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By NASA
ESA/Hubble & NASA, C. Kilpatrick This NASA/ESA Hubble Space Telescope image treats viewers to a wonderfully detailed snapshot of the spiral galaxy NGC 3430 that lies 100 million light-years from Earth in the constellation Leo Minor. Several other galaxies, located relatively nearby to this one, are just beyond the frame of this image; one is close enough that gravitational interaction is driving some star formation in NGC 3430 — visible as bright-blue patches near to but outside of the galaxy’s main spiral structure. This fine example of a galactic spiral holds a bright core from which a pinwheel array of arms appears to radiate outward. Dark dust lanes and bright star-forming regions help define these spiral arms.
NGC 3430’s distinct shape may be one reason why astronomer Edwin Hubble used to it to help define his classification of galaxies. Namesake of the Hubble Space Telescope, Edwin Hubble authored a paper in 1926 that outlined the classification of some four hundred galaxies by their appearance — as either spiral, barred spiral, lenticular, elliptical, or irregular. This straightforward typology proved extremely influential, and the detailed schemes astronomers use today are still based on Edwin Hubble’s work. NGC 3430 itself is a spiral lacking a central bar with open, clearly defined arms — classified today as an SAc galaxy.
Image credit: ESA/Hubble & NASA, C. Kilpatrick
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By NASA
2 min read
Hubble Images a Classic Spiral
This NASA/ESA Hubble Space Telescope image features the majestic spiral galaxy NGC 3430. ESA/Hubble & NASA, C. Kilpatrick This NASA/ESA Hubble Space Telescope image treats viewers to a wonderfully detailed snapshot of the spiral galaxy NGC 3430 that lies 100 million light-years from Earth in the constellation Leo Minor. Several other galaxies, located relatively nearby to this one, are just beyond the frame of this image; one is close enough that gravitational interaction is driving some star formation in NGC 3430 — visible as bright-blue patches near to but outside of the galaxy’s main spiral structure. This fine example of a galactic spiral holds a bright core from which a pinwheel array of arms appears to radiate outward. Dark dust lanes and bright star-forming regions help define these spiral arms.
NGC 3430’s distinct shape may be one reason why astronomer Edwin Hubble used to it to help define his classification of galaxies. Namesake of the Hubble Space Telescope, Edwin Hubble authored a paper in 1926 that outlined the classification of some four hundred galaxies by their appearance — as either spiral, barred spiral, lenticular, elliptical, or irregular. This straightforward typology proved extremely influential, and the detailed schemes astronomers use today are still based on Edwin Hubble’s work. NGC 3430 itself is a spiral lacking a central bar with open, clearly defined arms — classified today as an SAc galaxy.
Astronomer Edwin Hubble pioneered the study of galaxies based simply on their appearance. This “Field Guide” outlines Hubble’s classification scheme using images from his namesake telescope. Credit: NASA’s Goddard Space Flight Center; Lead Producer: Miranda Chabot; Lead Writer: Andrea Gianopoulos
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Hubble’s Galaxies
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Claire Andreoli
NASA’s Goddard Space Flight Center, Greenbelt, MD
claire.andreoli@nasa.gov
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Last Updated Jul 25, 2024 Editor Andrea Gianopoulos Location NASA Goddard Space Flight Center Related Terms
Astrophysics Astrophysics Division Galaxies Goddard Space Flight Center Hubble Space Telescope Missions Spiral Galaxies The Universe Keep Exploring Discover More Topics From Hubble
Hubble Space Telescope
Since its 1990 launch, the Hubble Space Telescope has changed our fundamental understanding of the universe.
Hubble’s Galaxies
Hubble Design
Hubble Science Highlights
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By NASA
The barred spiral galaxy NGC 6872 is interacting with a smaller galaxy to the upper left. The smaller galaxy has likely stripped gas from NGC 6872 to feed the supermassive black hole in its center.X-ray: NASA/CXC/SAO; Optical: NASA/ESA/STScI; Image Processing: NASA/CXC/SAO/J. Schmidt, L. Frattare, and J. Major To commemorate the 25th anniversary of NASA’s Chandra X-ray Observatory launch, the Chandra team released this never-seen-before image of NGC 6872, a spiral galaxy in the Pavo (Peacock) constellation, on July 22, 2024. This image and 24 others, which all include data from Chandra, demonstrate how X-ray astronomy explores all corners of the universe.
NGC 6872 is 522,000 light-years across, making it more than five times the size of the Milky Way galaxy; in 2013, astronomers from the United States, Chile, and Brazil found it to be the largest-known spiral galaxy, based on archival data from NASA’s Galaxy Evolution Explorer. This record was surpassed by NGC 262, a galaxy that measures 1.3 million light-years in diameter.
See more photos released for this celebration.
Image credit: X-ray: NASA/CXC/SAO; Optical: NASA/ESA/STScI; Image Processing: NASA/CXC/SAO/J. Schmidt, L. Frattare, and J. Major
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By NASA
3 min read
Hubble Studies a Potential Galactic Merger
This NASA/ESA Hubble Space Telescope image captures the dwarf irregular galaxy NGC 5238. ESA/Hubble & NASA, F. Annibali This NASA/ESA Hubble Space Telescope image features the dwarf irregular galaxy NGC 5238, located 14.5 million light-years from Earth in the constellation Canes Venatici. Its unexciting, blob-like appearance seems to resemble an oversized star cluster more than a classic image of a galaxy. Its lackluster appearance belies its complicated structure, which is the subject of a great deal of research. As the image reveals, Hubble is able to pick out the galaxy’s countless stars, as well as its associated globular clusters — glowing, bright spots both inside and around the galaxy swarmed by even more stars.
Astronomers theorize that NGC 5238 may have had a close encounter with another galaxy as recently as a billion years ago. NGC 5238’s distorted shape provides evidence for this interaction. As the two galaxies interacted, their gravity caused distortions in the distribution of stars in each galaxy. There’s no nearby galaxy which could have caused this disturbance, so astronomers think NGC 5238 devoured a smaller satellite galaxy. Astronomers look for traces of the consumed galaxy by closely examining the population of stars in NGC 5238, a task made for Hubble’s excellent resolution. One tell-tale sign of the smaller galaxy would be groups of stars with different properties from most of NGC 5238’s other stars, indicating they were originally formed in a separate galaxy. Another sign would be a burst of star formation that occurred abruptly at around the same time the two galaxies merged. The Hubble data used to create this image will help astronomers determine NGC 5238’s history.
Despite their small size and unremarkable appearance, it’s not unusual for dwarf galaxies like NGC 5238 to drive our understanding of galaxy formation and evolution. One main theory of galaxy evolution is that galaxies formed ‘bottom-up’ in a hierarchical fashion: star clusters and small galaxies were the first to form out of gas and dark matter. Over time, gravity gradually assembled these smaller objects into galaxy clusters and superclusters, which explains the shape of the largest structures we see in the universe today. A dwarf irregular galaxy like NGC 5238 merging with a smaller companion is just the type of event that might have started the process of galaxy assembly in the early universe. Hubble’s observations of tiny NGC 5238 may help test some of our most fundamental ideas of how the universe evolves!
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Galaxy Details and Mergers
Tracing the Growth of Galaxies
Hubble’s Galaxies
Hubble’s Star Clusters
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Claire Andreoli
NASA’s Goddard Space Flight Center, Greenbelt, MD
claire.andreoli@nasa.gov
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Last Updated Jul 18, 2024 Editor Andrea Gianopoulos Location NASA Goddard Space Flight Center Related Terms
Astrophysics Astrophysics Division Galaxies Goddard Space Flight Center Hubble Space Telescope Irregular Galaxies Missions The Universe Keep Exploring Discover More Topics From Hubble
Hubble Space Telescope
Since its 1990 launch, the Hubble Space Telescope has changed our fundamental understanding of the universe.
Hubble E-books
Hubble Science
Hubble Online Activities
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By NASA
3 min read
Hubble Measures the Distance to a Supernova
This NASA/ESA Hubble Space Telescope image features the galaxy NGC 3810. ESA/Hubble & NASA, D. Sand, R. J. Foley Measuring the distance to truly remote objects like galaxies, quasars, and galaxy clusters is a crucial task in astrophysics, particularly when it comes to studying the early universe, but it’s a difficult one to complete. We can only measure the distances to a few nearby objects like the Sun, planets, and some nearby stars directly. Beyond that, astronomers need to use various indirect methods; one of the most important examines Type Ia supernovae, and this is where the NASA/ESA Hubble Space Telescope excels.
NGC 3810, the galaxy featured in this image, was the host of a Type Ia supernova in 2022. In early 2023, Hubble focused on this and a number of other galaxies to closely examine recent Type Ia supernovae. Type Ia supernovae are the result of a white dwarf exploding, and their peak brightness is very consistent. This attribute allows astronomers to use Type Ia supernovae to measure distances: we know how bright a Type Ia supernova should be, so we can tell how far away it must be by how dim it appears. One snag with this method is intergalactic dust. Because intergalactic dust blocks some of the supernova’s light, astronomers need to determine how much light the dust reduces to accurately measure the supernova’s brightness and calculate its distance. Hubble’s unique capabilities offer them a clever way of doing this.
Astronomers use Hubble to take images of the same Type Ia supernovae in ultraviolet light, which the dust almost completely blocks out, and in infrared light, which passes through dust nearly unaffected. By carefully noting how much light comes through at each wavelength, astronomers can determine how much dust lies between Hubble and the supernova, letting them confidently calibrate the relationship between a supernova’s brightness and its distance. Hubble’s unique capability to observe in ultraviolet and infrared wavelengths of light in great detail with the same instrument makes it the perfect tool for these types of observations. Indeed, some of the data used to make this beautiful image of NGC 3810 focused on its 2022 supernova. You can see it as a point of light just below the galactic nucleus in the annotated image below.
This annotated Hubble image of NGC 3810 denotes the location of the Type Ia supernovae SN 2022zut, It was the eighteen thousand, one hundred and forty-second supernova found in 2022! ESA/Hubble & NASA, D. Sand, R. J. Foley There are many ways to measure cosmic distances, but Type Ia supernovae are one of the most useful and accurate tools because they are so bright. Astronomers must use other methods as well, either as an independent check against other distance measurements, or to measure at much closer or farther distances. One such method, that also works for galaxies, is comparing their rotation speed to their brightness; based on that method, NGC 3810 is about 50 million light-years from Earth.
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Hubble Space Telescope
Hubble’s Galaxies
The Death Throes of Stars
Exploring the Birth of Stars
Facebook logo @NASAHubble @NASAHubble Instagram logo @NASAHubble Media Contact:
Claire Andreoli
NASA’s Goddard Space Flight Center, Greenbelt, MD
claire.andreoli@nasa.gov
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Last Updated Jul 12, 2024 Editor Andrea Gianopoulos Location NASA Goddard Space Flight Center Related Terms
Astrophysics Astrophysics Division Galaxies Goddard Space Flight Center Hubble Space Telescope Missions Spiral Galaxies Stars Supernovae The Universe Keep Exploring Discover More Topics From Hubble
Hubble Space Telescope
Since its 1990 launch, the Hubble Space Telescope has changed our fundamental understanding of the universe.
Discovering a Runaway Universe
Our cosmos is growing, and that expansion rate is accelerating.
Hubble E-books
Hubble Images
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