Starship Asterisk*

[img3="Credit: ESA/Hubble & NASA"]https://www.spacetelescope.org/static/a ... w1625a.jpg[/img3][hr][/hr]

This NASA/ESA Hubble Space Telescope image shows the globular cluster NGC 1854, a gathering of white and blue stars in the southern constellation of Dorado (The Dolphinfish). NGC 1854 is located about 135 000 light-years away, in the Large Magellanic Cloud (LMC), one of our closest cosmic neighbours and a satellite galaxy of the Milky Way.

The LMC is a hotbed of vigorous star formation. Rich in interstellar gas and dust, the galaxy is home to approximately 60 globular clusters and 700 open clusters. These clusters are frequently the subject of astronomical research, as the Large Magellanic Cloud and its little sister, the Small Magellanic Cloud, are the only systems known to contain clusters at all stages of evolution. Hubble is often used to study these clusters as its extremely high-resolution cameras can resolve individual stars, even at the clusters’ crowded cores, revealing their mass, size and degree of evolution.

[img3="Credit: ESO/A. Boccaletti, C. Perrot, et al"]https://cdn.eso.org/images/screen/potw1625a.jpg[/img3][hr][/hr]

This Picture of the Week illustrates the remarkable capabilities of SPHERE (the Spectro-Polarimetric High-contrast Exoplanet REsearch instrument), a planet-hunting instrument mounted on ESO’s Very Large Telescope (VLT) in Chile: It shows a series of broken rings of dust around a nearby star. These concentric rings are located in the inner region of the debris disc surrounding a young star named HD 141569A, which sits some 370 light-years away from us.

In this image we see what is known as a transition disc, a short-lived stage between the protoplanetary phase, when planets have not yet formed, and a later time when planets have coalesced, leaving the disc populated only by any remaining — and predominantly dusty — debris.

What we see here are structures formed of dust, revealed for the first time in near-infrared light by SPHERE — at a high enough resolution to capture remarkable detail! The area shown in this image has a diameter of just 200 times the Earth–Sun distance.

Several features are visible, including a bright, prominent ring with well-defined edges — so asymmetric that it appears as a half-ring — multiple clumps, several concentric ringlets, and a pattern akin to a spiral arm. It is significant that these structures are asymmetric; this may reflect an uneven, or clumpy, distribution of dust in the disc, something for which astronomers do not currently have a firm explanation. It is possible that this phenomenon is caused by the presence of planets, but so far no planets of sufficient size to do this have been found in this system.

• Astronomy & Astrophysics 590:L7 (2016 June) DOI: 10.1051/0004-6361/201628396
  arXiv.org > astro-ph > arXiv:1605.00468 > 02 May 2016

[c][attachment=0]potw1626a[1].jpg[/attachment][/c][hr][/hr]

This image transports you to the most advanced visible-light astronomical observatory in the world: the Very Large Telescope (VLT), located at ESO’s Paranal Observatory in Chile. The shadowy figure gazing at the dark skies is photographer Babak Tafreshi, as captured by his fellow ESO Photo Ambassador Petr Horálek.

For a moment, place yourself in Babak’s — or indeed Petr’s — shoes. Here, you are king of the cosmos. The site is silent, dark, still. You stare up at the pristine Chilean night sky, which, with its extremely low levels of both light pollution and water vapour, offers spectacular nighttime scenery to delight any astrophotographer or stargazer. With your trusty camera on hand, a night of amazing photo opportunities lies ahead; you anticipate spending clear hour after clear hour documenting the heavens, with no fear of cloudy weather appearing, uninvited, to spoil the view.

The Large Magellanic Cloud is visible at the centre of the frame, while Canopus, the brightest star in the constellation Carina (The Keel), watches over the starry scene to the upper right. ...

[img3="Credit: ESA/Hubble & NASA, Aloisi, Ford
Acknowledgement: Judy Schmidt"]https://cdn.spacetelescope.org/archives ... w1626a.jpg[/img3][hr][/hr]

This NASA/ESA Hubble Space Telescope image reveals the iridescent interior of one of the most active galaxies in our local neighbourhood — NGC 1569, a small galaxy located about eleven million light-years away in the constellation of Camelopardalis (The Giraffe).

This galaxy is currently a hotbed of vigorous star formation. NGC 1569 is a starburst galaxy, meaning that — as the name suggests — it is bursting at the seams with stars, and is currently producing them at a rate far higher than that observed in most other galaxies. For almost 100 million years, NGC 1569 has pumped out stars over 100 times faster than the Milky Way!

As a result, this glittering galaxy is home to super star clusters, three of which are visible in this image — one of the two bright clusters is actually the superposition of two massive clusters. Each containing more than a million stars, these brilliant blue clusters reside within a large cavity of gas carved out by multiple supernovae, the energetic remnants of massive stars.

In 2008, Hubble observed the galaxy's cluttered core and sparsely populated outer fringes. By pinpointing individual red giant stars, Hubble’s Advanced Camera for Surveys enabled astronomers to calculate a new — and much more precise — estimate for NGC 1569’s distance. This revealed that the galaxy is actually one and a half times further away than previously thought, and a member of the IC 342 galaxy group.

Astronomers suspect that the IC 342 cosmic congregation is responsible for the star-forming frenzy observed in NGC 1569. Gravitational interactions between this galactic group are believed to be compressing the gas within NGC 1569. As it is compressed, the gas collapses, heats up and forms new stars.

[c][imghover=http://photojournal.jpl.nasa.gov/jpeg/PIA20701.jpg]http://photojournal.jpl.nasa.gov/figure ... 1_fig1.jpg[/imghover]Image Credit: NASA/JPL-Caltech/SwRI/MSSS

http://www.nasa.gov/juno
http://missionjuno.swri.edu/[/c][hr][/hr]

NASA's Juno spacecraft obtained this color view on June 21, 2016, at a distance of 6.8 million miles (10.9 million kilometers) from Jupiter.

As Juno makes its initial approach, the giant planet's four largest moons -- Io, Europa, Ganymede and Callisto -- are visible, and the alternating light and dark bands of the planet's clouds are just beginning to come into view.

Juno is approaching over Jupiter's north pole, affording the spacecraft a unique perspective on the Jupiter system. Previous missions that imaged Jupiter on approach saw the system from much lower latitudes, closer to the planet's equator.

The scene was captured by the mission's imaging camera, called JunoCam, which is designed to acquire high resolution views of features in Jupiter's atmosphere from very close to the planet.

bystander wrote:Juno on Jupiter's Doorstep
NASA | JPL-Caltech | SwRI | MSSS | 2016 June 24

[c][imghover=http://photojournal.jpl.nasa.gov/jpeg/PIA20701.jpg]http://photojournal.jpl.nasa.gov/figure ... 1_fig1.jpg[/imghover]Image Credit: NASA/JPL-Caltech/SwRI/MSSS

http://www.nasa.gov/juno
http://missionjuno.swri.edu/[/c][hr][/hr]

NASA's Juno spacecraft obtained this color view on June 21, 2016, at a distance of 6.8 million miles (10.9 million kilometers) from Jupiter.

As Juno makes its initial approach, the giant planet's four largest moons -- Io, Europa, Ganymede and Callisto -- are visible, and the alternating light and dark bands of the planet's clouds are just beginning to come into view.

Juno is approaching over Jupiter's north pole, affording the spacecraft a unique perspective on the Jupiter system. Previous missions that imaged Jupiter on approach saw the system from much lower latitudes, closer to the planet's equator.

The scene was captured by the mission's imaging camera, called JunoCam, which is designed to acquire high resolution views of features in Jupiter's atmosphere from very close to the planet.