Starship Asterisk*

Image Credit: ESO/Gerhard Hüdepohl

---

In a remote part of Chile’s Atacama Desert, at an altitude of over 2600 metres, sits Paranal Observatory. In terms of total light-collecting area, it is the largest observatory in the southern hemisphere, and is home to several of ESO’s cutting-edge telescopes. The main peak, visible here directly beneath the eerily tranquil yellow Moon, hosts ESO’s Very Large Telescope (VLT) and the 2.6-metre VLT Survey Telescope (VST). The VLT’s four Unit Telescopes can be seen on top of this peak, next to the smaller Auxiliary Telescopes on the far left and the VST towards the right.

As ESO continues to expand its array of telescopes in the southern hemisphere, more space is required for construction! A secondary peak around 1500 metres away from the VLT and VST — on the far right on this image — was chosen as the site for ESO’s Visible and Infrared Survey Telescope for Astronomy (VISTA). VISTA began observing in late 2009 and has returned some stunning images of the Universe at near-infrared wavelengths. By far the largest telescope in the world currently studying this kind of light, VISTA is able to obtain some truly unique images of the cosmos that would be invisible to most other telescopes.

Credit: ESA/Hubble & NASA, D. Rosario (CEA, Durham)

---

This image from the NASA/ESA Hubble Space Telescope shows IC 4653, a galaxy just above 80 million light-years from Earth. That may sound like quite a distance, but it’s not that far on a cosmic scale. At these kinds of distances, the types and structures of the objects we see are similar to those in our local area.

Thie galaxy's whirling arms tells us a story about what’s happening inside this galaxy. Stars are generally brighter and bluer when they are younger, so the blue patches mark sites of new star formation. Studying the structures of other galaxies is a key way to learn about the structure of our own, given that humans can’t leave the Milky Way to look back and see what it looks like from the outside. It helps to compare our observations of our home galaxy with those of nearby galaxies we can see in their entirety.

Susanna Kohler wrote:

---

This illustration shows some of the molecules that have been discovered in the hazy atmosphere of Saturn’s largest moon, Titan. Though nearly 98% of Titan’s stratosphere is molecular nitrogen, there’s just enough methane — CH₄ — for some interesting chemistry to happen when ultraviolet light is thrown into the mix. After this light breaks apart the methane molecules, complex hydrocarbons can form as these newly freed fragments link together in chains. A team of scientists led by Nicholas Lombardo (U. of Maryland, NASA Goddard SFC, Yale U.) has now made the first unambiguous detection on Titan of a hydrocarbon known as propadiene (C₂CCH₂; also called allene). This colorless, flammable gas had, before now, never been detected beyond Earth. Scientists believe that Titan’s atmosphere may resemble Earth’s primordial atmosphere, so understanding its component molecules is an important step to learn more about how our own planet evolved. To read more, check out the original article below.

• Astrophysical Journal Letters 881(2):L33 (2019 Aug 20) DOI: 10.3847/2041-8213/ab3860
• arXiv.org > astro-ph > arXiv:1908.07424 > 20 Aug 2019

Credit: ESO

---

This strikingly simple and serene view of NGC 1404 — a giant elliptical galaxy located 62 million light-years away in the constellation of Fornax (The Furnace) — hides the galaxy’s cruel reality.

NGC 1404 is one of the galaxies comprising the massive Fornax Cluster — and it is slowly falling inwards towards the cluster’s core. As it moves towards the cluster’s large centremost galaxy, NGC 1399, the galaxy’s reserves of hot gas are being forcibly ripped and stripped away, leaving an elongated tell-tale trail of gas in its wake. While not visible in this image, this gas stream can be seen clearly in X-ray images of the galaxy; in time, NGC 1404 will lose most of its hot gas, and therefore its ability to form new stars.

ESO’s Very Large Telescope (VLT) captured this image of NGC 1404 with its FORS instrument. The bright foreground star to the lower left of the frame is named HD 22862.

Image Credit: ESA/Hubble & NASA, A. Bellini et al

---

Galaxies may seem lonely, floating alone in the vast, inky blackness of the sparsely populated cosmos — but looks can be deceiving. The subject of this Picture of the Week, NGC 1706, is a good example of this. NGC 1706 is a spiral galaxy, about 230 million light-years away, in the constellation of Dorado (The Swordfish).

NGC 1706 is known to belong to something known as a galaxy group, which is just as the name suggests — a group of up to 50 galaxies which are gravitationally bound and hence relatively close to each other. Around half of the galaxies we know of in the Universe belong to some kind of group, making them incredibly common cosmic structures. Our home galaxy, the Milky Way, belongs to the Local Group, which also contains the Andromeda Galaxy, the Large and Small Magellanic Clouds, and the Triangulum Galaxy.

Groups are the smallest of galactic gatherings; others are clusters, which can comprise hundreds of thousands of galaxies bound loosely together by gravity, and subsequent superclusters, which bring together numerous clusters into a single entity.

starsurfer wrote: ↑Sun Oct 27, 2019 2:05 pm IC 4710
https://www.spacetelescope.org/images/potw1809a/
Copyright: ESA/Hubble & NASA
Acknowledgement: Judy Schmidt
potw1809a.jpg

bystander wrote: ↑Mon Oct 28, 2019 3:05 pm Lonely Hearts Club
ESA Hubble Picture of the Week | 2019 Oct 28

Image Credit: ESA/Hubble & NASA, A. Bellini et al

---

Galaxies may seem lonely, floating alone in the vast, inky blackness of the sparsely populated cosmos — but looks can be deceiving. The subject of this Picture of the Week, NGC 1706, is a good example of this. NGC 1706 is a spiral galaxy, about 230 million light-years away, in the constellation of Dorado (The Swordfish).

NGC 1706 is known to belong to something known as a galaxy group, which is just as the name suggests — a group of up to 50 galaxies which are gravitationally bound and hence relatively close to each other. Around half of the galaxies we know of in the Universe belong to some kind of group, making them incredibly common cosmic structures. Our home galaxy, the Milky Way, belongs to the Local Group, which also contains the Andromeda Galaxy, the Large and Small Magellanic Clouds, and the Triangulum Galaxy.

Groups are the smallest of galactic gatherings; others are clusters, which can comprise hundreds of thousands of galaxies bound loosely together by gravity, and subsequent superclusters, which bring together numerous clusters into a single entity.