Starship Asterisk*

bystander wrote: ↑Mon Feb 28, 2022 4:23 pm Not-So-Close Encounter
ESA Hubble Picture of the Week | 2022 Feb 28

Image Credit: ESA/Hubble & NASA, T. Boeker, B. Holwerda, Dark Energy Survey, DOE, FNAL/DECam, CTIO/NOIRLab/NSF/AURA, SDSS; Acknowledgement: R. Colombari

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The twin galaxies NGC 4496A and NGC 4496B dominate the frame in this image from the NASA/ESA Hubble Space Telescope. Both galaxies lie in the constellation Virgo, but despite appearing side-by-side in this image they are at vastly different distances from both Earth and one another. NGC 4496A is 47 million light-years from Earth while NGC 4496B is 212 million light-years away. The enormous distances between the two galaxies mean that the two cannot interact, and they only appear to overlap owing to a chance alignment.

Chance galactic alignments such as this provide astronomers with the opportunity to delve into the distribution of dust in these galaxies. Galactic dust adds to the beauty of astronomical images — it can be seen in this image as the dark tendrils threading through both NGC 4496A and NGC 4496B — but it also complicates astronomers’ observations. Dust absorbs starlight, making stars seem dimmer and shifting their light towards longer wavelengths, a process that astronomers refer to as “reddening” (not the same thing as redshift). By carefully measuring how starlight from background galaxies is affected by dust in intervening galaxies, astronomers can map out where the dust is in the foreground galaxy’s spiral arms. The resulting “dust maps” help astronomers calibrate measurements of everything from cosmological distances to the types of stars populating galaxies.

Image Credit: ESA/Hubble & NASA, T. Boeker, B. Holwerda, Dark Energy Survey, DOE, FNAL/DECam, CTIO/NOIRLab/NSF/AURA, SDSS; Acknowledgement: R. Colombari

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The twin galaxies NGC 4496A and NGC 4496B dominate the frame in this image from the NASA/ESA Hubble Space Telescope. Both galaxies lie in the constellation Virgo, but despite appearing side-by-side in this image they are at vastly different distances from both Earth and one another. NGC 4496A is 47 million light-years from Earth while NGC 4496B is 212 million light-years away. The enormous distances between the two galaxies mean that the two cannot interact, and they only appear to overlap owing to a chance alignment.

Chance galactic alignments such as this provide astronomers with the opportunity to delve into the distribution of dust in these galaxies. Galactic dust adds to the beauty of astronomical images — it can be seen in this image as the dark tendrils threading through both NGC 4496A and NGC 4496B — but it also complicates astronomers’ observations. Dust absorbs starlight, making stars seem dimmer and shifting their light towards longer wavelengths, a process that astronomers refer to as “reddening” (not the same thing as redshift). By carefully measuring how starlight from background galaxies is affected by dust in intervening galaxies, astronomers can map out where the dust is in the foreground galaxy’s spiral arms. The resulting “dust maps” help astronomers calibrate measurements of everything from cosmological distances to the types of stars populating galaxies.

Image Credit: ESO/Petr Horálek

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A stunning night view, taken close to the 1.54m Danish Telescope and the 3.6m telescope on the road at La Silla, shows the Milky Way above the horizon, accompanied by the Magellanic Clouds.

ESO’s 3.6m Telescope, seen here atop a hill at the centre of the image, is home to HARPS, an instrument dedicated to the discovery of planets outside the Solar System via the radial velocity method. This method enables the detection of a planet by measuring the wobbling motion of the central star caused by the gravitational pull of the planet itself.

The towers on the left are the support structures of the BlackGEM telescopes, which had not been installed yet when this image was taken. BlackGEM is an array of telescopes that will search for the light emitted by the optical counterparts of the most powerful gravitational-wave sources, namely colliding neutron stars and black holes.

On the right of the image, we see the Large and Small Magellanic Clouds, two irregular dwarf galaxies orbiting the Milky Way at a distance of approximately 160 000 and 200 000 light-years, respectively. In the Mapuche culture of south-central Chile, these neighbouring galaxies were known as lafken, labken or künchalabken (“the lagoons”) as well as rünanko (“the water wells”).

The red filamentary emission stretching across the sky in the horizon is called airglow, which is light naturally emitted by atoms and molecules in the atmosphere through various physical and chemical processes. Despite showing up prominently in this image, airglow is invisible to the unaided eye.

Credit: International Gemini Observatory/NOIRLab/NSF/AURA/J. Chu

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It’s difficult to believe that this photo was captured at nightime. The impressive peak of Maunakea — the dormant volcano that houses Gemini North, of the international Gemini Observatory, a Program of NSF’s NOIRLab — appears to be clearly lit under a bright blue sky. Shadows are even visible between the dormant volcano’s cracks and crevices.

There are two clues that this image was actually taken at nighttime. First, the bright streaks in the sky are actually star trails — streaks of starlight, which appear when a photographer uses a long exposure. They are due to the Earth’s rotation on its own axis. The second clue is subtler. In the bottom left corner of the image, artificial lights can be seen. These lights would not be required in daytime. The overall brightness of the image is caused by such a long exposure time, so the camera had time to collect a lot of starlight and moonlight, creating an image that appears to be Sun-drenched!

ESA/Hubble wrote:

A spectacular head-on collision between two galaxies, known as Arp 143, has fueled the unusual triangular-shaped star-formation frenzy as captured by the NASA/ESA Hubble Space Telescope.

The interacting galaxy duo Arp 143 contains the distorted, star-forming spiral galaxy NGC 2445, at right, along with its less flashy companion, NGC 2444, at left. Their frenzied collision takes place against the tapestry of distant galaxies, of which some can be seen through the interacting pair.

Astronomers suggest that the two galaxies passed through each other, igniting the uniquely shaped firestorm of star formation in NGC 2445, where thousands of stars are bursting into life. This galaxy is awash with new stars because it is rich in gas, the raw material from which stars are made. However, it hasn’t yet escaped the gravitational clutches of its partner at left. The pair is waging a cosmic tug-of-war, which NGC 2444 appears to be winning. That galaxy has pulled gas from NGC 2445, forming the oddball triangle of newly minted stars.

NGC 2444 is also responsible for yanking strands of gas from its partner, stoking the streamers of young, blue stars that appear to form a bridge between the two galaxies. These streamers are among the first in what appears to be a wave of star formation that started on the galaxy’s outskirts and continued inward. Researchers estimate the streamer stars were born between 50 million and 100 million years ago. But these infant stars are being left behind as NGC 2445 continues to pull slowly away from NGC 2444...

bystander wrote: ↑Tue Feb 22, 2022 12:24 am Hubble Captures a Peculiar Galactic Pair
ESA Hubble Picture of the Week | 2022 Feb 21

Image Credit: ESA/Hubble & NASA, A. Evans, R. Chandar

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This striking image from the NASA/ESA Hubble Space Telescope showcases Arp 298, a stunning pair of interacting galaxies. Arp 298 — which comprises the two galaxies NGC 7469 and IC 5283 — lies roughly 200 million light-years from Earth in the constellation Pegasus. The larger of the two galaxies pictured here is the barred spiral galaxy NGC 7469, and IC 5283 is its diminutive companion. NGC 7469 is also host to an active, supermassive black hole and a bright ring of star clusters.

The “Arp” in this galaxy pair’s name signifies that they are listed in the Atlas of Peculiar Galaxies compiled by the astronomer Halton Arp. The Atlas of Peculiar Galaxies is a rogues’ gallery of weird and wonderful galaxies containing peculiar structures, featuring galaxies exhibiting everything from segmented spiral arms to concentric rings. This interacting galaxy pair is a familiar sight for Hubble — a portrait of the merging galaxies in Arp 298 was published in 2008.

This image of Arp 298 contains data from three separate Hubble proposals. By combining observations from three proposals, Arp 298 is captured in glorious detail in seven different filters from two of Hubble’s instruments — the Wide Field Camera 3 (WFC3) and the Advanced Camera for Surveys (ACS). ...

Image Credit: ESA/Hubble & NASA, A. Evans, R. Chandar

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This striking image from the NASA/ESA Hubble Space Telescope showcases Arp 298, a stunning pair of interacting galaxies. Arp 298 — which comprises the two galaxies NGC 7469 and IC 5283 — lies roughly 200 million light-years from Earth in the constellation Pegasus. The larger of the two galaxies pictured here is the barred spiral galaxy NGC 7469, and IC 5283 is its diminutive companion. NGC 7469 is also host to an active, supermassive black hole and a bright ring of star clusters.

The “Arp” in this galaxy pair’s name signifies that they are listed in the Atlas of Peculiar Galaxies compiled by the astronomer Halton Arp. The Atlas of Peculiar Galaxies is a rogues’ gallery of weird and wonderful galaxies containing peculiar structures, featuring galaxies exhibiting everything from segmented spiral arms to concentric rings. This interacting galaxy pair is a familiar sight for Hubble — a portrait of the merging galaxies in Arp 298 was published in 2008.

This image of Arp 298 contains data from three separate Hubble proposals. By combining observations from three proposals, Arp 298 is captured in glorious detail in seven different filters from two of Hubble’s instruments — the Wide Field Camera 3 (WFC3) and the Advanced Camera for Surveys (ACS). ...

Image Credit: G. Hüdepohl (atacamaphoto.com)/ESO

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The Sun rises behind Cerro Armazones in this image from 2016, with the sunlight marking the flat silhouette of the mountain top and Venus witnessing the beginning of a new day from just above the mountain itself.

The picture is a stunning example of crepuscular rays, occurring when objects such as clouds or mountains block part of the incoming sunlight, a phenomenon typical at sunrise and sunset when the Sun is low on the horizon or below it.

The top of Cerro Armazones was flattened to become home to the Extremely Large Telescope (ELT), ESO’s next flagship observatory currently under construction. With its main mirror 39 metres in diameter, the ELT will be the world’s largest eye on the Universe, able to collect 100 000 000 times more light than the human eye. It will help astronomers find new planets where life may have developed, shed light on the nature of stars and black holes and unveil some of the most intimate secrets of the Universe.

The picture was taken from Paranal, where ESO operates observatories such as the Very Large Telescope (VLT), the Visible and Infrared Survey Telescope for Astronomy (VISTA) and the VLT Survey Telescope (VST).

starsurfer wrote: ↑Sat Feb 19, 2022 11:11 pm NGC 1672
https://noirlab.edu/public/images/iotw2205a/
Copyright: Dark Energy Survey/DOE/FNAL/DECam/CTIO/NOIRLab/NSF/AURA
Processing: T.A. Rector (University of Alaska Anchorage/NSF’s NOIRLab), J. Miller (Gemini Observatory/NSF’s NOIRLab), M. Zamani & D. de Martin (NSF’s NOIRLab)
https://noirlab.edu/public/media/archiv ... w2205a.jpg

Image Credit: Rubin Observatory/NSF/AURA/B. Quint

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This image captures not only Vera C. Rubin Observatory, a Program of NSF’s NOIRLab, but one of the celestial specimens Rubin Observatory will observe when it comes online: the Milky Way. The bright halo of gas and stars on the left side of the image highlights the very center of the Milky Way galaxy. The dark path that cuts through this center is known as the Great Rift, because it gives the appearance that the Milky Way has been split in half, right through its center and along its radial arms. In fact, the Great Rift is caused by a shroud of dust, which blocks and scatters visible light. This dust makes the Great Rift a difficult space to observe. Fortunately, Rubin is being built to conduct the Legacy Survey of Space and Time (LSST). This survey will observe the entire visible southern sky every few nights over the course of a decade, capturing about 1000 images of the sky every night and giving us a new view of our evolving Universe. The LSST is set to probe four areas of science, one of which is mapping the Milky Way to answer questions about its structure and formation. Once Rubin Observatory comes online in 2024, scientists will be able to access the data taken every night of operation.

Rubin Observatory is a joint initiative of the National Science Foundation (NSF) and the Department of Energy (DOE). Once completed, Rubin will be operated jointly by NSF’s NOIRLab and DOE's SLAC National Accelerator Laboratory to carry out the Legacy Survey of Space and Time.