Category Archives: Space Telescope

Hershel Looks at Orion


Click the image for the annotated version.

Credit: ESA/NASA/JPL-Caltech

The original caption:

The dusty side of the Sword of Orion is illuminated in this striking infrared image from the European Space Agency’s Hershel Space Observatory.

This immense nebula is the closest large region of star formation, situated about 1,500 light years away in the constellation of Orion. The parts that are easily observed in visible light, known alternatively as the Orion Nebula or Messier 42, correspond to the light blue regions. This is the glow from the warmest dust, illuminated by clusters of hot stars that have only recently been born in this chaotic region.

The red spine of material running from corner to corner reveals colder, denser filaments of dust and gas that are scattered throughout the Orion nebula. In visible light this would be a dark, opaque feature, hiding the reservoir of material from which stars have recently formed and will continue to form in the future.

Herschel data from the PACS instrument observations, at wavelengths of 100 and 160 microns, is displayed in blue and green, respectively, while SPIRE 250-micron data is shown in red.

Within the inset image, the emission from ionized carbon atoms (C+), overlaid in yellow, was isolated and mapped out from spectrographic data obtained by the HIFI instrument. A version without the inset is also available.

Herschel is a European Space Agency mission, with science instruments provided by consortia of European institutes and with important participation by NASA. While the observatory stopped making science observations in April 2013, after running out of liquid coolant as expected, scientists continue to analyze its data. NASA’s Herschel Project Office is based at JPL. JPL contributed mission-enabling technology for two of Herschel’s three science instruments. The NASA Herschel Science Center, part of IPAC, supports the U.S. astronomical community. Caltech manages JPL for NASA.

A Planetary Nebula?


This doesn’t look like a typical planetary nebula it is.

From ESA:
The two spiral arms winding towards the bright centre might deceive you into thinking you are looking at a galaxy a bit like our Milky Way. But the object starring in this image is of a different nature: PK 329-02.2 is a ‘planetary nebula’ within our home galaxy.

Despite the name, this isn’t a planet either. Planetary nebula is a misnomer that came about because of how much nebulas resembled giant, gaseous planets when looked through a telescope in the 1700s. Rather, what we see in this image is the last breath of a dying star.

When stars like the Sun are nearing the end of their lives, they let go of their gaseous outermost layers. As these clouds of stellar material move away from the central star they can acquire irregular and complex shapes. This complexity is evident in the faint scattered gas you see at the centre of the image. But there is also beautiful symmetry in PK 329-02.2, as the two bright blue spiral arms perfectly align with the two stars at the centre of the nebula.

It may look like the spiral arms are connected, but it is the stars that are companions. They are part of a visual binary, though only the one at the upper right gave rise to the nebula. While the stars will continue to orbit each other for millions or billions of years, the nebula – and its spiral arms – will spread out from the centre and eventually fade away over the next few thousands of years.

This planetary nebula with spiral arms is also known as Menzel 2, after the US astronomer Donald Menzel who discovered it in the 1920s. It is located in Norma, a constellation in the Southern celestial hemisphere where you can also find Menzel 1 and 3, two ‘bipolar planetary nebulas’ (shaped like butterflies or hourglasses).

Hubble’s Wide Field and Planetary Camera 2 captured this image, which was processed using green, blue, red and infrared filters. Astrophotography-enthusiast Serge Meunier entered a version of this image into the 2012 Hubble’s Hidden Treasures image processing competition.

Copyright ESA/Hubble & NASA; Acknowledgement: Serge Meunier

Hubble and PGC 83677


Oh my just look at this!

Hubble took this image of the lenticular galaxy PGC 83677 and it is just magnificent. We can see many other galaxies which are mere hazy spots at best in most of the images I’ve seen of the area.

The original caption:
A lone source shines out brightly from the dark expanse of deep space, glowing softly against a picturesque backdrop of distant stars and colorful galaxies.

Captured by the NASA/ESA Hubble Space Telescope’s Advanced Camera for Surveys (ACS), this scene shows PGC 83677, a lenticular galaxy — a galaxy type that sits between the more familiar elliptical and spiral varieties.

It reveals both the relatively calm outskirts and intriguing core of PGC 83677. Here, studies have uncovered signs of a monstrous black hole that is spewing out high-energy X-rays and ultraviolet light.

Text credit: ESA – Image: NASA/ESA/Hubble; acknowledgements: Judy Schmidt (Geckzilla)

Gaia’s First Map


The Gaia spacecraft gives us this view of our Milky Way. This map will improve in terms of artifact as Gaia makes more observations. Gaia will survey more than a BILLION stars by the time the mission ends. Gaia can determine stellar position so accurately it is estimated the spacecraft may find as many as 50,000 new planets by measuring the stellar wobble caused by an orbiting planet.

Copyright ESA/Gaia/DPAC

From ESA:
An all-sky view of stars in our Galaxy – the Milky Way – and neighbouring galaxies, based on the first year of observations from ESA’s Gaia satellite, from July 2014 to September 2015.

This map shows the density of stars observed by Gaia in each portion of the sky. Brighter regions indicate denser concentrations of stars, while darker regions correspond to patches of the sky where fewer stars are observed.

The Milky Way is a spiral galaxy, with most of its stars residing in a disc about 100 000 light-years across and about 1000 light-years thick. This structure is visible in the sky as the Galactic Plane – the brightest portion of this image –which runs horizontally and is especially bright at the centre.

Darker regions across the Galactic Plane correspond to dense clouds of interstellar gas and dust that absorb starlight along the line of sight.

Many globular and open clusters – groupings of stars held together by their mutual gravity – are also sprinkled across the image.

Globular clusters, large assemblies of hundreds of thousands to millions of old stars, are mainly found in the halo of the Milky Way, a roughly spherical structure with a radius of about 100 000 light-years, and so are visible across the image.

Open clusters are smaller assemblies of hundreds to thousands of stars and are found mainly in the Galactic Plane.

The two bright objects in the lower right of the image are the Large and Small Magellanic Clouds, two dwarf galaxies orbiting the Milky Way. Other nearby galaxies are also visible, most notably Andromeda (also known as M31), the largest galactic neighbour to the Milky Way, in the lower left of the image. Below Andromeda is its satellite, the Triangulum galaxy (M33).

A number of artefacts are also visible on the image. These curved features and darker stripes are not of astronomical origin but rather reflect Gaia’s scanning procedure. As this map is based on observations performed during the mission’s first year, the survey is not yet uniform across the sky.

These artefacts will gradually disappear as more data are gathered during the five-year mission.

High resolution versions of the Gaia map, with transparent background, are available to download from:

Acknowledgement: A. Moitinho & M. Barros (CENTRA – University of Lisbon), on behalf of DPAC

Hubble’s Fireball


WOW! Thanks to ESA/Hubble & NASA Acknowledgement: J. Schmidt ( for this image.

A higher resolution version is available from ESA.  Links go off-site so you will have to back track.

From the ESA press release (linked above):
This dramatic burst of colour shows a cosmic object with an equally dramatic history. Enveloped within striking, billowing clouds of gas and dust that form a nebula known as M1-67, sits a bright star named Hen 2-427 (otherwise known as WR 124).

This star is just as intense as the scene unfolding around it. It is a Wolf-Rayet star, a rare type of star known to have very high surface temperatures – well over 25000ºC, next to the Sun’s comparatively cool 5500ºC – and enormous mass, which ranges over 5–20 times our Sun’s. Such stars are constantly losing vast amounts of mass via thick winds that continuously pour from their surfaces out into space.

Hen 2-427 is responsible for creating the entire scene shown here, which has been captured in beautiful detail by the NASA/ESA Hubble Space Telescope. The star, thought to be a massive one in the later stages of its evolution, blasted the material comprising M1-67 out into space some 10 millennia ago – perhaps in multiple outbursts – to form an expanding ring of ejecta.

Since then, the star has continued to flood the nebula with massive clumps of gas and intense ionising radiation via its fierce stellar winds, shaping and sculpting its evolution. M1-67 is roughly ring-shaped but lacks a clear structure – it is essentially a collection of large, massive, superheated knots of gas all clustered around a central star.

Hen 2-427 and M1-67 lie 15 000 light-years away in the constellation of Sagitta (The Arrow). This image uses visible-light data gathered by Hubble’s Wide Field Planetary Camera 2, and was released in 2015 (the same data were previously processed and released in 1998).

A Long Dead Star


The original caption:
This NASA/ESA Hubble Space Telescope image captures the remnants of a long-dead star. These rippling wisps of ionised gas, named DEM L316A, are located some 160 000 light-years away within one of the Milky Way’s closest galactic neighbours — the Large Magellanic Cloud (LMC).

The explosion that formed DEM L316A was an example of an especially energetic and bright variety of supernova, known as a Type Ia. Such supernova events are thought to occur when a white dwarf star steals more material than it can handle from a nearby companion, and becomes unbalanced. The result is a spectacular release of energy in the form of a bright, violent explosion, which ejects the star’s outer layers into the surrounding space at immense speeds. As this expelled gas travels through the interstellar material, it heats it up and ionise it, producing the faint glow that Hubble’s Wide Field Camera 3 has captured here.

The LMC orbits the Milky Way as a satellite galaxy and is the fourth largest in our group of galaxies, the Local Group. DEM L316A is not alone in the LMC; Hubble came across another one in 2010 with SNR 0509 (heic1018), and in 2013 it snapped SNR 0519 (potw1317a).

Copyright ESA/Hubble & NASA, Y. Chu

The Heart of the Crab


This image is a composite of separate exposures acquired by the ACS/WFC instrument using several filters. Coloration results from assigning different hues (colors) to the grayscale image associated with an individual filter.The assigned colors represent not only changes in different filters, but also the same filters taken on different exposure dates to highlight features that change over time.

Credit: ESA / NASA Acknowledgment: J. Hester (ASU) and M. Weisskopf (NASA/GSFC)

From Hubblesite:
At the center of the Crab Nebula, located in the constellation Taurus, lies a celestial “beating heart” that is an example of extreme physics in space. The tiny object blasts out blistering pulses of radiation 30 times a second with unbelievable clock-like precision. Astronomers soon figured out that it was the crushed core of an exploded star, called a neutron star, which wildly spins like a blender on puree. The burned-out stellar core can do this without flying apart because it is 10 billion times stronger than steel. This incredible density means that the mass of 1.4 suns has been crushed into a solid ball of neutrons no bigger than the width of a large city. This Hubble image captures the region around the neutron star. It is unleashing copious amounts of energy that are pushing on the expanding cloud of debris from the supernova explosion — like an animal rattling its cage. This includes wave-like tsunamis of charged particles embedded in deadly magnetic fields.

On July 4, 1054, Chinese astronomers recorded the supernova that formed the Crab Nebula. The ultimate celestial firework, this “guest star” was visible during the daytime for 23 days, shining six times brighter than the planet Venus. The supernova was also recorded by Japanese, Arabic, and Native American stargazers. While searching for a comet that was predicted to return in 1758, French astronomer Charles Messier discovered a hazy nebula in the direction of the long-vanished supernova. He would later add it to his celestial catalog as “Messier 1.” Because M1 didn’t move across the sky like a comet, Messier simply ignored it other than just marking it as a “fake comet.” Nearly a century later the British astronomer William Parsons sketched the nebula. Its resemblance to a crustacean led to M1’s other name, the Crab Nebula. In 1928 Edwin Hubble first proposed associating the Crab Nebula to the Chinese “guest star” of 1054.

Neptune Has a New Spot


Neptune has a new spot and thanks to Hubble we can see it. Click the image for the larger version.

From Hubble (via NASA):
New images obtained on May 16, 2016, by NASA’s Hubble Space Telescope confirm the presence of a dark vortex in the atmosphere of Neptune. Though similar features were seen during the Voyager 2 flyby of Neptune in 1989 and by the Hubble Space Telescope in 1994, this vortex is the first one observed on Neptune in the 21st century.

The discovery was announced on May 17, 2016, in a Central Bureau for Astronomical Telegrams (CBAT) electronic telegram by University of California at Berkeley research astronomer Mike Wong, who led the team that analyzed the Hubble data.

Neptune’s dark vortices are high-pressure systems and are usually accompanied by bright “companion clouds,” which are also now visible on the distant planet. The bright clouds form when the flow of ambient air is perturbed and diverted upward over the dark vortex, causing gases to likely freeze into methane ice crystals.

“Dark vortices coast through the atmosphere like huge, lens-shaped gaseous mountains,” Wong said. “And the companion clouds are similar to so-called orographic clouds that appear as pancake-shaped features lingering over mountains on Earth.”

Beginning in July 2015, bright clouds were again seen on Neptune by several observers, from amateurs to astronomers at the W. M. Keck Observatory in Hawaii. Astronomers suspected that these clouds might be bright companion clouds following an unseen dark vortex. Neptune’s dark vortices are typically only seen at blue wavelengths, and only Hubble has the high resolution required for seeing them on distant Neptune.

In September 2015, the Outer Planet Atmospheres Legacy (OPAL) program, a long-term Hubble Space Telescope project that annually captures global maps of the outer planets, revealed a dark spot close to the location of the bright clouds, which had been tracked from the ground. By viewing the vortex a second time, the new Hubble images confirm that OPAL really detected a long-lived feature. The new data enabled the team to create a higher-quality map of the vortex and its surroundings.

Neptune’s dark vortices have exhibited surprising diversity over the years, in terms of size, shape, and stability (they meander in latitude, and sometimes speed up or slow down). They also come and go on much shorter timescales compared to similar anticyclones seen on Jupiter; large storms on Jupiter evolve over decades.

Planetary astronomers hope to better understand how dark vortices originate, what controls their drifts and oscillations, how they interact with the environment, and how they eventually dissipate, according to UC Berkeley doctoral student Joshua Tollefson, who was recently awarded a prestigious NASA Earth and Space Science Fellowship to study Neptune’s atmosphere. Measuring the evolution of the new dark vortex will extend knowledge of both the dark vortices themselves, as well as the structure and dynamics of the surrounding atmosphere.
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