Starship Asterisk*

Image Credit: Petr Horálek/ESO

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This stunning long-exposure photograph by ESO Photo Ambassador Petr Horálek captures the hive of activity that is ESO’s La Silla Observatory, the distant glow of roads and settlements in the Chilean Atacama Desert, and the unmissable faint green radiance of airglow (produced by light in Earth’s upper atmosphere).

Flirting with the horizon, the mythical Seven Sisters of the Pleiades open star cluster can be seen dancing above distant mountain peaks. Directly above them, the dazzling constellation of Orion (The Hunter) dominates the view, as giant clouds and arcs of ionised gas — called emission nebulae, and seen here as red patches — encompass the imagined form of mythological hunter. The familiar sight of the Milky Way is also visible, carving its way across the night sky.

The La Silla Observatory is located in northern Chile at an altitude of 2400 metres. It enjoys some of the darkest night skies on Earth and has been an ESO stronghold since the 1960s. This spectacular shot was captured from the vantage point of ESO’s 3.6-metre telescope — one of the most productive four-metre-class telescopes in the world.

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

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This striking image was taken by the NASA/ESA Hubble Space Telescope’s Wide Field Camera 3 (WFC3), a powerful instrument installed on the telescope in 2009. WFC3 is responsible for many of Hubble’s most breathtaking and iconic photographs, including Pictures of the Week.

Shown here, NGC 7773 is a beautiful example of a barred spiral galaxy. A luminous bar-shaped structure cuts prominently through the galaxy's bright core, extending to the inner boundary of NGC 7773's sweeping, pinwheel-like spiral arms. Astronomers think that these bar structures emerge later in the lifetime of a galaxy, as star-forming material makes its way towards the galactic centre — younger spirals do not feature barred structures as often as older spirals do, suggesting that bars are a sign of galactic maturity. They are also thought to act as stellar nurseries, as they gleam brightly with copious numbers of youthful stars.

Our galaxy, the Milky Way, is thought to be a barred spiral like NGC 7773. By studying galactic specimens such as NGC 7773 throughout the Universe, researchers hope to learn more about the processes that have shaped — and continue to shape — our cosmic home.

Credit: ESA/Hubble & NASA, D. Crenshaw and O. Fox

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When massive stars die at the end of their short lives, they light up the cosmos with bright, explosive bursts of light and material known as supernovae. A supernova event is incredibly energetic and intensely luminous — so much so that it forms what looks like an especially bright new star that slowly fades away over time.

These exploding stars glow so incredibly brightly when they first form that they can be spotted from afar using telescopes such as the NASA/ESA Hubble Space Telescope. The subject of this image, a spiral galaxy named NGC 4051 — about 45 million light-years from Earth — has hosted multiple supernovae in past years. The first was spotted in 1983 (SN 1983I), the second in 2003 (SN 2003ie), and the most recent in 2010 (SN 2010br). These explosive events were seen scattered throughout the centre and spiral arms of NGC 4051.

The SN 1983I and SN 2010br were both categorised as supernovae of type Ic. This type of supernova is produced by the core collapse of a massive star that has lost its outer layer of hydrogen and helium, either via winds or by mass transfer to a companion. Because of this, type Ic — and also type Ib — supernovae are sometimes referred to as stripped core-collapse supernovae.

This galaxy’s beautiful spiral structure can be seen well in this image, along with other intriguing objects (including an emission-line galaxy known as SDSS J120312.35+443045.1, visible as the bright smudge to the lower middle of the image, beneath the sweeping arm of NGC 4051). NGC 4501 sits in the southern part of a cluster of galaxies known as the Ursa Major I Cluster; this cluster is especially rich in spirals such as NGC 4051, and is a subset of the larger Virgo Supercluster, which also houses the Milky Way.

starsurfer wrote: ↑Sat Jun 15, 2019 7:23 pm NGC 7793
https://www.eso.org/public/images/eso0914b/
Copyright: ESO

Click to view full size image

Ann wrote: ↑Sat Jun 15, 2019 8:10 pm

starsurfer wrote: ↑Sat Jun 15, 2019 7:23 pm NGC 7793
https://www.eso.org/public/images/eso0914b/
Copyright: ESO

Click to view full size image

Click to view full size image

M33. Image Credit & Copyright: Robert Gendler, Subaru Telescope (NAOJ)
Image data: Subaru Telescope, Robert Gendler, Brigham Young University Obs.,
Johannes Schedler

When I first saw that picture of NGC 7793, my first thought was, Oh, that's another picture of M33.

Sure there are differences, but sure there are similarities too, aren't there?

Ann