Starship Asterisk*

Image Credit: ESO/Petr Horálek

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This beautiful photograph of the southern sky was taken by ESO Photo Ambassador Petr Horálek from ESO’s Paranal Observatory in Chile. Petr was not alone at Paranal. Standing to the bottom left of the image, next to an Auxiliary Telescope of the Very Large Telescope Interferometer (VLTI), are astrophotographers Yuri Beletsky and Babak Tafreshi, both of whom are also Photo Ambassadors for ESO. The duo are seen beneath a sky filled with stunning phenomena.

The bright, dominant band of the Milky Way cuts across the sky, with the Gum Nebula (Gum 12) appearing at the top of the frame in red. The Large Magellanic Cloud, a satellite galaxy of the Milky Way, is an especially bright blotch to the centre right — just below Canopus, the brightest star in both this view and the southern constellation of Carina. A beautiful green and reddish shimmer is also visible at the bottom of the image, seemingly rising up from the horizon. This phenomenon is known as airglow and consists of faint light emitted by the Earth's atmosphere. Airglow prevents the night sky from being completely dark, and is explained in detail in ESOcast 78.

Image Credit: ESA/Hubble & NASA, J. Walsh

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A bright foreground star isn’t enough to distract from the grandeur of the galaxy UGC 3885, captured here by the NASA/ESA Hubble Space Telescope. While this foreground star is incredibly bright to Hubble’s eye, it does not outshine the details of the background galaxy.

Many young blue stars are sprinkled throughout the circular patterns of UGC 3885’s arms, contrasted and complemented by dark lanes of dust also following the spiral structure. A glancing look at UGC 3885 may only leave you with an impression of the galaxy, but spare a moment longer and the intricacies of the galaxy begin to emerge. Located in the constellation of Lynx, UGC 3885 is a cosmic beauty to behold.

bystander wrote: ↑Mon Feb 01, 2021 4:38 pm The Modest Galaxy
ESA Hubble Picture of the Week | 2021 Feb 01

Image Credit: ESA/Hubble & NASA, J. Walsh

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A bright foreground star isn’t enough to distract from the grandeur of the galaxy UGC 3885, captured here by the NASA/ESA Hubble Space Telescope. While this foreground star is incredibly bright to Hubble’s eye, it does not outshine the details of the background galaxy.

Many young blue stars are sprinkled throughout the circular patterns of UGC 3885’s arms, contrasted and complemented by dark lanes of dust also following the spiral structure. A glancing look at UGC 3885 may only leave you with an impression of the galaxy, but spare a moment longer and the intricacies of the galaxy begin to emerge. Located in the constellation of Lynx, UGC 3885 is a cosmic beauty to behold.

Image Credit: ESO/MUSE/TIMER Survey

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Discovered in the year 1836 by John Herschel, NGC 6902 is a beautiful spiral galaxy located more than 130 million light-years away in the constellation of Sagittarius, the Archer. This image was taken with MUSE, the Multi Unit Spectroscopic Explorer instrument attached to one of the four 8.2-metre telescopes that make up the VLT, and shows the galaxy from a unique perspective. A zoom in towards the galaxy’s centre, the image shows a nuclear ring where the orange glow of intense star formation is visible.

Inside this ring lies a faint and small bar of stars. Researchers found that stars within it are distributed differently depending on their age, with younger stars aligned along the bar and older stars more dispersed. These locations of the young and old stars within the central bar of NGC 6902 confirm predictions made years earlier from simulations and models. This is the first time these predictions of galactic structure were confirmed with observations thanks to the incredible spatial resolution of the MUSE instrument.

Image Credit: ESA/Hubble & NASA, L. Stanghellini

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This week’s NASA/ESA Hubble Space Telescope Picture of the Week features an impressive portrait of M1-63, a beautifully captured example of a bipolar planetary nebula located in the constellation of Scutum (the Shield). A nebula like this one is formed when the star at its centre sheds huge quantities of material from its outer layers, leaving behind a spectacular cloud of gas and dust.

It is believed that a binary system of stars at the centre of the bipolar nebula is capable of creating hourglass or butterfly-like shapes like the one in this image. This is because the material from the shedding star is funnelled towards its poles, with the help of the companion, creating the distinctive double-lobed structure seen in nebulae such as M1-63.

Image Credit: ESO/Petr Horálek

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It may not be as famous as Halley’s Comet, but Comet 252P/LINEAR can still put on a show! In late March 2016, the comet made one of the closest approaches to Earth of all comets in history — just over 5.3 million kilometres distant, compared to Halley’s closest approach of 87 million kilometres. The light of Comet 252P/LINEAR is not elongated in a classic tail, but instead appears as a soft round glow, tinged green due to molecules of diatomic carbon fluorescing in the sunlight. This image from April 2016 captures the distinctly green comet: you can spot it just above the Milky Way, between the galaxy’s starry arch and the Very Large Telescope (VLT) Unit Telescope at the centre of the frame.

ESO’s VLT is located at the Paranal Observatory in Chile, an ideal location for comet-spotting. Paranal is one of the most spectacular observatories in the world, situated in the seemingly infinite Atacama Desert under the dark skies of the southern hemisphere. Comets are not the only treasure visible in these skies: the Milky Way puts on its nightly spectacle, its rich interstellar clouds bejewelled with stars, the diverse colours of natural airglow shine near the horizon, and high above sit two planets. In this sweeping panorama, they form a slightly distorted triangle that includes the red supergiant star Antares, with the intense shine of Mars to the left and the whitish glow of the gas giant Saturn beneath.

Image Credit: ESA/Hubble & NASA, B. Nisini

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Herbig-Haro objects are some of the rarer sights in the night sky, taking the form of thin spindly jets of matter floating amongst the surrounding gas and stars. The two Herbig-Haro objects catalogued as HH46 and HH47, seen in this image taken with the NASA/ESA Hubble Space Telescope, were spotted in the constellation of Vela (The Sails), at a distance of over 1400 light-years from Earth. Prior to its discovery in 1977 by the American astronomer R. D. Schwartz, the exact mechanism by which these multi-coloured objects formed was unknown.

Before 1997 it was theorised by Schwartz and others that the objects could be a type of reflection nebula, or a type of shock wave formed from the gas emitted from a star interacting with the surrounding matter. The mystery was finally solved when a protostar, unseen in this image, was discovered at the centre of the long jets of matter. The outflows of matter, some 10 light-years across, were ejected from the newly born star and violently propelled outwards at speeds of over 150 kilometres per second. Upon reaching the surrounding gas, the collision created the bright shock waves seen here.