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Wonderful Clouds over Qingdao
"On the evening of August 22nd, over Alishan Observatory in Qingdao, there was a large cloud formation that looked like a ladder. It was very beautiful."
Credit: Kun Zhou
Location: Qingdao, Shandong Province, China
Image Date: August 22, 2018
#Earth #Astronomy #Science #Planet #Atmosphere #Clouds #Moon #Moonlight #Astrophotography #Photography #Alishan #Observatory #Qingdao #青岛市 #Shandong #山东省 #Province #China #中国 #STEM #Education
"On the evening of August 22nd, over Alishan Observatory in Qingdao, there was a large cloud formation that looked like a ladder. It was very beautiful."
Credit: Kun Zhou
Location: Qingdao, Shandong Province, China
Image Date: August 22, 2018
#Earth #Astronomy #Science #Planet #Atmosphere #Clouds #Moon #Moonlight #Astrophotography #Photography #Alishan #Observatory #Qingdao #青岛市 #Shandong #山东省 #Province #China #中国 #STEM #Education
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Cosmic Collision Forges Galactic One Ring | NASA Chandra
What happens when one galaxy punches through another?
Astronomers have used NASA's Chandra X-ray Observatory to discover a ring of black holes or neutron stars in a galaxy 300 million light years from Earth. This ring, while not wielding power over Middle Earth, may help scientists better understand what happens when galaxies smash into one another in catastrophic impacts.
In this new composite image of the galaxy AM 0644-741 (AM 0644 for short), X-rays from Chandra (purple) have been combined with optical data from NASA's Hubble Space Telescope (red, green, and blue). The Chandra data reveal the presence of very bright X-ray sources, most likely binary systems powered by either a stellar-mass black hole or neutron star, in a remarkable ring.
Where did the ring of black holes or neutron stars in AM 0644 come from? Astronomers think that it was created when one galaxy was pulled into another galaxy by the force of gravity. The first galaxy generated ripples in the gas of the second galaxy, AM 0644, located in the lower right. These ripples then produced an expanding ring of gas in AM 0644 that triggered the birth of new stars. The first galaxy is possibly the one located in the lower left of the image.
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.
Image Credits:
X-ray: NASA/CXC/INAF/A. Wolter et al
Optical: NASA/STScI
Release Date: September 6, 2018
+NASA's Chandra X-ray Observatory
+Hubble Space Telescope
+NASA's Marshall Space Flight Center
+Space Telescope Science Institute
#NASA #Hubble #Astronomy #Space #Science #Galaxy #Ring #AM0644 #AM0644741 #Volans #Chandra #Xray #Observatory #Marshall #MSFC #Cosmos #Universe #STEM #Education
What happens when one galaxy punches through another?
Astronomers have used NASA's Chandra X-ray Observatory to discover a ring of black holes or neutron stars in a galaxy 300 million light years from Earth. This ring, while not wielding power over Middle Earth, may help scientists better understand what happens when galaxies smash into one another in catastrophic impacts.
In this new composite image of the galaxy AM 0644-741 (AM 0644 for short), X-rays from Chandra (purple) have been combined with optical data from NASA's Hubble Space Telescope (red, green, and blue). The Chandra data reveal the presence of very bright X-ray sources, most likely binary systems powered by either a stellar-mass black hole or neutron star, in a remarkable ring.
Where did the ring of black holes or neutron stars in AM 0644 come from? Astronomers think that it was created when one galaxy was pulled into another galaxy by the force of gravity. The first galaxy generated ripples in the gas of the second galaxy, AM 0644, located in the lower right. These ripples then produced an expanding ring of gas in AM 0644 that triggered the birth of new stars. The first galaxy is possibly the one located in the lower left of the image.
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.
Image Credits:
X-ray: NASA/CXC/INAF/A. Wolter et al
Optical: NASA/STScI
Release Date: September 6, 2018
+NASA's Chandra X-ray Observatory
+Hubble Space Telescope
+NASA's Marshall Space Flight Center
+Space Telescope Science Institute
#NASA #Hubble #Astronomy #Space #Science #Galaxy #Ring #AM0644 #AM0644741 #Volans #Chandra #Xray #Observatory #Marshall #MSFC #Cosmos #Universe #STEM #Education
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Natskies Space Science Express at K-Tech Academy, Kondhwa, Pune
#natskies #observatory #outreach #fun #oneuniverse #amazing #latestpost
#natskies #observatory #outreach #fun #oneuniverse #amazing #latestpost
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9/8/18
14 Photos - View album
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New post: sky - http://wallpaperhd.site/sky-2150 #Astronomy, #Exposure, #Night, #Observatory, #Photo, #Stars
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According to the #Syrian #Observatory for #HumanRights, #warplanes entered through #Lebanese #airspace and targeted #Iranian positions.
#TheCrystalEyes #iran
http://ow.ly/RIAc30lIIJC
#TheCrystalEyes #iran
http://ow.ly/RIAc30lIIJC
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Unrivalled vistas at La Silla | ESO
ESO’s La Silla Observatory, situated in northern Chile, offers the resident telescopes unrivalled views of both the cosmos and the region’s barren, but beautiful landscape. Photographed by Alberto Ghizzi Panizza from the ramp leading to ESO’s New Technology Telescope (NTT), this view captures La Silla under the magnificence of the Milky Way, which unmistakably carves its way across the night sky overhead.
Sitting proudly at the center of the frame is the ESO 3.6-meter telescope, host of the planet-hunting HARPS instrument. Below sits the small grey and white enclosure (nicknamed the sarcofago, or sarcophagus) of the Télescope à Action Rapide pour les Objets Transitoires (TAROT). To the far right, the silver-sheened back of the decommissioned 15-meter Swedish-ESO Submillimeter Telescope (SEST) can be seen atop an isolated peak, and, finally, to the left of the road in the foreground sits the corrugated paneling and white dome of the Swiss 1.2-meter Leonhard Euler Telescope.
La Silla is located in the southern part of the Atacama Desert, 600 kilometers north of Santiago de Chile and at an altitude of 2400 meters. The site was ESO's first ever observing site, and has been in operation since the 1960s.
Credit: Alberto Ghizzi Panizza/ESO
Release Date: September 3, 2018
+European Southern Observatory (ESO)
#ESO #Astronomy #Space #Science #Stars #MilkyWay #Galaxy #LaSilla #Observatory #Telescopes #Atacama #Desert #Chile #SouthAmerica #Astrophotography #Photography #STEM #Education
ESO’s La Silla Observatory, situated in northern Chile, offers the resident telescopes unrivalled views of both the cosmos and the region’s barren, but beautiful landscape. Photographed by Alberto Ghizzi Panizza from the ramp leading to ESO’s New Technology Telescope (NTT), this view captures La Silla under the magnificence of the Milky Way, which unmistakably carves its way across the night sky overhead.
Sitting proudly at the center of the frame is the ESO 3.6-meter telescope, host of the planet-hunting HARPS instrument. Below sits the small grey and white enclosure (nicknamed the sarcofago, or sarcophagus) of the Télescope à Action Rapide pour les Objets Transitoires (TAROT). To the far right, the silver-sheened back of the decommissioned 15-meter Swedish-ESO Submillimeter Telescope (SEST) can be seen atop an isolated peak, and, finally, to the left of the road in the foreground sits the corrugated paneling and white dome of the Swiss 1.2-meter Leonhard Euler Telescope.
La Silla is located in the southern part of the Atacama Desert, 600 kilometers north of Santiago de Chile and at an altitude of 2400 meters. The site was ESO's first ever observing site, and has been in operation since the 1960s.
Credit: Alberto Ghizzi Panizza/ESO
Release Date: September 3, 2018
+European Southern Observatory (ESO)
#ESO #Astronomy #Space #Science #Stars #MilkyWay #Galaxy #LaSilla #Observatory #Telescopes #Atacama #Desert #Chile #SouthAmerica #Astrophotography #Photography #STEM #Education
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A Tour of Ring Galaxy AM 0644 | NASA Chandra
Sept. 6, 2018: Astronomers have used NASA's Chandra X-ray Observatory to discover a ring of X-ray power. This ring sounds like it might belong in Tolkien's Middle Earth, but it is, in fact, found in a galaxy about 300 million light years from Earth.
The galaxy called AM 0644-741 is what astronomers refer to as a "ring" galaxy. Taking a look at the image quickly reveals why. Astronomers think ring galaxies are formed when one galaxy smashes into another in a catastrophic collision. The impact generates ripples in the interstellar gas of the targeted galaxy. These ripples, in turn, trigger new waves of star formation as gas expands outward from the site of the collision.
The most massive of these fledgling stars will lead short lives—in cosmic terms—of millions of years. After that, their nuclear fuel is spent and the stars explode as supernovas leaving behind either black holes with masses less than about a hundred times that of the Sun, or neutron stars with a mass approximately equal to one and a half times of the Sun.
Some of these black holes and neutron stars have closecompanion stars, and siphon gas from their stellar partner. This gas falls towards the black hole or neutron star, forming a spinning disk like water circling a drain, and becomes heated by friction. This superheated gas produces large amounts of X-rays that Chandra can detect.
Astronomers are on a quest to study AM 0644-741 and others like it to better understand the origins of ring galaxies and the intriguing objects that they contain.
Credit: NASA Chandra
Duration: 2 minutes, 40 seconds
Release Date: September 6, 2018
+NASA's Chandra X-ray Observatory
+Hubble Space Telescope
+European Space Agency, ESA
+NASA's Marshall Space Flight Center
+Space Telescope Science Institute
#NASA #Hubble #Astronomy #Space #Science #Galaxy #Ring #AM0644 #AM0644741 #Volans #Chandra #Xray #Observatory #Marshall #MSFC #Cosmos #Universe #STEM #Education #HD #Video
Sept. 6, 2018: Astronomers have used NASA's Chandra X-ray Observatory to discover a ring of X-ray power. This ring sounds like it might belong in Tolkien's Middle Earth, but it is, in fact, found in a galaxy about 300 million light years from Earth.
The galaxy called AM 0644-741 is what astronomers refer to as a "ring" galaxy. Taking a look at the image quickly reveals why. Astronomers think ring galaxies are formed when one galaxy smashes into another in a catastrophic collision. The impact generates ripples in the interstellar gas of the targeted galaxy. These ripples, in turn, trigger new waves of star formation as gas expands outward from the site of the collision.
The most massive of these fledgling stars will lead short lives—in cosmic terms—of millions of years. After that, their nuclear fuel is spent and the stars explode as supernovas leaving behind either black holes with masses less than about a hundred times that of the Sun, or neutron stars with a mass approximately equal to one and a half times of the Sun.
Some of these black holes and neutron stars have closecompanion stars, and siphon gas from their stellar partner. This gas falls towards the black hole or neutron star, forming a spinning disk like water circling a drain, and becomes heated by friction. This superheated gas produces large amounts of X-rays that Chandra can detect.
Astronomers are on a quest to study AM 0644-741 and others like it to better understand the origins of ring galaxies and the intriguing objects that they contain.
Credit: NASA Chandra
Duration: 2 minutes, 40 seconds
Release Date: September 6, 2018
+NASA's Chandra X-ray Observatory
+Hubble Space Telescope
+European Space Agency, ESA
+NASA's Marshall Space Flight Center
+Space Telescope Science Institute
#NASA #Hubble #Astronomy #Space #Science #Galaxy #Ring #AM0644 #AM0644741 #Volans #Chandra #Xray #Observatory #Marshall #MSFC #Cosmos #Universe #STEM #Education #HD #Video
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A Quick Look at Ring Galaxy AM 0644 | NASA Chandra
A new ring of black holes or neutron stars has been discovered in a galaxy about 300 million light years from Earth. This ring was forged when one galaxy smashed through the middle of another, creating ripples in the gas. As this gas expanded through the impacted galaxy, called AM 0644-741, it triggered waves of star formation.
The most massive of these stars lasted only a few million years, before exploding as supernovas and leaving behind black holes or neutron stars as their remains.
NASA's Chandra X-ray Observatory can detect some of these black holes and neutron stars as they siphon off material from stars that orbit them.
Studying 'ring' galaxies such as this one will help astronomers better understand what happens when galaxies clash in catastrophic impacts.
Credit: NASA Chandra
Duration: 1 minute, 8 seconds
Release Date: September 6, 2018
+NASA's Chandra X-ray Observatory
+Hubble Space Telescope
+European Space Agency, ESA
+NASA's Marshall Space Flight Center
+Space Telescope Science Institute
#NASA #Hubble #Astronomy #Space #Science #Galaxy #Ring #AM0644 #AM0644741 #Volans #Chandra #Xray #Observatory #Marshall #MSFC #Cosmos #Universe #STEM #Education #HD #Video
A new ring of black holes or neutron stars has been discovered in a galaxy about 300 million light years from Earth. This ring was forged when one galaxy smashed through the middle of another, creating ripples in the gas. As this gas expanded through the impacted galaxy, called AM 0644-741, it triggered waves of star formation.
The most massive of these stars lasted only a few million years, before exploding as supernovas and leaving behind black holes or neutron stars as their remains.
NASA's Chandra X-ray Observatory can detect some of these black holes and neutron stars as they siphon off material from stars that orbit them.
Studying 'ring' galaxies such as this one will help astronomers better understand what happens when galaxies clash in catastrophic impacts.
Credit: NASA Chandra
Duration: 1 minute, 8 seconds
Release Date: September 6, 2018
+NASA's Chandra X-ray Observatory
+Hubble Space Telescope
+European Space Agency, ESA
+NASA's Marshall Space Flight Center
+Space Telescope Science Institute
#NASA #Hubble #Astronomy #Space #Science #Galaxy #Ring #AM0644 #AM0644741 #Volans #Chandra #Xray #Observatory #Marshall #MSFC #Cosmos #Universe #STEM #Education #HD #Video
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First Successful Test of Einstein’s General Relativity Near Supermassive Black Hole After 26 Years of ESO Observations of the Milky Way's Heart | ESO
Image: Artist’s impression of S2 star passing supermassive black hole at center of Milky Way | July 26, 2018: Observations made with the European Southern Observatory’s Very Large Telescope have for the first time revealed the effects predicted by Einstein’s general relativity on the motion of a star passing through the extreme gravitational field near the supermassive black hole in the center of the Milky Way. This long-sought result represents the climax of a 26-year-long observation campaign using ESO’s telescopes in Chile.
Obscured by thick clouds of absorbing dust, the closest supermassive black hole to the Earth lies 26,000 light-years away at the center of the Milky Way. This gravitational monster, which has a mass four million times that of the Sun, is surrounded by a small group of stars orbiting around it at high speed. This extreme environment—the strongest gravitational field in our galaxy—makes it the perfect place to explore gravitational physics, and particularly to test Einstein’s general theory of relativity.
New infrared observations from the exquisitely sensitive GRAVITY [1], SINFONI and NACO instruments on ESO’s Very Large Telescope (VLT) have now allowed astronomers to follow one of these stars, called S2, as it passed very close to the black hole during May 2018. At the closest point this star was at a distance of less than 20 billion kilometers from the black hole and moving at a speed in excess of 25 million kilometers per hour—almost three percent of the speed of light [2].
The team compared the position and velocity measurements from GRAVITY and SINFONI respectively, along with previous observations of S2 using other instruments, with the predictions of Newtonian gravity, general relativity and other theories of gravity. The new results are inconsistent with Newtonian predictions and in excellent agreement with the predictions of general relativity.
These extremely precise measurements were made by an international team led by Reinhard Genzel of the Max Planck Institute for Extraterrestrial Physics (MPE) in Garching, Germany, in conjunction with collaborators around the world, at the Paris Observatory–PSL, the Université Grenoble Alpes, CNRS, the Max Planck Institute for Astronomy, the University of Cologne, the Portuguese CENTRA–Centro de Astrofisica e Gravitação and ESO. The observations are the culmination of a 26-year series of ever-more-precise observations of the center of the Milky Way using ESO instruments [3].
“This is the second time that we have observed the close passage of S2 around the black hole in our galactic center. But this time, because of much improved instrumentation, we were able to observe the star with unprecedented resolution,” explains Genzel. “We have been preparing intensely for this event over several years, as we wanted to make the most of this unique opportunity to observe general relativistic effects.”
The new measurements clearly reveal an effect called gravitational redshift. Light from the star is stretched to longer wavelengths by the very strong gravitational field of the black hole. And the change in the wavelength of light from S2 agrees precisely with that predicted by Einstein’s theory of general relativity. This is the first time that this deviation from the predictions of the simpler Newtonian theory of gravity has been observed in the motion of a star around a supermassive black hole.
The team used SINFONI to measure the velocity of S2 towards and away from Earth and the GRAVITY instrument in the VLT Interferometer (VLTI) to make extraordinarily precise measurements of the changing position of S2 in order to define the shape of its orbit. GRAVITY creates such sharp images that it can reveal the motion of the star from night to night as it passes close to the black hole—26,000 light-years from Earth.
“Our first observations of S2 with GRAVITY, about two years ago, already showed that we would have the ideal black hole laboratory,” adds Frank Eisenhauer (MPE), Principal Investigator of GRAVITY and the SINFONI spectrograph. “During the close passage, we could even detect the faint glow around the black hole on most of the images, which allowed us to precisely follow the star on its orbit, ultimately leading to the detection of the gravitational redshift in the spectrum of S2.”
More than one hundred years after he published his paper setting out the equations of general relativity, Einstein has been proved right once more—in a much more extreme laboratory than he could have possibly imagined!
Françoise Delplancke, head of the System Engineering Department at ESO, explains the significance of the observations: “Here in the Solar System we can only test the laws of physics now and under certain circumstances. So it’s very important in astronomy to also check that those laws are still valid where the gravitational fields are very much stronger.”
Continuing observations are expected to reveal another relativistic effect very soon—a small rotation of the star’s orbit, known as Schwarzschild precession—as S2 moves away from the black hole.
Xavier Barcons, ESO’s Director General, concludes: “ESO has worked with Reinhard Genzel and his team and collaborators in the ESO Member States for over a quarter of a century. It was a huge challenge to develop the uniquely powerful instruments needed to make these very delicate measurements and to deploy them at the VLT in Paranal. The discovery announced today is the very exciting result of a remarkable partnership.”
Notes
[1] GRAVITY was developed by a collaboration consisting of the Max Planck Institute for Extraterrestrial Physics (Germany), LESIA of Paris Observatory–PSL / CNRS / Sorbonne Université / Univ. Paris Diderot and IPAG of Université Grenoble Alpes / CNRS (France), the Max Planck Institute for Astronomy (Germany), the University of Cologne (Germany), the CENTRA–Centro de Astrofisica e Gravitação (Portugal) and ESO.
[2] S2 orbits the black hole every 16 years in a highly eccentric orbit that brings it within twenty billion kilometres—120 times the distance from Earth to the Sun, or about four times the distance from the Sun to Neptune—at its closest approach to the black hole. This distance corresponds to about 1500 times the Schwarzschild radius of the black hole itself.
[3] Observations of the center of the Milky Way must be made at longer wavelengths (in this case infrared) as the clouds of dust between the Earth and the central region strongly absorb visible light.
More information
This research was presented in a paper entitled “Detection of the Gravitational Redshift in the Orbit of the Star S2 near the Galactic Centre Massive Black Hole“, by the GRAVITY Collaboration, to appear in the journal Astronomy & Astrophysics on July 26, 2018.
The GRAVITY Collaboration team is composed of: R. Abuter (ESO, Garching, Germany), A. Amorim (Universidade de Lisboa, Lisbon, Portugal), N. Anugu (Universidade do Porto, Porto, Portugal), M. Bauböck (Max Planck Institute for Extraterrestrial Physics, Garching, Germany [MPE]), M. Benisty (Univ. Grenoble Alpes, CNRS, IPAG, Grenoble, France [IPAG]), J.P. Berger (IPAG; ESO, Garching, Germany), N. Blind (Observatoire de Genève, Université de Genève, Versoix, Switzerland), H. Bonnet (ESO, Garching, Germany), W. Brandner (Max Planck Institute for Astronomy, Heidelberg, Germany [MPIA]), A. Buron (MPE), C. Collin (LESIA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC Univ. Paris 06, Univ. Paris Diderot, Meudon, France [LESIA]), F. Chapron (LESIA), Y. Clénet (LESIA), V. Coudé du Foresto (LESIA), P. T. de Zeeuw (Sterrewacht Leiden, Leiden University, Leiden, The Netherlands; MPE), C. Deen (MPE), F. Delplancke-Ströbele (ESO, Garching, Germany), R. Dembet (ESO, Garching, Germany; LESIA), J. Dexter (MPE), G. Duvert (IPAG), A. Eckart (University of Cologne, Cologne, Germany; Max Planck Institute for Radio Astronomy, Bonn, Germany), F. Eisenhauer (MPE), G. Finger (ESO, Garching, Germany), N.M. Förster Schreiber (MPE), P. Fédou (LESIA), P. Garcia (Universidade do Porto, Porto, Portugal), R. Garcia Lopez (MPIA), F. Gao (MPE), E. Gendron (LESIA), R. Genzel (MPE; University of California, Berkeley, California, USA), S. Gillessen (MPE), P. Gordo (Universidade de Lisboa, Lisboa, Portugal), M. Habibi (MPE), X. Haubois (ESO, Santiago, Chile), M. Haug (ESO, Garching, Germany), F. Haußmann (MPE), Th. Henning (MPIA), S. Hippler (MPIA), M. Horrobin (University of Cologne, Cologne, Germany), Z. Hubert (LESIA; MPIA), N. Hubin (ESO, Garching, Germany), A. Jimenez Rosales (MPE), L. Jochum (ESO, Garching, Germany), L. Jocou (IPAG), A. Kaufer (ESO, Santiago, Chile), S. Kellner (Max Planck Institute for Radio Astronomy, Bonn, Germany), S. Kendrew (MPIA, ESA), P. Kervella (LESIA; MPIA), Y. Kok (MPE), M. Kulas (MPIA), S. Lacour (LESIA), V. Lapeyrère (LESIA), B. Lazareff (IPAG), J.-B. Le Bouquin (IPAG), P. Léna (LESIA), M. Lippa (MPE), R. Lenzen (MPIA), A. Mérand (ESO, Garching, Germany), E. Müller (ESO, Garching, Germany; MPIA), U. Neumann (MPIA), T. Ott (MPE), L. Palanca (ESO, Santiago, Chile), T. Paumard (LESIA), L. Pasquini (ESO, Garching, Germany), K. Perraut (IPAG), G. Perrin (LESIA), O. Pfuhl (MPE), P.M. Plewa (MPE), S. Rabien (MPE), J. Ramos (MPIA), C. Rau (MPE), G. Rodríguez-Coira (LESIA), R.-R. Rohloff (MPIA), G. Rousset (LESIA), J. Sanchez-Bermudez (ESO, Santiago, Chile; MPIA), S. Scheithauer (MPIA), M. Schöller (ESO, Garching, Germany), N. Schuler (ESO, Santiago, Chile), J. Spyromilio (ESO, Garching, Germany), O. Straub (LESIA), C. Straubmeier (University of Cologne, Cologne, Germany), E. Sturm (MPE), L.J. Tacconi (MPE), K.R.W. Tristram (ESO, Santiago, Chile), F. Vincent (LESIA), S. von Fellenberg (MPE), I. Wank (University of Cologne, Cologne, Germany), I. Waisberg (MPE), F. Widmann (MPE), E. Wieprecht (MPE), M. Wiest (University of Cologne, Cologne, Germany), E. Wiezorrek (MPE), J. Woillez (ESO, Garching, Germany), S. Yazici (MPE; University of Cologne, Cologne, Germany), D. Ziegler (LESIA) and G. Zins (ESO, Santiago, Chile).
ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It has 15 Member States: Austria, Belgium, 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 and with Australia as a strategic partner. 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 and its world-leading Very Large Telescope Interferometer as well as two survey telescopes, VISTA working in the infrared and the visible-light VLT Survey Telescope. ESO is also a major partner in two facilities on Chajnantor, APEX and ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre Extremely Large Telescope, the ELT, which will become “the world’s biggest eye on the sky”.
Research paper in Astronomy & Astrophysics
https://www.aanda.org/articles/aa/abs/2018/07/aa33718-18/aa33718-18.html
Credit: European Southern Observatory (ESO)
Release Date: July 26, 2018
+European Southern Observatory (ESO)
#ESO #Astronomy #Space #Science #BlackHole #Star #S2 #MilkyWay #Galaxy #Einstein #GeneralRelativity #Gravity #Physics #Astrophysics #Cosmos #Universe #VLT #Telescope #Paranal #Observatory #Chile #Atacama #Desert #SouthAmerica #Europe #Art #Illustration #STEM #Education
Image: Artist’s impression of S2 star passing supermassive black hole at center of Milky Way | July 26, 2018: Observations made with the European Southern Observatory’s Very Large Telescope have for the first time revealed the effects predicted by Einstein’s general relativity on the motion of a star passing through the extreme gravitational field near the supermassive black hole in the center of the Milky Way. This long-sought result represents the climax of a 26-year-long observation campaign using ESO’s telescopes in Chile.
Obscured by thick clouds of absorbing dust, the closest supermassive black hole to the Earth lies 26,000 light-years away at the center of the Milky Way. This gravitational monster, which has a mass four million times that of the Sun, is surrounded by a small group of stars orbiting around it at high speed. This extreme environment—the strongest gravitational field in our galaxy—makes it the perfect place to explore gravitational physics, and particularly to test Einstein’s general theory of relativity.
New infrared observations from the exquisitely sensitive GRAVITY [1], SINFONI and NACO instruments on ESO’s Very Large Telescope (VLT) have now allowed astronomers to follow one of these stars, called S2, as it passed very close to the black hole during May 2018. At the closest point this star was at a distance of less than 20 billion kilometers from the black hole and moving at a speed in excess of 25 million kilometers per hour—almost three percent of the speed of light [2].
The team compared the position and velocity measurements from GRAVITY and SINFONI respectively, along with previous observations of S2 using other instruments, with the predictions of Newtonian gravity, general relativity and other theories of gravity. The new results are inconsistent with Newtonian predictions and in excellent agreement with the predictions of general relativity.
These extremely precise measurements were made by an international team led by Reinhard Genzel of the Max Planck Institute for Extraterrestrial Physics (MPE) in Garching, Germany, in conjunction with collaborators around the world, at the Paris Observatory–PSL, the Université Grenoble Alpes, CNRS, the Max Planck Institute for Astronomy, the University of Cologne, the Portuguese CENTRA–Centro de Astrofisica e Gravitação and ESO. The observations are the culmination of a 26-year series of ever-more-precise observations of the center of the Milky Way using ESO instruments [3].
“This is the second time that we have observed the close passage of S2 around the black hole in our galactic center. But this time, because of much improved instrumentation, we were able to observe the star with unprecedented resolution,” explains Genzel. “We have been preparing intensely for this event over several years, as we wanted to make the most of this unique opportunity to observe general relativistic effects.”
The new measurements clearly reveal an effect called gravitational redshift. Light from the star is stretched to longer wavelengths by the very strong gravitational field of the black hole. And the change in the wavelength of light from S2 agrees precisely with that predicted by Einstein’s theory of general relativity. This is the first time that this deviation from the predictions of the simpler Newtonian theory of gravity has been observed in the motion of a star around a supermassive black hole.
The team used SINFONI to measure the velocity of S2 towards and away from Earth and the GRAVITY instrument in the VLT Interferometer (VLTI) to make extraordinarily precise measurements of the changing position of S2 in order to define the shape of its orbit. GRAVITY creates such sharp images that it can reveal the motion of the star from night to night as it passes close to the black hole—26,000 light-years from Earth.
“Our first observations of S2 with GRAVITY, about two years ago, already showed that we would have the ideal black hole laboratory,” adds Frank Eisenhauer (MPE), Principal Investigator of GRAVITY and the SINFONI spectrograph. “During the close passage, we could even detect the faint glow around the black hole on most of the images, which allowed us to precisely follow the star on its orbit, ultimately leading to the detection of the gravitational redshift in the spectrum of S2.”
More than one hundred years after he published his paper setting out the equations of general relativity, Einstein has been proved right once more—in a much more extreme laboratory than he could have possibly imagined!
Françoise Delplancke, head of the System Engineering Department at ESO, explains the significance of the observations: “Here in the Solar System we can only test the laws of physics now and under certain circumstances. So it’s very important in astronomy to also check that those laws are still valid where the gravitational fields are very much stronger.”
Continuing observations are expected to reveal another relativistic effect very soon—a small rotation of the star’s orbit, known as Schwarzschild precession—as S2 moves away from the black hole.
Xavier Barcons, ESO’s Director General, concludes: “ESO has worked with Reinhard Genzel and his team and collaborators in the ESO Member States for over a quarter of a century. It was a huge challenge to develop the uniquely powerful instruments needed to make these very delicate measurements and to deploy them at the VLT in Paranal. The discovery announced today is the very exciting result of a remarkable partnership.”
Notes
[1] GRAVITY was developed by a collaboration consisting of the Max Planck Institute for Extraterrestrial Physics (Germany), LESIA of Paris Observatory–PSL / CNRS / Sorbonne Université / Univ. Paris Diderot and IPAG of Université Grenoble Alpes / CNRS (France), the Max Planck Institute for Astronomy (Germany), the University of Cologne (Germany), the CENTRA–Centro de Astrofisica e Gravitação (Portugal) and ESO.
[2] S2 orbits the black hole every 16 years in a highly eccentric orbit that brings it within twenty billion kilometres—120 times the distance from Earth to the Sun, or about four times the distance from the Sun to Neptune—at its closest approach to the black hole. This distance corresponds to about 1500 times the Schwarzschild radius of the black hole itself.
[3] Observations of the center of the Milky Way must be made at longer wavelengths (in this case infrared) as the clouds of dust between the Earth and the central region strongly absorb visible light.
More information
This research was presented in a paper entitled “Detection of the Gravitational Redshift in the Orbit of the Star S2 near the Galactic Centre Massive Black Hole“, by the GRAVITY Collaboration, to appear in the journal Astronomy & Astrophysics on July 26, 2018.
The GRAVITY Collaboration team is composed of: R. Abuter (ESO, Garching, Germany), A. Amorim (Universidade de Lisboa, Lisbon, Portugal), N. Anugu (Universidade do Porto, Porto, Portugal), M. Bauböck (Max Planck Institute for Extraterrestrial Physics, Garching, Germany [MPE]), M. Benisty (Univ. Grenoble Alpes, CNRS, IPAG, Grenoble, France [IPAG]), J.P. Berger (IPAG; ESO, Garching, Germany), N. Blind (Observatoire de Genève, Université de Genève, Versoix, Switzerland), H. Bonnet (ESO, Garching, Germany), W. Brandner (Max Planck Institute for Astronomy, Heidelberg, Germany [MPIA]), A. Buron (MPE), C. Collin (LESIA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC Univ. Paris 06, Univ. Paris Diderot, Meudon, France [LESIA]), F. Chapron (LESIA), Y. Clénet (LESIA), V. Coudé du Foresto (LESIA), P. T. de Zeeuw (Sterrewacht Leiden, Leiden University, Leiden, The Netherlands; MPE), C. Deen (MPE), F. Delplancke-Ströbele (ESO, Garching, Germany), R. Dembet (ESO, Garching, Germany; LESIA), J. Dexter (MPE), G. Duvert (IPAG), A. Eckart (University of Cologne, Cologne, Germany; Max Planck Institute for Radio Astronomy, Bonn, Germany), F. Eisenhauer (MPE), G. Finger (ESO, Garching, Germany), N.M. Förster Schreiber (MPE), P. Fédou (LESIA), P. Garcia (Universidade do Porto, Porto, Portugal), R. Garcia Lopez (MPIA), F. Gao (MPE), E. Gendron (LESIA), R. Genzel (MPE; University of California, Berkeley, California, USA), S. Gillessen (MPE), P. Gordo (Universidade de Lisboa, Lisboa, Portugal), M. Habibi (MPE), X. Haubois (ESO, Santiago, Chile), M. Haug (ESO, Garching, Germany), F. Haußmann (MPE), Th. Henning (MPIA), S. Hippler (MPIA), M. Horrobin (University of Cologne, Cologne, Germany), Z. Hubert (LESIA; MPIA), N. Hubin (ESO, Garching, Germany), A. Jimenez Rosales (MPE), L. Jochum (ESO, Garching, Germany), L. Jocou (IPAG), A. Kaufer (ESO, Santiago, Chile), S. Kellner (Max Planck Institute for Radio Astronomy, Bonn, Germany), S. Kendrew (MPIA, ESA), P. Kervella (LESIA; MPIA), Y. Kok (MPE), M. Kulas (MPIA), S. Lacour (LESIA), V. Lapeyrère (LESIA), B. Lazareff (IPAG), J.-B. Le Bouquin (IPAG), P. Léna (LESIA), M. Lippa (MPE), R. Lenzen (MPIA), A. Mérand (ESO, Garching, Germany), E. Müller (ESO, Garching, Germany; MPIA), U. Neumann (MPIA), T. Ott (MPE), L. Palanca (ESO, Santiago, Chile), T. Paumard (LESIA), L. Pasquini (ESO, Garching, Germany), K. Perraut (IPAG), G. Perrin (LESIA), O. Pfuhl (MPE), P.M. Plewa (MPE), S. Rabien (MPE), J. Ramos (MPIA), C. Rau (MPE), G. Rodríguez-Coira (LESIA), R.-R. Rohloff (MPIA), G. Rousset (LESIA), J. Sanchez-Bermudez (ESO, Santiago, Chile; MPIA), S. Scheithauer (MPIA), M. Schöller (ESO, Garching, Germany), N. Schuler (ESO, Santiago, Chile), J. Spyromilio (ESO, Garching, Germany), O. Straub (LESIA), C. Straubmeier (University of Cologne, Cologne, Germany), E. Sturm (MPE), L.J. Tacconi (MPE), K.R.W. Tristram (ESO, Santiago, Chile), F. Vincent (LESIA), S. von Fellenberg (MPE), I. Wank (University of Cologne, Cologne, Germany), I. Waisberg (MPE), F. Widmann (MPE), E. Wieprecht (MPE), M. Wiest (University of Cologne, Cologne, Germany), E. Wiezorrek (MPE), J. Woillez (ESO, Garching, Germany), S. Yazici (MPE; University of Cologne, Cologne, Germany), D. Ziegler (LESIA) and G. Zins (ESO, Santiago, Chile).
ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It has 15 Member States: Austria, Belgium, 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 and with Australia as a strategic partner. 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 and its world-leading Very Large Telescope Interferometer as well as two survey telescopes, VISTA working in the infrared and the visible-light VLT Survey Telescope. ESO is also a major partner in two facilities on Chajnantor, APEX and ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre Extremely Large Telescope, the ELT, which will become “the world’s biggest eye on the sky”.
Research paper in Astronomy & Astrophysics
https://www.aanda.org/articles/aa/abs/2018/07/aa33718-18/aa33718-18.html
Credit: European Southern Observatory (ESO)
Release Date: July 26, 2018
+European Southern Observatory (ESO)
#ESO #Astronomy #Space #Science #BlackHole #Star #S2 #MilkyWay #Galaxy #Einstein #GeneralRelativity #Gravity #Physics #Astrophysics #Cosmos #Universe #VLT #Telescope #Paranal #Observatory #Chile #Atacama #Desert #SouthAmerica #Europe #Art #Illustration #STEM #Education
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The Heart of the Milky Way | ESO
This image shows a number of antennas from the Atacama Large Millimeter/submillimeter Array (ALMA), a state-of-the-art telescope array positioned high in the Chilean Andes. A full Moon can be seen above the red-tinted horizon, glowing brightly above the observatory.
ALMA sits on the Chajnantor Plateau, some 5000 meters above sea level. At this altitude, crystal-clear views of the cosmos can be seen on an almost nightly basis, as shown by the striking cosmic caterpillar gliding over the top of the ALMA antennas in this image. This bright streak is the Milky Way; the galaxy’s bulge of gas and intricate dust lanes is clearly illuminated against the star-studded night sky, with pink-hued patches marking areas of hot, ionised gas produced by newly formed stars. The brightest part of the Milky Way— the very heart of our galaxy—is situated approximately 25,000 light-years away from Earth.
Credit: Yuri Beletsky (LCO)/ESO
Release Date: July 23, 2018
+Yuri Beletsky
+European Southern Observatory (ESO)
#ESO #Astronomy #Space #Science #Stars #MilkyWay #Moon #ALMA #Telescope #Observatory #Chajnantor #Plateau #Chile #Andes #SouthAmerica #STEM #Education
This image shows a number of antennas from the Atacama Large Millimeter/submillimeter Array (ALMA), a state-of-the-art telescope array positioned high in the Chilean Andes. A full Moon can be seen above the red-tinted horizon, glowing brightly above the observatory.
ALMA sits on the Chajnantor Plateau, some 5000 meters above sea level. At this altitude, crystal-clear views of the cosmos can be seen on an almost nightly basis, as shown by the striking cosmic caterpillar gliding over the top of the ALMA antennas in this image. This bright streak is the Milky Way; the galaxy’s bulge of gas and intricate dust lanes is clearly illuminated against the star-studded night sky, with pink-hued patches marking areas of hot, ionised gas produced by newly formed stars. The brightest part of the Milky Way— the very heart of our galaxy—is situated approximately 25,000 light-years away from Earth.
Credit: Yuri Beletsky (LCO)/ESO
Release Date: July 23, 2018
+Yuri Beletsky
+European Southern Observatory (ESO)
#ESO #Astronomy #Space #Science #Stars #MilkyWay #Moon #ALMA #Telescope #Observatory #Chajnantor #Plateau #Chile #Andes #SouthAmerica #STEM #Education
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