30 Jun 2016

Jupiter “throws fireworks Party” for Juno’s arrival

Auroras on JupiterAstronomers are using the NASA/ESA Hubble Space Telescope to study auroras — stunning light shows in a planet’s atmosphere — on the poles of the largest planet in the Solar System, Jupiter.

I asked Dr Jonathan Nichols of the University of Leicester, for further information on these new Jupiter images.

Dr Nichols explained:

“These particular images were obtained on 19 May and 2 June as part of a series of observations during the Juno approach phase.

“The base of the auroral curtain is at 240 km (150 miles) above the 1 bar level, and the curtain extends around a thousand km (620 miles) in altitude.

“The auroras are so intense owing to the strong magnetic field of Jupiter and the planet's fast rotation - most of the auroral power derives from the outflow of plasma originating from Io. The role of the solar wind is not known - and one of the questions being examined using these data.

“We are taking data now and we'll have another set of observations 10-18 July after Juno Orbital Insertion. We'll also have a large program starting.” in November during the main phase of the mission.”

Dr. Jonathan Nichols is Reader and STFC Advanced Fellow in Planetary Auroras Radio and Space Plasma Physics Group.

This observation programme is supported by measurements made by NASA’s Juno spacecraft, currently on its way to Jupiter.

Jupiter, the largest planet in the Solar System, is best known for its colourful storms, the most famous being the Great Red Spot. Now astronomers have focused on another beautiful feature of the planet, using the ultraviolet capabilities of the NASA/ESA Hubble Space Telescope.

The extraordinary vivid glows shown in the new observations are known as auroras. They are created when high energy particles enter a planet’s atmosphere near its magnetic poles and collide with atoms of gas. As well as producing beautiful images, this programme aims to determine how various components of Jupiter’s auroras respond to different conditions in the solar wind, a stream of charged particles ejected from the Sun.

Uncovering the mysteries of Jupiter's aurora

This observation programme is perfectly timed as NASA’s Juno spacecraft is currently in the solar wind near Jupiter and will enter the orbit of the planet in early July 2016. While Hubble is observing and measuring the auroras on Jupiter, Juno is measuring the properties of the solar wind itself; a perfect collaboration between a telescope and a space probe.

“These auroras are very dramatic and among the most active I have ever seen”, says Jonathan Nichols from the University of Leicester, UK, and principal investigator of the study. “It almost seems as if Jupiter is throwing a firework party for the imminent arrival of Juno.”

To highlight changes in the auroras Hubble is observing Jupiter daily for around one month. Using this series of images it is possible for scientists to create videos that demonstrate the movement of the vivid auroras, which cover areas bigger than the Earth.

Not only are the auroras huge, they are also hundreds of times more energetic than auroras on Earth. And, unlike those on Earth, they never cease. Whilst on Earth the most intense auroras are caused by solar storms — when charged particles rain down on the upper atmosphere, excite gases, and cause them to glow red, green and purple — Jupiter has an additional source for its auroras.

The strong magnetic field of the gas giant grabs charged particles from its surroundings. This includes not only the charged particles within the solar wind but also the particles thrown into space by its orbiting moon Io, known for its numerous and large volcanos.

The new observations and measurements made with Hubble and Juno will help to better understand how the Sun and other sources influence auroras. While the observations with Hubble are still ongoing and the analysis of the data will take several more months, the first images and videos are already available and show the auroras on Jupiter’s north pole in their full beauty.

Richard Pearson F.R.A.S.

NASA’s OSIRIS probe prepares for launch

Spacecraft-AssembledScheduled for launch on Sept. 8, NASA's OSIRIS-REx mission will travel to an asteroid, study it and return a sample to Earth for analysis. All of these goals depend on accurate mapping of the target, Bennu, so the team is gearing up for the challenges of cartography of an asteroid.

"Mapping of Bennu is necessary, of course, but it's also an exciting and technically interesting aspect of the mission," said Ed Beshore, OSIRIS-REx deputy principal investigator at the University of Arizona in Tucson. The mission is managed by NASA's Goddard Space Flight Center in Greenbelt, Maryland.

The maps will be generated using information gathered by the five instruments aboard OSIRIS-REx, which stands for Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer. Upon its rendezvous with Bennu, the spacecraft will spend a year surveying the asteroid for both scientific and operations purposes - including searching for plumes of material coming from the asteroid, measuring non-gravitational forces acting on Bennu, and identifying the best location to collect a sample.

DSCN2862Most of the mapping work will be done during this survey phase. The team will document the shape of the asteroid, generate a suite of top-level maps, and perform reconnaissance on the final few candidates on the list of possible sampling sites. The reconnaissance maps will be so detailed that team members will be able to spot individual pebbles measuring about three-fourths of an inch (2 centimetres) across - roughly the maximum size of material that the sampling head can collect.

"Everything the spacecraft learns will be woven together like a tapestry to tell the story of Bennu," said Kevin Walsh, an OSIRIS-REx co-investigator at the Southwest Research Institute in Boulder, Colorado.

In the meantime, the groundwork for mapping is being laid.

The underlying framework is a 3-D shape model. This step is crucial because asteroids, unlike planets and moons, aren't nice and round. They tend to be bumpy and irregular, often like potatoes. Bennu is more of a lumpy ball that gets thicker around the middle - a shape astronomers compare to a spinning top.

This rough shape was determined from radar studies conducted from Earth since the asteroid's discovery in 1999. After OSIRIS-REx surveys Bennu, a new model that captures the subtleties of the asteroid's shape will be developed.

For the global maps, information from the spacecraft's instruments will be overlaid on the shape model. The team plans to incorporate some of these 3-D maps as a routine part of mission-critical operations. Three top-level operations maps are planned: one to evaluate which areas are safe enough to allow the spacecraft to move close to the asteroid, one to determine where the sampling arm can make good contact with the surface to perform its touch-and-go manoeuvre, and one to indicate where to find the material most suitable for sampling. A fourth top-level map will evaluate how scientifically valuable different regions of the asteroid are.

DSCN2911"These four maps will be the key to selecting a sampling site," said Lucy Lim, OSIRIS-REx assistant project scientist at Goddard. "To make sure the map-making goes smoothly once we arrive at Bennu, we started developing the algorithms and practicing all the steps long before launch."

Preparations also include establishing map conventions, such as specifying which of Bennu's poles is north. The team based this decision on the direction of the asteroid's rotation - a choice that fits with guidelines from the International Astronomical Union. Bennu spins in the direction opposite to Earth, so the asteroid's poles are reversed compared to our planet's poles.

The location of Bennu's prime meridian - zero degrees longitude - also has been chosen. It runs through a large bump seen on the preliminary shape model. Later, this selection will be refined, or perhaps redefined, depending on what Bennu looks like up close.

"We make as many decisions about mapping as we can ahead of time, because the work will be intensive once we arrive at Bennu," said Daniella DellaGiustina, the OSIRIS-REx lead image processing scientist at the University of Arizona. "But we have to allow some flexibility to make changes later, if we need to."

Navigation is another special consideration when mapping Bennu. Because the asteroid is so small, its gravitational force is very weak, accounting for only about half of the total force the orbiting spacecraft will feel when it's close to Bennu. The other half will come from pressure due to sunlight on the surface of the spacecraft.

The pressure exerted by sunlight is difficult to model, so the navigation team will have to perform frequent updates - perhaps daily. The instrument teams will have to adjust quickly to the changes in plans.

"This won't be an orbit the way we usually think of one - that's how important this force will be," said Michael Moreau, OSIRIS-REx flight dynamics system manager at Goddard. "OSIRIS-REx is going to take this work to a new level at Bennu."

NASA Goddard Space Flight Center in Greenbelt, Maryland provides overall mission management, systems engineering and safety and mission assurance for OSIRIS-REx. Dante Lauretta is the mission's principal investigator at the University of Arizona, Tucson. Lockheed Martin Space Systems in Denver is building the spacecraft. OSIRIS-REx is the third mission in NASA's New Frontiers Program. NASA Marshall Space Flight Center in Huntsville, Alabama, manages New Frontiers for the agency's Science Mission Directorate in Washington.

Launch management is the responsibility of NASA's Launch Services Program at the Kennedy Space Center in Florida.

29 Jun 2016

NGC 1569 in Camelopardalis is now at its best

Bursting at the seams

The obscure constellation of Camelopardalis lies high over-head in the northern sky at the moment, in it lies the starburst galaxy NGC1569: Mag +11 RA: 04h32m 22.2s DEC:+64°53'04." It is a good test for amateur Astrophotographers to image because its Surface brightness: 12.90 & Dimension: 3.7 x 1.8 ' are low yet it really is a splendid sight.

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.

Credit: ESA/Hubble & NASA, Aloisi, Ford. Acknowledgement: Judy Schmidt (Geckzilla)

28 Jun 2016

New halo stars of the globular clusters M3 and M13










Left: M3 On the right M13 -- Click on the images to enlarge

Australian astronomers have uncovered evidence of halo stars in two globular clusters residing in the Milky Way galaxy. According to a new study published on June 21 on the arXiv pre-print server, the globular clusters known as Messier 3 and Messier 13, have extra tidal halo stars. The new findings suggest that both clusters could be surrounded by extended stellar halos.

Messier 3 and Messier 13, containing 500,000 and 300,000 stars respectively, are among the best known globular clusters. However, previous studies focusing on finding extra tidal stars in these clusters haven't delivered any promising results so far. Now, a team of researchers led by Colin Navin of the Macquarie University in Australia have analysed the available data about the two clusters in order to reveal new insights on their structure.


For their research, the scientists used data from the Large Sky Area Multi-Object Fibre Spectroscopic Telescope (LAMOST) survey of the Northern hemisphere, which utilizes the Xinglong Observatory in China to obtain the spectra of about 10 million objects, including stars, galaxies and quasars. They chose LAMOST, as this survey covers a number of Northern hemispheric globular clusters and therefore has potential to search for extra tidal stars.

"We find candidate extra tidal stars in wide halos around the globular clusters Messier 3 and Messier 13 in the LAMOST Data Release 1," the researchers wrote in the paper.

First, the team identified the characteristics of globular clusters that were likely to have member stars in the Data Release 1 Catalogue. Spatially, they had to be within the survey area of LAMOST; then, the researchers chose to use globular clusters that had relatively high heliocentric radial velocities. After eliminating clusters that only had small numbers of candidate stars, they were left with Messier 3 and Messier 13 as likely candidates to search for extra tidal stars.


Finally, they found eight candidate extra tidal cluster halo stars in Messier 3 at distances up to about 10 times the tidal radius, and in Messier 13, they identified 12 candidate extra tidal cluster halo stars at distances up to approximately 14 times the tidal radius.

The scientists noted that if the status of these stars is confirmed, they would support previous studies that both clusters are surrounded by a halo of extra tidal stars or exhibit tidal tails. However, in order to validate their status, high-resolution spectroscopic observations of the chemical abundances are required.

"High-resolution spectroscopic observations of the candidate extra tidal cluster halo stars would be valuable in confirming their origin, and hence provide constraints for theoretical studies," the paper reads.

According to previous studies, a significant fraction of stars in the bulge and halo of the Milky Way originated in globular clusters. It is believed that a minimum of 17 percent of the present-day mass of the stellar halo originally formed in globular clusters. Notably, the tidal debris of globular clusters also act as indicators of a host galaxy's gravitational potential as the extra tidal stars spread out in a stream that traces the orbit of its progenitor.

The researchers hope to find more candidate extra tidal stars in Messier 3 and Messier 13, and possibly in other globular clusters, as the dataset grows. Meanwhile, they recommend that future observations focus on known photometric members of clusters.

27 Jun 2016

Jupiter imaged using the Very Large Telescope


Ashampoo_Snap_2016.06.07_22h16m39s_001_False colour images generated from VLT observations in February and March 2016, showing two different faces of Jupiter. The bluer areas are cold and cloud-free, the orangey areas are warm and cloudy, more colourless bright regions are warm and cloud-free, and dark regions are cold and cloudy (such as the Great Red Spot and the prominent ovals). The wave pattern over the North Equatorial Band shows up in orange.

This view was created from VLT/VISIR infrared images from February 2016 (left) and March 2016 (right). The orange images were obtained at 10.7 micrometres wavelength and highlight the different temperatures and presence of ammonia. The blue images at 8.6 micrometres highlight variations in cloud opacity.

Credit: ESO/L.N. Fletcher

In preparation for the imminent arrival of NASA’s Juno spacecraft, astronomers have used ESO’s Very Large Telescope to obtain spectacular new infrared images of Jupiter. They are part of a campaign to create high-resolution maps of the giant planet. These observations will inform the work to be undertaken by Juno over the coming months, helping astronomers to better understand the gas giant ahead of Juno’s close encounter.

A team led by Leigh Fletcher of the University of Leicester in the United Kingdom are presenting new images of Jupiter at the UK’s Royal Astronomical Society’s National Astronomy Meeting in Nottingham. Obtained with the VISIR instrument on ESO’s Very Large Telescope, the new images are part of a focused effort to improve understanding of Jupiter’s atmosphere prior to the arrival of NASA’s Juno spacecraft [1] in July this year.

Two faces of JupiterThe campaign has involved the use of several telescopes based in Hawaii and Chile, as well as contributions from amateur astronomers around the world. The maps do not just give snapshots of the planet, they also reveal how Jupiter’s atmosphere has been shifting and changing in the months prior to Juno’s arrival.

The Juno spacecraft was launched in 2011, and has travelled nearly 3000 million kilometres to reach the Jovian system. Spacecraft can collect data free from the limitations affecting telescopes on Earth so with that in mind, it might seem surprising that this ground-based campaign was considered so important.

Leigh Fletcher describes the significance of this research in preparing for Juno’s arrival: “These maps will help set the scene for what Juno will witness in the coming months. Observations at different wavelengths across the infrared spectrum allow us to piece together a three-dimensional picture of how energy and material are transported upwards through the atmosphere.”

Capturing sharp images through the Earth’s constantly shifting atmosphere is one of the greatest challenges faced by ground-based telescopes. This glimpse of Jupiter’s own turbulent atmosphere, rippling with cooler gas clouds, was possible thanks to a technique known as lucky imaging. Sequences of very short exposures were taken of Jupiter by VISIR, producing thousands of individual frames. The lucky frames, where the image is least affected by the atmosphere’s turbulence, are selected and the rest discarded. Those selected frames are aligned and combined to produce remarkable final pictures like the ones shown here.

Glenn Orton, leader of the ground-based campaign in support of Juno’s mission, elaborates on why the preparatory observations from Earth are so valuable: “The combined efforts of an international team of amateur and professional astronomers have provided us with an incredibly rich dataset over the past eight months. Together with the new results from Juno, the VISIR dataset in particular will allow researchers to characterise Jupiter’s global thermal structure, cloud cover and distribution of gaseous species.”

Whilst the modern Juno’s mission to unveil the mighty Jupiter will bring new and highly anticipated results, its way has been paved by ground-based efforts here on Earth.

25 Jun 2016

400 Years of mapping the Moon & Planets

A lecture by Henrik Hargitai  from  the NASA Ames Research Center
given to the © SETI Institute on 24 May 2016
Duration: 1h 08m

If you are interested in the history of astronomy then this illustrated talk is a Must-See program. Here you will have the opportunity to view many of the old charts & illustrations of the Moon & planets. It also gives an insight into how NASA choses the landing sights on Mars for its Rovers & landers.

You may also like to watch again my programs: The Story of the Refractor, and Observing the Moon from 2014.

Since Galileo, astronomers and planetary scientists work hard to draw accurate representations of planetary surfaces. Planetary mapping today is a tool of geological investigation, landing site selection and also a visual statement of our ever expanding horizon of discovery. From copper engravings to dynamic online maps, the technique of presenting planetary maps changed a lot. In this presentation I will show some early examples of how planetary maps can communicate unspoken preconceptions (no, its not the canals), and show how we mapped the Navua Valles, which may have episodically provided habitable environments on the inner rim of Hellas Basin on Mars. The talk is part of the International Map Year celebrations.

Richard Pearson F.R.A.S.

24 Jun 2016

News Update No. 02


Running Time: 10m

The image was obtained by New Horizons’ Long Range Reconnaissance Imager (LORRI) at a resolution of approximately 1.45 miles (2.33 kilometres) per pixel. The section of the canyon seen here measures approximately 185 miles (300 kilometres) long.

Hello everyone, here is my latest weekly update. I now have confirmation that I shall be going along to the Royal Greenwich Observatory on 14 July to film a program all about the wonderful 28 inch refractor telescope their. I will be meeting Dr. Louise Devoy once again who will inform us about the telescope and observatory it is housed in. This new program will be aired in the Autumn.

I shall be filming my next program over the next few days.

Best Wishes: Richard Pearson F.R.A.S.

Hubble Space Telescope confirms new Dark spot on Neptune


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.

dpm20160611_2051The 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 analysed the Hubble data.

This image of Neptune by Darryl Pfitzner Milika & Pat Nichols was taken on 11 June 2016. Darryl lives in south Australia.

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.

23 Jun 2016

Successful First Observations of Galactic Centre with GRAVITY

eso1622bAshampoo_Snap_2016.06.07_22h16m39s_001_A European team of astronomers have used the new GRAVITY instrument at ESO’s Very Large Telescope to obtain exciting observations of the centre of the Milky Way by combining light from all four of the 8.2-metre Unit Telescopes for the first time.

These results provide a taste of the ground-breaking science that GRAVITY will produce as it probes the extremely strong gravitational fields close to the central supermassive black hole and tests Einstein’s general relativity.

The GRAVITY instrument is now operating with the four 8.2-metre Unit Telescopes of ESO’s Very Large Telescope (VLT), and even from early test results it is already clear that it will soon be producing world-class science.

GRAVITY is part of the VLT Interferometer. By combining light from the four telescopes it can achieve the same spatial resolution and precision in measuring positions as a telescope of up to 130 metres in diameter. The corresponding gains in resolving power and positional accuracy — a factor of 15 over the individual 8.2-metre VLT Unit Telescopes — will enable GRAVITY to make amazingly accurate measurements of astronomical objects.

One of GRAVITY’s primary goals is to make detailed observations of the surroundings of the 4 million solar mass black hole at the very centre of the Milky Way [1]. Although the position and mass of the black hole have been known since 2002, by making precision measurements of the motions of stars orbiting it, GRAVITY will allow astronomers to probe the gravitational field around the black hole in unprecedented detail, providing a unique test of Einstein’s general theory of relativity.

In this regard, the first observations with GRAVITY are already very exciting. The GRAVITY team [2] has used the instrument to observe a star known as S2 as it orbits the black hole at the centre of our galaxy with a period of only 16 years. These tests have impressively demonstrated GRAVITY’s sensitivity as it was able to see this faint star in just a few minutes of observation.

The team will soon be able to obtain ultra-precise positions of the orbiting star, equivalent to measuring the position of an object on the Moon with centimetre precision. That will enable them to determine whether the motion around the black hole follows the predictions of Einstein’s general relativity — or not. The new observations show that the Galactic Centre is as ideal a laboratory as one can hope for.

eso1622a"It was a fantastic moment for the whole team when the light from the star interfered for the first time — after eight years of hard work," says GRAVITY’s lead scientist Frank Eisenhauer from the Max Planck Institute for Extra-terrestrial Physics in Garching, Germany. "First we actively stabilised the interference on a bright nearby star, and then only a few minutes later we could really see the interference from the faint star — to a lot of high-fives.” At first glance neither the reference star nor the orbiting star have massive companions that would complicate the observations and analysis. "They are ideal probes," explains Eisenhauer.

This artist’s impression shows stars orbiting the supermassive black hole at the centre of the Milky Way. In 2018 one of these stars, S2, will pass very close to the black hole and this event will be the best opportunity to study the effects of very strong gravity and test the predictions of Einstein’s general relativity in the near future. The orbit of S2 is shown in red and the position of the central black hole is marked with a red cross.

Credit: ESO/L. Calçada

This early indication of success does not come a moment too soon. In 2018 the S2 star will be at its closest to the black hole, just 17 light-hours away from it and travelling at almost 30 million kilometres per hour, or 2.5% of the speed of light. At this distance the effects due to general relativity will be most pronounced and GRAVITY observations will yield their most important results [3]. This opportunity will not be repeated for another 16 years.

Discovery of rings in the HD141569A debris disk


Star | HD141569A: RA 15h 49m 57.7s DEC -03 55’ 16.3” Mag 7.2

locationThis 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.

Debris disks are usually thought to be gas-poor, the gas being dissipated by accretion or evaporation during the protoplanetary phase. HD141569A is a 5 million year old star harbouring a famous debris disk, with multiple rings and spiral features. The analysis reveals there is still a large amount of (primordial) gas extending out to 250 AU inside the rings observed in scattered light. HD141569A is thus a hybrid disk with a huge debris component, where dust has evolved and is produced by collisions, with a large remnant reservoir of gas.

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.

Ashampoo_Snap_2016.06.22_22h51m53s_004_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.

During the formation of a Sun-like star, the object passes through the T-Tauri phase during which it is surrounded by a disk-shaped nebula. Out of this material are formed planetesimals, which can undergo an accretion process to form planets. The nebula continues to orbit the pre-main-sequence star for a period of 1–20 million years until it is cleared out by radiation pressure and other processes. Additional dust may then be generated about the star by collisions between the planetismals, which forms a disk out of the resulting debris. At some point during their lifetime, at least 45% of these stars are surrounded by a debris disk, which then can be detected by the thermal emission of the dust using an infrared telescope. Repeated collisions can cause a disk to persist for much of the lifetime of a star.

21 Jun 2016

Hubble sweeps scattered stars in Sagittarius


This colourful and star-studded view of the Milky Way galaxy was captured when the NASA/ESA Hubble Space Telescope pointed its cameras towards the constellation of Sagittarius (The Archer). Blue stars can be seen scattered across the frame, set against a distant backdrop of red-hued cosmic companions. This blue litter most likely formed at the same time from the same collapsing molecular cloud.

The colour of a star can reveal many of its secrets. Shades of red indicate a star much cooler than the sun, so either at the end of its life, or much less massive. These lower-mass stars are called red dwarfs and are thought to be the most common type of star in the Milky Way. Similarly, brilliant blue hues indicate hot, young, or massive stars, many times the mass of the sun.

A star's mass decides its fate; more massive stars burn brightly over a short lifespan, and die young after only tens of millions of years. Stars like the sun typically have more sedentary lifestyles and live longer, burning for approximately ten billion years. Smaller stars, on the other hand, live life in the slow lane and are predicted to exist for trillions of years, well beyond the current age of the universe.

© Hubble/ESA 20 June 2016

20 Jun 2016

Venus’s Magnetosphere starves the planets’ atmosphere of Oxygen

Image converted using ifftoanyESA’s Venus Express may have helped to explain the puzzling lack of water on Venus. The planet has a surprisingly strong electric field – the first time this has been measured at any planet – that is sufficient to deplete its upper atmosphere of oxygen, one of the components of water.

Venus is often called Earth’s twin, since the second planet from the Sun is only slightly smaller than our own. But its atmosphere is quite different, consisting mainly of carbon dioxide, with a little nitrogen and trace amounts of sulphur dioxide and other gases. It is much thicker than Earth’s, reaching pressures of over 90 times that of Earth at sea level, and incredibly dry, with a relative abundance of water about 100 times lower than in Earth’s gaseous shroud.

In addition, Venus now has a runaway greenhouse effect and a surface temperature high enough to melt lead. Also, unlike our home planet, it has no significant magnetic field of its own.

Scientists think Venus did once host large amounts of water on its surface over 4 billion years ago. But as it heated up, much of this water evaporated into the atmosphere, where it could then be ripped apart by sunlight and subsequently lost to space.

The solar wind – a powerful stream of charged subatomic particles blowing from the Sun – is one of the culprits, stripping hydrogen ions (protons) and oxygen ions from the planet’s atmosphere and so depriving it of the raw materials that make water. 

Now, scientists using Venus Express have identified another difference between the two planets: Venus has a substantial electric field, with a potential around 10 V.

This is at least five times larger than expected. Previous observations in search of electric fields at Earth and Mars have failed to make a decisive detection, but they indicate that, if one exists, it is less than 2 V.

“We think that all planets with atmospheres have a weak electric field, but this is the first time we have actually been able to detect one,” says Glyn Collinson from NASA’s Goddard Flight Space Center, lead author of the study.

In any planetary atmosphere, protons and other ions feel a pull from the planet’s gravity. Electrons are much lighter and thus feel a smaller pull – they are able to escape the gravitational tug more easily.

As the negative electrons drift upwards in the atmosphere and away into space, they are nevertheless still connected to the positive protons and ions via the electromagnetic force, and this results in an overall vertical electric field being created above the planet’s atmosphere.

19 Jun 2016

Ariane 5 delivers its heaviest commercial payload

Ariane_5_liftoff_node_full_image_2On its third mission this year, Ariane 5 lofted more than 10.7 tonnes – its heaviest commercial cargo so far.

Lift-off occurred last night at 21:39 GMT (23:39 CEST, 18:39 local time) from Europe’s Spaceport in Kourou, French Guiana to deliver the EchoStar-18 and BRIsat commercial satellites into their planned orbits.

EchoStar-18, weighing 6300 kg at lift-off and mounted in the upper position atop Ariane’s Sylda dual-payload carrier inside the fairing, was the first to be released about 29 minutes into the mission.

Following a series of burns controlled by Ariane’s on-board computer, the Sylda structure encasing the 3540 kg BRIsat was then jettisoned. BRIsat was released into its own transfer orbit about 13 minutes after the first satellite.

EchoStar-18 is owned and operated by Dish Network. Positioned at 110ºW in geostationary orbit, it will provide direct-to-home television broadcast services over North America.

BRIsat is owned and operated by Bank Rakyat Indonesia. Positioned at 150.5ºE in geostationary orbit, it will support banking services provided by this large Indonesian bank.

Both satellites have a design life of 15 years.

The payload mass for this launch was 10 731 kg. The satellites totalled about 9840 kg, with payload adapters and carrying structures making up the rest.

Flight VA230 was the 86th Ariane 5 mission.

An ‘Evening with Jupiter’


NASA HAVE NOW BEGUN THE COUNTOWN TO THE ARRIVAL OF THE JUNO PROBE AT THE PLANET JUPITER. To help celebrate this historic occasion we have a series of special programs all about the NASA mission, and the planet Jupiter. I have also amended our main show ‘Magnificent Jupiter’ to include the latest media video released by the Space Agency in the last few days.

It all adds up to let you spend the evening with Jupiter & its system of moons. So click on the above image, sit back relax and enjoy the next couple of hours in the company of ‘Magnificent Jupiter….. A night to remember.

Richard Pearson. F.R.A.S.

17 Jun 2016

Weekly News Bulletin: 01

I do try to update our Astronomy & Space website regularly with important topics of interest to amateur astronomers, and students. I have however, received a great many requests to provide narrated news updates because you all seem to like this approach, and many of you like to see more of me on on screen.

Here is my first news update, please let me know what you think, and what news I should include in future News bulletins. 

Best wishes. Richard Pearson F.R.A.S.

Email: rpearson46@yahoo.com


16 Jun 2016

Website Changes: Summary

DSC_0554Hello everyone, I trust that you are all fine.

As we head into Summer I thought I would make a few changes to the website to make things a little easier for you. I have introduced a more complete monthly Sky Diary that you can find by clicking on the banner under the page header.

All of our programs are FREE to watch, never miss an update or program, please subscribe with your Email in the box on the upper left. I have also began introducing regular news updates that hopefully are not repeats of what you find elsewhere on Face Book or in Face Book Groups so as to make our website exclusive and original to enhance your enjoyment when you visit us.

Yes you may share our monthly program ‘Astronomy & Space’, Yes you can play our programs in classrooms and at your monthly Astronomical Society meeting(s), and Yes do please share all of our posts with you friends.

Please let me know if you like these changes, or would prefer to see something different; my Email Address is rpearson46@yahoo.com.

Please note that I am not set up to receive voice messages on Face Book, and I do not publish my private telephone number. My Astronomy programs are viewed by over 80,000 people every month and I already receive a lot of messages from all of my viewers; I fear that I would be snowed under with phone calls …

However, it is really nice to hear from all of you, and I will try my best to answer all of your messages as soon as I can.

Best wishes & Clear skies everyone

Richard Pearson F.R.A.S.

15 Jun 2016

Alert: Two white spots now visible on the planet Neptune










dpm20151115_1058On 11 June at 12:51 UT, Australian amateurs Darryl Milika and Pat Nicholas imaged two bright spots on Neptune using a C14 and IR 610nm filter.

Neptune lies in the constellation Pisces: RA 22h 55m DEC –7 49’ 20” Mag +5.9

These spots have been confirmed by Ricardo Hueso in professional observations made by the team at the Calar Alto observatory in Spain using a 2.2m telescope (Agustín Sánchez-Lavega) on 17 May.

One has also been imaged by the Hubble Space Telescope. This is another set of images  from 1998.

hs-1998-34-a-webThis is the second time that Darrl Milika & Pat Nicholas have seen bright spots on the planet Neptune, they also saw a significantly sized white spot last November that is shown here.

Ricardo Hueso has also kindly provided a provisional ephemeris based on observation to date for the two objects. This is reproduced below with permission.

These spots are within the imaging capability of those with larger telescopes and further observations are urgently required.

2016-June-16 11:50:55 353.5
2016-June-17 06:13:50 44.3
2016-June-18 00:36:44 95.1
2016-June-18 18:59:39 145.8
2016-June-19 13:22:34 196.6
2016-June-20 07:45:29 247.4
2016-June-21 02:08:24 298.1
2016-June-21 20:31:19 348.9
2016-June-22 14:54:14 39.7
2016-June-23 09:17:09 90.5
2016-June-24 03:40:04 141.2
2016-June-24 22:02:59 192.0

2016-June-25 16:25:53 242.8
2016-June-26 10:48:48 293.5
2016-June-27 05:11:43 344.3
2016-June-27 23:34:38 35.1
2016-June-28 17:57:33 85.8
2016-June-29 12:20:28 136.6
2016-June-30 06:43:23 187.4
2016-July-01 01:06:18 238.1
2016-July-01 19:29:13 288.9
2016-July-02 13:52:08 339.7
2016-July-03 08:15:02 30.5
2016-July-04 02:37:57 81.2

Mike Foulkes Saturn Section Director: British Astronomical Association. 

First Detection of Methyl Alcohol in a Planet-forming Disc

Artist’s impression of the disc around the young star TW Hydrae

The protoplanetary disc around the young star TW Hydrae is the closest known example to Earth, at a distance of only about 170 light-years. As such it is an ideal target for astronomers to study discs. This system closely resembles what astronomers think the Solar System looked like during its formation more than four billion years ago.

RA 11h 01m 52s DEC −34° 42′ 17″ Apparent magnitude 11.27 ± 0.09

TW Hydrae is an orange dwarf star approximately 176 light-years away in the constellation of Hydra (the Sea Serpent). The star is the closest T Tauri star to the Solar System. TW Hydrae is about 80% of the mass of the Sun, but is only about 5-10 million years old. The star appears to be accreting from a face-on protoplanetary disk of dust and gas, which has been resolved in images from the Hubble Space Telescope. TW Hydrae is accompanied by about twenty other low-mass stars with similar ages and spatial motions, comprising the "TW Hydrae association" or TWA, one of the closest regions of recent "fossil" star-formation to the Sun

The Atacama Large Array (ALMA) is the most powerful observatory in existence for mapping the chemical composition and the distribution of cold gas in nearby discs. These unique capabilities have now been exploited by a group of astronomers led by Catherine Walsh (Leiden Observatory, the Netherlands) to investigate the chemistry of the TW Hydrae protoplanetary disc.



[Click on the images to enlarge]

The ALMA observations have revealed the fingerprint of gaseous methyl alcohol, or methanol (CH3OH), in a protoplanetary disc for the first time. Methanol, a derivative of methane, is one of the largest complex organic molecules detected in discs to date. Identifying its presence in pre-planetary objects represents a milestone for understanding how organic molecules are incorporated into nascent planets.

Furthermore, methanol is itself a building block for more complex species of fundamental prebiotic importance, like amino acid compounds. As a result, methanol plays a vital role in the creation of the rich organic chemistry needed for life.

Catherine Walsh, lead author of the study, explains: “Finding methanol in a protoplanetary disc shows the unique capability of ALMA to probe the complex organic ice reservoir in discs and so, for the first time, allows us to look back in time to the origin of chemical complexity in a planet nursery around a young Sun-like star.”

apjlaa1efaf1_hrGaseous methanol in a protoplanetary disc has a unique importance in astrochemistry. While other species detected in space are formed by gas-phase chemistry alone, or by a combination of both gas and solid-phase generation, methanol is a complex organic compound which is formed solely in the ice phase via surface reactions on dust grains.

The sharp vision of ALMA has also allowed astronomers to map the gaseous methanol across the TW Hydrae disc. They discovered a ring-like pattern in addition to significant emission from close to the central star.

The observation of methanol in the gas phase, combined with information about its distribution, implies that methanol formed on the disc’s icy grains, and was subsequently released in gaseous form. This first observation helps to clarify the puzzle of the methanol ice–gas transition [2], and more generally the chemical processes in astrophysical environments.

ABOVE | Channel maps for the stacked observed B7 CH3OH line emission. The white contours show the 2.5σ, 3.0σ, 4.0σ, levels for the CH3OH data and the gray contour shows the extent of the 317 GHz continuum. The black cross denotes the stellar position, and the dashed gray lines show the disk major and minor axes. The synthesized beams for the continuum (open ellipse) and line (filled ellipse) emission are shown in the bottom left panel.

Ashampoo_Snap_2016.06.14_20h24m08s_001_Ryan A. Loomis, a co-author of the study, adds: “Methanol in gaseous form in the disc is an unambiguous indicator of rich organic chemical processes at an early stage of star and planet formation. This result has an impact on our understanding of how organic matter accumulates in very young planetary systems.”

This successful first detection of cold gas-phase methanol in a protoplanetary disc means that the production of ice chemistry can now be explored in discs, paving the way to future studies of complex organic chemistry in planetary birthplaces. In the hunt for life-sustaining exoplanets, astronomers now have access to a powerful new tool.

[Discover more click on the above image]

14 Jun 2016

The Dimming of FU Orionis










This artist's concept illustrates how the brightness of out-bursting star FU Orionis has been slowly fading since its initial flare-up in 1936. The star is pictured with the disk of material that surrounds it. Researchers found that it has dimmed by about 13 percent at short infrared wavelengths from 2004 (left) to 2016 (right).


FU_OrionisRA 05h 45m 22.362s DEC +09° 04′ 12.31″ Mag + 8.94

FU Orionis is a variable star in the constellation of Orion, that in 1937 rose in apparent visual magnitude from 16.5 to 9.6, and has since been around magnitude 9. For a long time it was considered unique, but in 1970 a similar star, V1057 Cygni, was discovered, and a number of additional examples have been discovered since then. These stars constitute the FU Orionis class of variable stars, GCVS type FU, often nicknamed FUors.

In stellar evolution, an FU Orionis star (also FU Orionis object, or FUor) is a pre–main-sequence star which displays an extreme change in magnitude and spectral type. One example is the star V1057 Cyg, which became 6 magnitudes brighter and went from spectral type dKe to F-type supergiant. These stars are named after their type-star, FU Orionis.

413294main_ED09-0352-01_full_fullThe current model developed primarily by Lee Hartmann and Scott Jay Kenyon associates the FU Orionis flare with abrupt mass transfer from an accretion disc onto a young, low mass T Tauri star

The 2004 data were collected with NASA's Spitzer Space Telescope, and the 2016 data were collected with the Stratospheric Observatory for Infrared Astronomy (SOFIA) shown here on the left.

FU Orionis is a few hundred thousand years old. It is possible that when our sun was younger, it also went through a period of intense brightening followed by dimming.

These results were presented at the American Astronomical Association meeting in June 2016 in San Diego.

Did Jupiter form close to the infant Sun

Jupiter and its shrunken Great Red Spot

NASA’s Juno spacecraft which is due to arrive at the planet Jupiter on 4th July will help planetary scientists confirm the fascinating theory that the planet was originally a ‘hot Jupiter’ close to the new born sun.

OUR SOLAR SYSTEM was formed 4.5 billion years ago out of what is called the Solar Nebula or ‘protoplanetary-disk’. Using computer models a team of astronomers now believe that the Giant planet Jupiter was actually formed at the orbit of Mercury, and that the planet then migrated out to its present position in space.

At the moment Jupiter’s core is generally assumed to have formed beyond the snow line.

The “snow line” (also called frost line, ice line, snow boundary, etc.) is the distance from a central protostar at which ice grains can form, this occurs at temperatures of about 150-170 Kelvin.  At the snow line, the density of solid particles in the disk increases abruptly.  This increase in solid-particle surface density changes the time and mass-scales of planets that form beyond this distance. Observations of asteroids and inspection of meteorites in our solar system suggest that the snow line is located in ‘The Asteroid Belt’ 2.7 AU from the Sun (beyond this radius, the asteroids are much more water-rich). 

Now in a new research paper Sean N. Raymond and his team say that they now believe that Jupiter’s core may have accumulated in the innermost parts of the protoplanetary disk. A growing body of research suggests that small particles (“pebbles”) continually drift inward through the disk. If a fraction of drifting pebbles is trapped at the inner edge of the disk a several Earth-mass core can quickly grow. Subsequently, the core may migrate outward beyond the snow line via planet-disk interactions. Of course, to reach the outer Solar System Jupiter’s core must travel through the terrestrial planet-forming region (Mercury > Mars).

Ashampoo_Snap_2016.06.13_22h31m14s_004_Figure 6: (Raymond et al.) The inner Solar System sculpted by Jupiter’s outward-migrating core. Embryos are shown in blue and planetesimal in gray. Embryos were dynamically cleared from the inner parts of the disk, creating a mass deficit similar to the actual one. The core’s outward migration also stimulated the formation of a second large core of 1:12 ME SATURN that survived at 5.8 AU, in 4:5 resonance with Jupiter’s core. Finally, planetesimal from very close to the Sun were transported outward by the core’s migration and deposited in the asteroid belt.

[5.8 AU = about 53,914,000 miles] [Time Scale = 1 to 5 million years]

Sean N. Raymond and his team used N-body simulations including synthetic forces from an underlying gaseous disk to study how the outward migration of Jupiter’s core sculpts the terrestrial zone. If the outward migration is fast (104 million years), the core simply migrates past resident planetesimal and planetary embryos. However, if its migration is slower (105 million years) the core removes solids from the inner disk by shepherding objects in mean motion resonances. In many cases the disk interior to 0.5-1 AU is cleared of embryos and most planetesimal. By generating a mass deficit close to the Sun, the outward migration of Jupiter’s core may thus explain the absence of terrestrial planets closer than Mercury.

Jupiter’s migrating core would stimulates the growth of another large ( Earth-mass) core – that may provide a seed for Saturn’s core – trapped in exterior resonance. The migrating Jovian core may also transport a fraction of terrestrial planet forming debris, such as the putative parent bodies of iron meteorites, to the asteroid belt.

Lead Researcher: Sean N. Raymond Laboratoire d’Astrophysique de Bordeaux, CNRS and University´e de Bordeaux, UMR 5804, F-33270, Floirac, France

Monthly Notices of the Royal Astronomical Society, 2016MNRAS.458.2962R

Richard Pearson F.R.A.S.

13 Jun 2016

Looking in Orion the VLT images it’s first exoplanet


Astronomers hunt for planets orbiting other stars (exoplanets) using a variety of methods. One successful method is direct imaging; this is particularly effective for planets on wide orbits around young stars, because the light from the planet is not overwhelmed by light from the host star and is thus easier to spot.

This image demonstrates this technique. It shows a T-Tauri star named CVSO 30, located approximately 1200 light-years away from Earth in the 25 Orionis group (slightly northwest of Orion’s famous Belt). In 2012, astronomers found that CVSO 30 hosted one exoplanet (CVSO 30b) using a detection method known as transit photometry, where the light from a star observably dips as a planet travels in front of it. Now, astronomers have gone back to look at the system using a number of telescopes. The study combines observations obtained with the ESO’s Very Large Telescope (VLT) in Chile, the W. M. Keck Observatory in Hawaii, and the Calar Alto Observatory facilities in Spain.


(RA): 5h 25m 7.52s (Dec): 1° 34' 24.66" Field of view: 0.15 x 0.15 arc-minutes | Click on the images to enlarge.

Using the data astronomers have imaged what is likely to be a second planet! To produce the image, astronomers exploited the astrometry provided by VLT’s NACO and SINFONI instruments.

This new exoplanet, named CVSO 30c, is the small dot to the upper left of the frame (the large blob is the star itself). While the previously-detected planet, CVSO 30b, orbits very close to the star, whirling around CVSO 30 in just under 11 hours at an orbital distance of 0.008 au, CVSO 30c orbits significantly further out, at a distance of 660 au, taking a staggering 27 000 years to complete a single orbit. (For reference, the planet Mercury orbits the Sun at an average distance of 0.39 au, while Neptune sits at just over 30 au.)

If it is confirmed that CVSO 30c orbits CVSO 30, this would be the first star system to host both a close-in exoplanet detected by the transit method and a far-out exoplanet detected by direct imaging. Astronomers are still exploring how such an exotic system came to form in such a short timeframe, as the star is only 2.5 million years old; it is possible that the two planets interacted at some point in the past, scattering off one another and settling in their current extreme orbits.