Sunset in Mordor: Don’t be fooled by the title; the mysterious, almost mystical bright light emerging from these thick, ominous clouds is actually a telltale sign of star formation. Here, a very young star is being born in the guts of the dark cloud LDN 43 — a massive blob of gas, dust, and ices, gathered 520 light-years from Earth in the constellation of Ophiuchus (The Serpent Bearer). Stars are born from cosmic dust and gas, which floats freely in space until gravity forces it to bind together. The hidden newborn star in this image, revealed only by light reflected onto the plumes of the dark cloud, is named RNO 91. It is what astronomers call a pre-main sequence star, meaning that it has not yet started burning hydrogen in its core. The energy that allows RNO 91 to shine comes from gravitational contraction. The star is being compressed by its own weight until, at some point, a critical mass will be reached and hydrogen, its main component, will begin to fuse together, releasing huge amounts of energy in the process. This will mark the beginning of adulthood for the star. But even before this happens the adolescent star is bright enough to shine and generate powerful stellar winds, emitting intense X-ray and radio emission. RNO 91 is a variable star around half the mass of the Sun. Astronomers have been able to observe the existence of a dusty, icy disc surrounding it, stretching out to over 1700 times the distance from Earth to the Sun. It is believed that this disc may host protoplanets — planets in the process of being formed — and will eventually evolve into a fully-fledged planetary system. This image is based on data gathered by the NASA/ESA Hubble Space Telescope. A version of this image was entered into the Hubble’s Hidden Treasures image processing competition by contestant Judy Schmidt.

Name: LDN 43, RNO 91
Type: Milky Way : Star : Evolutionary Stage : Young Stellar ObjectMilky Way : Nebula : Appearance : Dark
Category: Nebulae
Constellation: Ophiuchus
Distance: 500 light years
Release date: 5 August 2013, 10:00
Credit: ESA/Hubble & NASAAcknowledgement: Judy Schmidt

Stars fleeing a cosmic crash: Astronomical pictures sometimes deceive us with tricks of perspective. Right in the centre of this image, two spiral galaxies appear to be suffering a spectacular collision, with a host of stars appearing to flee the scene of the crash in a chaotic stampede. However, this is just a trick of perspective. It is true that two spiral galaxies are colliding, but they are millions of light-years away, far beyond the cloud of blue and red stars near the merging spiral. This sprinkling of stars is actually an isolated, irregular dwarf galaxy named ESO 489-056. The dwarf galaxy is actually much more distant than many bright stars in the foreground of the image, which are located much closer to us, in the Milky Way. ESO 489-056 is located 16 million light-years from Earth in the constellation of Canis Major (The Greater Dog), in our local Universe. It is composed of a few billion red and blue stars — a very small number when compared to galaxies like the Milky Way, which is estimated to contain around 200 to 400 billion stars, or the Andromeda Galaxy, which contains a mind-boggling one trillion. A version of this image was entered into the Hubble's Hidden Treasures image processing competition by contestant Luca Limatola.

Name: ESO 489-56
Type: Local Universe : Galaxy : Type : IrregularLocal Universe : Galaxy : Type : InteractingLocal Universe : Galaxy : Size : Dwarf
Category: Galaxies
Constellation: Canis Major
Distance: 15 million light years
Release date: 12 August 2013, 10:00
Credit: ESA/Hubble & NASA Acknowledgement: Luca Limatola

A cosmic optical illusion: At first glance, this Hubble picture appears to capture two space colossi entangled in a fierce celestial battle, with two galaxies entwined and merging to form one. But this shows just how easy it is to misinterpret the jumble of sparkling stars and get the wrong impression — as it’s all down to a trick of perspective. By chance, these galaxies appear to be aligned from our point of view. In the foreground, the irregular dwarf galaxy PGC 16389 — seen here as a cloud of stars — covers its neighbouring galaxy APMBGC 252+125-117, which appears edge-on as a streak. This wide-field image also captures many other more distant galaxies, including a quite prominent face-on spiral towards the right of the picture. A version of this image was entered into the Hubble’s Hidden Treasures image processing competition by contestant Luca Limatola.

Name: APMBGC 252+125-117, ESO 252-1, PGC 16389
Type: Early Universe : Galaxy
Category: Galaxies
Constellation: Caelum
Release date: 19 August 2013, 10:00
Credit: ESA/Hubble & NASAAcknowledgement: Luca Limatola

Dark, dusty shells: The NASA/ESA Hubble Space Telescope has captured this image of PGC 10922, an example of a lenticular galaxy — a galaxy type that lies on the border between ellipticals and spirals. Seen face-on, the image shows the disc and tightly-wound spiral structures of dark dust encircling the bright centre of the galaxy. There is also a remarkable outer halo of faint wide arcs or shells extending outwards, covering much of the picture. These are likely to have been formed by a gravitational encounter or even a merger with another galaxy. Some dust also appears to have escaped from the central structure and has spread out across the inner shells. An extraordinarily rich background of more remote galaxies can also be seen in the image. A version of this image was entered into the Hubble's Hidden Treasures image processing competition by contestant Judy Schmidt.

Name: PGC 10922
Type: Local Universe : Galaxy : Type : Lenticular
Category: Galaxies
Constellation: Octans
Distance: 200 million light years
Release date: 26 August 2013, 10:00
Credit: ESA/Hubble & NASA Acknowledgement: Judy Schmidt

A spiral in the Air Pump: Lying over 110 million light-years away from Earth in the constellation of Antlia (The Air Pump) is the spiral galaxy IC 2560, shown here in an image from NASA/ESA Hubble Space Telescope. At this distance it is a relatively nearby spiral galaxy, and is part of the Antlia cluster — a group of over 200 galaxies held together by gravity. This cluster is unusual; unlike most other galaxy clusters, it appears to have no dominant galaxy within it. In this image, it is easy to spot IC 2560's spiral arms and barred structure. This spiral is what astronomers call a Seyfert-2 galaxy, a kind of spiral galaxy characterised by an extremely bright nucleus and very strong emission lines from certain elements — hydrogen, helium, nitrogen, and oxygen. The bright centre of the galaxy is thought to be caused by the ejection of huge amounts of super-hot gas from the region around a central black hole. There is a story behind the naming of this quirky constellation — Antlia was originally named antlia pneumatica by French astronomer Abbé Nicolas Louis de Lacaille, in honour of the invention of the air pump in the 17th century. A version of this image was entered into the Hubble's Hidden Treasures image processing competition by contestant Nick Rose.

Name: IC 2560
Type: Local Universe : Galaxy : Type : SpiralLocal Universe : Galaxy : Activity : AGN : Seyfert
Category: Galaxies
Constellation: Antlia
Distance: 110 million light years
Release date: 2 September 2013, 10:00
Credit: ESA/Hubble & NASAAcknowledgement: Nick Rose