- RECENT HEADLINES
- Iridis: Insight Astronomy Photographer of the Year 2016
- The Liverpool Telescope's tracking of Gaia
- Call for proposals for CAT semester 2017A
- Call for proposals for PATT semester 2017A
- Call for proposals for JMU semester 2017A
- LT adds spectroscopy to its automatic rapid-response capabilities
- Liverpool Telescope Involved in Gravitational Wave Followup Campaign
- Memorandum Of Understanding signed for development of new 4-metre class telescope
- Gravitational wave science used to search for catastrophic explosion
- LT's polarimetry helps disentangle the cause of double-peaked optical outbursts
JMU employee Robert Smith has claimed a prize in the prestigious international photography competition, the Insight Astronomy Photographer of the Year, with an image obtained from the Liverpool Telescope.
This composite of two images obtained with the Liverpool Telescope compares slit-less spectroscopy of two well known planetary nebulae, NGC6543 (Cat’s Eye Nebula) at the top, and NGC6720 (M57 Ring Nebula) below. In a spectrograph the light is dispersed into its constituent colours. If a target emits light at all wavelengths (such as the star at the centre of each nebula) then it is transformed into a horizontal line and all those colours add up to appear white to our eyes. Planetary nebulae, such as these, only emit light at very specific individual wavelengths. Each of the emission lines creates a separate image in the instrument. A normal image of the nebula is thus decomposed into its individual constituent colours. The particular wavelengths a nebula emits identify the gases of which it consists. Here, the brightest emissions are the red hydrogen-alpha and green oxygen-III lines. The observations were obtained robotically using the Liverpool Telescope and the SPRAT spectrograph which was built by a current LJMU PhD student, Andrzej S. Piascik. All the data used are publicly available from the LT data archive.
Insight Astronomy Photographer of the Year 2016, attracted over 4500 entries from 80 countries and all seven continents. This year saw the first entry from Antarctica! The Liverpool Telescope image, “Iridis”, took first place in the “Robotic Scope” category. The prizewinners were announced during a ceremony at the Royal Observatory Greenwich. The winning images offer a fascinating cross section of everything that can be considered astrophotography, encompassing pictorial landscape, views through powerful telescopes, highly technical image processing and even social commentary.
Creator of the "Iridis" image, Robert Smith, says he was inspired to create it when considering the idea of ‘science as art’. We often hear about the idea of representing scientific data in an appealing way as an expression of art, but why not look at it the other way around; ‘art as acience’? Astrophotography is not just a matter of making science look pretty, it shows us that beauty actually is science. The winners of this competition were obviously selected because they were beautiful, but each and every one is also an expression of astrophysical processes and could be the basis of a seminar in their own right. It is physics that creates that beauty. Looking at the swirling gas in a nebula or the aurorae, you are just literally seeing maths and physics.
“This picture tells us that data can be beautiful. It is as compelling visually as it is scientifically, revealing the mechanics of astrophysical knowledge in minimalist yet stunningly attractive way.” - Melanie Vandenbrouck (member of IAPY judging panel)
All the winning entries may be seen in a free exhibition at the Royal Observatory in Greenwich which runs until June next year and in the Insight Astronomy Photographer of the Year 2016 show, available to planetaria worldwide. Quite apart from seeing the Liverpool Telescope's contribution, a visit to the exhibition is very much worth while if you are near Greenwich over the next year. All the winners and short listed entries are absolutely spectacular and inspiring both in the artistry and science.
Delta-DOR radar tracking by the European Space Agency's Deep Space Antenna network achieves this accuracy, but the network has many missions to cater for and cannot track Gaia every day. Therefore the Liverpool Telescope (LT) and the European Southern Observatory's VLT Survey Telescope (VST) also track Gaia, with the Las Cumbres Observatory's twin Faulkes Telescopes providing backup in case of problems with the LT and VST at the same time..
A recent article in the news website The Conversation goes into this in more detail. Read the full story here:
The CAT Time Allocation Committee has issued a call for proposals for CAT time for observations in Semester 2017A (1st Jan 2017 → 31st Aug 2017).
The deadline for submission of proposals is 17:00 (Canarian local time) on Tuesday, 4th October 2016.
Full details of the the eligibility requirements and application procedure may be found on the CAT website. Briefly, CAT accepts applications for which the principal investigator (PI) is affiliatied to a Spanish Institution. PATT accepts proposals from PIs based in the UK. Some non-UK and non-Spanish PIs are eligible to apply through the OPTICON Trans-national Access programme, or through the International Scientific Committee (CCI). Non-UK PIs who are not eligible for CAT, OPTICON or CCI time may apply through PATT. Please note that each TAC has its own, different application forms.
In addition to the once-per-semester call for proposals, CAT reserves a small proportion of their time allocation to provide rapid response to unforeseen targets of opportunity. You may apply for Reactive Time at any time throughout the year as described here.
Full details of the 17A Call for Proposals are available from the CAT website.
Credit: R. Smith, LT Group
The LT Time Allocation Committee has issued a call for proposals for PATT time for observations in Semester 2017A (1st Jan 2017 → 31st Aug 2017). You may also apply for Reactive Time at any time throughout the year as described here. After taking off 20 hours set aside for Reactive Time, there are 280 hours available to be allocated for PATT in semester 2017A. The deadline for submission of proposals is 17:00 GMT on Monday, 3rd October 2016.
PATT accepts proposals from Principal Investigators (PIs) based in the UK. Employees of Liverpool John Moores University should usually apply through the internal LJMU call. Spanish PIs should apply for LT time through the Comision de Asignacion de Tiempos of the Instituto de Astrofísica de Canarias. Some Non-UK and non-Spanish PIs are eligible to apply through the OPTICON Trans-national Access programme, or through the International Scientific Committee (CCI). Non-UK PIs who are not eligible for CAT, OPTICON or CCI time may apply through PATT.
Full details of the Call for Proposals are available for download as a PDF file from here [ CallForProposals-PATT-17A.pdf ]. The file gives more information about the proposal process, reactive time applications, new and existing instruments, and the telescope's performance and rapid-response capabilities.
We would like to call the attention of applicants to three particular changes in 2017A.
- Some modifications have been made to the rules for Reactive Time. 20 hours of this time are available in 2017A, compared to 9 hours in previous semesters. We have also removed the requirement for applications to be of a maximum 3 hours in length, and this mode of application is now available for both unforseen and rare phenomena, where we define rare phenomena loosely as events that are likely to have a rate of less than one trigger per year.
- We have expanded our RTML capability, providing users with an alternative to the Phase II GUI for communicating with the telescope scheduling software. We can now on request supply users with a tool which will enable them to submit IO:O, IO:I, RISE, FRODOspec and SPRAT groups directly from the command line. This greatly simplifies the submission of long target lists, and also enables LT submission to be incorporated into user programs and scripts. An example use case would be the automatic submission of spectroscopic follow-up groups by a robotic transient discovery facility.
- We are also offering for the first time the ability for users to apply for PriorityZ Time at any time throughout the year. We define PriorityZ time as time when there is no A, B or C-ranked science group available for the scheduling software to pick, and so the telescope would otherwise sit idle. This can occur during periods of poor seeing during full moon, or during times of instrument failure. We estimate approximately 10-15 hours of such time are available per month, although this can of course vary significantly. PriorityZ time is well-suited to long-term proposals of bright targets with no significant time constraints. We would typically expect to approve a PriorityZ proposal for a period of two years.
Credit: R. Smith, LT Group
The Liverpool Telescope Time Allocation Committee is now accepting proposals for JMU time for LT observations in Semester 2017A (1 January 2017 → 31 August 2017). You may also apply for Reactive Time at any time throughout the year.
The deadline for submission of proposals is 17:00 GMT on Monday 3rd October 2016.
The total available time for JMU users in 2017A will be 300 hours. Ten hours have already been allocated in previous rounds and nine hours set aside for Reactive Time proposals, leaving 281 hours available to be allocated. Time is allocated approximately in the ratio 1:1 between Priority A and B. In addition 90 hours will be available as Priority C (backup).
Full details of the Call for Proposals are available for download as a PDF file from here [ CallForProposals-JMU-17A.pdf ]. The file gives more information about the proposal process, reactive time applications, new and existing instruments, and the telescope's performance and rapid-response capabilities.
Simplified flowchart of user RTML submission to LT.
© 2016 LT Group
The low-resolution spectrograph SPRAT recently joined IO:O and IO:I as an instrument that can also be accessed by an alternative method — that in some cases can be faster, more convenient, and allow for immediate response to transient events (TAC permitting of course). This method is RTML.
RTML and the LT
Regular users of the Liverpool Telescope (LT) will be familiar with the standard method of setting up their observations, namely the Java-based Phase 2 User Interface or "Phase2UI".
This user interface, accessible only to registered users of the LT, enables them to manually define their observation details: the coordinates of their targets; the timing of their observations; the instruments and filters to be used; and the number and length of the exposures. The interface transmits this information directly to the telescope's Phase 2 database, which is polled by the robotic scheduler repeatedly through the night between observations to decide what to observe next — i.e. to match the best observation to current conditions.
If using the Phase2UI at night, the new or updated observation group will be considered by the scheduler as soon as it makes its next poll. So it could potentially be chosen and observed mere seconds after the "Submit" button is pressed.
What may not be so widely known is the alternative way of entering observation details, which in some cases is faster and more convenient. It uses the "Remote Telescope Markup Language" (RTML) protocol*, which was invented in 1989 at the University of California at Berkely, USA. It's a special dialect of XML (Extensible Markup Language), and is used to remote-control telescopes, or to communicate with autonomous robotic telescopes.
We provide two different ways to use RTML to send your observation details to the LT. Like the Phase2UI, both of them insert the information straight into the phase 2 database. The advantage however is that they allow you to automate the Phase 2 process, particularly useful if you have a lot of targets or observation groups to enter. The two RTML interfaces are:
- command-line tools:
- one tool to generate the RTML, and another to send the RTML directly to the LT
- can be incorporated into customised scripts and programs
- example use: generating and entering many targets quickly
- LT-specific RTML Application Programming Interface (API):
- allows users to build their own customised GUI tools at their institutions
- GUI makes use of API to generate RTML and send directly to LT
We have in the past provided a third interface: bespoke webpages created by us for users who do not want to program with the command-line tools or API. These restricted-access pages contained HTML forms tailored to a user's specific observing programme. They generated observation details in RTML and transmitted directly to the LT. These pages are now being phased out.
Both RTML interfaces can also talk directly to the Target of Opportunity Control Agent (TOCA), the system that triggers the LT's rapid-response capability to interrupt the current observation and immediately observe your target instead. The LT already does this for Gamma-Ray Burst alerts via a different protocol, but it's also possible via RTML.
As you can imagine, overrides can be very disruptive. Therefore permission to have TOCA capability has to be requested at the Phase 1 stage and approved by the TAC.
RTML capability is being phased in across the LT's suite of instruments. IO:O and IO:I have been available for RTML response for some time, and now SPRAT has been added to the list. FRODOSpec and RISE are next, and we hope to have them available soon.
Applying for RTML capability
The RTML facility is available to all users who have TAC-awarded time allocations. Please contact us if this sounds interesting, and we will provide full user instructions.
Artist's impression of the two binary black hole systems discovered by aLIGO. Credit: LIGO/A.Simmonet
The Liverpool Telescope (LT) is part of a followup collaboration of telescopes set up to find the electromagnetic (EM) component of gravitational wave events detected by the Advanced Laser Interferometer for Gravitational-wave Observations (aLIGO). The flare of light is not expected to last long, so the "traditional" telescopes that detect only EM radiation must respond rapidly to characterise the source objects.
The LT helped in the search for the EM component for the very first gravitational wave (GW) detection event on 14th September 2015. It did so again for the second event, which although announced by aLIGO last week (see https://www.ligo.caltech.edu/news/ligo20160615), actually occurred on 26th December 2015.
aLIGO alerts of GW events are passed to observatories for followup as little as 30 minutes after detection. They give a search area within which the GW event could have occurred. This search area however is huge, and only facilities with very wide fields of view can efficiently make the initial sweep to look for new transient objects. Once flagged, the LT and other EM facilities can characterise each candidate in the list.
In both events no EM facility found an EM component, but the strategy for instant followup of such alerts is now in place, and has been tested successfully several times.
In a paper entitled "Liverpool Telescope follow-up of candidate electromagnetic counterparts during the first run of Advanced LIGO" Chris Copperwheat et al discusses the LT contribution to the follow-up campaign, and describes in detail the LT's followup strategy and its observations of the candidates GW objects. The paper is currently available from here: https://arxiv.org/abs/1606.04574.
LJMU Vice-Chancellor, Prof Nigel Weatherill and the Director of the Instituto de Astrofisica de Canarias (IAC) Prof Rafael Rebolo López have signed a Memorandum of Understanding to explore the design, construction and operation of the new 4.0 metre telescope which will be on a bigger scale than the current Liverpool Telescope (LT) which has been studying the cosmos and making discoveries for over a decade.
The new telescope will be built on the Spanish Canary Island of La Palma and will be 4 times more sensitive and 10 times faster to respond to unexpected celestial events than the current world-record-holding 2-metre LT, also based on La Palma.
The new optical telescope will have the capability to see deeper into the cosmos, observe exploding stars (supernovae, gamma ray bursts, exoplanets and binary stars) and search for new planets, enabling a different type of science. This kind of study (time-domain astrophysics) will greatly increase in the coming decades, therefore the development of the new 4-metre class facility is vital in being able to explore the Universe in greater detail than ever before.
As well as being scientifically world-leading, the design and construction of the new telescope will exploit new technologies in advanced materials, optics and control systems. Researchers are keen for businesses in the region to provide that technology.
The project is also very exciting for the National Schools’ Observatory, which currently gives school children free access to the LT, and will expand to make use of the new telescope, creating an unrivalled opportunity to enthuse a generation of children about science, technology, engineering and mathematics.
Professor Iain Steele from LJMU's Astrophysics Research Institute (ARI) said: "The timing of this agreement is perfect. With new international discovery facilities like the LIGO and Virgo gravitational wave detectors and the Large Synoptic Survey Telescope coming on line over the next decade, a new high sensitivity spectroscopic capability is desperately needed. The new telescope will fill that niche perfectly”.
Professor Chris Collins, Head of the ARI, added: “This is a major opportunity to greatly expand the excellent science currently carried out by the Liverpool Telescope to cosmological distances. Investigating the exotic physics which govern many distant ultra-energetic sources using data from a large and fast reacting new 4m robotic telescope will keep us busy for many years to come.”
Dr Johan Knapen, IAC, commented: "The project builds on the hugely successful collaboration between LJMU and the IAC in building and operating the LT, which has been making discoveries for a decade. We look forward to working closely with LJMU in this project, which is of the highest calibre both technologically and scientifically."
Professor Rafael Rebolo López, IAC, said: "The new telescope will identify hundreds of exceptional astronomical sources each year, from binary black holes and supernovas, to counterparts of gravitational waves sources. By linking the new telescopes observations with those we can make with the Gran Telescopio Canarias we will be able to characterize these new sources in great detail. Both telescopes complement each other very well.”
Prof Ahmed Al-Shamma'a, Dean of the LJMU Faculty of Engineering and Technology said: "The combination of expertise of LJMU's Faculty of Engineering and Technology and the IAC's leading role as a technology development centre for astronomy puts in a unique position to deliver the technology needed for the project. The new telescope is now in the initial design phase and will be of interest to research centres, universities and companies that want to stand out in a technology sector that will have a major development in the coming decades.”
Researchers at Liverpool John Moores University's (LJMU) Astrophysics Research Institute (ARI) using the Liverpool Telescope (LT) were actually among the first to use new gravitational wave science, before the recent announcement by the USA's Caltech and MIT-run Laser Interferometer Gravitational Wave Observatory (LIGO) that they had made the first direct detection of gravitational waves.
Recognised as world leaders in this field, the ARI was asked to participate in a global study using gravitational wave astronomy months before the LIGO revealed gravitational waves had been detected. LIGO made the detection in September and a global collaboration of astronomers was asked to search for the merger of two neutron stars - a catastrophic and explosive event which should be detectable by the world's major telescopes. The LIGO detector gives only an approximate position, so astronomers were required to search a huge area of sky to find the light from the explosion.
The team from LJMU's Astrophysics Research Institute was led by Professor Iain Steele and Dr Chris Copperwheat and one of the many telescopes deployed in the search was the Liverpool Telescope, which used the SPRAT spectrograph, built by LJMU PhD Student Andrzej Piascik, to characterise candidate detections. A paper was published in the Astrophysical Journal giving a complete overview of these observations.
Dr Chris Copperwheat commented: “The search for the explosion was unsuccessful, which was not surprising given that the LIGO was also able to reveal that the event was not from a merging pair of neutron stars but from a merging pair of black holes, which are not expected to have a detectable signature.
“Nevertheless, the exercise was an important test of the capabilities of the astronomical community to coordinate and perform the challenging observations required to follow an event such as this one. We believe there are many more neutron star binaries in the universe than black hole binaries, so given that LIGO has proved its capabilities, the detection of a neutron star merger is now only a matter of time.
“The detection of such an explosive event and the observation of the associated light is the next milestone in this new and transformative field of gravitational wave astronomy.”
Over the next few years the LIGO detectors will be complemented by additional detectors currently under construction around the world, and the combined array should reach full sensitivity by around 2022, at which point astronomers are likely to be able to detect hundreds of gravitational wave events every year.
LJMU is currently developing a new, larger robotic telescope, codenamed Liverpool Telescope 2, which is also expected to come into operation in 2022. One of the core science topics for Liverpool Telescope 2 is gravitational wave astronomy, and the new facility will enable LJMU's Astrophysics Research Institute to play a major role in exploring this new frontier.
Professor Chris Collins, Head of the ARI, added: “It is hugely exciting that we have started doing gravity wave science with the Liverpool Telescope. The recent LIGO results open the way for astronomers to study those energetically violent events in the Universe that give rise to gravity wave ripples."
This story was adapted slightly from that which appeared on the LJMU News site on 11 March 2016.
Credit: Valtonen et al, 2016.
The Liverpool Telescope (LT) recently took part in a ground-breaking campaign to accurately measure the rotational rate of one of the most massive black holes in the universe: the powerhouse behind blazar OJ287. Details behind the discovery are given in a paper in the Astrophysical Journal Letters entitled "Primary Black Hole Spin in OJ287 as Determined by the General Relativity Centenary Flare" by M. J. Valtonen et al (2016).Quasars, Blazars and Black Holes
Quasi-stellar radio sources, or "quasars" for short, are the very bright centres of distant galaxies which emit huge amounts of light, via relativistic jets due to the accretion of large amounts of matter onto their massive black holes. When the jet is pointed toward the observer, the source is called a "blazar". From observations dating back to 1891, the particular blazar "OJ287" has been seen to outburst optically roughly every 12 years. More recent studies have shown that these outbursts actually have double peaks.
Prof. Mauri Valtonen of University of Turku, Finland and his collaborators developed a model to explain the outbursts: two black holes orbiting each other with a period of 12 years, interacting every orbit. The model states that one black hole (the "primary") is ~200 times the mass of the other (the "secondary"), and has an accretion disc. The secondary is in a large very elliptical orbit about the primary, and the plane of its orbit is inclined to that of the accretion disc, so it makes two crossings of the disc every orbit. Each time the secondary punches through the disc, the material it encounters is heated up to very high temperatures. This heated material flows out from both sides of the primary accretion disk and thermally radiates strongly for a few weeks.
Meanwhile, the interaction of the secondary black hole with the primary's accretion disk also results in accretion onto the secondary black hole. It is postulated that the second peak in the outburst is caused by jet emission rather than emission from the accretion disc. Evidence for jet emission is the presence of strong polarisation during the second, but not the first, flare. An accretion disc cannot create a strong polarisation signal; in this case it is likely that the magnetic fields within the jet cause the polarisation signal.
The thermal outbursts can be used as good markers to pinpoint the times when the secondary crosses the plane of the primary's accretion disc. This is useful because Einstein's General Theory of Relativity says the secondary's orbit should precess, at a rate that depends mainly on the two black hole masses and the rotation rate of the primary.The Liverpool Telescope Gets Involved
In 2010, Valtonen and collaborators were able to use the exact timing of eight outbursts to accurately put the secondary's orbital precession rate at an incredible 39 degrees per 12-year orbit, some 27,000 times faster than the relativistic contribution to Mercury's orbital precession rate.
The model also predicted that the next twin-peaked outburst would occur around 25 November 2015, ironically the 100th anniversary of Einstein's General Theory of Relativity. An international observing campaign campaign was set up, calling on observatories from around the world - including the Liverpool Telescope.Countdown to the Next Event
Credit: Valtonen et al, 2016.
OJ287 has actually been observed by the LT since 2011, and was more closely monitored from September 2015 as part of the leadup to the predicted outburst. When the increase in flux began in late November 2015, PhD student Helen Jermak, the Principal Investigator of proposal JL16A08 using the RINGO3 polarimeter on the LT, was prompted to increase the cadence of the OJ287 monitoring observations from every 3 days to hourly, to closely follow the "flare" of this outburst.
The LT automatically tracked the source many times per night, taking photometric and polarimetric data with RINGO3. The polarimetry taken during the second peak allowed the authors to study the effect of the interaction between the secondary black hole and primary accretion disc on the primary's jet.Another Black Hole Binary and More Gravitational Waves
Thanks to the valuable contribution of this data plus that of other observatories, Valtonen and his co-workers were able to directly measure the rotation rate of the more massive black hole to be one third of the maximum spin rate allowed in General Relativity.
The collected data from this latest outburst also allowed the team to confirm the loss of orbital energy to gravitational waves within two per cent of General Relativity's prediction. This provides the first indirect evidence for the existence of a massive spinning black hole binary emitting gravitational waves.
This is encouraging news for the Pulsar Timing Array efforts that will directly detect gravitational waves from such systems in the near future. Therefore, the present optical outburst of OJ287 makes a fitting contribution to the centenary celebrations of General Relativity and adds to the excitement of the first direct observation of a transient gravitational wave signal by LIGO.