Found Images: 2019 February

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Have you seen a great image or video somewhere that you think would make a great APOD? Nominate it for APOD! Please post as much information here as you have about the image/video with a link to any source(s) for it you know of here, and the editors will take a look.

When posting the image itself, please do not post anything larger than a thumbnail here; please honor the copyright holder's copyright.

Please keep hotlinked images under 400K.

Thank you!

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Safe Havens for Young Planets
ESO Picture of the Week | 2019 Feb 04

Credit: ALMA (ESO/NAOJ/NRAO), S. Andrews et al.; NRAO/AUI/NSF, S. Dagnello

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This week’s Picture of the Week focuses on one of twenty protoplanetary discs explored and imaged by ALMA’s first Large Program, known as the Disk Substructures at High Angular Resolution Project (DSHARP). The disc is called AS 209, and its substructures are particularly pronounced thanks to its thin, high-contrast rings and almost face-on orientation towards us.

Though concentric rings — shown here in particularly beautiful clarity — are a common substructure among such discs, their widths, separations, and number can vary greatly. It’s still unclear how these substructures form, and how planets emerge from them. Quantifying and studying these similarities and differences was a motivator for constructing ALMA, and was the main objective of DSHARP. These details may hold clues to the type of planetary system that will eventually emerge.

One interpretation is that there may be a rapid and complex interplay between young protoplanets and the disc itself far earlier in the evolution of the planetary system than previously thought. A leading theory of planet formation requires dust within these discs to clump into grains, then pebbles, and eventually planetesimals. This theory has always been stumped, however, by the fact that once an object reaches a certain mass, the dynamics of these discs would cause it to be sucked into the host star at the centre, thus halting its growth into a true planet. The results from the DSHARP program suggest that disc substructures may perturb these dynamics and provide safe havens where young planetesimals can continue growing — making the substructures observed here crucial to our own existence.

Next week’s picture will be the final instalment in the DSHARP series, and will showcase another of the twenty images: this time a multiple star system.

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The Darkness Within?
ESA Hubble Picture of the Week | 2019 Feb 04

Image Credit: ESA/Hubble & NASA, R. O'Connell

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This atmospheric image shows a galaxy named Messier 85, captured in all its delicate, hazy glory by the NASA/ESA Hubble Space Telescope. Messier 85 slants through the constellation of Coma Berenices (Berenice’s Hair), and lies around 50 million light-years from Earth. It was first discovered by Charles Messier’s colleague Pierre Méchain in 1781, and is included in the Messier catalogue of celestial objects.

Messier 85 is intriguing — its properties lie somewhere between those of a lenticular and an elliptical galaxy, and it appears to be interacting with two of its neighbours: the beautiful spiral NGC 4394, located out of frame to the upper left, and the small elliptical MCG 3-32-38, located out of frame to the centre bottom.

The galaxy contains some 400 billion stars, most of which are very old. However, the central region hosts a population of relatively young stars of just a few billion years in age; these stars are thought to have formed in a late burst of star formation, likely triggered as Messier 85 merged with another galaxy over four billion years ago. Messier 85 has a further potentially strange quality. Almost every galaxy is thought to have a supermassive black hole at its centre, but from measurements of the velocities of stars in this galaxy, it is unclear whether Messier 85 contains such a black hole.

This image combines infrared, visible and ultraviolet observations from Hubble’s Wide Field Camera 3.

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NGC 918
http://www.distant-lights.at/ngc918-2018_10_11.htm
Copyright: Thomas Henne

Click to view full size image

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NGC 7070A
http://www.chart32.de/index.php/component/k2/item/247
Copyright: CHART32
Processing: Johannes Schedler

Click to view full size image

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vdB14-5 and Sh2-202
http://www.astrosurf.com/ilizaso/orriak ... Q_U16m.htm
Copyright: Iñaki Lizaso

The small nebula near the top is vdB11.

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Seagull Nebula (IC 2177)
http://www.pbase.com/strongmanmike2002/ ... ull_nebula
Copyright: Michael Sidonio

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WR 16 nebula
http://www.atacama-photographic-observa ... php?id=104
Copyright: Thierry Demange, Richard Galli and Thomas Petit

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Sh2-82
https://www.hansonastronomy.com/sharpless-82
Copyright: Mark Hanson

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Thor's Helmet Nebula (NGC 2359)
http://www.pbase.com/gailmarc/image/162574185
Copyright: Marcus Davies

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NGC 6752
http://www.cielaustral.com/galerie/photo89.htm
Copyright: Ciel Austral

Click to view full size image

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G110.3+11.3
http://www.capella-observatory.com/Imag ... R110_3.htm
Copyright: Stefan Binnewies, Frank Sackenheim and Josef Pöpsel

This supernova remnant is near vdB152.

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NGC 7538
http://www.cxielo.ch/gallery/v/nebulae/ ... x.jpg.html
Copyright: Martin Rusterholz

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Sh2-71
https://pbase.com/skybox/image/168762791
Copyright: Kevin Quin

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Worlds with Many Suns
ESO Picture of the Week | 2019 Feb 11

Credit: ALMA (ESO/NAOJ/NRAO), S. Andrews et al.; NRAO/AUI/NSF, S. Dagnello

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This week’s Picture of the Week highlights another of the 20 images to come out of ALMA’s first Large Program, the Disk Substructures at High Angular Resolution Project (DSHARP). DSHARP explored a number of nearby protoplanetary discs to learn more about the earliest stages of planet formation, and a staggering quantity of data from the project has just been released.

This object, called AS 205, is notable for being a multiple star system, one of two such systems imaged by DSHARP (the other being HT Lup). While two discs are discernible here, the lower right disc is in fact shared by two stars in a binary system, so we are actually looking at a system of three fledgling stars.

Although most high-resolution studies have so far focused on single stars, multiple systems are far from uncommon in the Universe. It is thought that over half of all stars may exist in multiple systems, an estimate that may be even higher for young stars. The presence of companion stars is likely to have complex implications for a disc and its substructures. This is due to as the gravitational influence of a stellar neighbour, which may distort and redistribute the material within the disc. Data from AS 205 and HT Lup indicate that stars and their neighbouring discs interact strongly.

Despite their unsettled birth environments, planets have been detected in multiple stellar systems — some orbiting just one of the stars, others orbiting the entire system. The latter are more likely to have stable orbits than the former, which get caught up in volatile interstellar dynamics.

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Adding to Uranus’s Legacy
ESA Hubble Picture of the Week | 2019 Feb 11

Credits: NASA, ESA, A. Simon (GSFC), and M.H. Wong and A. Hsu (UC Berkeley)

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One of the NASA/ESA Hubble Space Telescope’s many scientific objectives is to study the planets within the Solar System — and in past years, our system’s outer planets have been observed several times as part of Hubble’s Outer Planet Atmosphere Legacy (OPAL) programme.

This programme has given us this new image of the planet Uranus, the seventh planet in the Solar System in order of increasing distance from the Sun. Past observations of Uranus using Hubble have led to many interesting insights about the cold ice giant; in 2006 the telescope managed to capture a shot in which the moon Ariel and its accompanying shadow were traversing the face of Uranus (opo0642b), and in 2011 Hubble was able to spot faint auroras in its atmosphere (opo1221a).

Observations made over the course of several years also allowed astronomers to study the planet’s faint ring system as its inclination changed with respect to Earth’s orbit. This new image, taken with Hubble’s Wide Field Camera 3 (WFC3), adds to the legacy of images already taken and will provide scientists with even more new insights into our distant neighbour.

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FEST 1-109
http://www.astro-austral.cl/imagenes/ne ... 9/info.htm
Copyright: José Joaquin Pérez

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Abell 22
https://pbase.com/jshuder/image/168533725
Copyright: Jim Shuder

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Angel Nebula
http://bf-astro.com/dustAngel/dustAngel.htm
Copyright: Bob Franke

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NGC 2170
https://www.flickr.com/photos/andyinsea/25388442997/
Copyright: Andy Ermolli

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IC 448
http://afesan.es/Deepspace/slides/vdB%2 ... os%29.html
Copyright: Antonio Sánchez

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M14
http://www.astroimager.net/Page-AP160-CCD-416.html
Copyright: Jim Janusz

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NGC 7006
http://www.capella-observatory.com/Imag ... GC7006.htm
Copyright: Stefan Binnewies, Frank Sackenheim and Josef Pöpsel

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A Storm is Coming
ESA Hubble Picture of the Week | 2019 Feb 18

Credit: NASA, ESA, A.A. Simon (GSFC), and M.H. Wong and A.I. Hsu (UC Berkeley)

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Since Pluto’s demotion from fully-fledged planet to dwarf planet, Neptune holds the title of outermost planet in the Solar System. This new image of the planet was made during Hubble’s Outer Planet Atmosphere Legacy (OPAL) programme, under which it has observed the four outermost planets, including Neptune, on a yearly basis since 2014.

The observations of Neptune carried out in September and November 2018 show the first evidence of a huge storm brewing, with the discovery of a new northern Great Dark Spot (visible here to the upper left of the planet’s disc, partially overlapping a large patch of white). This new dark storm is of a similar size and shape to the storm discovered in 1989 by the Voyager 2 space probe.

While the future evolution of the storm will be tracked through the continued yearly Hubble observations and also by ground-based telescopes, older OPAL observations from Hubble show that its appearance was preceded by increased cloud activity throughout the region. There are hints of the storm forming in images from as early as 2015. This slow origin process indicates that the storm developed deep within Neptune's atmosphere, pulling up dark material from its depths, and only became visible once the top of it reached higher altitudes.

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Picturesque Poison
ESO Picture of the Week | 2019 Feb 18

Credit: ALMA (ESO/NAOJ/NRAO); M. Cordiner, NASA/CUA

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In December 2018, the comet 46P/Wirtanen passed within 11.6 million kilometres of the Earth — about 30 times the distance from the Earth to the Moon. This close pass gave astronomers the chance to observe the comet in detail, and ALMA (the Atacama Large Millimeter/submillimeter Array) took full advantage. ALMA’s speciality is observing the cooler components of the Universe, such as gas and dust, and the array often focuses on specific molecules. This image is no exception, as it highlights one key thing: the hydrogen cyanide gas in the coma around the comet’s nucleus.

But why would scientists be looking for an infamous poison? Well, it turns out that hydrogen cyanide is as common as mystery novels have led us to believe — throughout the cosmos, at least! Because it’s a simple organic molecule that forms relatively easily, it’s been observed in comets, stellar atmospheres, and the clouds of dust and gas that exist between stars. This image builds on those observations by showing clearly the hydrogen cyanide emanating from the nucleus of this comet. Further ALMA observations showed that other, more complex organic molecules were present, too.

This matters because, while it may be poisonous to many organisms on Earth today, hydrogen cyanide may have played an important role in getting life started on Earth. It’s very reactive, so it easily interacts with surrounding chemicals to create new molecules — including some of those essential for life, such as amino acids. One theory posits that hydrogen cyanide, brought here in part by comets, jump-started organic chemistry here on Earth, eventually leading to the beginning of life. ALMA’s imaging of 46P/Wirtanen further supports the idea that comets could have brought this life-giving material to the early Earth.

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