Starship Asterisk*

[img3="Credit: Adhemar Duro/ESO"]https://cdn.eso.org/images/screen/potw1727a.jpg[/img3][hr][/hr]

This picture was taken at the northern tip of the Salar de Atacama — the largest salt flat in Chile. The flat is close to the town of San Pedro de Atacama, a town in northern Chile very popular among Chilean tourists and international visitors. The salt flat is home to two similar freshwater lagoons that lie very close together: the Ojos de Salar, which translates to “Eyes of the Salt Pan”.

During the day, the site is visited by tourists, who stop by on their excursions from San Pedro de Atacama. Here, one of the two water-filled holes in the middle of the arid landscape is shown at dusk, when the site is again peaceful and quiet. The eye of water perfectly reflects the view of the sky as it changes from day to night. While the clouds on the right horizon are still been dipped in orange by the setting Sun, the sky on the left already shows some stars.

The site is not far from the Chajnantor Plateau. This high plateau, 5000 metres above sea level, hosts the Atacama Large Millimeter / submillimeter Array (ALMA) — an observatory of revolutionary design, composed of 66 high-precision antennas. The Atacama Desert is the perfect location for ALMA, as low humidity and high altitude combine to give ideal conditions for astronomical observation.

This image was taken by ESO Photo Ambassador, Adhemar Duro.

[img3="Credit: ESA/Hubble & NASA"]https://cdn.spacetelescope.org/archives ... w1727a.jpg[/img3][hr][/hr]

IC 342 is a challenging cosmic target. Although it is bright, the galaxy sits near the equator of the Milky Way’s galactic disc, where the sky is thick with glowing cosmic gas, bright stars, and dark, obscuring dust. In order for astronomers to see the intricate spiral structure of IC 342, they must gaze through a large amount of material contained within our own galaxy — no mean feat! As a result IC 342 is relatively difficult to spot and image, giving rise to its intriguing nickname: the “Hidden Galaxy”.

Located very close (in astronomical terms!) to the Milky Way, this sweeping spiral galaxy would be among the brightest in the sky were it not for its dust-obscured location. The galaxy is very active, as indicated by the range of colours visible in this NASA/ESA Hubble Space Telescope image, depicting the very central region of the galaxy. A beautiful mixture of hot, blue star-forming regions, redder, cooler regions of gas, and dark lanes of opaque dust can be seen, all swirling together around a bright core. In 2003, astronomers confirmed this core to be a specific type of central region known as an HII nucleus — a name that indicates the presence of ionised hydrogen — that is likely to be creating many hot new stars.

Ann wrote: I searched for previous pictures that might show (or at least hint) that something interesting is going on in the center of IC 342. This 500 KB picture, by foldtime, was the best I could find.

Ann wrote:Thanks, bystander, that's really fascinating!

I searched for previous pictures that might show (or at least hint) that something interesting is going on in the center of IC 342. This 500 KB picture, by foldtime, was the best I could find.

Ann

[img3="Image Credit: Yuri Beletsky (LCO)/ESO"]https://cdn.eso.org/images/screen/potw1728a.jpg[/img3][hr][/hr]

In this scene, one of the most recognisable constellations in the night sky — Orion (The Hunter), with his famous belt and sword — rises over the slumbering Swedish-ESO Submillimetre Telescope (SEST) at ESO’s La Silla Observatory in Chile.

This mythical collection of stars sits on the celestial equator, making it visible in both hemispheres. Within Orion itself, the distinctive blue and pink hues of the Orion Nebula are visible just above the stellar trio comprising Orion’s Belt. Hundreds of new stars are being forged in the depths of this stellar nursery. Telescopes have observed numerous stars wrapped in cocoons of gas and dust — shrouds that will transform into protoplanetary discs as the turbulent youngsters mature.

This image also captures the noticeably reddish colours of Betelgeuse and Aldebaran — giant stars that belong to the constellations of Orion and Taurus (The Bull) respectively. These stars can be seen to the left of the telescope dish, tracing a curved line down towards the ground. Just before meeting the horizon, this line crosses a fuzzy collection of stars — the Pleiades star cluster. According to classical mythology, Orion was a hunter who chased after the Pleiades, the beautiful daughters of Atlas, in order to find love.

[img3="Image Credit: ESA/Hubble & NASA"]https://cdn.spacetelescope.org/archives ... w1728a.jpg[/img3][hr][/hr]

Discovered by British astronomer William Herschel over 200 years ago, NGC 2500 lies about 30 million light-years away in the northern constellation of Lynx (The Lynx). As this NASA/ESA Hubble Space Telescope image shows, NGC 2500 is a particular kind of spiral galaxy known as a barred spiral, its wispy arms swirling out from a bright, elongated core.

Barred spirals are actually more common than was once thought. Around two-thirds of all spiral galaxies — including the Milky Way — exhibit these straight bars cutting through their centres. These cosmic structures act as glowing nurseries for newborn stars, and funnel material towards the active core of a galaxy. NGC 2500 is still actively forming new stars, although this process appears to be occurring very unevenly. The upper half of the galaxy — where the spiral arms are slightly better defined — hosts many more star-forming regions than the lower half, as indicated by the bright, dotted islands of light.

There is another similarity between NGC 2500 and our home galaxy. Together with Andromeda, Triangulum, and many smaller natural satellites, the Milky Way is part of the Local Group of galaxies, a gathering of over 50 galaxies all loosely held together by gravity. NGC 2500 forms a similar group with some of its nearby neighbours, including NGC 2541, NGC 2552, NGC 2537, and the bright, Andromeda-like spiral NGC 2481 (known collectively as the NGC 2841 group).

bystander wrote:Just Like Home
ESA Hubble Picture of the Week | 2017 Jul 10

[img3="Image Credit: ESA/Hubble & NASA"]https://cdn.spacetelescope.org/archives ... w1728a.jpg[/img3][hr][/hr]

Discovered by British astronomer William Herschel over 200 years ago, NGC 2500 lies about 30 million light-years away in the northern constellation of Lynx (The Lynx). As this NASA/ESA Hubble Space Telescope image shows, NGC 2500 is a particular kind of spiral galaxy known as a barred spiral, its wispy arms swirling out from a bright, elongated core.

Barred spirals are actually more common than was once thought. Around two-thirds of all spiral galaxies — including the Milky Way — exhibit these straight bars cutting through their centres. These cosmic structures act as glowing nurseries for newborn stars, and funnel material towards the active core of a galaxy. NGC 2500 is still actively forming new stars, although this process appears to be occurring very unevenly. The upper half of the galaxy — where the spiral arms are slightly better defined — hosts many more star-forming regions than the lower half, as indicated by the bright, dotted islands of light.

There is another similarity between NGC 2500 and our home galaxy. Together with Andromeda, Triangulum, and many smaller natural satellites, the Milky Way is part of the Local Group of galaxies, a gathering of over 50 galaxies all loosely held together by gravity. NGC 2500 forms a similar group with some of its nearby neighbours, including NGC 2541, NGC 2552, NGC 2537, and the bright, Andromeda-like spiral NGC 2481 (known collectively as the NGC 2841 group).