From AAO: “Remarkable planet discovery”

Australian Astronomical Observatory

July 12, 2017
Science Contacts:
Dr. Simon O’Toole
Web & eReseach Administrator, Australian Astronomical Observatory
+61 434 916 378
simon.otoole@aao.gov.au

Prof. Andrew Hopkins
Head of Research and Outreach, Australian Astronomical Observatory,
+61 432 855 049
andrew.hopkins@aao.gov.au

Media contact:
Andrew Hopkins,
04 3285 5049
andrew.hopkins@aao.gov.au

Rhianwen Whitney,
rhianwen.whitney@usq.edu.au
07 4631 2977

A long time ago in a galaxy far, far away, Luke Skywalker lived on a planet circling twin suns.

While Star Wars is science-fiction, two stars in orbit of each other is firmly based in reality.

An astronomy student working with an Australian Astronomical Observatory (AAO) astronomer has uncovered evidence of a new planet orbiting a binary star (two stars that orbit a common centre of mass).

Adding interest to this discovery is the observation that the planet orbits the stars on a tilt – an example of the weird and wonderful diversity of the Universe.

The binary star, KIC 5095269, system was first observed by NASA’s Kepler space telescope.

NASA/Kepler Telescope

The newly-discovered planet has a mass 7.7 times more than Jupiter and orbits the binary star every 237.7 days.

“My PhD research involves performing an eclipse timing variation study of binary stars in order to look for any third bodies that may be present, like stars/brown dwarfs or planets,” PhD student Kelvin Getley, who lead authored the journal article [MNRAS] announcing the discovery, said.

“I created a program that determined when one star passes in front of another as seen from Earth, and compared them to what we’d expect to see if there was nothing else in the system.

“My PhD supervisors, Professor Brad Carter and Dr Rachel King from the University of Southern Queensland (USQ), and Simon O’Toole from the AAO, guided and advised me, and helped come up with tests that could be done on the system to try to make sure what we were seeing was possible.”

Supervisor and AAO astronomer Dr O’Toole is an expert in exoplanetary systems.

“This is a really neat result,” Dr O’Toole said, “Planets orbiting two stars have been found before, but the cool thing here is that Kelvin has discovered a planet with a tilted orbit, more reminiscent of Pluto than the other planets in our Solar System.”

Professor Carter leads USQ’s Astrophysics Research Program Team and commended Mr Getley on his work and discovery.

“Kelvin’s research demonstrates that evidence for new worlds can be gathered through an innovative analysis of the Kepler space telescope’s treasure trove of observational data,” he said.

Mr Getley is studying a PhD in Astronomy and is an external USQ student living in Charlton, Victoria, with the support of the AAO.

“Being an astronomer is something that I’ve wanted to be basically my entire life,” he said.

“My granddad was interested in astronomy as a hobby so I grew up reading his books. Doing this research, and making a discovery like this is amazing.”

The AAO is a division of the Department of Industry, Innovation and Science.

See the full article here .

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Stem Education Coalition

Anglo-Australian telescope

The Australian Astronomical Observatory, a division of the Department of Industry, Innovation and Science, operates the Anglo-Australian and UK Schmidt telescopes on behalf of the astronomical community of Australia. To this end the Observatory is part of and is funded by the Australian Government. Its function is to provide world-class observing facilities for Australian optical astronomers.

From AAO: “A new laser at the AAT!”

Australian Astronomical Observatory

A new laser at the AAT! Last week we took delivery of the new laser frequency comb for the Veloce spectrograph (https://newt.phys.unsw.edu.au/~cgt/Veloce/Veloce.html), which will replace the AAT’s venerable UCLES instrument early next year. The laser frequency comb will provide Veloce with an ultra-stable calibration source, enabling it to separate tiny Doppler shifts in the wavelength of light from a star caused by orbiting exoplanets from slight drifts in the instrument itself. With this Veloce will be able to measure Doppler shifts of less than 1 part in 300 000 000, equivalent to measuring the motion of a star to a precision of less than 3.6 kilometres per hour!

^AJH

See the full article here .

Please help promote STEM in your local schools.

Stem Education Coalition

Anglo-Australian telescope

The Australian Astronomical Observatory, a division of the Department of Industry, Innovation and Science, operates the Anglo-Australian and UK Schmidt telescopes on behalf of the astronomical community of Australia. To this end the Observatory is part of and is funded by the Australian Government. Its function is to provide world-class observing facilities for Australian optical astronomers.

From AAO: “Supernova 1987A illuminates after 30 years”

Australian Astronomical Observatory

February 23, 2017
Science contact:
Dr. Ángel R. López-Sánchez (AAO/MQU)
Ph: + 61 406 265 917
angel.lopez-sanchez@aao.gov.au

Media contact:
Amanda Bauer (AAO)
Ph: +61 293 724 852 / +61 447 029 368
amanda.bauer@aao.gov.au
61 2 9372 4852/ +61 447 029 368

New CACTI AAT image of the neighbourhood of SN1987A. Credit: Ángel R. López-Sánchez (AAO/MQU), Steve Lee, Robert Patterson, Robert Dean and Jennifer Riding (AAO) & Sarah Martel (UNSW/AAO).

Exactly 30 years ago, humans witnessed the first supernova explosion visible to the unaided eye in almost 400 years. The event provided an unprecedented opportunity for the 3.9metre Anglo-Australian Telescope (AAT), which went on to play a key role in the study of Supernova 1987A.

The stellar outburst seen in 1987 on Earth resulted from the explosion of a massive star called Sanduleak -69° 202 in the Large Magellanic Cloud, one of our closest galaxy neighbours and only visible from the southern hemisphere. Light from the explosion had taken 170,000 years to travel through space before hitting terrestrial telescopes.

Once alerted to news of the supernova in February 1987, astronomers and engineers working at the Australian Astronomical Observatory immediately devised plans for how to make the best observations with the AAT. Observing the supernova became a top priority for the next three weeks, the assumed time that it would remain bright.

But just in case the supernova continued to be visible, AAO’s Peter Gillingham rapidly assembled a very high resolution “Wooden Spectrograph”, since no telescope in the southern hemisphere at the time had this type of technology available to take advantage of observing such a rare, bright supernova. With luck, Supernova 1987A remained observable for several months after it exploded.

Resulting observations hinted that this supernova explosion was not symmetric – it was clumpy and very unusual compared to previously observed exploded stars. This asymmetry was later confirmed in beautiful images taken with the Hubble Space Telescope (Figure 1 below).

Current AAO Director Warrick Couch was an AAO staff member at the time of the supernova’s appearance and recalls “from my perspective, it was an extraordinarily frantic and yet exhilarating time as the Observatory used its entire armoury of skills, inventiveness, and high-tech instruments to capture this remarkable and rapidly evolving event with the AAT.”

What does the neighborhood around Supernova 1987A look like today? AAO astronomer Angel Lopez-Sanchez captured a wide-field image of the region on 16th February 2017 with the new CACTI camera on the AAT (Figures 2 and 5 and see video). The image shows the remnant of Supernova 1987A, with the pink glow of its hydrogen gas, and filaments of gas and dust that stretch over 300 light years to either side.

The new image also reveals a group of pearl-like bubbles, 110 light years away from the explosion site. These bubbles are a sign of youth, indicating this fertile stellar nursery continues to form new stars.

Figure 1: The neighborhood and the remnant of SN 1987A.
Left: New image around the remnant of SN 1987A in the Large Magellanic Cloud taken with the 3.9m Anglo-Australian Telescope. Credit: Ángel R. López-Sánchez (AAO/MQU), Steve Lee, Robert Patterson, Robert Dean and Jennifer Riding (AAO) & Sarah Martel (UNSW / AAO). Top right: Wide Hubble Space Telescope image of the central area, data collected between 1994 and 1997. Credit: Hubble Heritage Team (AURA/STScI/NASA/ESA). Bottom right: Deep Hubble Space Telescope image obtained in 2011 showing the asymmetric structure of the SN 1987A remnant. Credit: ESA/Hubble & NASA.

Figure 3: Supernova 1987A after exploding in February 1987 (left), and an image taken before the explosion (right).
Credit: David Malin / Australian Astronomical Observatory.

Figure 4: The Tarantula Nebula loom to the upper left of where the star Sanduleak -69° 202 exploded as supernova 1987A.
Credit: David Malin / Australian Astronomical Observatory.

igure 5: New CACTI AAT image of the neighbourhood of SN1987A
Diffuse gas and dust in the outskirts of the Tarantula Nebula within the Large Magellanic Cloud. The remnant of SN 1987A appears as a bright red blob near the centre of the image. Data taken on 16th February 2017 using the CACTI camera in 2dF at the 3.9m Anglo-Australian Telescope. A Hubble Space Telescope (HST) image is included at the position where SN 1987A is located. Credit: Ángel R. López-Sánchez (AAO/MQU), Steve Lee, Robert Patterson, Robert Dean and Jennifer Riding (AAO) & Sarah Martel (UNSW / AAO).

Acess mp4nvideo here .
This 40 seconds animation shows a zooming into the SN1987A remnant in the Large Magellanic Cloud. It compiles 4 images: the full view of the Tarantula Nebula, as seen by the AAT years before the explosion on 23 February 1987, a new image of the neighbourhood of the supernova obtained with the new CACTI camera at the AAT, and wide and deep images obtained with the Hubble Space Telescope showing the asymmetry of the SN 1987A remnant.

Credit: Australian Astronomical Observatory. Credit of the composition: Ángel R. López-Sánchez (AAO/MQU). Credit of the individual images: Tarantula Nebula with the AAT: David Malin (AAO), CACTI image with the AAT: Credit: Ángel R. López-Sánchez (AAO/MQU), Steve Lee, Robert Patterson, Robert Dean and Jennifer Riding (AAO) & Sarah Martel (UNSW / AAO), Wide Hubble Space Telescope image: WFPC2, Hubble Heritage Team (AURA/STScI/NASA/ESA), Deep Hubble Space Telescope image: ACS, ESA/Hubble & NASA.

See the full article here .

Please help promote STEM in your local schools.

Stem Education Coalition

Anglo-Australian telescope

The Australian Astronomical Observatory, a division of the Department of Industry, Innovation and Science, operates the Anglo-Australian and UK Schmidt telescopes on behalf of the astronomical community of Australia. To this end the Observatory is part of and is funded by the Australian Government. Its function is to provide world-class observing facilities for Australian optical astronomers.

From AAO: Women in STEM – “AAO student intern Lizzie Elmer targets opportunity”

Australian Astronomical Observatory

September 16, 2016
This is a guest post from AAO student intern Lizzie Elmer who came from the University of Nottingham to work with us from June to September 2016.

Student intern Lizzie Elmer with the 2dF instrument on the AAT telescope. (Credit: Lizzie Elmer)

AAO Anglo Australian Telescope near Siding Spring, New South Wales, Australia

In June, I landed at Sydney airport more than a little apprehensive about my student fellowship. Suddenly living on the other side of the world for three months seemed a lot more daunting than it had while I was safely in England! I had given myself a few days to settle into my accommodation and get over my jet lag, and then headed to the North Ryde offices of the AAO for my first day. Before I knew it I found myself sat at a desk with a new email address and a pile of reading to help me get started on my project.

My project was to program a “Target of Opportunity” mode for the 2dF – AAOmega instrument. This is an override mode so that if a priority astronomical event happens during the night, like a supernova explosion or a gravitational wave event, the target can be viewed within a few minutes with the 4-metre Anglo-Australian Telescope (AAT).

The whole way through my project, my supervisors (Chris Lidman and Tony Farrell) were always on hand to answer the smallest questions and give me encouragement. With their help, I managed to have a completed version of the code ready for testing halfway through my 12 weeks. After this, there were sky tests to organise and documentation to write up, as well as a mini project to help Chris prepare a catalogue for his observing time.

In late July, the two other student fellows and I were given the opportunity to visit the AAT in person. After a safety induction, we were given access to the telescope control room and allowed to sit in on the night time observing!

We were very lucky that while we were there the skies were perfectly clear and I was overwhelmed by just how many stars were visible when there was no light pollution. As a Londoner, I always thought the stars from the English countryside were pretty impressive but they paled to nothing next to seeing the Milky Way above Siding Spring Observatory.

While on site, Chris organised for us to tour many of the telescopes on site at Siding Spring.

Siding Spring Campus

Given the size of the site, I felt like we saw every type of telescope possible by the end of our stay! My favourite (other than the AAT of course!) was the iTelescope set up.

http://hosting.itelescope.net/

This building contains 25 smaller telescopes that can be controlled remotely by amateur astronomers. I love that there is a facility on site that is accessible to those outside of the research community.

We also had the chance to explore some of the local bush and take in some of the breath-taking views of the Warrumbungle National Park. Then Doug Gray, the AAO site manager, enlisted our help for the incredibly complex job of helping him build a new bookshelf.

Back in Sydney, everyone in the office was friendly and welcoming. I got into the habit of joining in the morning and afternoon tea breaks organised by the tea and biscuit club, so quickly felt like I was part of what was going on.

One of the best parts for me was the organised ‘Ladies who Lunch’ once a month. I loved hearing about the developments in diversity awareness and what experiences the women in the office have had in a very male-dominated field. I also enjoyed the weekly colloquia where speakers from various institutions around the world presented their research.

I had the chance to give a short talk on my own project towards the end of my internship. Although this was a little nerve racking, my project was really well received and it was great to see that I had been working on something people really wanted.

The telescope control software showing Lizzie’s Target of Opportunity code. (Credit: AAO)

As I finished the code for my project fairly quickly, we were able to get some service time on the AAT to test the software while I was still in the country; seeing the tab on the telescope’s user interface that would run my code was very exciting! Unfortunately, it was cloudy on our allocated night of observing, but I got the chance to control the telescope and run the software with the dome shut. When the software ran successfully, it was a relief to see that it didn’t break the 2dF robot or the telescope! Now there are just final tests to check that the correct target is being viewed, and then it will be ready for use!

It has been an absolutely incredible experience to work at the AAO for 12 weeks. I have learnt so much just by listening to people talk about their research, and it has helped me know for sure that I want to start a career in astronomy. Thank you to everyone for being so helpful and making me feel so welcome.

See the full article here .

Please help promote STEM in your local schools.

Stem Education Coalition

Anglo-Australian telescope

The Australian Astronomical Observatory, a division of the Department of Industry, Innovation and Science, operates the Anglo-Australian and UK Schmidt telescopes on behalf of the astronomical community of Australia. To this end the Observatory is part of and is funded by the Australian Government. Its function is to provide world-class observing facilities for Australian optical astronomers.

From AAO: “4MOST — 4-metre Multi-Object Spectroscopic Telescope”

Australian Astronomical Observatory

The Instrumentation Group at the AAO is developing the AESOP instrument for a major international consortium called 4MOST, for the European Southern Observatory (ESO). The AESOP positioner is based on the AAO’s patented ‘Echidna’ fibre-positioning technology, which has been deployed at Japan’s 8-m Subaru telescope in Hawai’i.

NAOJ/Subaru Telescope at Mauna Kea Hawaii, USA

Because the AAO is providing a critical technology that cannot be sourced elsewhere, Australia is the only one of the 13 international partners in this consortium that is not an ESO member.

4MOST will upgrade the 4-m VISTA telescope in Chile with a revolutionary, massively multiplexed spectroscopic capability and is intended to complement three key all­-sky, space­-based ob­servatories: Gaia, EUCLID, and eROSITA.

In addition to several European-led surveys, Simon Driver of UWA will lead the WAVES survey with 4MOST: a 2 million galaxy survey designed to unlock some of the mysteries of dark matter and galaxy formation.

https://www.4most.eu/

The 4MOST consortium has been selected by the European Southern Observatory (ESO) to provide the ESO community with a fibre-fed spectroscopic survey facility on the VISTA telescope with a large enough field-of-view to survey a large frac­tion of the southern sky in a few years.

ESO/Vista Telescope

The facility will be able to simultaneously obtain spectra of ~2400 objects distributed over an hexagonal field-of-view of 4 square degrees. This high multiplex of 4MOST, combined with its high spectral resolution, will enable detection of chemical and kinematic substructure in the stellar halo, bulge and thin and thick discs of the Milky Way, thus help unravel the origin of our home galaxy. The instrument will also have enough wavelength coverage to secure velocities of extra-galactic objects over a large range in red­shift, thus enabling measurements of the evolution of galaxies and the structure of the cosmos.

This exceptional instrument enables many science goals, but the design is especially intended to complement three key all­-sky, space­-based ob­servatories of prime European interest: Gaia, EUCLID, and eROSITA.

ESA/Gaia satellite

ESA/Euclid spacecraft

eROSITA

Such a facility has been identified as of critical importance in a number of recent European strategic documents (Bode et al., 2008; de Zeeuw & Molster, 2007; Drew et al., 2010; Turon et al., 2008) and forms the perfect com­plement to the many all­-sky survey pro­jects around the world.

4MOST is currently in its Preliminary Design Phase with an expected start of science operations in 2021.

See the full article here .

Please help promote STEM in your local schools.

Stem Education Coalition

Anglo-Australian telescope

The Australian Astronomical Observatory, a division of the Department of Industry, Innovation and Science, operates the Anglo-Australian and UK Schmidt telescopes on behalf of the astronomical community of Australia. To this end the Observatory is part of and is funded by the Australian Government. Its function is to provide world-class observing facilities for Australian optical astronomers.

From Australian Astronomical Observatory: “Full concept animation of the GMT” Video

Australian Astronomical Observatory

Great fly through animation of the Giant Magellan Telescope, currently under construction in Chile. Australia is a 10% partner.
Incredible.

The Giant Magellan Telescope (GMT) is a ground-based extremely large telescope under construction, planned for completion in 2025.
The location of the telescope is Las Campanas Observatory.

Watch, enjoy, learn.

The Giant Magellan Telescope will be one of the next class of super giant earth-based telescopes that promises to revolutionize our view and understanding of the universe. It will be operational in about 10 years and will be located in Chile.

The GMT has a unique design that offers several advantages. It is a segmented mirror telescope that employs seven of today’s largest stiff monolith mirrors as segments. Six off-axis 8.4 meter or 27-foot segments surround a central on-axis segment, forming a single optical surface with an aperture of 24.5 meters, or 80 feet in diameter. The GMT will have a resolving power 10 times greater than the Hubble Space Telescope. The GMT project is the work of a distinguished international consortium of leading universities and science institutions.

The $1 billion project is US-led in partnership with Australia, Brazil, and Korea, with Chile as the host country.

Organizations

The project is US-led in partnership with Australia, Brazil, and Korea, with Chile as the host country.[4] The following organizations are members of the consortium developing the telescope.[27]

Observatories of the Carnegie Institution of Washington
University of Chicago
Harvard University
Smithsonian Astrophysical Observatory
Texas A&M University
University of Arizona
University of Texas at Austin
Australian National University
Astronomy Australia Limited
Korea Astronomy and Space Science Institute (한국천문연구원)
University of São Paulo

See the full article here .

Please help promote STEM in your local schools.

Stem Education Coalition

Anglo-Australian telescope

The Australian Astronomical Observatory, a division of the Department of Industry, Innovation and Science, operates the Anglo-Australian and UK Schmidt telescopes on behalf of the astronomical community of Australia. To this end the Observatory is part of and is funded by the Australian Government. Its function is to provide world-class observing facilities for Australian optical astronomers.

From Astronomy: “Cosmic beacons reveal the Milky Way’s ancient core”

Astronomy Magazine

April 22, 2016
Leibniz Institute for Astrophysics, Potsdam, Germany

The plane of our galaxy as seen in infrared light from the WISE satellite.

NASA/Wise Telescope

The bulge is a distinct component in the central part of the galaxy and rotates cylindrically. An ancient population, which does not exhibit cylindrical rotation, has been detected in the inner Milky Way. This population is estimated to be 1 percent of the mass of the bulge, and it is likely to have been one of the first parts of the Milky Way to form.
NOAO/AURA/NSF/AIP/A. Kunder

An international team of astronomers led by Andrea Kunder of the Leibniz Institute for Astrophysics Potsdam (AIP) in Germany has discovered that the central 2,000 light-years within the Milky Way Galaxy hosts an ancient population of stars. These stars are more than 10 billion years old and their orbits in space preserve the early history of the formation of the Milky Way.

For the first time the team kinematically disentangled this ancient component from the stellar population that currently dominates the mass of the central galaxy. The astronomers used the AAOmega spectrograph on the Anglo Australian Telescope near Siding Spring, Australia, and focused on a well-known and ancient class of stars, called RR Lyrae variables.

AAO Anglo Australian Telescope near Siding Spring, Australia

These stars pulsate in brightness roughly once a day, which make them more challenging to study than their static counterparts, but they have the advantage of being “standard candles.” RR Lyrae stars allow exact distance estimations and are found only in stellar populations more than 10 billion years old, for example, in ancient halo globular clusters. The velocities of hundreds of stars were simultaneously recorded toward the constellation Sagittarius over an area of the sky larger than the full Moon. The team therefore was able to use the age stamp on the stars to explore the conditions in the central part of our Milky Way when it was formed.

Just as London and Paris are built on more ancient Roman or even older remains, our Milky Way Galaxy also has multiple generations of stars that span the time from its formation to the present. Since heavy elements, referred to by astronomers as “metals,” are brewed in stars, subsequent stellar generations become more and more metal-rich. Therefore, the most ancient components of our Milky Way are expected to be metal-poor stars. Most of our galaxy’s central regions are dominated by metal-rich stars, meaning that they have approximately the same metal content as our Sun and are arrayed in a football-shaped structure called the “bar.” These stars in the bar were found to orbit in roughly the same direction around the galactic center. Hydrogen gas in the Milky Way also follows this rotation; hence, it was widely believed that all stars in the center would rotate in this way. But to the astronomers’ astonishment, the RR Lyrae stars do not follow football-shaped orbits, but have large random motions more consistent with their having formed at a great distance from the center of the Milky Way. “We expected to find that these stars rotate just like the rest of the bar,” states lead investigator Kunder. Juntai Shen of the Shanghai Astronomical Observatory said, “They account for only one percent of the total mass of the bar, but this even more ancient population of stars appears to have a completely different origin than other stars there, consistent with having been one of the first parts of the Milky Way to form.”

The RR Lyrae stars are moving targets — their pulsations result in changes in their apparent velocity over the course of a day. The team accounted for this and was able to show that the velocity dispersion or random motion of the RR Lyrae star population was high relative to the other stars in the Milky Way’s center. The next steps will be to measure the exact metal content of the RR Lyrae population, which gives additional clues to the history of the stars and enhance by three or four times the number of stars studied, that presently stands at almost 1,000.

See the full article here .

Please help promote STEM in your local schools.

Stem Education Coalition

From AAO: ” The Taipan Galaxy Survey”

Australian Astronomical Observatory

The Taipan galaxy survey

Taipan is a multi-object spectroscopic galaxy survey starting in late 2016 that will cover the whole southern sky and will obtain spectra for over 1 million galaxies in the local Universe (z<0.3) over 4 years. This will be the most comprehensive spectroscopic survey of the southern hemisphere ever undertaken.

The Taipan galaxy survey will use the refurbished 1.2m UK Schmidt Telescope at Siding Spring Observatory with the new TAIPAN instrument which includes an innovative starbugs optical fibre positioner and a purpose-built spectrograph.

Siding Spring Observatory

1.2m UK Schmidt Telescope at Siding Spring Observatory

The main science goals of Taipan are:

to measure the present-day expansion rate of the Universe, H0, to 1% precision, and the growth rate of structure to 5%;
to make the most extensive map of the mass distribution and motions in the local Universe using peculiar velocities;
to understand the role of mass and environment in the evolution of galaxies.

The TAIPAN instrument will also be used for the FunnelWeb stellar survey, which will characterize the brightest 2 million stars in our Milky Way Galaxy, and inform future studies of exoplanets that may orbit those stars.

The TAIPAN instrument

The TAIPAN instrument is a prototype for MANIFEST, which will be installed on the Giant Magellan Telescope by mid-2020s.

Giant Magellan Telescope

TAIPAN consists of a 150-fibre robot positioner and a dedicated spectrograph, and will achieve ‘first light’ on the UK Schmidt Telescope in mid-2016.

The starbugs are a brand new technology developed at the Australian Astronomical Observatory to enable parallel repositioning of hundreds of fibres at once [Image credit: AAO].

See the full article here .

Please help promote STEM in your local schools.

Stem Education Coalition

Anglo-Australian telescope

The Australian Astronomical Observatory, a division of the Department of Industry, Innovation and Science, operates the Anglo-Australian and UK Schmidt telescopes on behalf of the astronomical community of Australia. To this end the Observatory is part of and is funded by the Australian Government. Its function is to provide world-class observing facilities for Australian optical astronomers.

From AAO: “AESOP”

Australian Astronomical Observatory

AESOP is the fibre positioner unit for the 4MOST instrument planned for the 4-metre European Southern Observatories VISTA telescope in Chile.

4MOST 4-metre Multi-Object Spectroscopic Telescope

ESO/VISTA telescope

The 4MOST project, led by the Astrophysical Institute Potsdam (Germany), involves a number of European partners. The AAO component, AESOP, deploys 2400 optical fibres to required positions on the curved focal surface of the telescope. Each fibre can be deployed anywhere within a fixed patrol area. Field reconfigurations are achieved in an iterative closed-loop process with positional feedback from a metrology system. Optical fibres are connectorised at their exit from the positioner system, where they feed a fibre bundle terminated a series of optical spectrographs. The proposed design for AESOP is an evolution of the AAO’s tilting spine technology, first designed and implemented in the FMOS-Echidna instrument for the Subaru telescope.

FMOS on the NAOJ Subaru telescope

NAOJ Subaru telescope

See the full article here .

Please help promote STEM in your local schools.

Stem Education Coalition

Anglo-Australian telescope

The Australian Astronomical Observatory, a division of the Department of Industry, Innovation and Science, operates the Anglo-Australian and UK Schmidt telescopes on behalf of the astronomical community of Australia. To this end the Observatory is part of and is funded by the Australian Government. Its function is to provide world-class observing facilities for Australian optical astronomers.

From AAO: “A ring of fireworks around a nearby galactic collision”

Australian Astronomical Observatory

October 15, 2015
No Writer Credit

Using the 1.2m UKST, a team of astronomers has discovered the closest collisional ring around a galaxy. This very rare structure, that has been dubbed Kathryn’s Wheel, is quickly converting gas into stars in a massive fireworks display.

An international team of astronomers led by Prof. Quentin Parker (The University of Hong Kong / Australian Astronomical Observatory) has discovered that the nearby galaxy ESO 179-13 possesses a giant ring rich of nebulae and new-formed stars around it. This rare structure has been induced by the direct collision of two galaxies, that has triggered the fireworks in the system. This huge star-forming ring has been dubbed Kathryn’s Wheel in honour of the wife of one of its discoverers, Prof. Albert Zijlstra, (University of Manchester, UK).

The system was discovered as part of the observations of the AAO/UK Schmidt Telescope (UKST) Survey for Galactic H-alpha emission. Completed in late 2003, this survey used the 1.2m UKST at Siding Spring Observatory (NSW, Australia) to get wide-field photographic data of the Southern Galactic Plane and the Magellanic Clouds using a H-alpha filter. This special filter is able to trace the gaseous hydrogen (and not the stellar emission) within galaxies, allowing astronomers to detect the ionized gas from nebulae. The survey films were scanned by the SuperCosmos measuring machine at the Royal Observatory, Edinburgh (UK), to provide the online digital atlas “SuperCOSMOS H-alpha Survey” (SHS).

(Left)[?] Colour image of the collision, made by combining data obtained at the Cerro-Tololo InterAmerican Observatory (CTIO) 4-metre telescope in Chile. The H-alpha image is shown in red and reveals the star-forming ring around the galaxy ESO 179-13, that has been dubbed “Kathryn’s Wheel”. Image credit: Ivan Bojicic / the research team. (Left) [?] Image showing only the pure H-alpha emission of the system highlighting just the areas of active star formation. For clarity any remaining stellar residuals have been removed. Image credit: Quentin Parker / the research team.

CTIO/Victor M Blanco 4 meter telescope in Chile

The galaxy ESO 179-13 is located in the Ara (the Altar) constellation, at a distance of 30 million light years. The reason why this magnificent collisional ring structure has been unknown by astronomers is that the galaxy is located behind our own Milky Way and very close to a bright foreground star.

Prof. Parker and his team used the SHS survey to search for dying sun-like stars in our Galaxy traced by the emission of the atmospheres released by the dying stars (planetary nebulae), that usually show ring morphologies. The astronomers were very surprised to find such ring structures not around a star, but around a nearby galaxy (ESO 179-13). Follow-up observations of the system confirmed that the ring is consequence of the collision of two galaxies of similar mass. The ring structure is created by a powerful shock wave that sweeps up gas and dust, triggering the formation of new stars as the shock wave moves outwards. The most famous collisional ring galaxy is the Cartwheel (ESO 350-40) galaxy, which is located at 500 million light-years away in the Southern constellation of the Sculptor (that is, 40 times further than Kathryn’s Wheel).

This image shows the Cartwheel Galaxy as seen from Hubble Space Telescope [HST]

HST

The discovery SHS images of the system reveal 3 main structures (A, B and C) plus tens of H-alpha emitting knots making the ring. Component A is the remnant of the main galaxy, the collisional ring is centred on it. Component A does not possess ionized gas (that is, it does not have star-formation at the moment). On the other hand, component B seems to be the irregular, dwarf galaxy (“the bullet”) that impacted with the main galaxy. Component B does possess a clumpy and intense H-alpha emission.

Discovery images of the “Kathryn’s Wheel” using the data obtained at the 1.2m UKST by the “SuperCOSMOS H-alpha Survey” (SHS). The left panel (SR) shows the red image tracing mainly the stars. The three main components of the system are labelled. The central panel shows the image using the H-alpha filter (Ha), which sees both the diffuse ionized gas and the stars. The right panel (Ha-SR) shows the continuum-substracted image of the system, revealling for the very first time the intense collisional star-forming ring. Image credit: Quentin Parker / the research team.

Furthermore, Kathryn’s Wheel possesses a lot of diffuse, neutral hydrogen in its surroundings. This cold gas is the raw fuel that galaxies need to create new stars. Observations using the 64-m Parkes radiotelescope (“The Dish”, Parkes, NSW) as part of the “HI Parkes All-Sky Survey” (HIPASS) revealed that the amount of neutral gas around Kathryn’s Wheel is similar to the amount of mass found in stars in the system. Astronomers are unsure about from where this cold gas is coming from, although they suspect it mainly belonged to the main galaxy before the collision started. However, as the remnant of the galaxy (component A) does not have star-formation at the moment, it seems that the diffuse gas has been expelled from the centre of the system to the outskirts of the galaxy.

Collisional ring galaxies are extremely rare in the Universe, only 20 of these objects are known. Kathryn’s Wheel is an ideal target for detailed studies aiming to understand how these rare collisional ring galaxies are formed, the physics behind these structures, and their role in galaxy evolution. Interestingly, the collisional ring is not very massive: its mass is only a few thousand million Suns. This is less than ~1% of the Milky Way mass, indicating that ring galaxies can be formed around small galaxies, something that was not considered so far.

The results were published in MNRAS in August 2015 (link is external).

MNRAS 452, 3759–3775 (2015) doi:10.1093/mnras/stv1432
Kathryn’s Wheel: a spectacular galaxy collision discovered in the Galactic neighbourhood
Authors: Quentin A. Parker (quentinp@hku.hk (link sends e-mail)), Albert A. Zijlstra, Milorad Stupar, Michelle Cluver, David J. Frew, George Bendo and Ivan Bojicic

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