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Posts Tagged ‘subaru telescope’

Discovery Of An Extremely Young Stellar Clump In The Distant Universe


Credits: CEA/HST

Credits: CEA/HST

As part of an observing program carried out with the Subaru Telescope and the Hubble Space Telescope, a group of researchers from the “Service d’Astrophysique-Laboratoire AIM” of CEA-IRFU led by Anita Zanella discovered the birth cry of a massive star-forming clump in the disk of a very distant galaxy. This giant clump is less than 10 million years old, and it is the very first time that such a young star-forming region is observed in the distant Universe. This discovery sheds new light on how stars were born within distant galaxies. The physical properties of this object reveal that newly-born clumps in such galaxies survive from stellar winds and supernovae feedback, and can thus live for a few hundred million years unlike the predictions from several theoretical models. Their long lifetime could enable their migration toward the inner regions of the galaxy, hence contributing to the total mass of the galactic bulge and the growth of the central black hole. These results are published in the “Nature” journal from May 2015.

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Subaru Telescope Observers Superflare Stars With Large Starspots


Artificial image of a superflare star. Credit: Kyoto University

Artificial image of a superflare star. Credit: Kyoto University

A team of astronomers has used the High Dispersion Spectrograph on the Subaru Telescope to conduct spectroscopic observations of Sun-like “superflare” stars first observed and cataloged by the Kepler Space Telescope. The investigations focused on the detailed properties of these stars and confirmed that Sun-like stars with large starspots can experience superflares.

The team, made up of astronomers from Kyoto University, University of Hyogo, the National Astronomical Observatory of Japan (NAOJ), and Nagoya University, targeted a set of solar-type stars emitting very large flares that release total energies 10-10000 times greater than the biggest solar flares. Solar flares are energetic explosions in the solar atmosphere and are thought to occur by intense releases of magnetic energy around the sunspots. Large flares often cause massive bursts of high-speed plasma called coronal mass ejections (CMEs), can lead to geomagnetic storms on Earth. Such storms can have severe impacts on our daily life by affecting such systems as communications and power grids.

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Subaru Telescope Detects Rare Form Of Nitrogen In Comet ISON

February 24, 2014 Leave a comment

A team of astronomers, led by Ph.D. candidate Yoshiharu Shinnaka and Professor Hideyo Kawakita, both from Kyoto Sangyo University, successfully observed the Comet ISON during its bright outburst in the middle of November 2013. Subaru Telescope’s High Dispersion Spectrograph (HDS) detected two forms of nitrogen–14NH2 and 15NH2–in the comet. This is the first time that astronomers have reported a clear detection of the relatively rare isotope 15NH2 in a single comet and also measured the relative abundance of two different forms of nitrogen (“nitrogen isotopic ratio”) of cometary ammonia (NH3). Their results support the hypothesis that there were two distinct reservoirs of nitrogen the massive, dense cloud (“solar nebula”) from which our Solar System may have formed and evolved.

Why did the team focus on studying these different forms of nitrogen in the comet? Comets are relatively small Solar System objects composed of ice and dust, which formed 4.6 billion years ago in the solar nebula when our Solar System was in its infancy. Because they usually reside in cold regions far from the Sun, e.g., the Kuiper belt and Oort cloud, they probably preserve information about the physical and chemical conditions in the early Solar System. Different forms and abundances of the same molecule provide information about their source and evolution. Were they from a stellar nursery (a primordial interstellar cloud) or from a distinctive cloud (solar nebula) that may have formed our Solar System’s star, the Sun? Scientists do not yet understand very well how cometary molecules separate into isotopes with different abundances. Isotopes of nitrogen from ammonia (NH3) may hold the key.

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A Fluffy Disk Around A Baby Star

August 27, 2013 Leave a comment

Artist’s rendition. Credit: NAOJ

Artist’s rendition. Credit: NAOJ

An international team of astronomers that are members of the Strategic Exploration of Exoplanets and Disks with Subaru Telescope (SEEDS) Project has used Subaru Telescope’s High Contrast Instrument for the Subaru Next Generation Adaptive Optics (HiCIAO) to observe a disk around the young star RY Tau (Tauri). The team’s analysis of the disk shows that a “fluffy” layer above it is responsible for the scattered light observed in the infrared image. Detailed comparisons with computer simulations of scattered light from the disk reveal that this layer appears to be a remnant of material from an earlier phase of stellar and disk development, when dust and gas were falling onto the disk.

Since 2009, the five-year SEEDS Project (Note) has focused on direct imaging of exoplanets, i.e., planets orbiting stars outside of our Solar System, and disks around a targeted total of 500 stars. Planet formation, an exciting and active area for astronomical research, has long fascinated many scientists. Disks of dust and gas that rotate around young stars are of particular interest, because astronomers think that these are the sites where planets form–in these so-called “protoplanetary disks.”

Full Story: http://www.naoj.org/Pressrelease/2013/08/22/index.html

Constructing A 3D Map Of The Large-Scale Structure Of The Universe


An international team led by astronomers from Kyoto University, the University of Tokyo and the University of Oxford has released its first version of a 3D map of the Universe from its FastSound project, which is surveying galaxies in the Universe over nine billion light years away. Using the Subaru Telescope’s new Fiber Multi-Object Spectrograph, the team’s 3D map includes 1,100 galaxies and shows the large-scale structure of the Universe nine billion years ago.

The FastSound project, one of Subaru Telescope’s Strategic Programs, began its observations in March 2012 and will continue them into the spring of 2014. Although surveys with 3D maps of the Universe have been conducted on the nearby Universe (e.g., the Sloan Digital Sky Survey with coverage up to five billion light years away), the FastSound project distinguishes itself by developing a 3D map of the far-distant Universe, covering the largest volume of the Universe farther than ten billion light years away (in comoving distance).

Full Story: http://www.naoj.org/Topics/2013/08/07/index.html

Subaru Telescope’s Imaging Discovery Of A Second Jupiter Shows The Power And Significance Of The SEEDS Project


Astronomers in the Strategic Explorations of Exoplanets and Disks with Subaru (SEEDS) Project have recently discovered and captured an image of the least massive planet ever imaged so far–a so-called “second Jupiter”. This discovery marks an important step toward the direct imaging of much fainter Earth-like planets in the future and may lead to new models of planet formation. It also illustrates the important role that the SEEDS project plays in observational astronomy.

Exoplanets are planets orbiting stars other than our Sun, outside of our Solar System. As of July 2013, most of the 890 exoplanets reported thus far have been discovered by indirect observation techniques, e.g. monitoring the host star for radial velocity variation or planetary transits (Note 1). Such techniques require observations over at least one orbital period and are impractical for detecting planets that are widely separated from their host stars and have long orbital periods. In contrast, direct imaging may be the most important way to observe exoplanets, because it yields information about the planet’s luminosity, temperature, atmosphere, and orbit.

Full Story: http://subarutelescope.org/Pressrelease/2013/08/04/index.html
Also: http://www.nasa.gov/content/goddard/astronomers-image-lowest-mass-exoplanet-around-a-sun-like-star/

Confirmed Signs of Unseen Planets in Star’s Dust Ring

January 3, 2012 Leave a comment

The SEEDS (Strategic Exploration of Exoplanets and Disks with Subaru Telescope/HiCIAO) project, a five-year international collaboration launched in 2009 and led by Motohide Tamura of NAOJ (National Astronomical Observatory of Japan) has yielded another impressive image that contributes to our understanding of the link between disks and planet formation. Researchers used Subaru’s planet-finder camera, HiCIAO (High Contrast Instrument for the Subaru Next Generation Adaptive Optics), to take a crisp high-contrast image of the dust ring around HR 4796 A, a young (8-10 million years old) nearby star, only 240 light years away from Earth. The ring consists of dust grains in a wide orbit, roughly twice the size of Pluto’s orbit, around the central star. The resolution of the image of the inner edge of the ring is so precise that an offset between its center and the star’s position can be measured. Although data from the Hubble Space Telescope led another research group to suspect such an offset, the Subaru data not only confirm its presence but also reveal it to be larger than previously assumed.

What caused the wheel of dust around HR 4796 A to run off its axis? The most plausible explanation is that the gravitational force of one or more planets orbiting in the gap within the ring must be tugging at the dust, thus unbalancing their course around the star in predictable ways. Computer simulations have already shown that such gravitational tides can shape a dust ring into eccentricity, and findings from another the eccentric dust ring around the star Formalhaut may be observational evidence for the process. Since no planet candidates have been spotted near HR 4796 A yet, the planets causing the dust ring to wobble are probably simply too faint to detect with current instruments. Nevertheless, the Subaru image allows scientists to infer their presence from their influence on the circumstellar dust.

Full Story: http://www.subarutelescope.org/Pressrelease/2011/12/29/index.html