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  • richardmitnick 5:47 pm on August 24, 2015 Permalink | Reply
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    From Gemini Observatory: “Gemini Inspires Graduate Student” 

    NOAO

    Gemini Observatory
    Gemini Observatory

    24 Aug 2015
    alexis

    Last week, University of Alabama in Huntsville (UAH) graduate student, Sarthak Dasadia, visited Gemini North. Sarthak, an amateur astronomer and staff person at a local planetarium near his home in India, would often collect scientific data to send to various institutes such as the American Meteor Society. He recounts,

    “Internet was a privilege back then, and my parents only allowed an hour a week which was enough to search and contact different astronomy institutes.”

    While researching astronomical images, he came across Gemini Observatory. Noting the address, he sent a letter expressing his interest in astronomy and got a reply. Xiaoyu Zhang, Gemini North’s Librarian, sent material including images, posters, and a copy of the Gemini Virtual Observatory tour.

    “I can’t express how important it was for me to receive mail from a foreign institute,” he says. “This encouraged me to pursue a degree in physics and astronomy.”

    That was in 2006.

    Currently, Sarthak is studying merging galaxy clusters at UAH. He also gave a talk at the International Astronomical Union (IAU) General Assembly in Honolulu last week. “The day I heard [that the IAU was in Hawai‘i], I knew I wanted to visit Gemini.”

    “I’m thrilled that we encouraged Sarthak to work towards a degree in physics and astronomy,” says Zhang. “I wish him the best as he continues his education and leaves his mark on the universe!”

    1
    This image was taken at Gemini North. Photo credit: Sarthak Dasadia

    2
    Sarthak at the Mauna Kea Visitor Station

    See the full article here.

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    Gemini North
    Gemini North, Hawai’i

    Gemini South
    Gemini South, Chile
    AURA Icon

    The Gemini Observatory consists of twin 8.1-meter diameter optical/infrared telescopes located on two of the best observing sites on the planet. From their locations on mountains in Hawai‘i and Chile, Gemini Observatory’s telescopes can collectively access the entire sky.
    Gemini was built and is operated by a partnership of six countries including the United States, Canada, Chile, Australia, Brazil and Argentina. Any astronomer in these countries can apply for time on Gemini, which is allocated in proportion to each partner’s financial stake.

     
  • richardmitnick 8:37 am on July 30, 2015 Permalink | Reply
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    From Gemini: “Inquiring Into the Secrets of the Galactic Center” 

    NOAO

    Gemini Observatory
    Gemini Observatory

    30 Jul 2015
    Manuel Paredes

    1
    Anja Feldmeier preparing for a full observation night in the control room at the Gemini South telescope, Chile.

    Gemini’s “Bring One, Get One” program, which provides support for early-career scientists to observe at Gemini, recently allowed Anja Feldmeier, a PhD student at ESO in Garching, Germany, to participate in observations at Gemini South as part of a program to study the rotational curve of the Galactic Center.

    Anja works with Dr. Nadine Neumayer (MPIA, Heidelberg) to observe the central part of the Milky Way’s galactic plane, home to the nuclear star cluster observed by the team with Flamingos-2 (F-2).

    Gemini Flamingos 2
    F-2

    Neumayer and Feldmeier acquired spectra from the star cluster in order to measure the radial velocities of the stars. In this way, they measure the rotation of the cluster and study its stellar population. The goal of the research is to understand its formation history.

    “F-2, at Gemini South, is the only instrument with which we can observe such a large field of view in a reasonable amount of time,” said Anja. The field of view of F-2 is about 20 arcminutes across, or about 110 parsecs across at the distance of the Galactic Center. “Although our observations require a non-standard drift scan mode, the Gemini staff was very supportive and made it possible for us to get the data we need to reach our science goal,” she explained.

    See the full article here.

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    Gemini North
    Gemini North, Hawai’i

    Gemini South
    Gemini South, Chile
    AURA Icon

    The Gemini Observatory consists of twin 8.1-meter diameter optical/infrared telescopes located on two of the best observing sites on the planet. From their locations on mountains in Hawai‘i and Chile, Gemini Observatory’s telescopes can collectively access the entire sky.
    Gemini was built and is operated by a partnership of six countries including the United States, Canada, Chile, Australia, Brazil and Argentina. Any astronomer in these countries can apply for time on Gemini, which is allocated in proportion to each partner’s financial stake.

     
  • richardmitnick 9:01 pm on July 24, 2015 Permalink | Reply
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    From Gemini: “Gemini Studies a Plethora of Brown Dwarfs Candidates” 

    NOAO

    Gemini Observatory
    Gemini Observatory

    July 23, 2015
    No Writer Credit

    An international team of astronomers from Canada and the United States recently discovered 42 new brown dwarfs using data from the near-infrared imager and spectrograph Flamingos-2 at Gemini South and other telescopes in Chile and Hawai’i. The team used Flamingos-2’s near-infrared spectroscopic capabilities to study a total of 101 targets from 2013 to 2015.

    Gemini South telescope
    Gemini South Interior
    Gemini South

    The work, led by Jonathan Gagne, from the University of Montreal, confirmed signs of low-gravity for 42 of the objects with estimated masses between 8 to 75 times that of Jupiter. Further, the team identified previously unrecognized signs of low gravity for 24 known brown dwarfs.

    This kind of object has an important role in explaining part of the process of star formation, as current stellar formation models include the production of a non-negligible fraction of free-floating planets. Additionally, the research shows that some objects, that were thought to be brown dwarfs, were indeed much less massive, and similar to planetary mass objects.

    Gagne’s research also provides a context for ongoing work with the Gemini Planet Imager (GPI) because these objects are easier to observe without the glare from a nearby host star of GPI targets.

    Gemini Planet Imager
    Gemini Planet Imager

    “One big question that remains unanswered is whether these isolated planets significantly differ from objects in orbit around stars. There are some reasons to expect differences, but no one has been able to demonstrate a difference to date,” explains Etienne Artigau, an astronomer on the team who is also at the University of Montreal. This work will be published in The Astrophysical Journal Supplement Series, and a preprint is now available.

    1
    Figure 1. NIR Spectral type histogram of all known low-gravity dwarfs and those presented in this work. Green bars delimited by dashed lines represent the known population prior to BASS, purple bars delimited by dash-dotted lines represent known dwarfs for which low-gravity features were identified here for the first time, and orange bars delimited by solid lines represent new discoveries from BASS. The BASS survey has contributed significantly in increasing the number of known low-gravity M6–L5 dwarfs.

    See the full article here.

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    Gemini North
    Gemini North, Hawai’i

    Gemini South
    Gemini South, Chile
    AURA Icon

    The Gemini Observatory consists of twin 8.1-meter diameter optical/infrared telescopes located on two of the best observing sites on the planet. From their locations on mountains in Hawai‘i and Chile, Gemini Observatory’s telescopes can collectively access the entire sky.
    Gemini was built and is operated by a partnership of six countries including the United States, Canada, Chile, Australia, Brazil and Argentina. Any astronomer in these countries can apply for time on Gemini, which is allocated in proportion to each partner’s financial stake.

     
  • richardmitnick 6:16 am on July 11, 2015 Permalink | Reply
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    From GEMINI: “NGC 2346: A COSMIC BUTTERFLY’S DELICATE WINGS” 

    NOAO

    Gemini Observatory
    Gemini Observatory

    July 9, 2015
    Media Contact:
    Dr. Katy Garmany
    NOAO Deputy Press Officer
    +1 520-318-8526
    kgarmany@noao.edu

    Science Contact:
    Dr. Letizia Stanghellini
    NOAO
    lstanghellini@noao.edu

    1
    The new image of NGC 2346 showing unprecedented resolution of the molecular hydrogen gas. The image is about 1 arc minute on a side: north is up, east is to the left. In contrast, the size of the full moon is 30 arc minutes. Image from GeMS/GSAOI Multi-Conjugat Adaptive Optics System.

    2
    Computer simulation showing how the nebula is expected to evolve over a period of about 9,000 years. Presently the nebula is just starting this process. The thumbnail above shows the process in nine, 1,000 year, steps.

    NOAO scientists, using the Gemini Observatory 8-meter telescope in Chile, have obtained the highest resolution image ever obtained for the planetary nebula NGC 2346. Shaped like a butterfly, or an hourglass, but known scientifically as a bipolar planetary nebula, this object is at a distance of 2,300 light-years from our Sun in the constellation Monoceros.

    The new observations of this gaseous nebula, shown in the first figure, resolve details comparable in size to our own solar system. The team detected previously unresolved knots and filaments of molecular hydrogen gas — details that no other telescope on the ground or in space, not even the Hubble Space Telescope, has been able to resolve.

    Molecular hydrogen in the bipolar lobes of NGC 2346 was detected almost 30 years ago, although previous observations suggested only a smooth torus. This filamentary structure observed by the team matches the mechanism they have proposed in which a hot bubble of gas surrounding the central star breaks out and fragments the shell of surrounding gas. The gaseous knots probably represent a common phenomenon that occurs whenever two fluids (or gases) of different densities come in contact, and the lighter fluid is pushing on the heavier fluid. This is easily seen by anyone who has ever watched colored oil in a glass of water.

    The authors have constructed computer models to understand how the gases are expected to interact: the accompanying movie* shows how the gas will evolve in time. As first author Arturo Manchado said, “In this movie we show the model results in time steps up to 9,000 years. The blue color corresponds with the emission of the molecular hydrogen gas. The model shows an initial toroid of cool gas at the equator. Once the swept-up shell is highly fragmented, the toroid is no longer visible and only the large clumps will be seen.”

    NGC 2346 is a star caught in the final phases of its lifecycle. It began life as a double star system, each companion about twice as massive as the Sun and both revolving around their common center of gravity. The more massive of the two stars burned through its fuel faster than its lower mass companion, expanded as a red giant, and has now shed its outer layers to become a white dwarf star, with a present mass between 0.3 and 0.7 solar mass. The bipolar nebula, or butterfly shape of this planetary, has probably been sculpted by the star pair, although this is still under study. With an orbital period of 16 days, the two stars are closer together than the Sun and Mercury. Material spilling from the more massive star over the lifetime of the pair makes it difficult to calculate the initial mass of the star.

    The observations were taken with the new near infrared Adaptive Optics Imager system on the Gemini telescope during the initial testing phase of this instrument. Adaptive optics is a novel technique that allows for real time correction of distortions to an astronomical image caused by the Earth’s atmosphere.

    Reference:
    High Resolution Imaging of NGC 2346 with GSAOI/GeMS: Disentangling the Planetary Nebula Molecular Structure to Understand Its Origin and Evolution, Arturo Manchado, Letizia Stanghellini, Eva Villaver, Guillermo Garcia-Segura, Richard A. Shaw & D. A. Garcia-Hernandez, 2015, Astrophysical Journal [http://apj.aas.org, preprint: http://arxiv.org/abs/1506.03712%5D.

    NOAO is operated by Association of Universities for Research in Astronomy Inc. (AURA) under a cooperative agreement with the National Science Foundation.

    *Movie is available in the full article.

    See the full article here.

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    Gemini North
    Gemini North, Hawai’i

    Gemini South
    Gemini South, Chile
    AURA Icon

    The Gemini Observatory consists of twin 8.1-meter diameter optical/infrared telescopes located on two of the best observing sites on the planet. From their locations on mountains in Hawai‘i and Chile, Gemini Observatory’s telescopes can collectively access the entire sky.
    Gemini was built and is operated by a partnership of six countries including the United States, Canada, Chile, Australia, Brazil and Argentina. Any astronomer in these countries can apply for time on Gemini, which is allocated in proportion to each partner’s financial stake.

     
  • richardmitnick 7:14 am on May 30, 2015 Permalink | Reply
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    From NAOJ: “Astronomers Discover a Young Solar System Around a Nearby Star” 

    NAOJ

    NAOJ

    May 29, 2015
    No Writer Credit

    1
    Image of HD 115600 showing a bright debris ring viewed nearly edge-on and located just beyond a Pluto-like distance to its star. One or more unseen solar system-like planets are causing the disk center to be offset from the star’s position (cross)

    An international team led by Thayne Currie of the Subaru Telescope and using the Gemini South telescope, has discovered a young planetary system that shares remarkable similarities to our own early solar system.

    Gemini South telescope
    Gemini South Interior
    Gemini South

    Their images reveal a ring-like disk of debris surrounding a Sun-like star, in a birth environment similar to the Sun’s. The disk appears to be sculpted by at least one unseen solar system-like planet, is roughly the same size as our solar system’s Edgeworth-Kuiper Belt (commonly called the Kuiper Belt), and may contain dust and icy particles. This work provides a valuable key to understanding the early formation of the Sun and planets.

    2
    Known objects in the Kuiper belt beyond the orbit of Neptune (scale in AU; epoch as of January 2015).

    The discovery of the bright ring of orbiting the star HD 115600 changes everything, said Currie, a Subaru Project Fellow research astronomer. “It’s kind of like looking at outer solar system when it was a toddler.”

    Remarkably, the ring is almost exactly the same distance from its host star as the Kuiper Belt is from the Sun (Figure 1), and it receives about the same amount of light. The star itself is just slightly more massive than the Sun and is a member of a massive grouping of 10- to 20-million-year-old stars called the Scorpius-Centaurus OB association. Its birth cloud is very similar to the nebula in which the Sun formed some 4.5 billion years ago.

    There are strong indications that the ring around HD 115600 is being shaped by interactions with an unseen solar system-like planet. The team measured the position of the ring with respect to the star and found that the ring was significantly offset and has an eccentric shape (meaning that it’s not very circular). This is likely due to the gravitational effect of a massive planet. The calculated eccentricity of the disk is among the largest known thus far, possibly more than the ring around the planet-hosting star Fomalhaut (which has at least one planet).

    By using models that predict how planets of different masses and orbital separations shape a debris disk, the team calculated what kind of planet might be distorting HD 115600’s ring. They found that eccentric versions of planets much like Jupiter, Saturn, Uranus, or Neptune could explain the shape and other properties of the ring.

    Other clues suggest that the ring may have a composition similar to the Kuiper Belt. Its spectrum implies some types of dust, as well as major Kuiper Belt constituents such as ice and silicates. When compared with other debris disks, this one is much more efficient at scattering starlight, which implies it has a higher-reflecting, ice-like composition.

    The discovery of the ring was made using the Gemini Planet Imager (GPI), an instrument dedicated to detecting planets and Kuiper Belt-like disks at never-before-seen scales. It is similar to the Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) instrument currently being commissioned on the Subaru Telescope.

    Gemini Planet Imager
    GPI

    The results are very promising. “Even in just one of our many 50-second exposures, we could see what previous instruments failed to see in more than 50 minutes,” Currie said. “Given this success with GPI, I’m very optimistic that Subaru’s own, state-of-the-art planet-hunting instrument, SCExAO, will soon discover many Kuiper belt-like disks and young planets and will put us well on our way towards seeing another Earth.”

    Comparing the Kuiper Belt to HD 115600’s Disk

    Located just beyond Neptune’s orbit, the Kuiper Belt contains numerous icy dwarf planets such as Pluto, Haumea, and Makemake. It is also home to thousands of remnants from the earliest stages of icy planet formation, and thus provides a key to understanding the early solar system.

    The study of cold, Kuiper belt-like debris rings around nearby young Sun-like stars provides the best picture of what our own early, outer solar system might have been like. However, the few such rings that have been imaged so far haven’t always been similar to ours. They usually surround stars much more massive than the Sun, or lie at greater distances than the Kuiper Belt, or are located in sparse star-forming regions unlike the massive and populous region in which the Sun was born. Until now, studies of these disks lacked the scattered-light spectra needed to explore them. Such studies can tell give information about the structure of the ring, as well as its motions.

    The paper reporting these results is accepted for publication in The Astrophysical Journal Letters with a title Direct Imaging and Spectroscopy of a Young Extrasolar Kuiper Belt in the Nearest OB Association and can be found here.

    Authors:

    Thayne Currie (Subaru Telescope, National Astronomical Observatory of Japan, USA)
    Carey M. Lisse (The Johns Hopkins University, USA)
    Marc Kuchner (NASA-Goddard Space Flight Center, USA)
    Nikku Madhusudhan (University of Cambridge, UK)
    Scott J. Kenyon (Harvard-Smithsonian Center for Astrophysics, USA)
    Christian Thalmann (ETH-Zurich, Switzerland)
    Joseph Carson (The College of Charleston, USA)
    John Debes (Space Telescope Science Institute, USA)
    Links:
    SCExAO Project website is here.
    Press release from Gemini Observatory is here.

    See the full article here.

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    The National Astronomical Observatory of Japan (NAOJ) is an astronomical research organisation comprising several facilities in Japan, as well as an observatory in Hawaii. It was established in 1988 as an amalgamation of three existing research organizations – the Tokyo Astronomical Observatory of the University of Tokyo, International Latitude Observatory of Mizusawa, and a part of Research Institute of Atmospherics of Nagoya University.

    In the 2004 reform of national research organizations, NAOJ became a division of the National Institutes of Natural Sciences.

    NAOJ Subaru Telescope

    NAOJ Subaru Telescope interior
    Subaru

    ALMA Array
    ALMA

    sft
    Solar Flare Telescope

    Nobeyama Radio Telescope - Copy
    Nobeyama Radio Observatory

    Nobeyama Solar Radio Telescope Array
    Nobeyama Radio Observatory: Solar

    Misuzawa Station Japan
    Mizusawa VERA Observatory

    NAOJ Okayama Astrophysical Observatory Telescope
    Okayama Astrophysical Observatory

    The National Astronomical Observatory of Japan (NAOJ) is an astronomical research organisation comprising several facilities in Japan, as well as an observatory in Hawaii. It was established in 1988 as an amalgamation of three existing research organizations – the Tokyo Astronomical Observatory of the University of Tokyo, International Latitude Observatory of Mizusawa, and a part of Research Institute of Atmospherics of Nagoya University.

    In the 2004 reform of national research organizations, NAOJ became a division of the National Institutes of Natural Sciences.

     
  • richardmitnick 9:20 am on May 27, 2015 Permalink | Reply
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    From phys.org: “Discovery shows what the solar system looked like as a ‘toddler'” 

    physdotorg
    phys.org

    May 27, 2015
    No Writer Credit

    1
    Left: Image of HD 115600 showing a bright debris ring viewed nearly edge-on and located just beyond a Pluto-like distance to the star. Right: A model of the HD 115600 debris ring on the same scale. Credit: T. Currie

    Astronomers have discovered a disc of planetary debris surrounding a young sun-like star that shares remarkable similarities with the Kuiper Belt that lies beyond Neptune, and may aid in understanding how our solar system developed.

    2
    Kuiper Belt

    An international team of astronomers, including researchers from the University of Cambridge, has identified a young planetary system which may aid in understanding how our own solar system formed and developed billions of years ago.

    Using the Gemini Planet Imager (GPI) at the Gemini South telescope in Chile, the researchers identified a dTisc-shaped bright ring of dust around a star only slightly more massive than the sun, located 360 light years away in the Centaurus constellation.

    Gemini Planet Imager
    GPI

    Gemini South telescope
    Gemini South

    The disc is located between about 37 and 55 Astronomical Units (3.4 – 5.1 billion miles) from its host star, which is almost the same distance as the solar system’s Kuiper Belt is from the sun. The brightness of the disc, which is due to the starlight reflected by it, is also consistent with a wide range of dust compositions including the silicates and ice present in the Kuiper Belt.

    The Kuiper Belt lies just beyond Neptune, and contains thousands of small icy bodies left over from the formation of the solar system more than four billion years ago. These objects range in size from specks of debris dust, all the way up to moon-sized objects like Pluto – which used to be classified as a planet, but has now been reclassified as a dwarf planet.

    The star observed in this new study is a member of the massive 10-20 million year-old Scorpius-Centaurus OB association, a region similar to that in which the sun was formed. The disc is not perfectly centred on the star, which is strong indication that it was likely sculpted by one or more unseen planets. By using models of how planets shape a debris disc, the team found that ‘eccentric’ versions of the giant planets in the outer solar system could explain the observed properties of the ring.

    “It’s almost like looking at the outer solar system when it was a toddler,” said principal investigator Thayne Currie, an astronomer at the Subaru Observatory in Hawaii.

    The current theory on the formation of the solar system holds that it originated within a giant molecular cloud of hydrogen, in which clumps of denser material formed. One of these clumps, rotating and collapsing under its own gravitation, formed a flattened spinning disc known as the solar nebula. The sun formed at the hot and dense centre of this disc, while the planets grew by accretion in the cooler outer regions. The Kuiper Belt is believed to be made up of the remnants of this process, so there is a possibility that once the new system develops, it may look remarkably similar to our solar system.

    “To be able to directly image planetary birth environments around other stars at orbital distances comparable to the solar system is a major advancement,” said Dr Nikku Madhusudhan of Cambridge’s Institute of Astronomy, one of the paper’s co-authors. “Our discovery of a near-twin of the Kuiper Belt provides direct evidence that the planetary birth environment of the solar system may not be uncommon.”

    This is the first discovery with the new cutting-edge Gemini instrument. “In just one of our many 50-second exposures we could see what previous instruments failed to see in more than 50 minutes,” said Currie.

    The star, going by the designation HD 115600, was the first object the research team looked at. “Over the next few years, I’m optimistic that GPI will reveal many more debris discs and young planets. Who knows what strange, new worlds we will find,” Currie added.

    The paper is accepted for publication in The Astrophysical Journal Letters.

    See the full article here.

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    About Phys.org in 100 Words

    Phys.org™ (formerly Physorg.com) is a leading web-based science, research and technology news service which covers a full range of topics. These include physics, earth science, medicine, nanotechnology, electronics, space, biology, chemistry, computer sciences, engineering, mathematics and other sciences and technologies. Launched in 2004, Phys.org’s readership has grown steadily to include 1.75 million scientists, researchers, and engineers every month. Phys.org publishes approximately 100 quality articles every day, offering some of the most comprehensive coverage of sci-tech developments world-wide. Quancast 2009 includes Phys.org in its list of the Global Top 2,000 Websites. Phys.org community members enjoy access to many personalized features such as social networking, a personal home page set-up, RSS/XML feeds, article comments and ranking, the ability to save favorite articles, a daily newsletter, and other options.

     
  • richardmitnick 12:59 pm on April 4, 2015 Permalink | Reply
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    From Gemini Observatory: “Star Pair’s Dusty Disk Shines Light on Planet Formation” 

    NOAO

    Gemini Observatory
    Gemini Observatory

    April 2, 2015
    No Writer Credit

    1
    Left: J-band polarized intensity (P⊥) images. Right: P⊥ scaled by r2, where r is the distance in pixels from the central binary, corrected for projection effects. Both images are shown on a linear scale and oriented north up and east left. The coronagraph is represented by the black filled circles.

    Astronomers using the Gemini South telescope in Chile have discovered striking new evidence for planet formation in a dusty disk surrounding a pair of stars in Sagittarius. The team took advantage of an offering for Early Science using the Gemini Planet Imager [GPI] to study infrared light scattered off dust grains in the disk around the binary system V4046 Sgr.

    Gemini Planet Imager
    GPI

    “The Gemini Planet Imager allows us to study nearby planet forming disks in sufficient detail that we can obtain direct-image evidence for young planets in orbits similar to those of the giant planets in our own solar system,” says Valerie Rapson of the Rochester Institute of Technology, who led the research team. Indeed, the GPI imaging reveals an intriguing double ring structure around the V4046 Sgr binary that is most likely due to the formation of a giant planet (or planets) at some 4-12 times the Earth-Sun distance (approximately between Jupiter and Uranus, if orbiting our Sun).”This is perhaps the best such evidence yet for planet formation so close to a binary system,” says Rapson. Analysis of the data also indicates that the dust grains orbiting the star are sorted by particle size, as predicted by recent planet formation models. The result is published in The Astrophysical Journal Letters and the preprint is at http://arxiv.org/abs/1503.06192, see abstract below.

    Abstract:

    We report the presence of scattered light from dust grains located in the giant planet formation region of the circumbinary disk orbiting the ∼20-Myr-old close (∼0.045 AU separation) binary system V4046 Sgr AB based on observations with the new Gemini Planet Imager (GPI) instrument. These GPI images probe to within ∼7 AU of the central binary with linear spatial resolution of ∼3 AU, and are thereby capable of revealing dust disk structure within a region corresponding to the giant planets in our solar system. The GPI imaging reveals a relatively narrow (FWHM ∼10 AU) ring of polarized near-infrared flux whose brightness peaks at ∼14 AU. This ∼14 AU radius ring is surrounded by a fainter outer halo of scattered light extending to ∼45 AU, which coincides with previously detected mm-wave thermal dust emission. The presence of small grains that efficiently scatter starlight well inside the mm-wavelength disk cavity supports current models of planet formation that suggest planet-disk interactions can generate pressure traps that impose strong radial variations in the particle size distribution throughout the disk.

    See the full article here.

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    Gemini North
    Gemini North, Hawai’i

    Gemini South
    Gemini South, Chile
    AURA Icon

    The Gemini Observatory consists of twin 8.1-meter diameter optical/infrared telescopes located on two of the best observing sites on the planet. From their locations on mountains in Hawai‘i and Chile, Gemini Observatory’s telescopes can collectively access the entire sky.
    Gemini was built and is operated by a partnership of six countries including the United States, Canada, Chile, Australia, Brazil and Argentina. Any astronomer in these countries can apply for time on Gemini, which is allocated in proportion to each partner’s financial stake.

     
  • richardmitnick 4:34 am on March 5, 2015 Permalink | Reply
    Tags: , , Gemini Observatory   

    From Gemini: “FAR FROM HOME: WAYWARD CLUSTER IS BOTH TINY AND DISTANT “ 

    NOAO

    Gemini Observatory
    Gemini Observatory

    March 3, 2015
    Media Contacts:

    Peter Michaud
    Public Information and Outreach
    Gemini Observatory, Hilo, HI
    Email: pmichaud”at”gemini.edu
    Cell: (808) 936-6643

    Science Contacts:

    Dongwon Kim
    Australia National University
    Email: dongwon.kim”at”anu.edu.au
    Office: +61 2 6125 8022

    Helmut Jerjen
    Australia National University
    Email: helmut.jerjen”at”anu.edu.au
    Office: +61 2 6125 8038

    1
    GMOS image of Kim 2, in g band. The image is 4 arcminutes across.

    Like the lost little puppy that wanders too far from home, astronomers have found an unusually small and distant group of stars that seems oddly out of place. The cluster, made of only a handful of stars, is located far away, in the Milky Way’s “suburbs.” It is located where astronomers have never spotted such a small cluster of stars before.

    The new star cluster was discovered by Dongwon Kim, a PhD student at the Australian National University (ANU), together with a team of astronomers (Helmut Jerjen, Antonino Milone, Dougal Mackey, and Gary Da Costa) who are conducting the Stromlo Milky Way Satellite Survey* at ANU.

    “This cluster is faint, very faint, and truly in the suburbs of our Milky Way,” said Kim. “In fact, this group of stars is about ten times more distant than the average globular star cluster in the halo of our galaxy — it’s a lost puppy,” Mackey adds. Globular clusters are spherical cities of stars that form a vast, extended halo around the core of our galaxy, the brightest of which are easily seen in amateur telescopes or even binoculars. However, this new discovery required one of the world’s largest telescopes to confirm, “it’s definitely a diminutive oddball,” says Milone.

    The oddly small, far-flung, cluster was discovered using the Dark Energy Camera (DECam) on the 4-meter Blanco Telescope at the Cerro Tololo Inter-American Observatory (CTIO) in Chile. “This discovery sheds new light on the formation and evolution of the Milky Way,” said Daniel Evans, National Science Foundation program director for Gemini Observatory. “It’s great to see so many telescopes come together to produce this result, not the least being Gemini Observatory with its incredible light-gathering power.”

    CTIO Victor M Blanco 4m Telescope
    CTIO Victor M Blanco 4m Telescope interior
    Dark Energy Camera
    4-meter Blanco Telescope and DECam

    The team’s first evidence of the unusually remote star cluster came when they ran detection algorithms on a 500 square-degree imaging data field obtained with DECam. “Such objects are too faint and optically elusive to be seen by eye. The cluster stars are sprinkled so thinly over the image, you look right through them without noticing. They are hiding in the sea of stars from the Milky Way. Sophisticated computer programs are our tools to find them,” said Jerjen.

    Because it is so faint, ultra-deep follow-up observations using the Gemini Multi-Object Spectrograph [GMOS] (in imaging mode) confirmed that the new globular cluster is among the faintest Milky Way globular clusters ever found.

    Gemini Multi Object Spectrograph
    GMOS

    Seven out of 150 known Milky Way globular clusters are comparably faint but none are located as far out toward the edge of the Milky Way. This new globular cluster has 10-20 times fewer stars than any of the other outer halo globular clusters. Also, its star density is less than half of that of other Milky Way globular clusters in the same luminosity (brightness) range.

    The new star cluster, named Kim 2, also shows evidence of significant mass loss over its history. Computer simulations predict that, as a consequence of their evolution over many billions of years, including the slow loss of member stars due to the gravitational pull of the Milky Way, star clusters ought to be arranged such that their more massive stars are concentrated toward their centers. “This ‘mass segregation’ has been difficult to observe, particularly in low mass clusters, but the excellent Gemini data reveal that Kim 2 appears to be mass segregated and has therefore likely lost much of its original mass,” said Da Costa. The finding suggests that a substantial number of low-luminosity globular clusters must have existed in the halo when the Milky Way was younger, but most of them might have evaporated due to internal dynamical processes.

    The observed properties of the new star cluster also raise the question about how such a low luminosity system could have survived until today. One possible scenario is that Kim 2 is not actually a genuine member of the Milky Way globular cluster family, but a star cluster originally located in a satellite dwarf galaxy and was accreted into the Milky Way’s halo. This picture is also supported by the fact that the stars in Kim 2 appear to be more chemically enriched with heavier elements than the other outer halo globular clusters and are young relative to the oldest globular clusters in the Milky Way. As a consequence of spending much of its life in a dwarf galaxy Kim 2 could have largely escaped the destructive influence of tidal forces, thus helping it to survive until the present epoch.

    There are many Milky Way globular clusters formerly and currently associated with satellite dwarf galaxies. It is possible that a significant fraction of the ancient satellite dwarf galaxies were completely disrupted by the tidal field of the Milky Way while the high density of the globular clusters allowed them to survive in our galaxy’s halo. Indeed, Kim 2 is found close to the vast polar structure of Milky Way satellite galaxies, a disc-like region surrounding the Milky Way where satellite galaxies and young halo clusters preferentially congregate. A similar distribution of satellite galaxies is also found in the neighbouring Andromeda Galaxy.

    A large fraction of the Milky Way’s halo is thought to be populated with optically elusive satellite galaxies and star clusters. New discoveries of satellite galaxies and globular clusters will therefore provide valuable information about the formation and the structure of the Milky Way. Previous surveys like the Sloan Digital Sky Survey have contributed to many new discoveries in the northern sky. However, most of the southern sky still remains unexplored to date. The detection of Kim 2 suggests that there are a substantial number of interesting astronomical objects waiting to be discovered in the southern hemisphere and the Stromlo Milky Way Satellite Survey team plans to continue searching for them.

    The team’s paper, accepted for publication in the Astrophysical Journal, is available as a preprint at http://arxiv.org/abs/1502.03952.

    • The Stromlo Milky Way Satellite Survey is led by Australian National University’s Associate Professor Helmut Jerjen. The research team includes Dongwon Kim, Antonino Milone, Dougal Mackey, and Gary Da Costa (all from the Australian National University). See project website at: http://www.mso.anu.edu.au/~jerjen/SMS_Survey.html

    See the full article here.

    Please help promote STEM in your local schools.

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    Gemini North
    Gemini North, Hawai’i

    Gemini South
    Gemini South, Chile
    AURA Icon

    The Gemini Observatory consists of twin 8.1-meter diameter optical/infrared telescopes located on two of the best observing sites on the planet. From their locations on mountains in Hawai‘i and Chile, Gemini Observatory’s telescopes can collectively access the entire sky.
    Gemini was built and is operated by a partnership of six countries including the United States, Canada, Chile, Australia, Brazil and Argentina. Any astronomer in these countries can apply for time on Gemini, which is allocated in proportion to each partner’s financial stake.

     
  • richardmitnick 4:17 pm on January 9, 2015 Permalink | Reply
    Tags: , , , Gemini Observatory   

    From Astronomy- “Galactic herding: new image brings galaxy diversity to life” 

    Astronomy magazine

    Astronomy Magazine

    January 08, 2015
    No Writer Credit
    By Gemini Observatory, Hilo, Hawaii

    A new Gemini image of galaxy group VV 166 provides clarity and definition to the group’s different morphological types.

    Gemini North telescope
    Gemini North Interior
    Gemini North, Mauna Kea, Hawaii

    Galaxy groups are the most evident structures in the nearby universe. They are important laboratories for studying how galaxies form and evolve beyond our Local Group of galaxies, which includes the Milky Way and the Andromeda Galaxy. Exploring the nature of these extragalactic “herds” may help unlock the secrets to the overall structure of the universe.

    l
    Andrew Z. Colvin

    Herd dynamics

    Unlike animal herds, which are generally the same species traveling together, most galaxies move through space in associations composed of myriad types, shapes, and sizes. Galaxy groups differ in their richness, size, and internal structure as well as the ages of their members. Some group galaxies are composed mainly of ancient stars, while others radiate with the power and splendor of youth.

    These facts raise important questions for astronomers: Do all the galaxies in a group share a common origin? Are some just chance alignments? Or do galaxy groups pick up “strays” along the way and amalgamate them into the group?

    Probing galactic group interiors

    The new Gemini image of a grouping called VV 166, named after its position in the catalog by B. Vorontsov-Vel’yaminov, provides clarity and definition to the group’s different morphological types despite its great distance of about 300 million light-years — some 30 times farther away than the closest galaxy groups to our Local Group. One of its most fascinating features is a perfect alignment of three disparate galaxies in a precise equilateral triangle: blue-armed spiral NGC 70 at top, elliptical galaxy NGC 68 to its lower right, and lenticular galaxy NGC 71 to its lower left.

    70
    NGC 70, located in the central NGC 68 group. The galaxies below are NGC 68 (right) and NGC 71 (left)

    The blue spiral (NGC 70) looks like an elephant among lions. This massive galaxy is impressive as it spans 180,000 light-years, or nearly twice the extent of the Milky Way’s reach. Its spiral arms appear blue because they are dominated by active regions of star formation. Here, hot young stars burn with an intense blue light that overpowers that from any older red and yellow stars that might populate the galaxy.

    The opposite is true in the galaxy’s central bulge, where the extinction of star formation has left it to glow with the warm light of ancient red giant and supergiant suns. The galaxy’s sharp starlike core is a telltale sign of an active galactic nucleus powered by a centrally located supermassive black hole feasting on a disk of interstellar gas only a few light-days across.

    In contrast, NGC 68 (lower right) is a much older system known as an elliptical galaxy. NGC 68 is about half the size of the blue spiral and hosts little dust and gas, so star formation is all but absent, as is any spiral structure; the galaxy’s overall yellowish hue reveals that most of its stars are old and red. If there’s an outlier in the image, it might be NGC 68, given that it is about 20 million light-years closer to us than NGC 70. In fact, some researchers have argued that NGC 68 is nothing but a chance alignment. Indeed, while small galaxy groups prevail in the nearby universe, many may not be real gravitationally bound systems at all. But this does not appear to be the case with VV 166, for most of these galaxies are indeed bound as a group.

    Although NGC 71 looks much like NGC 68 — a smooth featureless glow, below and to the left of NGC 68 — it is actually a lens-shaped galaxy seen face on, so it appears more like a sphere. Lenticular galaxies are mysterious creatures, as they appear to be trapped between classifications: like a spiral galaxy, it has a bulge and a disk but no spiral arms; like an elliptical galaxy, it is largely devoid of dust and gas. Possibly galaxies like NGC 71 were originally spiral systems and have either consumed or somehow lost their interstellar material through other galactic interactions.

    The image also shows possible evidence for such a dynamic interaction. Careful inspection reveals that blue spiral’s arms appear distorted between NGC 68 and NGC 71, indicating a possible tidal interaction with one or more of the galaxies. These graceful interactions are choreographed as the group whizzes collectively through space at about 4,000 miles (6,500 kilometers) per second. The image also sharply resolves a flurry of starlight around the elliptical and lenticular systems. Often the brightest cluster galaxy has an extraordinarily diffuse and extended outer halo.

    Just beyond the triangle to the lower left is the group’s fourth-brightest member, a barred spiral galaxy known as NGC 72. Its prominent bar slices across its nucleus. Dusty arms wind out from either end of the bar and form a distinct nuclear ring — the result of recent star formation. Our Milky Way Galaxy has a similar bar component spanning nearly 30,000 light-years from end to end, as well as a circumnuclear ring. But we have evidence that our Milky Way is a “grand-design” spiral with more splendid and numerous arms.

    Despite the apparent diversity of galaxy types in VV 166, the relative proportions of morphologies that we see here may provide a representative sample of galactic types found throughout the universe. It’s possible that some members of VV 166 may have grown by drawing in smaller galaxies from the local environment and consuming them. Or, perhaps, like some herds of animals, galaxy groups may be joined by other “species” — sometimes passively, sometimes violently; this would help to explain the observed mix of morphological types in these groups.

    On the larger cosmological scale, galaxy groups are like beads in the long filamentary structures that make up the skeleton of our universe. These filaments are made up of isolated galaxies, groups, clusters, and superclusters. In time, the isolated galaxies may merge with the groups, which will themselves merge with other groups to form larger clusters of galaxies. As with the animal kingdom, the universe has its hierarchy and includes all things great, and even greater.

    See the full article here.

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  • richardmitnick 4:52 pm on January 8, 2015 Permalink | Reply
    Tags: , , , , Gemini Observatory,   

    From Gemini Observatory: “THE GEMINI PLANET IMAGER PRODUCES STUNNING OBSERVATIONS IN ITS FIRST YEAR” 

    NOAO

    Gemini Observatory
    Gemini Observatory

    January 6, 2015
    Media Contacts:

    Peter Michaud
    Public Information and Outreach Manager
    Gemini Observatory, Hilo, HI
    Email: pmichaud”at”gemini.edu
    Cell: (808) 936-6643
    Desk: (808) 974-2510

    Science Contacts:

    Marshall Perrin
    STScI
    Email: mperrin”at”stsci.edu
    Phone: (410) 507-5483

    James R. Graham
    University of California Berkeley
    Email: jrg”at”berkeley.edu
    Cell: (510) 926-9820

    Stunning exoplanet images and spectra from the first year of science operations with the Gemini Planet Imager (GPI) were featured today in a press conference at the 225th meeting of the American Astronomical Society (AAS) in Seattle, Washington. The Gemini Planet Imager GPI is an advanced instrument designed to observe the environments close to bright stars to detect and study Jupiter-like exoplanets (planets around other stars) and see protostellar material (disk, rings) that might be lurking next to the star.

    1
    Figure 1. GPI imaging of the planetary system HR 8799 in K band, showing 3 of the 4 planets. (Planet b is outside the field of view shown here, off to the left.) These data were obtained on November 17, 2013 during the first week of operation of GPI and in relatively challenging weather conditions, but with GPI’s advanced adaptive optics system and coronagraph the planets can still be clearly seen and their spectra measured (see Figure 2). Image credit: Christian Marois (NRC Canada), Patrick Ingraham (Stanford University) and the GPI Team.

    2
    Figure 2. GPI spectroscopy of planets c and d in the HR 8799 system. While earlier work showed that the planets have similar overall brightness and colors, these newly-measured spectra show surprisingly large differences. The spectrum of planet d increases smoothly from 1.9-2.2 microns while planet c’s spectrum shows a sharper kink upwards just beyond 2 microns. These new GPI results indicate that these similar-mass and equal-age planets nonetheless have significant differences in atmospheric properties, for in-stance more open spaces between patchy cloud cover on planet c versus uniform cloud cover on planet d, or perhaps differences in atmospheric chemistry. These data are helping refine and improve a new generation of atmospheric models to explain these effects. Image credit: Patrick Ingraham (Stanford University), Mark Marley (NASA Ames), Didier Saumon (Los Alamos National Laboratory) and the GPI Team.

    Marshall Perrin (Space Telescope Science Institute), one of the instrument’s team leaders, presented a pair of recent and promising results at the press conference. He revealed some of the most detailed images and spectra ever of the multiple planet system HR 8799. His presentation also included never-seen details in the dusty ring of the young star HR 4796A. “GPI’s advanced imaging capabilities have delivered exquisite images and data,” said Perrin. “These improved views are helping us piece together what’s going on around these stars, yet also posing many new questions.”

    The GPI spectra obtained for two of the planetary members of the HR 8799 system presents a challenge for astronomers. GPI team member Patrick Ingraham (Stanford University), lead the paper on HR 8799. Ingraham reports that the shape of the spectra for the two planets differ more profoundly than expected based on their similar colors, indicating significant differences between the companions. “Current atmospheric models of exoplanets cannot fully explain the subtle differences in color that GPI has revealed. We infer that it may be differences in the coverage of the clouds or their composition.” Ingraham adds, “The fact that GPI was able to extract new knowledge from these planets on the first commissioning run in such a short amount of time, and in conditions that it was not even designed to work, is a real testament to how revolutionary GPI will be to the field of exoplanets.”

    Perrin, who is working to understand the dusty ring around the young star HR 4796A, said that the new GPI data present an unprecedented level of detail in studies of the ring’s polarized light. “GPI not only sees the disk more clearly than previous instruments, it can also measure how polarized its light appears, which has proven crucial in under-standing its physical properties.” Specifically, the GPI measurements of the ring show it must be partially opaque, implying it is far denser and more tightly compressed than similar dust found in the outskirts of our own Solar System, which is more diffuse. The ring circling HR 4796A is about twice the diameter of the planetary orbits in our Solar System and its star about twice our Sun’s mass. “These data taken during GPI commissioning show how exquisitely well its polarization mode works for studying disks. Such observations are critical in advancing our understanding of all types and sizes of planetary systems – and ultimately how unique our own solar system might be,” said Perrin.

    3
    Figure 3. GPI imaging polarimetry of the circumstellar disk around HR 4796A, a ring of dust and planetesimals similar in some ways to a scaled up version of the solar system’s Kuiper Belt.

    Kuiper Belt
    Kuiper Belt, for illustration of the discussion

    These GPI observations reveal a complex pattern of variations in brightness and polarization around the HR 4796A disk. The western side (tilted closer to the Earth) appears brighter in polarized light, while in total intensity the eastern side appears slightly brighter, particularly just to the east of the widest apparent separation points of the disk. Reconciling this complex and apparently-contradictory pattern of brighter and darker regions required a major overhaul of our understanding of this circumstellar disk. Image credit: Marshall Perrin (Space Telescope Science Institute), Gaspard Duchene (UC Berkeley), Max Millar-Blanchaer (University of Toronto), and the GPI Team.

    4
    Figure 4. Diagram depicting the GPI team’s revised model for the orientation and composition of the HR 4796A ring. To explain the observed polarization levels, the disk must consist of relatively large (> 5 µm) silicate dust particles, which scatter light most strongly and polarize it more for forward scattering. To explain the relative faintness of the east side in total intensity, the disk must be dense enough to be slightly opaque, comparable to Saturn’s optically thick rings, such that on the near side of the disk our view of its brightly illuminated inner portion is partially obscured. This revised model requires the disk to be much narrower and flatter than expected, and poses a new challenge for theories of disk dynamics to explain. GPI’s high contrast imaging and polarimetry capabilities together were essential for this new synthesis. Image credit: Marshall Perrin (Space Telescope Science Institute).

    During the commissioning phase, the GPI team observed a variety of targets, ranging from asteroids in our solar system, to an old star near its death. Other teams of scientists have been using GPI as well and already astronomers around the world have published eight papers in peer-reviewed journals using GPI data. “This might be the most productive new instrument Gemini has ever had,” said Professor James Graham of the University of California, who leads the GPI science team and who will describe the GPI exoplanet survey in a talk scheduled at the AAS meeting on Thursday, January 8th.

    The Gemini Observatory staff integrated the complex instrument into the telescope’s software and helped to characterize GPI’s performance. “Even though it’s so complicated, GPI now operates almost automatically,” said Gemini’s instrument scientist for GPI Fredrik Rantakyro. “This allows us to start routine science operations.” The instrument is now available to astronomers and their proposals are scheduled to start ob-serving in early 2015. In addition, “shared risk” observations are already underway, starting in November 2014.

    The one thing GPI hasn’t done yet is discovered a new planet. “For the early tests, we concentrated on known planets or disks” said GPI PI Bruce Macintosh. Now that GPI is fully operational, the search for new planets has begun. In addition to observations by astronomers world-wide, the Gemini Planet Imager Exoplanet Survey (GPIES) will look at 600 carefully selected stars over the next few years. GPI ‘sees’ planets through the infrared light they emit when they’re young, so the GPIES team has assembled a list of the youngest and closest stars. So far the team has observed 50 stars, and analysis of the data is ongoing. Discovering a planet requires confirmation observations to distinguish a true planet orbiting the target star from a distant star that happens to sneak into GPI’s field of view – a process that could take years with previous instruments. The GPIES team found one such object in their first survey run, but GPI observations were sensitive enough to almost immediately rule it out. Macintosh said, “With GPI, we can tell almost instantly that something isn’t a planet – rather than months of uncertainty, we can get over our disappointment almost immediately. Now it’s time to find some real planets!”

    About GPI/GPIES

    The Gemini Planet Imager (GPI) instrument was constructed by an international collaboration led by Lawrence Livermore National Laboratory under Gemini’s supervision. The GPI Exoplanet Survey (GPIES) is the core science program to be carried out with it. GPIES is led by Bruce Macintosh, now a professor at Stanford University and James Graham, professor at the University of California at Berkeley and is designed to find young, Jupiter-like exoplanets. They survey will observe 600 young nearby stars in 890 hours over three years. Targets have been carefully selected by team members at Arizona State University, the University of Georgia, and UCLA. The core of the data processing architecture is led by Marshall Perrin of the Space Telescope Science Institute, with the core software originally written by University of Montreal, data management infrastructure from UC Berkeley and Cornell University, and contributions from all the other team institutions. The SETI institute located in California manages GPIES’s communications and public out-reach. Several teams located at the Dunlap Institute, the University of Western Ontario, the University of Chicago, the Lowell Observatory, NASA Ames, the American Museum of Natural History, University of Arizona and the University of California at San Diego and at Santa Cruz also contribute to the survey. The GPI Exoplanet Survey is supported by the NASA Origins Program NNX14AG80, the NSF AAG pro-gram, and grants from other institutions including the University of California Office of the President. Dropbox Inc. has generously provided storage space for the entire survey’s archive.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Gemini North
    Gemini North, Hawai’i

    Gemini South
    Gemini South, Chile
    AURA Icon

    The Gemini Observatory consists of twin 8.1-meter diameter optical/infrared telescopes located on two of the best observing sites on the planet. From their locations on mountains in Hawai‘i and Chile, Gemini Observatory’s telescopes can collectively access the entire sky.
    Gemini was built and is operated by a partnership of six countries including the United States, Canada, Chile, Australia, Brazil and Argentina. Any astronomer in these countries can apply for time on Gemini, which is allocated in proportion to each partner’s financial stake.

     
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