Releases from NASA, NASA Galex, NASA's Goddard Space Flight Center, HubbleSite, Hinode, Spitzer, Cassini, ESO, ESA, Chandra, HiRISE, Royal Astronomical Society, NRAO, Astronomy Picture of the Day, Harvard-Smithsonian Center For Astrophysics, Max Planck Institute for Astrophysics, Gemini Observatory, Subaru Telescope, W. M. Keck Observatory, Fermi Gamma-ray Space Telescope, JPL-Caltech, etc
used data from NASA's Wide-field Infrared Survey Explorer (WISE)
mission to highlight the X-shaped structure in the bulge of the Milky
Way. Credit: NASA/JPL-Caltech/D.Lang. › Full image and caption
To reveal the X
shape in the Milky Way's central bulge, researchers took WISE
observations and subtracted a model of how stars would be distributed in
a symmetrical bulge. Credit: NASA/JPL-Caltech/D.Lang.› Larger image
A new understanding of our galaxy's structure began in an unlikely
way: on Twitter. A research effort sparked by tweets led scientists to
confirm that the Milky Way's central bulge of stars forms an "X" shape. The newly published study uses data from NASA's Wide-field Infrared
Survey Explorer (WISE) mission.
The unconventional collaboration started in May 2015 when Dustin
Lang, an astronomer at the Dunlap Institute of the University of
Toronto, posted galaxy maps to Twitter,
using data from WISE's two infrared surveys of the entire sky in 2010.
Infrared light allows astronomers to see the structures of galaxies in
spite of dust, which blocks crucial details in visible light. Lang was
using the WISE data in a project to map the web of galaxies far outside
our Milky Way, which he made available through an interactive website.
But it was the Milky Way's appearance in the tweets that got the
attention of other astronomers. Some chimed in about the appearance of
the bulge, a football-shaped central structure that is three-dimensional
compared to the galaxy's flat disk. Within the bulge, the WISE data
seemed to show a surprising X structure, which had never been as clearly
demonstrated before in the Milky Way. Melissa Ness, a postdoctoral
researcher at the Max Planck Institute for Astronomy in Heidelberg,
Germany, recognized the significance of the X shape, and contacted Lang.
The two met a few weeks later at a conference in Michigan, and
decided to collaborate on analyzing the bulge using Lang's WISE maps.
Their work resulted in a new study published in the Astronomical Journal confirming an X-shaped distribution of stars in the bulge.
"The bulge is a key signature of formation of the Milky Way," said
Ness, the study's lead author. "If we understand the bulge we will
understand the key processes that have formed and shaped our galaxy."
The Milky Way is an example of a disk galaxy -- a collection of stars
and gas in a rotating disk. In these kinds of galaxies, when the thin
disk of gas and stars is sufficiently massive, a "stellar bar" may form,
consisting of stars moving in a box-shaped orbit around the center. Our
own Milky Way has a bar, as do nearly two-thirds of all nearby disk
Over time, the bar may become unstable and buckle in the center. The
resulting "bulge" would contain stars that move around the galactic
center, perpendicular to the plane of the galaxy, and in and out
radially. When viewed from the side, the stars would appear distributed
in a box-like or peanut-like shape as they orbit. Within that structure,
according to the new study, there is a giant X-shaped structure of
stars crossing at the center of the galaxy.
A bulge can also form when galaxies merge, but the Milky Way has not merged with any large galaxy in at least 9 billion years.
"We see the boxy shape, and the X within it, clearly in the WISE
image, which demonstrates that internal formation processes have driven
the bulge formation," Ness said. "This also reinforces the idea that our
galaxy has led a fairly quiet life, without major merging events since
the bulge was formed, as this shape would have been disrupted if we had
any major interactions with other galaxies."
The Milky Way's X-shaped bulge had been reported in previous studies.
Images from the NASA Cosmic Background Explorer (COBE) satellite's Diffuse Infrared Background Experiment
suggested a boxy structure for the bulge. In 2013, scientists at the
Max Planck Institute for Extraterrestrial Physics published 3-D maps of
the Milky Way that also included an X-shaped bulge, but these studies
did not show an actual image of the X shape. Ness and Lang's study uses
infrared data to show the clearest indication yet of the X shape.
Additional research is ongoing to analyze the dynamics and properties of the stars in the Milky Way's bulge.
Collaborating on this study was unusual for Lang -- his expertise is
in using computer science to understand large-scale astronomical
phenomena, not the dynamics and structure of the Milky Way. But he was
able to enter a new field of research because he posted maps to social
media and used openly accessible WISE data.
"To me, this study is an example of the interesting, serendipitous
science that can come from large data sets that are publicly available,"
he said. "I'm very pleased to see my WISE sky maps being used to answer
questions that I didn't even know existed."
NASA's Jet Propulsion Laboratory, Pasadena, California, manages and
operates WISE for NASA's Science Mission Directorate in Washington. The
spacecraft was put into hibernation mode in 2011, after it scanned the
entire sky twice, thereby completing its main objectives. In September
2013, WISE was reactivated, renamed NEOWISE and assigned a new mission
to assist NASA's efforts to identify potentially hazardous near-Earth
Fifty years ago Captain Kirk and the crew
of the starship Enterprise began their journey into space — the final
frontier. Now, as the newest Star Trek film hits cinemas, the NASA/ESA
Hubble space telescope is also exploring new frontiers, observing
distant galaxies in the galaxy cluster Abell S1063 as part of the
Frontier Fields programme.
Space... the final frontier. These are the stories of the Hubble
Space Telescope. Its continuing mission, to explore strange new worlds
and to boldly look where no telescope has looked before.
The newest target of Hubble’s mission is the distant galaxy cluster
Abell S1063, potentially home to billions of strange new worlds.
This view of the cluster, which can be seen in the centre of the
image, shows it as it was four billion years ago. But Abell S1063 allows
us to explore a time even earlier than this, where no telescope has
really looked before. The huge mass of the cluster distorts and
magnifies the light from galaxies that lie behind it due to an effect
called gravitational lensing.
This allows Hubble to see galaxies that would otherwise be too faint to
observe and makes it possible to search for, and study, the very first
generation of galaxies in the Universe. “Fascinating”, as a famous Vulcan might say.
The first results from the data on Abell S1063 promise some
remarkable new discoveries. Already, a galaxy has been found that is
observed as it was just a billion years after the Big Bang.
Astronomers have also identified sixteen background galaxies whose
light has been distorted by the cluster, causing multiple images of them
to appear on the sky. This will help astronomers to improve their
models of the distribution of both ordinary and dark matter in the
galaxy cluster, as it is the gravity from these that causes the
distorting effects. These models are key to understanding the mysterious
nature of dark matter.
Abell S1063 is not alone in its ability to bend light from background
galaxies, nor is it the only one of these huge cosmic lenses to be
studied using Hubble. Three other clusters have already been observed as
part of the Frontier Fields programme,
and two more will be observed over the next few years, giving
astronomers a remarkable picture of how they work and what lies both
within and beyond them .
Data gathered from the previous galaxy clusters were studied by teams
all over the world, enabling them to make important discoveries, among
them galaxies that existed only hundreds of million years after the Big
Bang (heic1523) and the first predicted appearance of a gravitationally lensed supernova (heic1525).
Such an extensive international collaboration would have made Gene
Roddenberry, the father of Star Trek, proud. In the fictional world
Roddenberry created, a diverse crew work together to peacefully explore
the Universe. This dream is partially achieved by the Hubble programme
in which the European Space Agency (ESA), supported by 22 member states,
and NASA collaborate to operate one of the most sophisticated
scientific instruments in the world. Not to mention the scores of other
international science teams that cross state, country and continental
borders to achieve their scientific aims.
 The Hubble Frontier Fields is a three-year, 840-orbit programme
which will yield the deepest views of the Universe to date, combining
the power of Hubble with the gravitational amplification of light around
six different galaxy clusters to explore more distant regions of space
than could otherwise be seen.
More Information The Hubble Space Telescope is a project of international cooperation between ESA and NASA. Image credit: NASA, ESA, and J. Lotz (STScI)
This NASA/ESA Hubble Space Telescope image reveals the vibrant core of the galaxy NGC 3125. Discovered by John Herschel in 1835, NGC 3125 is a great example of a starburst galaxy — a galaxy in which unusually high numbers of new stars are forming, springing to life within intensely hot clouds of gas.
Located approximately 50 million light-years away in the constellation of Antlia (The Air Pump), NGC 3125 is similar to, but unfathomably brighter and more energetic than, one of the Magellanic Clouds.
Spanning 15 000 light-years, the galaxy displays massive and violent
bursts of star formation, as shown by the hot, young, and blue stars
scattered throughout the galaxy’s rose-tinted core. Some of these clumps
of stars are notable — one of the most extreme Wolf–Rayet star clusters in the local Universe, NGC 3125-A1, resides within NGC 3125.
Despite their appearance, the fuzzy white blobs dotted around the edge of this galaxy are not stars, but globular clusters. Found within a galaxy’s halo,
globular clusters are ancient collections of hundreds of thousands of
stars. They orbit around galactic centres like satellites — the Milky
Way, for example, hosts over 150 of them.
is one slice through the map of the large-scale structure of the
Universe from the Sloan Digital Sky Survey and its Baryon Oscillation
Spectroscopic Survey. Each dot in this picture indicates the position of
a galaxy 6 billion years into the past. The image covers about 1/20th
of the sky, a slice of the Universe 6 billion light-years wide, 4.5
billion light-years high, and 500 million light-years thick. Colour
indicates distance from Earth, ranging from yellow on the near side of
the slice to purple on the far side. Galaxies are highly clustered,
revealing superclusters and voids whose presence is seeded in the first
fraction of a second after the Big Bang. This image contains 48,741
galaxies, about 3% of the full survey dataset. Grey patches are small
regions without survey data. Image credit: Daniel Eisenstein and SDSS-III.Hi-res image
What are the properties of Dark Energy? This question is one of the most intriguing ones in astronomy and scientists are one step closer in answering this question with the largest three-dimensional map of the universe so far: This map contains 1.2 million galaxies in a volume spanning 650 cubic billion light years. Hundreds of scientists from the Sloan Digital Sky Survey III (SDSS-III) – including researchers at the Max Planck Institutes for Extraterrestrial Physics and for Astrophyics - used this map to make one of the most precise measurements yet of dark energy. They found excellent agreement with the standard cosmological model and confirmed that dark energy is highly consistent with a cosmological constant.
"We have spent a decade collecting measurements of 1.2 million
galaxies over one quarter of the sky to map out the structure of the
Universe over a volume of 650 cubic billion light years,” says Jeremy
Tinker of New York University, a co-leader of the scientific team that
led this effort. Hundreds of scientists are part of the Sloan Digital
Sky Survey III (SDSS-III) team.
These new measurements were carried out by the Baryon Oscillation
Spectroscopic Survey (BOSS) programme of SDSS-III. Shaped by a
continuous tug-of-war between dark matter and dark energy, the map
revealed by BOSS allows astronomers to measure the expansion rate of the
Universe by determining the size of the so-called baryonic acoustic
oscillations (BAO) in the three-dimensional distribution of galaxies.
Pressure waves travelled through the young Universe up to when it was
only 400,000 years old at which point they became frozen in the matter
distribution of the Universe. The end result is that galaxies are
preferentially separated by a characteristic distance, which astronomers
call the BAO scale. The primordial size of the BAO scale is exquisitely
determined from observations of the cosmic microwave background.
Ariel Sanchez of the Max-Planck Institute of Extraterrestrial Physics
(MPE) led the effort to estimate the exact amount of dark matter and
dark energy based on the BOSS data and explains: "Measuring the acoustic
scale across cosmic history gives a direct ruler with which to measure
the Universe’s expansion rate. With BOSS, we have traced the BAO’s
subtle imprint on the distribution of galaxies spanning a range of time
from 2 to 7 billion years ago."
For the very precise measurements, however, the data had to be
painstakingly analysed. Especially the determination of distances to the
galaxies posed a big challenge. This is inferred from the galaxy
spectra, which show that a galaxy’s light is shifted to the red part of
the spectrum because it moves away from us. This so-called redshift is
correlated with a galaxy’s distance: The farther a galaxy is away from
us, the faster it moves.
“However, galaxies also have peculiar motions and the peculiar
velocity component along the line-of-sight leads to the so-called
redshift space distortion,” explains Shun Saito from the Max Planck
Institute for Astrophysics (MPA), who contributed sophisticated models
to the BOSS data analysis. “This makes the galaxy distribution
anisotropic because the line-of-sight direction is now special – only
along this direction the distance is measured through a redshift, which
is contaminated by peculiar velocity. In other words, the characteristic
anisotropic pattern allows us to measure the peculiar velocity of
galaxies – and because the motion of galaxies is governed by gravity, we
can use this measurement to constrain to what level Einstein’s general
relativity is correct at cosmological scales. In order to properly
interpret the data, we have developed a refined model to describe the galaxy distribution.”
Another approach, used by a junior MPE researcher for his PhD thesis,
is to use the angular positions of galaxies on the sky instead of
physical 3D positions. “This method uses only observables,” explains
Salvador Salazar. “We make no prior assumptions about the cosmological
Around the world, other groups all used slightly different models and
methodologies to analyse the huge BOSS data set. “We now have seven
measurements, which are slightly different, but highly correlated,”
Ariel Sanchez points out. “To extract the most information about the
cosmological parameters, we had to find not only the best methods and
models for data analysis but also the optimal combination of these
This analysis has now born fruit: the BOSS data show that dark
energy, which is driving the cosmological expansion, is consistent with a
cosmological constant within an error of only 5%. This constant, called
Lambda, was introduced by Albert Einstein to counter the attractive
force of matter, i.e. it has a repellent effect. Moreover, all results
are fully consistent with the standard cosmological model, giving
further strength to this still relatively young theory.
In particular, the map also reveals the distinctive signature of the
coherent movement of galaxies toward regions of the Universe with more
matter, due to the attractive force of gravity. Crucially, the observed
amount of infall matches well to the predictions of general relativity.
This supports the idea that the acceleration of the expansion rate is
driven by a phenomenon at the largest cosmic scales, such as dark
energy, rather than a breakdown of our gravitational theory.
1. Jan Niklas Grieb, Ariel G. Sánchez, Salvador Salazar-Albornoz et al. (the BOSS collaboration) The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: Cosmological implications of the Fourier space wedges of the final sample submitted to MNRAS Source
2. Salvador Salazar-Albornoz, Ariel G. Sanchez, Jan Niklas Grieb et al. The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: Angular clustering tomography and its cosmological implications submitted to MNRAS Source
3. Ariel G. Sanchez, Jan Niklas Grieb, Salvador Salazar-Albornoz et al. The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: combining correlated Gaussian posterior distributions submitted to MNRAS Source
4. Ariel G. Sanchez, Roman Scoccimarro, Martin Crocce et al. The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: cosmological implications of the configuration-space clustering wedges submitted to MNRAS Source
5. Florian Beutler, Hee-Jong Seo, Shun Saito et al. The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: Anisotropic galaxy clustering The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: Baryon Acoustic Oscillations in Fourier-space submitted to MNRAS Source
Using NASA's Hubble Space Telescope, astronomers have conducted the
first search for atmospheres around temperate, Earth-sized planets
beyond our solar system and found indications that increase the chances
of habitability on two exoplanets.
Specifically, they discovered that the exoplanets TRAPPIST-1b and
TRAPPIST-1c, approximately 40 light-years away, are unlikely to have
puffy, hydrogen-dominated atmospheres usually found on gaseous worlds.
"The lack of a smothering hydrogen-helium envelope increases the
chances for habitability on these planets," said team member Nikole
Lewis of the Space Telescope Science Institute (STScI) in Baltimore,
Maryland. "If they had a significant hydrogen-helium envelope, there is
no chance that either one of them could potentially support life
because the dense atmosphere would act like a greenhouse."
Julien de Wit of the Massachusetts Institute of Technology in
Cambridge, Massachusetts, led a team of scientists to observe the
planets in near-infrared light using Hubble's Wide Field Camera 3. They
used spectroscopy to decode the light and reveal clues to the chemical
makeup of an atmosphere. While the content of the atmospheres is
unknown and will have to await further observations, the low
concentration of hydrogen and helium has scientists excited about the
"These initial Hubble observations are a promising first step in
learning more about these nearby worlds, whether they could be rocky
like Earth, and whether they could sustain life," said Geoff Yoder,
acting associate administrator for NASA's Science Mission Directorate
in Washington, D.C. "This is an exciting time for NASA and exoplanet
The planets orbit a red dwarf star at least 500 million years old, in
the constellation of Aquarius. They were discovered in late 2015
through a series of observations by the TRAnsiting Planets and
PlanetesImals Small Telescope (TRAPPIST), a Belgian robotic telescope
located at the European Southern Observatory’s (ESO’s) La Silla
Observatory in Chile.
TRAPPIST-1b completes a circuit around its red dwarf star in 1.5 days
and TRAPPIST-1c in 2.4 days. The planets are between 20 and 100 times
closer to their star than Earth is to the sun. Because their star is so
much fainter than our sun, researchers think that at least one of the
planets, or possibly both, may be within the star's habitable zone,
where moderate temperatures could allow for liquid water to pool.
On May 4, astronomers took advantage of a rare simultaneous transit,
when both planets crossed the face of their star within minutes of each
other, to measure starlight as it filtered through any existing
atmosphere. This double-transit, which occurs only every two years,
provided a combined signal that offered simultaneous indicators of the
atmospheric characteristics of the planets.
The researchers hope to use Hubble to conduct follow-up observations
to search for thinner atmospheres, composed of elements heavier than
hydrogen, like those of Earth and Venus.
"With more data, we could perhaps detect methane or see water
features in the atmospheres, which would give us estimates of the depth
of the atmospheres," said Hannah Wakeford, the paper's second author,
at NASA's Goddard Space Flight Center in Greenbelt, Maryland.
Observations from future telescopes, including NASA's James Webb
Space Telescope, will help determine the full composition of these
atmospheres and hunt for potential biosignatures, such as carbon
dioxide and ozone, in addition to water vapor and methane. Webb also
will analyze a planet's temperature and surface pressure — key factors
in assessing its habitability.
These planets are the first Earth-sized worlds found in the Search
for habitable Planets EClipsing ULtra-cOOl Stars (SPECULOOS) survey,
which will search more than 1,000 nearby red dwarf stars for
Earth-sized worlds. So far, the survey has analyzed only 15 of those
"These Earth-sized planets are the first worlds that astronomers can
study in detail with current and planned telescopes to determine
whether they are suitable for life," said de Wit. "Hubble has the
ability to play the central atmospheric pre-screening role to tell
astronomers which of these Earth-sized planets are prime candidates for
more detailed study with the Webb telescope."
The results of the study appear in the July 20 issue of the journal Nature.
Kuiper Belt objects (KBOs) - 2014 FZ7 and 2015 FJ345
Image Credit: Johns Hopkins University Applied Physics
Laboratory/Southwest Research Institute (JHUAPL/SwRI) & S. Sheppard,
Animation of Kuiper Belt Object 2014 FZ71 created from the discovery
images. Each image in the sequence was taken approximately three hours
apart. Image Credit: Scott S. Sheppard/Chad Trujillo/DECam
Two new Kuiper Belt objects, 2014 FZ71 and 2015 FJ345, are among the
most distant bodies in the Solar System. They are always further than
50AU from the Sun, and only Sedna and 2012 VP113 have larger perihelia.
The discovery was made using data from DECam on the Blanco 4-m telescope
The new trans-Neptunian objects were discovered by Scott Sheppard,
Chad Trujillo, and David Tholen in their search for objects beyond the
outer edge of the Kuiper Belt (at about 50 AU). Unlike the more extreme
Sedna and 2012 VP113, the new objects have moderate eccentricities. All
the new moderately eccentric objects beyond the Kuiper Belt edge are
near strong Neptune mean motion resonances. These new moderately
eccentric objects likely obtained their unusual orbits through a
combined interaction between Neptune’s mean motion resonance and the
Kozai resonance. The discovery images for 2014 FZ71, shown at right,
were obtained on 24 March 2014. An arrow indicates the approximate
position of 2014 FZ71, which moves relative to the background stars and
galaxies in this sequence of 3 images taken approximately 3 hours apart.
Image montage showing the Maunakea Observatories, Kepler Space Telescope, and night sky with K2 Fields and discovered planetary systems (dots) overlaid. An international team of scientists discovered more than 100 planets based on images from Kepler operating in the ‘K2 Mission’. The team confirmed and characterized the planets using a suite of telescopes worldwide, including four on Maunakea (the twin telescopes of Keck Observatory, the GeminiNorth Telescope, and the Infrared Telescope Facility). The planet image on the right is an artist’s impression of a representative planet. Image Credit: Art by Karen Teramura (UHIfA) based on night sky image of the ecliptic plane by Miloslav Druckmüller and Shadia Habbal, and Kepler Telescope and planet images by NASA. Full resolution JPEG
Gemini Observatory plays a key role in the latest harvest of over 100 confirmed exoplanets from NASA’s K2 mission, the repurposed Kepler spacecraft. Three instruments on the Gemini North telescope delivered precise images verifying many of the candidate stars as planetary system hosts. Researchers note that these systems could contain a considerable number of rocky, potentially earthlike exoplanets.
The Gemini North telescope on Hawaii’s Maunakea helped verify many of the over 100 new worlds announced in the initial crop of discoveries from the NASA K2 mission, according to Ian Crossfield of the University of Arizona. Crossfield led the international team of scientists who announced the findings, which are published online in The Astrophysical Journal Supplement Series. A preprint of the paper is available here.
“Gemini North was instrumental because it delivered extremely high-resolution images of over 70 of the almost 200 potential planetary systems that K2 uncovered,” says Crossfield. ”In total we used three instruments, or cameras, on Gemini to complete our studies – so you could say that Gemini was instrumental in that way too!”
Once K2’s data are analyzed to identify potential exoplanet candidates, many of the world’s most powerful telescopes, like Gemini, are set into motion. This is so astronomers can rule out other explanations that can produce the signature of a planet orbiting a star. “This is where the discovery happens,” says astronomer Christopher Davis of the US National Science Foundation, which funds over 70% of Gemini. “Once other possibilities are eliminated, like nearby background stars, the team can say with extreme certainty that we have a new exoplanet system.”
One of the instruments used at Gemini is a visiting instrument called the Differential Speckle Survey Instrument (DSSI) which is led by Steve Howell of NASA’s Ames Research Center. “These observations are a critical part of the exoplanet validation process,” says Howell. “It’s essentially the only way to validate small, earth-sized planets orbiting around other stars.” Howell’s DSSI instrument uses many extremely short (typically about 60 millisecond) exposures of a star to capture fine detail by combining the images and subtracting momentary distortions caused by the Earth’s atmosphere. With this technique astronomers can see details at, or very near, the theoretical limit of the 8-meter Gemini mirror which is like being able to resolve two automobile headlights at a distance of about 2000 miles.
In its initial mission, Kepler surveyed just one patch of sky in the northern hemisphere, measuring the frequency with which planets whose size and temperature are similar to Earth occur around stars like our Sun. But when the satellite lost its ability to precisely stare at its original target area in 2013, a brilliant fix created a second life for the telescope that is proving remarkably fruitful.
The new K2 mission provides fields of view within the ecliptic which presents greater opportunities for Earth-based observatories in both the northern and southern hemispheres. Additionally, the new mission opened up the observations to the entire scientific community, not just specific targets picked by science team members. K2 now looks at new types of populations, including a larger fraction of cooler, smaller, red dwarf-type stars, which are much more common in our Milky Way than Sun-like stars. The space observatory discovers new planets by measuring the subtle dip in a star's brightness caused by a planet passing in front of its star.
The Gemini followup observations were made as part of what is called a Large and Long program intended to provide access to Gemini for studies requiring more observing time, or extended periods of observations to yield high-impact results. In addition to observations with DSSI, Gemini’s Near-InfraRed Imager (NIRI) with the Altair adaptive optics system, and the Gemini Near-InfraRed Spectrograph (GNIRS) were used to make the verification observations.
In addition to Gemini, follow-up ground-based observations were made by W. M. Keck Observatory also on Maunakea in Hawai‘i, the Automated Planet Finder of the University of California Observatories, and the Large Binocular Telescope operated by the University of Arizona.
Public Information and Outreach
Gemini Observatory, Hilo, HI
Email:firstname.lastname@example.org Cell: (808) 936-6643 Alexis-Ann Acohido
Public Information and Outreach
Gemini Observatory, Hilo, HI
Email:email@example.com Phone: (808) 974-2528 Doug Carroll
Director of Media Relations and Communications
University of Arizona
Email:firstname.lastname@example.org Phone: (520) 621-9017
University of Arizona & UC Santa Cruz
Email:email@example.com Phone: (949) 923-0578
Project Scientist, Kepler and K2 Mission
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Expansion maps of the three detected bubbles, which show the detected
expansion velocity in each pixel, all in the same velocity scale.
are contours of the region's Hydrogen alpha
emission; it can be seen that the bubbles are roughly concentric with
each other and the region.
Figure extracted from Camps Fariña et al. (2016). Large format:JPEG
A group of astronomers, led by researchers at the Instituto de
Astrofísica de Canarias (IAC), has found the first known case of three
supernova remnants one inside the other.
Using a method developed within the group for detecting huge expanding
bubbles of gas in interstellar space, they were observing the galaxy M33
in our Local Group of galaxies and found an example of a triple-bubble.
The results help to understand the feedback phenomenon, a fundamental
process controlling star formation and the dissemination of metals
produced in massive stars.
The group has been building up a database of these superbubbles with
observations of a number of galaxies and, using the very high resolution
2D spectrograph GHaFaS (Galaxy Halpha Fabry-Perot System) on the
William Herschel Telescope (WHT), has been able to detect and measure
some tens of them in different galaxies, which range in size from a few
light years to as big as a thousand light years across.
Superbubbles around large young star clusters are known to have a
complex structure due to the effects of powerful stellar winds and
supernova explosions of individual stars, whose separate bubbles may end
merging into a superbubble, but this is the first time that they, or any
other observers, have found three concentric expanding supernova
shells. They are concentric because the supernovae which produced them
exploded at intervals of only 10,000 years, close to simultaneously on
astronomical timescales, so they are still relatively spherical and
surround their parent star cluster.
"This phenomenon—says John Beckman, one of the co-authors on the
paper—allows us to explore the interstellar medium in a unique way, we
can measure how much matter there is in a shell, approximately a couple
of hundred times the mass of the sun in each of the shells". However, if
it is known that a supernova expels only around ten times the mass of
the sun, where do the second and third shells get their gas from if the
first supernova sweeps up all the gas?
The answer to that must come from the structure of the surrounding gas:
the inhomogeneous interstellar medium. "It must be—says Artemi Camps
Fariña, who is first author on the paper—that the interstellar medium is
not at all uniform, there must be dense clumps of gas, surrounded by
space with gas at a much lower density. A supernova does not just sweep
up gas, it evaporates the outsides of the clumps, leaving some dense gas
behind which can make the second and the third shells".
"The presence of the bubbles—adds Artemi— explains why star formation on
cosmological timescales has been much slower than simple models of
galaxy evolution predicted. These bubbles are part of a widespread
feedback process in galaxy discs and if it were not for feedback, spiral
galaxies would have very short lives, and our own existence would be
improbable", concludes. The idea of an inhomogeneous interstellar medium
is not new, but the triple bubble gives a much clearer and quantitative
view of the structure and the feedback process. The results will help
theorists working on feedback to a better understanding of how this
process works in all galaxy discs.
A. Camps Fariña, J. E. Beckman, J. Font, A. Borlaff, J. Zaragoza, P.
Amram, 2016, "Three supernova shells around a young star cluster in
M33", MNRAS, 461, L87. DOI: 10.1093/mnrasl/slw106. Paper on MNRAS|arXiv.
This artist's impression depicts the accretion disc surrounding a black hole, in which the inner region of the disc precesses. › Full image and caption
The European Space Agency's orbiting X-ray observatory, XMM-Newton,
has proved the existence of a "gravitational vortex" around a black
hole. The discovery, aided by NASA's Nuclear Spectroscopic Telescope Array (NuSTAR) mission,
solves a mystery that has eluded astronomers for more than 30 years,
and will allow them to map the behavior of matter very close to black
holes. It could also open the door to future investigations of Albert
Einstein's general relativity.
Matter falling into a black hole heats up as it plunges to its doom.
Before it passes into the black hole and is lost from view forever, it
can reach millions of degrees. At that temperature it shines X-rays into
In the 1980s, pioneering astronomers using early X-ray telescopes
discovered that the X-rays coming from stellar-mass black holes in our
galaxy flicker. The changes follow a set pattern. When the flickering
begins, the dimming and re-brightening can take 10 seconds to complete.
As the days, weeks and then months progress, the period shortens until
the oscillation takes place 10 times every second. Then, the flickering
suddenly stops altogether.
The phenomenon was dubbed the Quasi Periodic Oscillation (QPO). "It
was immediately recognized to be something fascinating because it is
coming from something very close to a black hole," said Adam Ingram,
University of Amsterdam, the Netherlands, who began working to
understand QPOs for his doctoral thesis in 2009.
During the 1990s, astronomers had begun to suspect that the QPOs were
associated with a gravitational effect predicted by Einstein's general
relativity: that a spinning object will create a kind of gravitational
"It is a bit like twisting a spoon in honey. Imagine that the honey
is space and anything embedded in the honey will be "dragged" around by
the twisting spoon," explained Ingram. "In reality, this means that
anything orbiting a spinning object will have its motion affected." In
the case of an inclined orbit, it will "precess." This means that the
whole orbit will change orientation around the central object. The time
for the orbit to return to its initial condition is known as a
In 2004, NASA launched Gravity Probe B to measure this so-called
Lense-Thirring effect around Earth. After painstaking analysis,
scientists confirmed that the spacecraft would turn through a complete
precession cycle once every 33 million years.
Around a black hole, however, the effect would be much more
noticeable because of the stronger gravitational field. The precession
cycle would take just a matter of seconds or less to complete. This is
so close to the periods of the QPOs that astronomers began to suspect a
Ingram began working on the problem by looking at what happened in
the flat disc of matter surrounding a black hole. Known as an accretion
disc, it is the place where material gradually spirals inwards towards
the black hole. Scientists had already suggested that, close to the
black hole, the flat accretion disc puffs up into a hot plasma, in which
electrons are stripped from their host atoms. Termed the hot inner
flow, it shrinks in size over weeks and months as it is eaten by the
black hole. Together with colleagues, Ingram published a paper in 2009
suggesting that the QPO is driven by the Lense-Thirring precession of
this hot flow. This is because the smaller the inner flow becomes, the
closer to the black hole it would approach and so the faster its
Lense-Thirring precession cycle would be. The question was: how to prove
"We have spent a lot of time trying to find smoking gun evidence for this behavior," said Ingram.
The answer is that the inner flow is releasing high-energy radiation
that strikes the matter in the surrounding accretion disc, making the
iron atoms in the disc shine like a fluorescent light tube. The iron
releases X-rays of a single wavelength -- referred to as "a spectral
Because the accretion disc is rotating, the iron line has its
wavelength distorted by the Doppler effect. Line emission from the
approaching side of the disc is squashed -- blue shifted -- and line
emission from the receding disc material is stretched -- red shifted. If
the inner flow really is precessing, it will sometimes shine on the
approaching disc material and sometimes on the receding material, making
the line wobble back and forth over the course of a precession cycle.
Seeing this wobbling is where XMM-Newton came in. Ingram and
colleagues from Amsterdam, Cambridge, Southampton and Tokyo applied for a
long-duration observation that would allow them to watch the QPO
repeatedly. They chose black hole H 1743-322, which was exhibiting a
four-second QPO at the time. They watched it for 260,000 seconds with
XMM-Newton. They also observed it for 70,000 seconds with NASA's NuSTAR
"The high-energy capability of NuSTAR was very important," Ingram
said. "NuSTAR confirmed the wobbling of the iron line, and additionally
saw a feature in the spectrum called a 'reflection hump' that added
evidence for precession."
After a rigorous analysis process of adding all the observational
data together, they saw that the iron line was wobbling in accordance
with the predictions of general relativity. "We are directly measuring
the motion of matter in a strong gravitational field near to a black
hole," says Ingram.
This is the first time that the Lense-Thirring effect has been
measured in a strong gravitational field. The technique will allow
astronomers to map matter in the inner regions of accretion discs around
black holes. It also hints at a powerful new tool with which to test
Einstein's theory is largely untested in such strong gravitational
fields. So if astronomers can understand the physics of the matter that
is flowing into the black hole, they can use it to test the predictions
of general relativity as never before - but only if the movement of the
matter in the accretion disc can be completely understood.
"If you can get to the bottom of the astrophysics, then you can
really test the general relativity," says Ingram. A deviation from the
predictions of general relativity would be welcomed by a lot of
astronomers and physicists. It would be a concrete signal that a deeper
theory of gravity exists.
Larger X-ray telescopes in the future could help in the search
because they are more powerful and could more efficiently collect
X-rays. This would allow astronomers to investigate the QPO phenomenon
in more detail. But for now, astronomers can be content with having seen
Einstein's gravity at play around a black hole.
"This is a major breakthrough since the study combines information
about the timing and energy of X-ray photons to settle the 30-year
debate around the origin of QPOs. The photon-collecting capability of
XMM-Newton was instrumental in this work," said Norbert Schartel, ESA
Project Scientist for XMM-Newton.
The results reported in this article are published in the Monthly Notices of the Royal Astronomical Society.
The European Space Agency's X-ray Multi-Mirror Mission, XMM-Newton,
was launched in December 1999. The largest scientific satellite to have
been built in Europe, it is also one of the most sensitive X-ray
observatories ever flown. More than 170 wafer-thin, cylindrical mirrors
direct incoming radiation into three high-throughput X-ray telescopes.
XMM-Newton's orbit takes it almost a third of the way to the moon,
allowing for long, uninterrupted views of celestial objects.
NuSTAR is a Small Explorer mission led by Caltech in Pasadena and
managed by NASA's Jet Propulsion Laboratory, also in Pasadena, for
NASA's Science Mission Directorate in Washington.
or GRBs, are some of the most violent and energetic events in the
Universe. Although these events are the most luminous explosions in the
universe, a new study using NASA's Chandra X-ray
Observatory, NASA's Swift satellite and other telescopes suggests that
scientists may be missing a majority of these powerful cosmic
Astronomers think that some GRBs are the product of the collision and merger of two neutron stars or a neutron star and a black hole.
The new research gives the best evidence to date that such collisions
will generate a very narrow beam, or jet, of gamma rays. If such a
narrow jet is not pointed toward Earth, the GRB produced by the
collision will not be detected.
Collisions between two neutron stars or a neutron star and black hole are expected to be strong sources of gravitational waves
that could be detected whether or not the jet is pointed towards the
Earth. Therefore, this result has important implications for the number
of events that will be detectable by the Laser Interferometry
Gravitational-Wave Observatory (LIGO) and other gravitational wave
On September 3, 2014, NASA's Swift observatory picked up a GRB -
dubbed GRB 140903A due to the date it was detected. Scientists used
optical observations with the Gemini Observatory telescope in Hawaii to
determine that GRB 140903A was located in a galaxy about 3.9 billion light years away, relatively nearby for a GRB.
The large panel in the graphic is an illustration
showing the aftermath of a neutron star merger, including the
generation of a GRB. In the center is a compact object - either a black
hole or a massive neutron star - and in red is a disk of material left
over from the merger, containing material falling towards the compact
object. Energy from this infalling material drives the GRB jet shown in
yellow. In orange is a wind of particles blowing away from the disk and
in blue is material ejected from the compact object and expanding at
very high speeds of about one tenth the speed of light.
The image on the left of the two smaller panels shows an optical view
from the Discovery Channel Telescope (DCT) with GRB 140903A in the
middle of the square and a close-up X-ray view from Chandra on the
right. The bright star in the optical image is unrelated to the GRB.
The gamma-ray blast lasted less than two seconds. This placed it into
the "short GRB" category, which astronomers think are the output from
neutron star-neutron star or black hole-neutron star collisions
eventually forming either a black hole or a neutron star with a strong
magnetic field. (The scientific consensus is that GRBs that last longer
than two seconds result from the collapse of a massive star.)
About three weeks after the Swift discovery of GRB 140903A, a team of
researchers led by Eleonora Troja of the University of Maryland,
College Park (UMD), observed the aftermath of the GRB in X-rays with
Chandra. Chandra observations of how the X-ray emission from this GRB
decreases over time provide important information about the properties
of the jet.
Specifically, the researchers found that the jet is beamed into an
angle of only about five degrees based on the X-ray observations, plus
optical observations with the Gemini Observatory and the DCT and radio
observations with the National Science Foundation's Karl G. Jansky Very
Large Array. This is roughly equivalent to a circle with the diameter of
your three middle fingers held at arms length. This means that
astronomers are detecting only about 0.4% of this type of GRB when it
goes off, since in most cases the jet will not be pointed directly at
Previous studies by other astronomers had suggested that these
mergers could produce narrow jets. However, the evidence in those cases
was not as strong because the rapid decline in light was not observed at
multiple wavelengths, allowing for explanations not involving jets.
Several pieces of evidence link this event to the merger of two
neutron stars, or between a neutron star and black hole. These include
the properties of the gamma ray emission, the old age and the low rate
of stars forming in the GRB's host galaxy and the lack of a bright supernova. In some previous cases strong evidence for this connection was not found.
New studies have suggested that such mergers could be the production site of elements
heavier than iron, such as gold. Therefore, the rate of these events is
also important to estimate the total amount of heavy elements produced
by these mergers and compare it with the amounts observed in the Milky Way galaxy.
A paper describing these results was recently accepted for publication in The Astrophysical Journal and is available online.
The first author of this paper is Eleonora Troja and the co-authors are
T. Sakamoto (Aoyama Gakuin University, Japan), S.Cenko (GSFC), A. Lien
(University of Maryland, Baltimore), N. Gehrels (GSFC), A. Castro-Tirado
(IAA-CSIC, Spain), R. Ricci (INAF-Istituto di Radioastronomia, Italy),
J. Capone, V. Toy, & A. Kutyrev (UMD), N. Kawai (Tokyo Institute of
Technology, Japan), A. Cucchiara (GSFC), A. Fruchter (STScI),
J.Gorosabel (UMD), S. Jeong (IAA-CSIC), A. Levan (University of Warwick,
UK), D. Perley (University of Copenhagen, Denmark), R.Sanchez-Ramirez
(Instituto de Astrof ÌÄ±sica de Andaluc ÌÄ±a, Spain), N.Tanvir
(University of Leicester, UK), S. Veilleux (UMD).
NASA's Marshall Space Flight Center in Huntsville, Alabama, manages
the Chandra program for NASA's Science Mission Directorate in
Washington. The Smithsonian Astrophysical Observatory in Cambridge,
Massachusetts, controls Chandra's science and flight operations.
Fast Facts for GRB 140903A: Scale: X-ray image is 15 arcsec across (about 244,00 light years) Category:Miscellaneous Objects,Black Holes Coordinates (J2000): RA 15h 52m 03.27s | Dec +27° 36' 09.30" Constellation:Corona Borealis Observation Date: 06 Sep and 18 Sep 2014 Observation Time: 22 hours 13 min. Obs. ID: 15873, 15986 Instrument:ACIS References: Troja, E. et al, 2016, ApJ (accepted);arXiv:1605.03573 Color Code: X-ray (Blue), Optical (Yellow) Distance Estimate: About 3.9 billion light years (z=0.351)
This image was taken by the NASA/ESA Hubble Space Telescope’s Advanced Camera for Surveys
(ACS), and shows a starburst galaxy named MCG+07-33-027. This galaxy
lies some 300 million light-years away from us, and is currently
experiencing an extraordinarily high rate of star formation — a starburst.
Normal galaxies produce only a couple of new stars per year, but
starburst galaxies can produce a hundred times more than that! As
MCG+07-33-027 is seen face-on, the galaxy’s spiral arms and the bright
star-forming regions within them are clearly visible and easy for
astronomers to study.
In order to form newborn
stars, the parent galaxy has to hold a large reservoir of gas, which is
slowly depleted to spawn stars over time. For galaxies in a state of
starburst, this intense period of star formation has to be triggered
somehow — often this happens due to a collision with another galaxy.
MCG+07-33-027, however, is special; while many galaxies are located
within a large cluster of galaxies, MCG+07-33-027 is a field galaxy,
which means it is rather isolated. Thus, the triggering of the starburst
was most likely not due to a collision with a neighbouring or passing
galaxy and astronomers are still speculating about the cause.
The protoplanetary disc around V883 Orionis (artist's impression)
The Atacama Large
Millimeter/submillimeter Array (ALMA) has made the first ever resolved
observation of a water snow line within a protoplanetary disc. This line
marks where the temperature in the disc surrounding a young star drops
sufficiently low for snow to form. A dramatic increase in the brightness
of the young star V883 Orionis flash heated the inner portion of the
disc, pushing the water snow line out to a far greater distance than is
normal for a protostar, and making it possible to observe it for the
first time. The results are published in the journal Nature on 14 July
Young stars are often surrounded by dense, rotating discs of gas and
dust, known as protoplanetary discs, from which planets are born. The
heat from a typical young solar-type star means that the water within a
protoplanetary disc is gaseous up to distances of around 3 au from the star  — less than 3 times the average distance between the Earth and the Sun — or around 450million kilometres .
Further out, due to the extremely low pressure, the water molecules
transition directly from a gaseous state to form a patina of ice on dust
grains and other particles. The region in the protoplanetary disc where
water transitions between the gas and solid phases is known as the
water snow line .
But the star V883 Orionis is unusual. A dramatic increase in its
brightness has pushed the water snow line out to a distance of around 40
au (about 6 billion kilometres or roughly the size of the orbit of the
dwarf planet Pluto in our Solar System). This huge increase, combined with the resolution of ALMA at long baselines , has allowed a team led by Lucas Cieza (Millennium ALMA Disk Nucleus
and Universidad Diego Portales, Santiago, Chile) to make the first ever
resolved observations of a water snow line in a protoplanetary disc.
The sudden brightening that V883 Orionis experienced is an example of
what occurs when large amounts of material from the disc surrounding a
young star fall onto its surface. V883 Orionis is only 30% more massive
than the Sun, but thanks to the outburst it is experiencing, it is
currently a staggering 400 times more luminous — and much hotter .
Lead author Lucas Cieza explains: “The ALMA
observations came as a surprise to us. Our observations were designed to
look for disc fragmentation leading to planet formation. We saw none of
that; instead, we found what looks like a ring at 40 au. This
illustrates well the transformational power of ALMA, which delivers
exciting results even if they are not the ones we were looking for.”
The bizarre idea of snow orbiting in space is fundamental to planet
formation. The presence of water ice regulates the efficiency of the
coagulation of dust grains — the first step in planet formation. Within
the snow line, where water is vapourised, smaller, rocky planets like
our own are believed to form. Outside the water snow line, the presence
of water ice allows the rapid formation of cosmic snowballs, which
eventually go on to form massive gaseous planets such as Jupiter.
The discovery that these outbursts may blast the water snow line to
about 10 times its typical radius is very significant for the
development of good planetary formation models. Such outbursts are
believed to be a stage in the evolution of most planetary systems, so
this may be the first observation of a common occurrence. In that case,
this observation from ALMA could contribute significantly to a better
understanding of how planets throughout the Universe formed and evolved.
 ] 1 au, or one astronomical unit, is the mean distance between
the Earth and the Sun, around 149.6 million kilometres.This unit is
typically used to describe distances measured within the Solar System
and planetary systems around other stars.
 This line was between the orbits
of Mars and Jupiter during the formation of the Solar System, hence the
rocky planets Mercury, Venus, Earth and Mars formed within the line, and
the gaseous planets Jupiter, Saturn, Uranus and Neptune formed outside.
 The snow lines for other molecules, such as carbon monoxide and methane, have beenobserved previouslywith ALMA, at distances of greater than 30 au from the protostar within
other protoplanetary discs. Water freezes at a relatively high
temperature and this means that the water snow line is usually much too
close to the protostar to observe directly.
 Resolution is the ability to
discern that objects are separate. To the human eye, several bright
torches at a distance would seem like a single glowing spot, and only at
closer quarters would each torch be distinguishable. The same principle
applies to telescopes, and these new observations have exploited the
exquisite resolution of ALMA in its long baseline modes. The resolution
of ALMA at the distance of V883 Orionis is about 12 au — enough to
resolve the water snow line at 40 au in this outbursting system, but not
for a typical young star.
 Stars like V883 Orionis are classed asFU Orionis stars, after the original star that was found to have this behaviour. The outbursts may last for hundreds of years.
This research was presented in a paper entitled “Imaging the water snow-line during a protostellar outburst”, by L. Cieza et al., to appear in Nature on 14 July 2016.
The team is composed of Lucas A. Cieza (Millennium ALMA Disk Nucleus; Universidad Diego Portales, Santiago, Chile), Simon Casassus (Universidad de Chile, Santiago, Chile), John Tobin (Leiden Observatory, Leiden University, The Netherlands), Steven Bos (Leiden Observatory, Leiden University, The Netherlands), Jonathan P. Williams (University of Hawaii at Manoa, Honolulu, Hawai`i, USA), Sebastian Perez (Universidad de Chile, Santiago, Chile), Zhaohuan Zhu (Princeton University, Princeton, New Jersey, USA), Claudio Cáceres (Universidad Valparaiso, Valparaiso, Chile), Hector Canovas (Universidad Valparaiso, Valparaiso, Chile), Michael M. Dunham (Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts, USA), Antonio Hales (Joint ALMA Observatory, Santiago, Chile), Jose L. Prieto (Universidad Diego Portales, Santiago, Chile), David A. Principe (Universidad Diego Portales, Santiago, Chile), Matthias R. Schreiber (Universidad Valparaiso, Valparaiso, Chile), Dary Ruiz-Rodriguez (Australian National University, Mount Stromlo Observatory, Canberra, Australia) and Alice Zurlo (Universidad Diego Portales & Universidad de Chile, Santiago, Chile).
The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of ESO, the U.S. National Science Foundation (NSF) and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its Member States, by NSF in cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC) and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI).
ALMA construction and operations are led by ESO on behalf of its Member States; by the National Radio Astronomy Observatory (NRAO), managed by Associated Universities, Inc. (AUI), on behalf of North America; and by the National Astronomical Observatory of Japan (NAOJ) on behalf of East Asia. The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.
ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It is supported by 16 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world’s largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is a major partner in ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre European Extremely Large Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.