Tuesday, August 01, 2023

Nebula NGC 3582: The Heart of a Stellar Nursery | Gemini South Telescope

Nebula NGC 3582: The Heart of a Stellar Nursery | Gemini South Telescope


At the heart of a star-forming region called RCW 57, this image shows the complex interaction of interstellar gas and dark dust clouds among newly formed stars. The glowing gas is energized by ultraviolet radiation from the young stars. The intricate wispy structures in the cloud are formed by radiation from the young stars and the explosions of nearby, very massive stars that have exceptionally short lives compared to stars like our sun. 

Distance: 10,000 light years

A study by M. Maercker in 2006 revealed that the region is overly abundant with massive star formation with over 33 star-forming regions in the extended area at the end stages of formation. 

This region of the sky is only visible from observers in the southern hemisphere and is a popular showpiece for small telescopes and binoculars in the far-southern constellation of Carina. 

The Gemini image was obtained with the Gemini Multi-Object Spectrograph at the Gemini South telescope using two pointings to make a mosaic image that has a field of view of 9.0 x 5.0 arcsminutes. The exposures were taken through three narrowband filters: [OIII] (blue), [SII] (green) and H-alpha (red).


Credit: International Gemini Observatory

Release Date: April 1, 2009


#NASA #Astronomy #Space #Science #Nebulae #Nebula #NGC3582 #RCW57 #Carina #Constellation #MilkyWayGalaxy #Cosmos #Universe #GeminiSouthTelescope #NOIRLab #AURA #NSF #Chile #SouthAmerica #STEM #Education

NGC 3582 Nebula Close-up in Carina | Victor Blanco Telescope

NGC 3582 Nebula Close-up in Carina | Victor Blanco Telescope

NGC3582 is a nebula in the Sagittarius arm of the Milky Way galaxy. It is part of star-forming region RCW 57 in Carina. This image was taken in 2007 using the Mosaic-2 imager on the 4-meter Victor Blanco telescope at Cerro Tololo Inter-American Observatory.


Credit: T.A. Rector/University of Alaska Anchorage, T. Abbott and NOIRLab/NSF/AURA

Release Date: June 30, 2020


#NASA #Astronomy #Space #Science #Nebulae #Nebula #NGC3582 #RCW57 #Carina #Constellation #MilkyWayGalaxy #Cosmos #Universe #Telescope #CerroTololoObservatory #CTIO #NOIRLab #AURA #NSF #Chile #SouthAmerica #STEM #Education

Zooming in on Star-forming Region NGC 3582 in Carina | ESO

Zooming in on Star-forming Region NGC 3582 in Carina | ESO

This sequence starts with a wide-field view of the most spectacular parts of the southern Milky Way. As we zoom in we see the Southern Cross (Crux) and the famous Eta Carinae nebula. A little later we close in on the star-forming region NGC 3582, lying about 10,000 light-years from us in the constellation of Carina (The Keel). The final detailed view shows a new image of NGC 3582 and its surroundings from the MPG/ESO 2.2-meter telescope at the European Southern Observatory’s La Silla Observatory in Chile.


Credit: ESO/A. Fujii/Digitized Sky Survey 2 

Duration: 56 seconds

Release Date: Nov. 27, 2015


#NASA #ESO #Astronomy #Space #Science #Nebulae #Nebula #NGC3582 #Carina #Constellation #MilkyWayGalaxy #Cosmos #Universe #Telescope #LaSillaObservatory #Chile #Europe #STEM #Education #HD #Video

Star formation Region NGC 3582 in Carina | ESO

Star Formation Region NGC 3582 in Carina | ESO


This picture of the star formation region NGC 3582 was taken using the Wide Field Imager at the European Southern Observatory's La Silla Observatory in Chile. The image reveals giant loops of gas ejected by dying stars that bear a striking resemblance to solar prominences. 

Distance: 10,000 light years


Credit: ESO, Digitized Sky Survey 2 and Joe DePasquale 

Release Date: April 13, 2011


#NASA #ESO #Astronomy #Space #Science #Nebulae #Nebula #NGC3582 #Carina #Constellation #MilkyWayGalaxy #Cosmos #Universe #Telescope #LaSillaObservatory #Chile #Europe #STEM #Education

Monday, July 31, 2023

Tonight's Sky: August 2023 (Northern Hemisphere)

Tonight's Sky: August 2023 (Northern Hemisphere)

In August 2023, a flock of star-studded figures soars overhead. Look for the Vega and Lyra constellations, which point to Epsilon Lyrae and the Ring Nebula. You can also spot three bright summer stars: Vega, Deneb, and Altair, which form the Summer Triangle. Keep watching for space-based views of these and other stars and nebulas.

“Tonight’s Sky” is a monthly video of constellations you can observe in the night sky. The series is produced by the Space Telescope Science Institute, home of science operations for the Hubble Space Telescope, in partnership with NASA’s Universe of Learning. 


Credit: Space Telescope Science Institute (STScI)

Duration: 5 minutes

Release Date: July 26, 2023

#NASA #Space #Astronomy #Science #Earth #Planets #SolarSystem #Stars #Vega #Lyra #EpsilonLyrae #Nebulae #RingNebula #Vega #Deneb #Altair #SummerTriangle #Constellations #MilkyWayGalaxy #Skywatching #STScI #UnitedStates #Canada #Mexico #NorthernHemisphere #STEM #Education #HD #Video

Greenland's Frederikshåb Glacier: Mass Melting Summer 2023 | NASA Earth Science

Greenland's Frederikshåb Glacier: Mass Melting Summer 2023 | NASA Earth Science

Landsat 8 image of Frederikshåb Glacier on June 14, 2023

Landsat 9 image of Frederikshåb Glacier on July 24, 2023

Landsat 9 image of melt ponds north of Frederikshåb Glacier on July 8, 2023 (labeled)


More than halfway through the 2023 melting season, Greenland has seen a substantial transformation of its snow cover. Melting has been above average for much of the season, including on several days in June and July when melt was detected across 800,000 square kilometers (302,000 square miles)—up to 50 percent—of Greenland Ice Sheet’s surface, according to the National Snow and Ice Data Center.

Summer melting was ramping up on June 14, 2023, when the Operational Land Imager (OLI) on Landsat 8 acquired the first image of Frederikshåb Glacier. This lobe-shaped piedmont glacier, located in southwest Greenland, flows downward from the Greenland Ice Sheet, winds past a series of valleys and nunataks, then flattens out on smoother terrain along the coast.

The second image, acquired with the OLI-2 on Landsat 9, shows the same area on July 24, after more than a month of additional melting. Notice the dramatic reduction in the extent of brighter (high albedo) surface snow.

Since September 2021, when Landsat 9 joined Landsat 8 in orbit over Earth, scientists have been getting more frequent detailed views of Earth. The Landsat 8 and Landsat 9 satellites together acquire about 1,500 scenes from across the planet every day. This comes in handy for observing the planet’s icy regions, where seasonal changes can be quick and dramatic.

Another seasonal change visible in the image pair above is the transition from “clean” snow to “dirty” ice. One reason for the darker color is due to the presence of particles, such as black carbon or dust, that have accumulated on the ice. As the snow and ice melt, these impurities are left behind. Darkening of the ice surface lowers its albedo, which can hasten melting through the absorption of additional solar energy in the summer months.

Another change is in the presence of ponded water, or “melt ponds,” on the surface of the ice sheet. Deep blue in color, they form where snow has melted and pooled in low spots on the ice sheet’s undulating topography. They can be an important indicator of the strength of Greenland’s melting season, which generally runs from May to early September.

Only a few melt ponds are visible in the July 24 image (images 3 & 4), possibly because meltwater had already run off the ice sheet or been channeled down through the ice. However, abundant melt ponds were visible about 100 kilometers (60 miles) north of Frederikshåb on July 8, when the OLI-2 on Landsat 9 acquired the image above.

The changes are the result of the increasing warmth of summer weather that took hold across the region in late June. This is when warm southwesterly winds and clear skies significantly enhanced the amount of melting on the ice sheet, especially toward the island’s south.

So far in Greenland’s 2023 melting season, spikes in daily melt area have stayed below those of 2012, a year with exceptionally widespread melting. Still, as of mid-July, daily melt extents have been consistently higher than the 1981-2010 average, and 2023 is on par with several other high melt years in recent decades.

“The drama of unprecedented melt in 2012 may not be exceeded this year,” said Christopher Shuman, a University of Maryland, Baltimore County, glaciologist based at NASA’s Goddard Space Flight Center. “But so far, 2023 looks to be a big, broad melt year.”


Image Credit: NASA Earth Observatory images by Wanmei Liang, using Landsat data from the U.S. Geological Survey

Story Credit: Kathryn Hansen

Release Date: July 29, 2023


#NASA #Space #Satellites #Science #Planet #Earth #Glaciers #FrederikshåbGlacier #Melting #Greenland #Denmark #Danmark #Ocean #LandsatProgram #Landsat8 #Landsat9 #OLI #USGS #Weather #Meteorology #ClimateChange #GlobalHeating #Climate #Environment #GreenhouseGases #GHG #EarthObservation #RemoteSensing #GSFC #UnitedStates #STEM #Education

NASA Mars Ascent Vehicle Continues Progress Toward Mars Sample Return

NASA Mars Ascent Vehicle Continues Progress Toward Mars Sample Return

NASA’s Mars Ascent Vehicle (MAV) recently reached some major milestones in support of the Mars Sample Return (MSR) program. This video shows recent tests of the first and second stage solid rocket motors needed for the launch. 

Mars Sample Return will bring scientifically selected samples to Earth for study using the most sophisticated instrumentation around the world. This strategic partnership with the European Space Agency (ESA) features the first mission to return samples from another planet.

The two-stage MAV rocket is an important part of the joint plan between NASA and ESA to bring scientifically selected Martian samples to Earth in the early 2030s.

NASA’s Mars Sample Return Campaign promises to revolutionize humanity’s understanding of Mars by bringing scientifically selected samples to Earth for study using the most sophisticated instruments around the world. The campaign would fulfill a solar system exploration goal, a high priority since the 1970s and in the last three National Academy of Sciences Planetary Decadal Surveys.

This strategic NASA and ESA partnership would be the first mission to return samples from another planet and the first launch from the surface of another planet. The samples collected by NASA’s Perseverance Mars rover during its exploration of an ancient lakebed are thought to present the best opportunity to reveal clues about the early evolution of Mars, including the potential for past life. By better understanding the history of Mars, we can improve our understanding of all rocky planets in the solar system, including Earth.

Learn more about the Mars Sample Return Program: https://mars.nasa.gov/msr/


Credit: NASA Marshall Space Center/Jonathan Deal and Joe Kuner

Duration: 2 minutes

Release Date: July 31, 2023


#NASA #ESA #Space #Astronomy #Science #Mars #RedPlanet #Planet #Astrobiology #Geology #JezeroCrater #PerseveranceRover #Robotics #MarsAscentVehicle #MAV #RocketMotorTest #MarsSampleReturn #MSR #SampleRetrievalLander #EarthReturnOrbiter #Technology #Engineering #JPL #MarshallSpaceFlightCenter #MSFC #UnitedStates #STEM #Education #HD #Video

Antares Rocket & Cygnus Spacecraft Rollout: CRS-19 Cargo Resupply | NASA

Antares Rocket & Cygnus Spacecraft Rollout: CRS-19 Cargo Resupply | NASA








Northrop Grumman’s CRS-19 Antares rocket and Cygnus cargo spacecraft were rolled out to MARS Pad 0A at the Mid-Atlantic Regional Spaceport in Wallops Island, Virginia. This is Northrop Grumman’s 19th contracted cargo resupply mission with NASA to the International Space Station. Cygnus will deliver more than 8,200 pounds of science and research, crew supplies and vehicle hardware to the orbital laboratory and its crew. Cygnus will once again host NASA’s Spacecraft Fire Safety Experiment (SAFFIRE), enabling scientists to continue studying the way fire behaves in microgravity.

The CRS-19 Cygnus spacecraft is named after NASA astronaut Dr. Laurel Clark who flew aboard Space Shuttle Columbia (STS-107). Antares is scheduled to launch no earlier than 8:31 p.m. EDT, Tuesday, Aug. 1, 2023. 

Check out Northrop Grumman’s CRS-19/NG-19 Mission page for more launch information: 

https://www.northropgrumman.com/space/nasa-commercial-resupply-mission-ng-19

An international partnership of space agencies provides and operates the elements of the International Space Station (ISS). The principals are the space agencies of the United States, Russia, Europe, Japan, and Canada. The ISS has been the most politically complex space exploration program ever undertaken.


Image Credit: NASA/Patrick Black, Northrop Grumman/Thom Baur

Image Capture Dates: July 28-29, 2023


#NASA #Space #ISS #NorthropGrumman #AntaresRocket #CygnusSpacecraft #CommercialCargo #CRS19 #NG19 #LaurelClark #STS107 #CommercialResupply #Expedition69 #HumanSpaceflight #WallopsFlightFacility #WFF #WallopsIsland #Virginia #MidAtlanticRegionalSpaceport #GSFC #UnitedStates #CommercialSpace #Technology #Engineering #STEM #Education

Irregular Galaxy NGC 6822: Near-infrared view | James Webb Space Telescope

Irregular Galaxy NGC 6822: Near-infrared view | James Webb Space Telescope

This scaled image shows the irregular galaxy NGC 6822, which was observed by the Near-InfraRed Camera (NIRCam) mounted on the NASA/European Space Agency/Canadian Space Agency James Webb Space Telescope.

Webb’s near-infrared NIRCam image shows the galaxy’s countless stars in incredible detail. Here, the dust and gas that pervade the galaxy are reduced to translucent red wisps, laying the stars bare for astronomical study. The power of Webb’s ice-cold infrared instruments and the incredible resolution of its primary mirror is necessary to examine stars hidden in dusty environments, and the results as shown here are spectacular.

The brightest stars appear in pale blue and cyan colors in this image, colors which are assigned to the shortest wavelengths of light that NIRCam can detect: red and near infrared. The amount of light emitted by any star decreases at longer and longer wavelengths, towards the mid-infrared, so the stars that are more faint to NIRCam also appear more warmly colored here. A bright blue orb to the lower left of the gas is particularly prominent: this is a globular cluster, packed with stars.

This image has been cropped and downscaled from the full NIRCam resolution to match that of the MIRI image. See a combined MIRI+NIRCam view, and more information about NGC 6822, here.


Credit: ESA/Webb, NASA & CSA, M. Meixner

Release Date: July 31, 2023


#NASA #ESA #Astronomy #Space #Science #Galaxies #Galaxy #NGC6822 #IrregularGalaxy #LowMetallicity #InterstellarDust #Sagittarius #Constellation #JamesWebbSpaceTelescope #JWST #NIRCam #Infrared #NearInfrared #Cosmos #Universe #UnfoldTheUniverse #Europe #CSA #Canada #GSFC #STScI #UnitedStates #STEM #Education

Irregular Galaxy NGC 6822: The Life & Times of Dust | James Webb Space Telescope

Irregular Galaxy NGC 6822: The Life & Times of Dust | James Webb Space Telescope

This image shows the irregular galaxy NGC 6822, which was observed by the Near-InfraRed Camera (NIRCam) and Mid-InfraRed Instrument (MIRI) mounted on the NASA/European Space Agency/Canadian Space Agency James Webb Space Telescope. As their names suggest, NIRCam and MIRI probe different parts of the electromagnetic spectrum. This allows the instruments to observe different components of the same galaxy, with MIRI especially sensitive to its gas-rich regions (the yellow swirls in this image) and NIRCam suitable for observing its densely packed field of stars.

NGC 6822 lies about 1.5 million light-years away, and is the Milky Way’s nearest galactic neighbor that is not one of its satellites. It has a low metallicity, meaning that it contains low proportions of elements that are not hydrogen and helium. Metallicity is an absolutely key concept in astronomy, in part because elements other than hydrogen and helium are largely produced by stars over their lifetimes. Therefore, in the very early Universe (before the first generation of stars had been born, lived and died) everything had very low metallicity. This makes contemporary low-metallicity objects (like NGC 6822) objects of interest for understanding how processes such as the evolution of stars and the life cycle of interstellar dust likely occurred in the early Universe. This was the motivation for these observations of NGC 6822 with Webb—to better understand how stars form and how dust evolves in low-metallicity environments.

Image Description: A dense field of stars with clouds of gas and dust billowing across it. The clouds are patchy and wispy, dense and glowing parts obscuring the center of the image. Bright galaxies with various shapes and sizes shine through the gas and stars. Some of the star images are a bit larger than the rest, with visible diffraction spikes; two foreground stars are bright in the lower-right corner.

The study of NGC 6822 has an interesting history that long predates modern investigations with Webb. It was first discovered by E. E. Barnard, who presented his discovery in a very brief paper in 1884 in The Sidereal Messenger: a short-lived but important American monthly astronomical journal that was published between 1882 and 1891. As with many astronomical objects that appeared diffuse with telescopes of the time, NGC 6822 was miscategorized as an “exceedingly faint nebula”. 

Over the next few years, a series of confusions arose around NGC 6822 over its apparent size, brightness, and even what kind of object it was, because astronomers at the time did not properly account for how different the same object might look with different telescopes. Edwin Hubble, namesake of the NASA/ESA Hubble Space telescope, went on to study NGC 6822 in depth and published a far more detailed paper of his own in 1925. This work was exceptionally important for humanity’s evolving understanding of the Universe, because, in Hubble’s own words: “N.G.C. 6822, [was] the first object definitely assigned to a region outside the galactic system”. This paper contributed to solving the debate that was raging amongst astronomers about the extent of the Universe at the time by demonstrating that there were astronomical objects that lay beyond the Milky Way. The study of this galaxy was notably continued by Susan Keyser, who was the first woman to receive a PhD in astronomy from Caltech. Her 1966 thesis remained the most thorough investigation of this galaxy until the 2000s. Now, the study of this key local galaxy is being continued by Webb. 


Credit: ESA/Webb, NASA & CSA, M. Meixner

Release Date: July 31, 2023


#NASA #ESA #Astronomy #Space #Science #Galaxies #Galaxy #NGC6822 #IrregularGalaxy #LowMetallicity #InterstellarDust #Sagittarius #Constellation #JamesWebbSpaceTelescope #JWST #NIRCam #MIRI #Cosmos #Universe #UnfoldTheUniverse #Europe #CSA #Canada #GSFC #STScI #UnitedStates #STEM #Education

Globular Star Cluster NGC 6652 in Sagittarius | Hubble

Globular Star Cluster NGC 6652 in Sagittarius | Hubble

The glittering, glitzy contents of the globular cluster NGC 6652 sparkle in this star-studded image from the NASA/European Space Agency Hubble Space Telescope. The core of the cluster is suffused with the pale blue light of countless stars, and a handful of particularly bright foreground stars are adorned with criss-crossing diffraction spikes. NGC 6652 lies in our own Milky Way galaxy in the constellation Sagittarius, just under 30,000 light-years from Earth and only 6,500 light-years from the Galactic center.

Image Description: A dense spherical cluster of stars. The stars merge into a bright core in the center, and spread out to the edges gradually, giving way to an empty, dark background. Most of the stars are small points of light. A few stars with cross-shaped diffraction spikes appear larger, and stand out in front.

Globular clusters are stable, tightly gravitationally bound clusters containing anywhere between tens of thousands and millions of stars. The intense gravitational attraction between the closely packed stars in globular clusters is what gives these star-studded objects their regular, spherical shape.

This image combines data from two of Hubble’s third-generation instruments; the Advanced Camera for Surveys and Wide Field Camera 3. As well as two instruments, this image draws on two different observing programs from two different teams of astronomers. The first team set out to survey globular clusters in the Milky Way galaxy in the hope of shedding light on topics ranging from the ages of these objects to the gravitational potential of the galaxy as a whole. The second team of astronomers used a trio of exquisitely sensitive filters in Hubble’s Wide Field Camera 3 to disentangle the proportions of carbon, nitrogen, and oxygen in globular clusters such as NGC 6652.


Credit: European Space Agency (ESA)/Hubble & NASA, A. Sarajedini, G. Piotto

Release Date: July 31, 2023


#NASA #ESA #Astronomy #Space #Science #Stars #StarClusters #StarCluster #NGC6652 #GlobularCluster #Sagittarius #Constellation #Cosmos #Universe #HST #HubbleSpaceTelescope #STScI #GSFC #UnitedStates #Europe #STEM #Education

Sunday, July 30, 2023

Zooming to Dwarf Irregular Galaxy I Zwicky 18 | Hubble

Zooming to Dwarf Irregular Galaxy I Zwicky 18 | Hubble


Summary: A zoom from a wide-field image of Ursa Major towards the galaxy I Zwicky 18. I Zwicky 18 is 59 million light-years from Earth and is located in the Ursa Major constellation.

Called I Zwicky 18, this galaxy has a youthful appearance that resembles galaxies typically found only in the early universe. Hubble has now found faint, older stars within this galaxy, suggesting that the galaxy may have formed at the same time as most other galaxies.

I Zwicky 18 is classified as a dwarf irregular galaxy and is much smaller than our Milky Way Galaxy. The concentrated bluish-white knots embedded in the heart of the galaxy are two major starburst regions where stars are forming at a furious rate. The wispy blue filaments surrounding the central starburst regions are bubbles of gas that have been blown away by stellar winds and supernovae explosions from a previous generation of hot, young stars. This gas is now heated by intense ultraviolet radiation unleashed by hot, young stars.

A companion galaxy lies just above and to the left of I Zwicky 18. The companion may be interacting with I Zwicky 18 by gravitationally tugging on the galaxy. The interaction may have triggered the galaxy's recent star formation that is responsible for the youthful appearance. Besides the bluish-white young stars, white-reddish stars also are visible in both I Zwicky 18 and its companion. These stars may be as old as 10 billion years. The reddish extended objects surrounding I Zwicky 18 and its companion are ancient, fully formed galaxies of different shapes that are much farther away.


Credit: European Space Agency (ESA)/Hubble (M. Kornmesser & L. L. Christensen)

Duration: 54 seconds

Release Date: Feb. 17, 2016


#NASA #ESA #Astronomy #Space #Science #Stars #Galaxies #Galaxy #IZwicky18 #IZw18 #IrregularGalaxy #GasBubbles #UrsaMajor #Constellation #Cosmos #Universe #HST #HubbleSpaceTelescope #STScI #GSFC #UnitedStates #Europe #STEM #Education #HD #Video

Panning across Dwarf Irregular Galaxy I Zwicky 18 | Hubble

Panning across Dwarf Irregular Galaxy I Zwicky 18 | Hubble

Summary: A companion galaxy can be seen above and to the left of I Zwicky 18. Gravitational interactions between the two galaxies may have triggered I Zwicky 18's recent star formation that is responsible for its youthful appearance.

I Zwicky 18 is 59 million light-years from Earth and is located in the Ursa Major constellation.

Called I Zwicky 18, this galaxy has a youthful appearance that resembles galaxies typically found only in the early universe. Hubble has now found faint, older stars within this galaxy, suggesting that the galaxy may have formed at the same time as most other galaxies.

I Zwicky 18 is classified as a dwarf irregular galaxy and is much smaller than our Milky Way Galaxy. The concentrated bluish-white knots embedded in the heart of the galaxy are two major starburst regions where stars are forming at a furious rate. The wispy blue filaments surrounding the central starburst regions are bubbles of gas that have been blown away by stellar winds and supernovae explosions from a previous generation of hot, young stars. This gas is now heated by intense ultraviolet radiation unleashed by hot, young stars.

A companion galaxy lies just above and to the left of I Zwicky 18. The companion may be interacting with I Zwicky 18 by gravitationally tugging on the galaxy. The interaction may have triggered the galaxy's recent star formation that is responsible for the youthful appearance. Besides the bluish-white young stars, white-reddish stars also are visible in both I Zwicky 18 and its companion. These stars may be as old as 10 billion years. The reddish extended objects surrounding I Zwicky 18 and its companion are ancient, fully formed galaxies of different shapes that are much farther away.


Credit: European Space Agency (ESA)/Hubble (M. Kornmesser & L. L. Christensen)

Duration: 26 seconds

Release Date: Feb. 17, 2016


#NASA #ESA #Astronomy #Space #Science #Stars #Galaxies #Galaxy #IZwicky18 #IZw18 #IrregularGalaxy #GasBubbles #UrsaMajor #Constellation #Cosmos #Universe #HST #HubbleSpaceTelescope #STScI #GSFC #UnitedStates #Europe #STEM #Education #HD #Video

Dwarf Irregular Galaxy I Zwicky 18: Big Blue Gas Bubbles | Hubble

Dwarf Irregular Galaxy I Zwicky 18: Big Blue Gas Bubbles | Hubble


Called I Zwicky 18, this galaxy has a youthful appearance that resembles galaxies typically found only in the early universe. Hubble has now found faint, older stars within this galaxy, suggesting that the galaxy may have formed at the same time as most other galaxies.

I Zwicky 18 is classified as a dwarf irregular galaxy and is much smaller than our Milky Way Galaxy. The concentrated bluish-white knots embedded in the heart of the galaxy are two major starburst regions where stars are forming at a furious rate. The wispy blue filaments surrounding the central starburst regions are bubbles of gas that have been blown away by stellar winds and supernovae explosions from a previous generation of hot, young stars. This gas is now heated by intense ultraviolet radiation unleashed by hot, young stars.

A companion galaxy lies just above and to the left of I Zwicky 18. The companion may be interacting with I Zwicky 18 by gravitationally tugging on the galaxy. The interaction may have triggered the galaxy's recent star formation that is responsible for the youthful appearance. Besides the bluish-white young stars, white-reddish stars also are visible in both I Zwicky 18 and its companion. These stars may be as old as 10 billion years. The reddish extended objects surrounding I Zwicky 18 and its companion are ancient, fully formed galaxies of different shapes that are much farther away.

Hubble data also allowed astronomers for the first time to identify Cepheid variable stars in I Zwicky 18. These flashing stellar mile-markers were used to determine that I Zwicky 18 is 59 million light-years from Earth, almost 10 million light-years more distant than previously believed.


Credit: NASA, European Space Agency (ESA), and A. Aloisi (ESA and Space Telescope Science Institute)

Release Date: Oct. 16, 2007


#NASA #ESA #Astronomy #Space #Science #Stars #Galaxies #Galaxy #IZwicky18 #IZw18 #IrregularGalaxy #GasBubbles #UrsaMajor #Constellation #Cosmos #Universe #HST #HubbleSpaceTelescope #STScI #GSFC #UnitedStates #Europe #STEM #Education

Sagittarius Dwarf Galaxy Close-up | Hubble

Sagittarius Dwarf Galaxy Close-up | Hubble

This image from the Hubble Space Telescope shows a small galaxy called the Sagittarius dwarf irregular galaxy, or "SagDIG" for short. SagDIG is relatively nearby, and Hubble's sharp vision is able to reveal many thousands of individual stars within the galaxy. It is approximately 3 million light-years away in the constellation of Sagittarius (The Archer). It is the most distant member of the Local Group of galaxies, of which the Milky Way is a member.

Credit: NASA, European Space Agency (ESA), and The Hubble Heritage Team STScI/AURA

Release Date: Nov. 11, 2004


#NASA #ESA #Astronomy #Space #Science #Stars #Galaxies #Galaxy #SagittariusDwarfGalaxy #SagDIG #IrregularGalaxy #Sagittarius #Constellation #Cosmos #Universe #HST #HubbleSpaceTelescope #STScI #GSFC #UnitedStates #Europe #STEM #Education

The Sagittarius Dwarf Irregular Galaxy: Like a Hidden Diamond | ESO

The Sagittarius Dwarf Irregular Galaxy: Like a Hidden Diamond | ESO

Squint or you’ll miss it! At the very center of this image, taken with the VIMOS instrument attached to the European Southern Observatory’s Very Large Telescope (VLT), you can just about see the faint and fuzzy blue form of a distant galaxy known as the Sagittarius Dwarf Irregular Galaxy.

Discovered in 1977 with the European Southern Observatory (ESO) 1-meter Schmidt telescope, situated at ESO’s La Silla observatory, the irregularly shaped—hence the name—dwarf galaxy is approximately 3 million light-years away in the constellation of Sagittarius (The Archer). It is the most distant member of the Local Group of galaxies, of which the Milky Way is a member.

Unlike normal galaxies, dwarf galaxies are typically smaller and host a relatively small number of stars. Gravitational tugs from nearby galaxies can often distort the spherical and disc-like shapes of these fragile galaxies—this very process may be responsible for the slightly rectangular shape of this particular dwarf galaxy.


Credit: European Southern Observatory (ESO)/M. Bellazzini et al.

Release Date: Jan. 29, 2018


#NASA #ESO #Astronomy #Space #Science #Stars #Galaxies #Galaxy #SagittariusDwarfGalaxy #SagDIG #IrregularGalaxy #Sagittarius #Constellation #Cosmos #Universe #VLT #Telescope #LaSillaObservatory #Chile #Europe #STEM #Education