The Flickr Seyfertgalaxy Image Generatr

NGC 2685 is an object of great scientific interest, because polar-ring galaxies are very rare galaxies. A polar-ring galaxy is a type of galaxy with an outer ring of gas and stars that rotates over the poles of the galaxy. They are thought to form when two galaxies gravitationally interact with each other.

Also known as the “Helix Galaxy”, it is located about 48 million light years distant in the constellation Ursa Major. It also falls in the classification of Seyfert galaxies.

Seyfert galaxies account for about 10% of all galaxies and are some of the most intensely studied objects in astronomy, as they are thought to be powered by the same phenomena that occur in quasars, although they are closer and less luminous than quasars. These galaxies have supermassive black holes at their centers which are surrounded by accretion discs of in-falling material.

Capture info:
Location: SkyPi Remote Observatory, Pie Town NM US
Telescope: Officina Stellare RiDK 400
Camera: QHY600M
Mount: Paramount MEII
Data: LRGB 12.5, 9, 8, 8.5 hrs respectively
Processing: Pixinsight

NGC 185 (also known as Caldwell 18) is a dwarf spheroidal galaxy located 2.08 million light-years from Earth, appearing in the constellation Cassiopeia. It is a member of the Local Group, and is a satellite of the Andromeda Galaxy (M31). Unlike most dwarf elliptical galaxies, NGC 185 contains young stellar clusters. NGC 185 has an active galactic nucleus (AGN) and is usually classified as a type 2 Seyfert galaxy, though its status as a Seyfert is questioned. It is possibly the closest Seyfert galaxy to Earth, and is the only known Seyfert in the Local Group. (ref: Wikipedia)

Tech Specs: Orion 8” RC Telescope, ZWO ASI2600MC camera running at 0F, 81 x 60 second exposures, Celestron CGEM-DX pier mounted, ZWO EAF and ASIAir Pro, processed in PixInsight. Image Date: September 8, 2024. Location: The Dark Side Observatory (W59), Weatherly, PA, USA (Bortle Class 4).

Looking past its long spiral arms filled with stars and the dark threads of dust crossing it, your eye might be caught by the shining point at the centre of UGC 3478, the spiral galaxy starring in this Hubble Picture of the Week. This point is the galaxy’s nucleus, and indeed there is something special about it: it is a growing giant black hole which astronomers call an active galactic nucleus, or AGN.

UGC 3478, located in the constellation Camelopardalis, is what is known as a Seyfert galaxy. This is a type of galaxy with an AGN at its core. Like all such “active galaxies”, the brightness that you see here hides a supermassive black hole at the centre of the galaxy. A disc of gas spirals into this black hole, and as the material crashes together and heats up it emits very strong radiation. The spectrum of this radiation includes hard X-ray emission, which clearly mark it out from the stars in the galaxy. Despite the strong brightness of the compact central region, we can still clearly see the disc of the galaxy around it, which makes the galaxy a Seyfert galaxy.

Many active galaxies are known to astronomers at vast distances from Earth, thanks to the great brightness of their nuclei highlighting them next to other, dimmer galaxies. At 128 million light-years from Earth, UGC 3478 is positively neighbourly to us. The data used to make this image comes from a Hubble survey of nearby powerful AGNs found in relatively high-energy X-rays, like this one, which it is hoped can help astronomers to understand how the galaxies interact with the supermassive black holes at their hearts.

[Image Description: A spiral galaxy, with two glowing spiral arms. They are filled with thin lines of dark dust, and surrounded by a faint cloud. One arm stretches further from the galaxy than the other. The point at the centre of the spiral is particularly bright. It is on a black background, mostly empty, except for some distant galaxies and a few bright stars in the foreground.]

Credits: ESA/Hubble & NASA, M. Koss, A. Barth; CC BY 4.0

NGC 5033, a spiral galaxy located in the constellation Canes Venatici. This image reveals the intricate structure and dynamic features within the galaxy, showcasing a beautiful palette derived from LRGB data. The galaxy's bright nucleus, likely powered by a supermassive black hole, and its faint spiral arms are prominently featured. The arms, dotted with star-forming regions and massive blue star clusters, span over 100,000 light-years, making NGC 5033 similar in size to our own Milky Way.

Technical Details:

Telescope: 🔭 ASA RC600 24inch F4.5
Mount: 🌌 ASA DDM200
Camera: 📷 Moravian C3 Pro
Filters: 🎨 FLI LRGB
Exposure:

Luminance: 300s x 9
Red: 60s x 3
Green: 60s x 3
Blue: 60s x 3
Total Integration:

Luminance: 45 minutes
RGB: 9 minutes

Processing:
The image was processed using MaximDL, PixInsight, and Photoshop to enhance the galaxy's vivid details and colors, bringing out the majestic spiral arms and the core's luminosity.

Location and Date:
Namibia, June 2022

Enjoy this celestial masterpiece, which highlights both the beauty and complexity of NGC 5033, a well-studied example of a Seyfert galaxy with a rich and varied structure.

Thanks for watching,
Haim

This Picture of the Week from the NASA/ESA Hubble Space Telescope depicts the galaxy NGC 4951, a spiral galaxy that’s located 49 million light-years from Earth in the constellation Virgo.

The data used to make this image were captured by Hubble as part of a programme to examine how matter and energy travel in nearby galaxies. Galaxies continuously undergo a cycle of star formation whereby the gas in a galaxy forms molecular clouds, which collapse to create new stars, which then disperse the clouds they formed from with powerful radiation or stellar winds in a process called feedback. The remaining gas is left to form new clouds elsewhere. This cycle of moving matter and energy determines how fast a galaxy forms stars and how quickly it burns through its supplies of gas — that is, how it evolves over the course of its life. Understanding this evolution depends on the nebulae, stars and star clusters in the galaxy: when they formed and their past behaviour. Hubble has always excelled at measuring populations of stars, and the task of tracking gas and star formation in galaxies including NGC 4951 is no exception.

NGC 4951 is also a Seyfert galaxy, a type of galaxy that has a very bright and energetic nucleus called an active galactic nucleus. This image demonstrates well how energetic the galaxy is, and some of the dynamic galactic activity which transports matter and energy throughout it: a shining core surrounded by swirling arms, glowing pink star-forming regions, and thick dust.

[Image Description: A spiral galaxy, tilted diagonally. It has thick, cloudy spiral arms wrapping around the core. They are filled with pink patches marking new star formation, young blue stars, and dark wisps of dust that block light. The galaxy glows brightly from its core. It is on a dark background, with a few distant galaxies and unrelated stars around it.]

Credits: ESA/Hubble & NASA, D. Thilker, M. Zamani (ESA/Hubble); CC BY 4.0

Date: 2023-08-25
Location: Krivaja Vojnicka, Croatia
Telescope: SW 130 PDS
Camera: Canon 2000D
Mount: SW EQ3 (Asterion mod)
Exp: 200x120s

Additional Ha signal provided by Luka Faltis

This luminous image from the Hubble Space Telescope shows Z 229-15, a celestial object that lies about 390 million light-years from Earth in the constellation Lyra. Z 229-15 is one of those interesting celestial objects defined as several different things: sometimes as an active galactic nucleus (an AGN); sometimes as a quasar; and sometimes as a Seyfert galaxy. Which of these is Z 229-15 really? The answer is that it is all these things all at once, because these three definitions have significant overlap.

An AGN is a small region at the heart of certain galaxies (called active galaxies) that is far brighter than just the galaxy’s stars would be. The extra luminosity is due to the presence of a supermassive black hole at the galaxy’s core. Material sucked into a black hole doesn’t fall directly into it, but instead is drawn into a swirling disk, from where it is inexorably tugged towards the black hole. This disk of matter gets so hot that it releases a large amount of energy across the electromagnetic spectrum, and that’s what makes AGNs appear so bright.

Quasars are a particular type of AGN; they are typically both extremely bright and extremely distant from Earth – several hundred million light-years is considered nearby for a quasar, making Z 229-15 positively local. Often an AGN is so bright that the rest of the galaxy cannot be seen, but Seyfert galaxies are active galaxies that host very bright AGNs (quasars) while the rest of the galaxy is still observable. So Z 229-15 is a Seyfert galaxy that contains a quasar, and that, by definition, hosts an AGN. Classification in astronomy can be a challenge!

Credit: ESA/Hubble & NASA, A. Barth, R. Mushotzky

For more information, visit: science.nasa.gov/missions/hubble/hubble-views-an-intrigui...

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The lenticular galaxy NGC 5283 is the subject of this Hubble Space Telescope image. NGC 5283 contains an active galactic nucleus, or AGN. An AGN is an extremely bright region at the heart of a galaxy where a supermassive black hole exists. When dust and gas fall into the black hole, the matter heats up and emits light across the electromagnetic spectrum.

NGC 5283 is a Seyfert galaxy. About 10 percent of all galaxies are Seyfert galaxies, and they differ from other galaxies that contain AGNs because the galaxy itself is clearly visible. Other AGNs emit so much radiation that they outshine or make it impossible to observe the structure of their host galaxy!

Hubble observed this galaxy as part of a survey for a dataset about nearby AGNs, which will serve as a resource for astronomers investigating AGN physics, black holes, host galaxy structure, and more.

Credit: NASA, ESA, A. Barth (University of California - Irvine), and M. Revalski (STScI); Processing: Gladys Kober (NASA/Catholic University of America)

For more information, visit: science.nasa.gov/missions/hubble/hubble-views-a-beautiful...

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This Hubble Space Telescope image features a bright spiral galaxy known as MCG-01-24-014, which is located about 275 million light-years from Earth. In addition to being a well-defined spiral galaxy, MCG-01-24-014 has an extremely energetic core, known as an active galactic nucleus (AGN), so it is referred to as an active galaxy.

Even more specifically, it is categorised as a Type-2 Seyfert galaxy. Seyfert galaxies host one of the most common subclasses of AGN, alongside quasars. Seyfert galaxies tend to be relatively nearby ones where the host galaxy remains plainly detectable alongside its central AGN, while quasars are very distant AGNs whose incredible luminosities outshine their host galaxies.

Credit: ESA/Hubble & NASA, C. Kilpatrick

For more information, visit: science.nasa.gov/missions/hubble/hubble-sights-a-galaxy-w...

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Bright blue spiral arms twist around the bright-white center of this starry galaxy. This new Hubble Space Telescope image features NGC 6951, an intermediate spiral galaxy 78 million light-years away in the Cepheus constellation. Discovered independently by French astronomer Jerome Coggia in 1877 and American astronomer Lewis Swift in 1878, NGC 6951 intrigues scientists with its stellar history. The galaxy had its highest rates of star formation about 800 million years ago, then sat quietly for 300 million years before beginning to birth stars again. The average age of a star cluster, or gravitationally-bound group of stars, in this galaxy is 200 to 300 million years old, though some are as old as one billion years. Turbulent regions of gas, shown in dark red, surround the bright blue pinpricks that are star clusters.

Astronomers often classify NGC 6951 as a Type II Seyfert galaxy, a type of active galaxy that emits large amounts of infrared radiation and has slow-moving gaseous matter near its center. Some astronomers classify NGC 6951 as a low-ionization nuclear emission-line region (LINER) galaxy, which is similar to a Type II Seyfert galaxy but with a cooler nucleus that emits weakly ionized or neutral atoms like oxygen, nitrogen, and sulfur. The whole galaxy is about 75,000 light-years across, and since it is close to the northern celestial pole, it is visible from the northern hemisphere.

At the center of NGC 6951 lies a supermassive black hole surrounded by a ring of stars, gas, and dust about 3,700 light-years across. This “circumnuclear ring” is between 1 and 1.5 billion years old and has been forming stars for most of that time. Scientists hypothesize that interstellar gas flows through the dense, starry bar of the galaxy to the circumnuclear ring, which supplies new material for star formation. Up to 40 percent of the mass in the ring comes from relatively new stars that are less than 100 million years old. Spiral lanes of dust, shown in dark orange, connect the center of the galaxy to its outer regions, contributing more material for future star formation.

Some of the stars in NGC 6951 have also experienced terrific stellar explosions known as supernovae; astronomers have counted as many as six supernovae in this galaxy in the past 25 years. Scientists continue to study NGC 6951 to better understand the environments that produce supernovae. Studying the emissions from supernovae helps astronomers understand the progenitor star, its age, luminosity, and position.

Credit: NASA, ESA, A. Filippenko (University of California - Berkeley), R. Foley (University of California - Santa Cruz), C. Kilpatrick (Northwestern University), and D. Sand (University of Arizona); Processing: Gladys Kober (NASA/Catholic University of America)

For more information on Hubble's Galaxies, visit: science.nasa.gov/mission/hubble/hubble-news/hubbles-galax...

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A striking orange and blue streak fills this new image from the Hubble Space Telescope. Hubble’s visible and infrared capabilities captured this edge-on view of lenticular galaxy NGC 612. Lenticular galaxies have a central bulge and disk much like spiral galaxies, but they lack the characteristic arms. They typically have older star populations and little ongoing star formation. In NGC 612, dust and cool hydrogen gas make up the majority of the galactic disc, the plane of matter we see in orange and dark red. This galaxy appears in the Sculptor constellation and is easily visible from Earth’s southern hemisphere.

NGC 612 is an active galaxy, which means that its center appears more than 100 times brighter than the combined light of its stars. It is also a Seyfert galaxy, the most common type of active galaxy. Seyfert galaxies emit large amounts of infrared radiation despite looking normal in visible light. NGC 612 is a Type II Seyfert, which means matter near the center of the galaxy moves rather calmly around the nucleus. The stars in this galaxy are unusually young, with ages around 40 to 100 million years.

NGC 612 is also an extremely rare example of a non-elliptical radio galaxy, a type of galaxy that shows significant radio emissions – in this case, an association with radio source PKS 0131-36. Astronomers have only discovered five such radio-emitting lenticular galaxies in the universe. One theory attributes NGC 612’s unusual radio emissions to a past interaction with a companion spiral galaxy. Another theory focuses on the galaxy’s bright and dominant bulge, which is similar to those seen in elliptical radio galaxies. By imaging this galaxy, astronomers hope to uncover more about what causes galaxies to emit radio waves.

British astronomer John Herschel discovered NGC 612 in 1837. It is about 400 million light-years from Earth and has a mass of around 1.1 trillion times that of our Sun.

Credit: NASA's Hubble Space Telescope, ESA, A. Barth (University of California - Irvine), and B. Boizelle (Brigham Young University) ; Processing: Gladys Kober (NASA/Catholic University of America)

For more on Hubble's Galaxies, visit: science.nasa.gov/mission/hubble/hubble-news/hubbles-galax...

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This Hubble Picture of the Week — taken using NASA/ESA Hubble Space Telescope’s Advanced Camera for Surveys (ACS) — shows Arp 107, a celestial object that comprises a pair of galaxies in the midst of a collision. The larger galaxy (in the left of this image) is an extremely energetic galaxy type known as a Seyfert galaxy, which house active galactic nuclei at their cores. Seyfert galaxies are notable because despite the immense brightness of the active core, radiation from the entire galaxy can be observed. This is evident in this image, where the spiraling whorls of the whole galaxy are readily visible. The smaller companion is connected to the larger by a tenuous-seeming ‘bridge’, composed of dust and gas. The colliding galactic duo lie about 465 million light-years from Earth.

Arp 107 is part of a catalogue of 338 galaxies known as the Atlas of Peculiar Galaxies, which was compiled in 1966 by Halton Arp. It was observed by Hubble as part of an observing programme that specifically sought to fill in an observational ‘gap’, by taking limited observations of members of the Arp catalogue. Part of the intention of the observing programme was to provide the public with images of these spectacular and not-easily-defined galaxies, and as such, it has provided a rich source for Hubble Pictures of the Week. In fact, several recent releases, including this one and this one, have made use of observations from the same observing programme.

[Image Description: A pair of merging galaxies. The galaxy on the left has a large, single spiral arm curving out from the core and around to below it, with very visible glowing dust and gas. The right galaxy has a bright core but only a bit of very faint material. A broad curtain of gas connects the two galaxies’ cores and hangs beneath them. A few small stars and galaxies are scattered around the black background.]

Credits: ESA/Hubble & NASA, J. Dalcanton; CC BY 4.0

This Hubble Space Telescope image finds the large spiral galaxy, NGC 3227, wrapped in a turbulent gravitational dance with its companion, the elliptical galaxy NGC 3226. The pair – collectively known as Arp 94 – is relatively nearby, between 50 and 60 million light-years away toward the constellation Leo, the Lion. A close look at the area between the two galaxies, reveals faint tidal streams of gas and dust that link the galaxies in their gravitational dance.

NGC 3227 is a Seyfert galaxy, a type of galaxy with a very active nucleus. Seyfert galaxies hold supermassive black holes at their cores. As matter spirals into the black hole, it releases vast amounts of radiation along the black hole’s axis of rotation. giving the galaxy its active nucleus.

Hubble looked at NGC 3227 and 3226 as part of a program to measure black hole masses by observing the dynamics of gas at the centers of bright cluster galaxies. The color red in this image represents both visible red and near infrared wavelengths of light.

For more information, visit: www.nasa.gov/image-feature/goddard/2022/hubble-captures-a...

Visit Hubble's Galaxies at www.nasa.gov/content/discoveries-hubbles-galaxies

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The Hubble Space Telescope captured this spectacular image of the bright star-forming ring that surrounds the heart of the barred spiral galaxy NGC 1097. In this image, the larger-scale structure of the galaxy is barely visible: its comparatively dim spiral arms, which surround its heart in a loose embrace, reach out beyond the edges of this frame.

This face-on galaxy, lying 45 million light-years away from Earth in the southern constellation of Fornax (The Furnace), is particularly attractive for astronomers. NGC 1097 is a Seyfert galaxy. Lurking at the very center of the galaxy, a supermassive black hole 100 million times the mass of our Sun is gradually consuming the matter around it. The area immediately around the black hole shines powerfully with radiation coming from the material falling in. The distinctive ring around the black hole is bursting with new star formation due to an inflow of material toward the central bar of the galaxy. These star-forming regions are glowing brightly thanks to emission from clouds of ionized hydrogen.

The ring is around 5000 light-years across, although the spiral arms of the galaxy extend tens of thousands of light-years beyond it.

NGC 1097 is not wandering alone through space. It has two small galaxy companions, which dance "the dance of stars and the dance of space" like the gracious dancer of the famous poem The Dancer by Khalil Gibran. The satellite galaxies are NGC 1097A, an elliptical galaxy orbiting 42,000 light-years from the center of NGC 1097 and a small dwarf galaxy named NGC 1097B. Both galaxies are located out beyond the frames of this image.

Credit: ESA/Hubble & NASA
Acknowledgement: E. Sturdivant

For more information, visit: esahubble.org/images/potw1252a/

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Tendrils of dark dust can be seen threading across the heart of the spiral galaxy NGC 7172 in this image from the Hubble Space Telescope. The galaxy lies approximately 110 million light-years from Earth in the constellation Piscis Austrinus. The lane of dust threading its way across NGC 7172 — which is viewed side-on in this image — is obscuring the luminous heart of the galaxy, making NGC 7172 appear to be nothing more than a normal edge-on spiral galaxy.

When astronomers inspected NGC 7172 across the electromagnetic spectrum they quickly discovered that there was more to it than meets the eye: NGC 7172 is a Seyfert galaxy — a type of galaxy with an intensely luminous active galactic nucleus powered by matter accreting onto a supermassive black hole.

Credit: ESA/Hubble & NASA, D. J. Rosario, A. Barth
Acknowledgement: L. Shatz

For more information, visit: esahubble.org/images/potw2213a/

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This image from the NASA/ESA Hubble Space Telescope reveals tendrils of dark dust threading across the heart of the spiral galaxy NGC 7172. The galaxy lies approximately 110 million light-years from Earth in the constellation Piscis Austrinus. The lane of dust threading its way across NGC 7172 is obscuring the luminous heart of the galaxy, making NGC 7172 appear to be nothing more than a normal spiral galaxy viewed from the side.

When astronomers inspected NGC 7172 across the electromagnetic spectrum they quickly discovered that there was more to it than meets the eye: NGC 7172 is a Seyfert galaxy – a type of galaxy with an intensely luminous active galactic nucleus powered by matter accreting onto a supermassive black hole.

This image combines data from two sets of Hubble observations, both proposed to study nearby active galactic nuclei. The image also combines data from two instruments -– Hubble’s Advanced Camera for Surveys and Wide Field Camera 3.

Text credit: European Space Agency (ESA)
Image credit: ESA/Hubble & NASA, D. J. Rosario, A. Barth; Acknowledgment: L. Shatz

For more information: www.nasa.gov/image-feature/goddard/2022/hubble-views-a-ga...

Tendrils of dark dust can be seen threading across the heart of the spiral galaxy NGC 7172 in this image from the NASA/ESA Hubble Space Telescope. The galaxy lies approximately 110 million light-years from Earth in the constellation Piscis Austrinus. The lane of dust threading its way across NGC 7172 — which is viewed side-on in this image — is obscuring the luminous heart of the galaxy, making NGC 7172 appear to be nothing more than a normal edge-on spiral galaxy.

When astronomers inspected NGC 7172 across the electromagnetic spectrum they quickly discovered that there was more to it than meets the eye: NGC 7172 is a Seyfert galaxy — a type of galaxy with an intensely luminous active galactic nucleus powered by matter accreting onto a supermassive black hole.

This image combines data from two sets of Hubble observations, both of which were proposed to study nearby active galactic nuclei. The image also combines data from two instruments — Hubble’s Advanced Camera for Surveys (ACS) and Wide Field Camera 3 (WFCS).

Credits: ESA/Hubble & NASA, D. J. Rosario, A. Barth; CC BY 4.0
Acknowledgement: L. Shatz

This image from the NASA/ESA Hubble Space Telescope feels incredibly three-dimensional for a piece of deep-space imagery. The image shows Arp 282, an interacting galaxy pair composed of the Seyfert galaxy NGC 169 (bottom) and the galaxy IC 1559 (top). Interestingly, both galaxies have monumentally energetic cores known as active galactic nuclei (AGN), although that is difficult to tell from this image, which is fortunate. If the image revealed the full emission of both AGNs, their brilliance would obscure the beautifully detailed tidal interactions we see in this image. Tidal forces occur when an object’s gravity causes another object to distort or stretch. The direction of tidal forces is away from the lower-mass object and toward the higher mass object. When two galaxies tidally interact, gas, dust, and even entire star systems can move toward one galaxy and away from the other. The image reveals this process in action as delicate streams of matter visibly link the two galaxies.

Astronomers now accept that an important aspect of how galaxies evolve is the way they interact with one another. Galaxies can merge, collide, or brush past one another – each interaction significantly affecting their shapes and structures. As common as such interactions may be, it is rare to capture an image of two galaxies interacting in such a visibly dynamic way.

Text credit: European Space Agency (ESA)
Image credit: ESA/Hubble & NASA, J. Dalcanton, Dark Energy Survey, Department of Energy (DOE), Cerro Tololo Inter-American Observatory/NoirLab/National Science Foundation/Association of Universities for Research in Astronomy (AURA), Sloan Digital Sky Survey (SDSS); Acknowledgment: J. Schmidt

For more information: www.nasa.gov/image-feature/goddard/2022/hubble-views-a-co...

Meet NGC 5728, a spiral galaxy around 130 million light-years from Earth. This image was captured using Hubble’s Wide Field Camera 3 (WFC3), which is extremely sensitive to visible and infrared light. Therefore, this image beautifully captures the regions of NGC 5728 that are emitting visible and infrared light. However, there are many other types of light that galaxies such as NGC 5728 can emit, which WFC3 cannot see.

In this image, NCG 5728 appears to be an elegant, luminous, barred spiral galaxy. What this image does not show, however, is that NGC 5728 is also a monumentally energetic type of galaxy, known as a Seyfert galaxy. This extremely energetic class of galaxies are powered by their active cores, which are known as active galactic nuclei (AGNs). There are many different types of AGNs, and only some of them power Seyfert galaxies. NGC 5728, like all Seyfert galaxies, is distinguished from other galaxies with AGNs because the galaxy itself can be seen clearly. Other types of AGNs, such as quasars, emit so much radiation that it is almost impossible to observe the galaxy that houses them. As this image shows, NGC 5728 is clearly observable, and at optical and infrared wavelengths it looks quite normal. It is fascinating to know that the galaxy’s centre is emitting vast amounts of light in parts of the electromagnetic spectrum that WFC3 just isn’t sensitive to! Just to complicate things, the AGN at NGC 5728’s core might actually be emitting some visible and infrared light — but it may be blocked by the dust surrounding the galaxy’s core.

Credits: ESA/Hubble, A. Riess et al., J. Greene; CC BY 4.0

Meet NGC 5728, a spiral galaxy around 130 million light-years from Earth. This image was acquired using Hubble’s Wide Field Camera 3 (WFC3), which is extremely sensitive to visible and infrared light. Therefore, it beautifully captures the regions of NGC 5728 that are emitting light at those wavelengths. However, there are many other types of light that galaxies such as NGC 5728 emit, which WFC3 can’t see.

In this image, NCG 5728 appears to be an elegant, luminous, barred spiral galaxy. What this image doesn’t show, is that NGC 5728 is also a monumentally energetic type of galaxy, known as a Seyfert galaxy. Powered by their active cores, Seyfert galaxies are an extremely energetic class of galaxies known as active galactic nuclei (AGNs). There are many different types of AGNs, but Seyfert galaxies are distinguished from other galaxies with AGNs because the galaxy itself is clearly seen. Other AGNs, such as quasars, emit so much radiation that it is almost impossible to observe the galaxy that houses them. As this image shows, NGC 5728 is clearly observable, and at visible and infrared wavelengths it looks quite normal. It is fascinating to know that the galaxy’s center is emitting vast amounts of light in parts of the electromagnetic spectrum that WFC3 just isn’t sensitive to! Just to complicate things, the AGN at NGC 5728’s core might actually be emitting some visible and infrared light – but it may be blocked by the dust surrounding the galaxy’s core.

Text credit: ESA (European Space Agency)
Image credit: ESA/Hubble, A. Riess et al., J. Greene

For more information: www.nasa.gov/image-feature/goddard/2021/hubble-views-a-ga...