpace
see Atlas V/TDRS-L Launch Galley below Story updated[/caption]
Space photographer Mike Killian has captured an absolutely stunning astrophoto of this week’s Atlas V blastoff that innovatively combines astronomy and rocketry – its the streak shot featured above. See additional Atlas launch imagery below – and here.
Mike’s awe inspiring imagery melds Thursday night’s (Jan. 23) spectacular Atlas V liftoff of NASA’s latest Tracking & Data Relay Satellite (TDRS) from Cape Canaveral, Florida, with brilliant star trails, reflecting the Earth’s rotation, moving in the crystal clear dark sky overhead and brilliantly glowing xenons and flaming reflections in the waters beneath.
Update 30 Jan: This fabulous star trails/streak image has been featured as the APOD on Jan 30, 2014.
TDRS-L awaits launch atop Atlas V rocket. Credit: Mike Killian/mikekillianphotography.com
The 3.8 ton TDRS-L communications satellite was successfully delivered by the Atlas V to orbit where it will become an essential member of NASA’s vital network to relay all the crucial science and engineering data from a wide variety of science satellites – including the Hubble Space Telescope and the International Space Station.
The United Launch Alliance Atlas V launched at 9:33 p.m. from Pad 40.
Read my complete Atlas V/TDRS-L launch story – here.
Killian’s very creative image makes it looks as though the fiery rocket plume is slicing and dicing a path though the wandering stars as its thundering off the pad, arcing out over the Atlantic Ocean and soaring on to orbit.
And it’s all perfectly framed – as detailed below in my interview with Mike Killian.
Water reflection shot of NASA TDRS-L satellite launch aboard Atlas V rocket on Jan. 23, 2014. Credit: Walter Scriptunas II – www.scriptunasimages.com
Mike is a space friend of mine and we recently spent launch week together photographing the Jan. 9 Antares rocket launch from NASA’s Wallops Island Flight Facility in Virginia, amidst the bone chilling cold of the Polar Vortex – which by the way has returned! See a photo of us freezing together at NASA Wallops – below!!
Be sure to enjoy the Atlas V gallery herein including more space photog friends including Jeff Seibert, Alan Walters, Walter Scriptunas II and nasatech.net
NASA TDRS-L relay satellite launch aboard Atlas V rocket on Jan. 23, 2014. Credit: Jeff Seibert/wired4space.com
Mike’s magnificent new astrophoto was snapped from the Press Site at the Kennedy Space Center – located right next to the world famous countdown clock and the Vehicle Assembly Building (VAB).
The two launch sites – NASA Wallops and Cape Canaveral/NASA Kennedy Space Center – sit about 800 miles apart on the US East Coast.
His stunning new astrophoto was several years in the making and the result of rather careful planning and of course some good luck too.
Mike is a very experienced and exceptionally talented and accomplished photographer in general.
So for the benefit of Universe Today readers, I asked Mike to describe how he planned, executed and processed the fabulous Jan. 23 star trail/Atlas launch photo.
“I’ve wanted to attempt this shot for 2 years now & finally the conditions for it came together Thursday night – no moonlight, no clouds, barely a breeze, mostly dry air & enough TIME between sunset and liftoff to capture some descent star trails,” Mike Killian told me.
What was the shooting time and equipment involved?
“Approximate total shooting time was about 3 hours, 380 20-second exposures @ ISO 400, shot with a Canon T4i w/ a 11-16mm Tokina 2.8 lens,” said Killian.
“For the launch I adjusted those setting for the rocket’s bright flame, did that exposure, then took the images and stacked using Photoshop. All images are the exact same framing.”
Killian took the photos from right along the edge of the water basin at the Press Site at the Kennedy Space Center, located right next to the VAB where NASA’s Saturn V Moon rockets and Space Shuttles were processed for launch.
NASA TDRS-L relay satellite launch aboard Atlas V rocket on Jan. 23, 2014. Credit: Jeff Seibert/wired4space.com
Why shoot from Kennedy Space Center instead of Cape Canaveral?
“I chose to shoot from the water’s edge at Turn Basin mainly because of the water, I always like a nice reflection from the xenon lights and the launch itself.
“Plus I knew nobody would shoot from there, as both the VAB roof & Cape Canaveral were available for media to view from (both have fantastic views).”
“I wanted to do something different.”
“Generally we get an hour or so at whatever area we are shooting any given launch from, before heading back to the press site.”
“But since the Turn Basin is AT the press site, the location was open for several hours due to TDRS-L being a night launch.”
“So I had enough time to attempt this shot from about as close as you can get (4 miles or so)!
Is Mike pleased with the result?
“I’m happy with how this one came out!” Mike ecstatically told me.
For some background on the VAB and the imminent end of public tours inside – read my new VAB story, here.
And here’s my daytime shot showing the Turn Basin and Mike’s approximate shooting location at the KSC Press Site. Mike is shooting in the opposite direction – from waters edge looking to the right.
View of the Vehicle Assembly Building (VAB) and the Turn Basin adjacent to the Kennedy Space Center Press Center and the countdown clock. Credit: Ken Kremer – kenkremer.com
Stay tuned here for Ken’s continuing Orion, Chang’e-3, Orbital Sciences, SpaceX, commercial space, LADEE, Mars and more news.
Remote camera shot of NASA TDRS-L relay satellite launch aboard Atlas V rocket on Jan. 23, 2014. Credit: Walter Scriptunas II – www.scriptunasimages.comThe TDRS-L mission begins as the Atlas V-401 roars from the pad. Credit: nasatech.netNASA’s TDRS-L blasts off atop Atlas V rocket on Jan. 23, 2014. Credit: Mike Killian/mikekillianphotography.com
Spectacular Go Pro TDRS Launch Video by Matthew Travis
Space journalists Ken Kremer/Universe Today (left) and Mike Killian and Alan Walters of AmericaSpace (center, right) setting remote cameras at Antares launch pad amidst bone chilling cold. Credit: Ken Kremer – kenkremer.comPhoto Credit: Alan Walters / AmericaSpace
A composite image (X-ray and optical wavelengths) showing galaxy cluster RX J1532.9+3021 and the black hole at its center. Credit: X-ray: NASA/CXC/Stanford/J.Hlavacek-Larrondo et al, Optical: NASA/ESA/STScI/M.Postman & CLASH team
Got gas? The black hole in galaxy cluster RX J1532.9+3021 is keeping it all for itself and stopping trillions of stars from coming to be, according to new research. You can see data above from NASA’s Chandra X-ray Observatory (purple) and the Hubble Space Telescope (yellow).
The drama is taking place about 3.9 billion light-years from Earth, showing an extreme phenomenon that has been noted in other galaxies on smaller scales, Chandra officials stated.
“The large amount of hot gas near the center of the cluster presents a puzzle,” a statement read. “Hot gas glowing with X-rays should cool, and the dense gas in the center of the cluster should cool the fastest. The pressure in this cool central gas is then expected to drop, causing gas further out to sink in towards the galaxy, forming trillions of stars along the way. However, astronomers have found no such evidence for this burst of stars forming at the center of this cluster.”
Black hole with disc and jets visualization courtesy of ESA
What’s blocking the stars (according to data from Chandra and the National Science Foundation’s Karl G. Jansky Very Large Array) could be supersonic jets blasting from the black hole and shoving the gas in the area away, forming cavities on either side of the galaxy. These cavities, by the way, are immense — at 100,000 light-years across each, this makes them about as wide as our home galaxy, the Milky Way.
The big question is where that power came from. Perhaps the black hole is “ultramassive” (10 billion times of the sun) and has ample mass to shoot out those jets without eating itself up and producing radiation. Or, the black hole could be smaller (a billion times that of the sun) but spinning quickly, which would allow it to send out those jets.
NASA's Hubble Space Telescope and Spitzer Space Telescope joined forces to discover and characterize four unusually bright galaxies as they appeared more than 13 billion years ago, just 500 million years after the big bang. Credit: NASA, ESA, G. Illingworth (University of California, Santa Cruz), P. Oesch (University of California, Santa Cruz; Yale University), R. Bouwens and I. Labbé (Leiden University), and the Science Team.
What was the Universe like more than 13 billion years ago, just 500 million years after the big bang? New data from the Hubble and Spitzer space telescopes reveal some surprisingly bright galaxies that are about 10 to 20 times more luminous than anything seen previously in that epoch.
Garth Illingworth from the University of California, Santa Cruz said the discovery of these four bright galaxies came from combining the power of both telescopes, but these galaxies lie right at the limit of the telescopes’ capabilities.
“We’re actually reaching back 13.2 billion years through the life of the Universe — that’s 96% of the life of the Universe that we are looking back at these galaxies,” said Illingworth, speaking at the American Astronomical Society meeting in Washington D.C. this week. “That’s an astonishing undertaking and an astonishing accomplishment that Hubble and Spitzer have achieved.”
Detail of the Hubble and Spitzer observations of a galaxy from the early Universe. Credit: NASA, ESA, G. Illingworth (University of California, Santa Cruz), P. Oesch (University of California, Santa Cruz; Yale University), R. Bouwens and I. Labbé (Leiden University), and the Science Team.
Illingworth said the typical galaxy candidate from that far back in time is very faint and hard to see. But these new galaxies are about 15-20 % brighter than what astronomers have seen before at redshift 10.
The tiny are bright because they are bursting with star formation activity. The brightest one is forming stars approximately 50 times faster than the Milky Way does today. Although these fledgling galaxies are only one-twentieth the size of the Milky Way, they probably contain around a billion stars crammed together.
Astronomers think these bright, young galaxies grew exceptionally fast because of interactions and mergers of smaller infant galaxies that started forming stars even earlier in the Universe. Since the ancient time billions of years ago when the light that we now see started its long journey to us, they have probably kept growing to become similar to the largest modern galaxies. Many of the stars of these infant galaxies likely live on today in the centers of giant elliptical galaxies, much larger even than our own Milky Way.
Slide from Garth Illingworth’s presentation at the 223rd American Astronomical Society meeting, describing the discovery of bright galaxies from early in the Universe. Credit: Garth Illingworth.
Illingworth said this era appears to be a timeframe where things were changing quite rapidly. “We’ve gone back to a very interesting time when the Universe is changing,” he said.
The galaxies were first detected with Hubble, and astronomers were able to measure their star-formation rates and sizes. But using Spitzer, the scientists were also able to measure the galaxies’ masses.
“This is the first-ever measurement of the mass density of the galaxies when the Universe was at 500 million years of age,” Illingworth said. “These galaxies are about a billion times the mass of our Sun, which is massive for those times, but still only 1% the mass of the Milky Way.”
Illingworth added that the mass measurements are rough estimates because of how challenging the task was.
Illingworth and team member Ivo Labbé from Leiden University said they are looking forward to finding out more about these galaxies, particularly from future observations with the upcoming James Webb Space Telescope.
“At the same time, the extreme masses and star formation rates are really mysterious,” Labbé said, “and we are eager to confirm them with future observations on our powerful telescopes.”
You can find out more about these early galaxies — and more — at the First Galaxies website.
To determine what’s in the atmosphere of an exoplanet, astronomers watch the planet pass in front of its host star and look at which wavelengths of light are transmitted and which are partially absorbed. Credit:
NASA's Goddard Space Flight Center
For the first time, astronomers have found conclusive evidence of water in the hazy atmospheres of planets orbiting other stars. Using the Hubble Space Telescope, two teams of scientists found faint but clear signatures of water in the atmospheres of five exoplanets. All five are so-called ‘hot Jupiters,’ massive worlds that orbit close to their host stars.
“To actually detect the atmosphere of an exoplanet is extraordinarily difficult. But we were able to pull out a very clear signal, and it is water,” said Drake Deming from the University of Maryland, who led a study characterizing the atmospheres of two of the five planets.
“We’re very confident that we see a water signature for multiple planets,” said Avi Mandell, a planetary scientist at NASA’s Goddard Space Flight Center, and lead author of another paper on the remaining three exoplanets. “This work really opens the door for comparing how much water is present in atmospheres on different kinds of exoplanets, for example hotter versus cooler ones.”
The five planets are all well-studied, and would not be friendly places for life as we know it — with blazing temperatures and unusual conditions. WASP-17b is an unusual planet in a retrograde orbit, and sodium had already been detected in its atmosphere.
The atmosphere of WASP-12b already has been found to hold vast amounts of carbon as well as water. WASP-19b orbits a nearby star, and has one of the shortest orbital periods of any known planetary body, about 0.7888399 days or approximately 18.932 hours. XO-1b has the distinction of being discovered by amateur astronomers
The astronomers involved in the new studies say the strengths of the water signatures in each world varied, with WASP-17b and HD209458b having the strongest signals.
Currently, studying exoplanet atmospheres can be done when the planets are passing in front of their stars. Researchers can identify the gases in a planet’s atmosphere by determining which wavelengths of the star’s light are transmitted and which are partially absorbed. Deming’s team employed a new technique with longer exposure times, which increased the sensitivity of their measurements.
In both studies, scientists used Hubble’s Wide Field Camera 3 to explore the details of absorption of light through the planets’ atmospheres. The observations were made in a range of infrared wavelengths where a pattern that signifies the presence of water would appear if water were present. The teams compared the shapes and intensities of the absorption profiles, and the consistency of the signatures gave them confidence they saw water.
“These studies, combined with other Hubble observations, are showing us that there are a surprisingly large number of systems for which the signal of water is either attenuated or completely absent,” said Heather Knutson of the California Institute of Technology, a co-author on Deming’s paper. “This suggests that cloudy or hazy atmospheres may in fact be rather common for hot Jupiters.”
Remnants of a gamma-ray burst (called GRB 130603B) are visible in these Hubble Space Telescope pictures. Credit: NASA, ESA, and Z. Levay (STScI/AURA)
As astute readers of Universe Today, you likely know what a supernova is: a stellar explosion that signals the end game for certain kinds of stars. Above, however, is a picture of a kilonova, which happens when two really dense objects come together.
This fireball arose after a short-term (1/10 of a second) gamma-ray burst came into view of the Swift space telescope on June 3. Nine days later, the Hubble Space Telescope looked at the same area to see if there were any remnants, and spotted a faint red object that was confirmed in independent observations.
It’s the first time astronomers have been able to see a connection between gamma-ray bursts and kilonovas, although it was predicted before. They’re saying this is the first evidence that short-duration gamma ray bursts arise as two super-dense stellar objects come together.
So what’s the connection? Astronomers suspect it’s this sequence of events:
Two binary neutron stars (really dense stars) start to move closer to each other;
The system sends out gravitational radiation that make ripples in space-time;
These waves make the stars move even closer together;
In the milliseconds before the explosion, the two stars “merge into a death spiral that kicks out highly radioactive material,” as NASA states, with material that gets warmer, gets bigger and sends out light;
The kilonova occurs with the detonation of a white dwarf. While it’s bright, 1,000 times brighter than a nova, it’s only 1/10th to 1/100th the brightness of an average supernova.
An artistic image of the explosion of a star leading to a gamma-ray burst. (Source: FUW/Tentaris/Maciej Fro?ow)
“This observation finally solves the mystery of the origin of short gamma ray bursts,” stated Nial Tanvir of the University of Leicester in the United Kingdom, who is also the lead author.
“Many astronomers, including our group, have already provided a great deal of evidence that long-duration gamma ray bursts (those lasting more than two seconds) are produced by the collapse of extremely massive stars. But we only had weak circumstantial evidence that short bursts were produced by the merger of compact objects. This result now appears to provide definitive proof supporting that scenario.”
