- RECENT HEADLINES
- LT helps discover huge nova "super-remnant" in another galaxy
- Liverpool Telescope helps find source of high energy neutrinos
- Exploring new astronomical database technologies — a collaborative workshop between LJMU and Thailand
- New Robotic Telescope workshop held in Liverpool
This is a composite image of Liverpool Telescope data (bottom left) and Hubble Space Telescope data (top right) of the nova super-remnant. M31N 2008-12a is in the middle of the image. Credit: Matt Darnley / LJMU.
An international team of astrophysicists have uncovered an enormous bubble currently being "blown" by the regular eruptions from a binary star system within the Andromeda Galaxy.
As reported in this week's Nature, recent observations with the Liverpool Telescope and Hubble Space Telescope, supported by spectroscopy from the Gran Telescopio Canarias, and the Hobby-Eberly Telescope (some of the largest astronomy facilities on Earth) discovered this enormous shell-like nebula surrounding ‘M31N 2008-12a’, a recurrent novae located in our neighbouring Andromeda Galaxy. At almost 400 lightyears across and still growing, this shell is far bigger than a typical nova remnant (usually around a lightyear in size) and even larger than most supernova remnants.
Dr Matt Darnley, lead author on the study and Reader in Time Domain Astrophysics at Liverpool John Moores University's Astrophysics Research Institute explains: “Each year ‘12a’ (as we lovingly refer to it) undergoes a thermonuclear eruption on the surface of its white dwarf. These are essentially hydrogen bombs, which eject material equivalent to about the mass of the Moon in all directions at a few thousand kilometres per second. These ejecta act like a snow plough, piling the surrounding ‘interstellar medium’ up to form the shell we observe – the outer ‘skin’ of the bubble, or the ‘super-remnant’ as we have named it.”
These new observations coupled with state-of-the-art hydrodynamic simulations (carried out at LJMU and the University of Manchester) have revealed that this vast shell is in fact the remains of not just one nova eruption but possibly millions – all from the same system.
Despite its uniqueness and staggering scale, the discovery of this super-remnant may have further significance.
Dr Matt Darnley continued: “Studying 12a and its super-remnant could help is to understand how some white dwarfs grow to their critical upper mass and how they actually explode once they gets there as a ‘Type Ia Supernova’. Type Ia supernovae are critical tools used to work out how the universe expands and grows.”
In a related work, also led by Matt Darnley, this team has predicted that 12a will ultimately explode as a Type Ia Supernova in less than 20,000 years – a very short time in cosmological terms.
Dr Rebekah Hounsell, second author on both studies and a post-doctoral researcher at the University of Pennsylvania, explains: “These are some of the largest explosions in the Universe (type Ia supernovae). Such an event in the Andromeda galaxy (M31) would be one of the closest supernovae observed by telescopes (the last one in M31 was in 1885 and in the Large Magellanic Cloud in 1987). The last one in our own galaxy (that we actually saw) was 1604. Although we’ve predicted that 12a will undergo a supernovae explosion in less than twenty thousand years – that sounds a long time, but of course that could still mean within the next decade or so.”
The Liverpool Telescope contributed to the multiwavelength follow-up campaign of the blazar TXS 0506+056, published last month in Science (IceCube Collaboration, Science, 2018, 361, 1378: arXiv:1807.08816). The campaign was prompted by the detection on 22 September 2017 of a neutrino with an energy of ~290 tera electron volts, by the IceCube Neutrino Observatory at the South Pole. The observatory consists of thousands of sensors buried in a cubic kilometre of Antarctic ice, designed to detect the Cherenkov radiation from charged particles.
The neutrino detection was consistent with the gamma-ray blazar TXS 0506+056, which was observed to be in a flaring state at the time. The extensive campaign which followed involved observations from across the electromagnetic spectrum, with the Liverpool Telescope contributing early spectra of the galaxy obtained with its SPRAT classification spectrograph.
The observation of a neutrino in spatial coincidence with a gamma-ray–emitting blazar during an active phase suggests that blazars are a source of high-energy neutrinos, and moreover this event marks the beginning of the era of neutrino astronomy, a 'multimessenger' method combining both electromagnetic and non-electromagnetic means of observation.
Previous detections of individual astrophysical sources of neutrinos are limited to the Sun and the famous supernova 1987A: the era of neutrino astronomy will hopefully reveal the sources of high energy cosmic rays in the Universe, since neutrinos, gamma-rays and cosmic rays should all be produced by the same physical processes.
The ARI-NARIT joint development team. Left to right: Bovornpratch Vijarnwannaluk, Pathompong Butpan, Utane Sawangwit, Marco Lam, Andrzej Piascik, Chris Copperwheat, Robert Smith, Iain Steele.
Liverpool John Moores University (LJMU) Astrophysics Research Institute (ARI) recently hosted a 3-week Newton Fund collaboration workshop with the National Astronomical Research Institute of Thailand (NARIT). LJMU and NARIT both own and operate their own 2-metre class telescopes: LJMU's Liverpool Telescope, and NARIT's Thai National Observatory.
Both institutes developed a common interest in exploiting new technologies for data management and archiving. These new systems will be used for their existing telescope facilities, and also for LJMU's proposed 4-metre class New Robotic Telescope (commonly known as "Liverpool Telescope 2"), on which NARIT is collaborating.
The joint development team compared the feasibility of using PostgreSQL (PSQL) and Elasticsearch (ES) as the core engine of a new archive system for astronomical data. LJMU developers Dr Marco Lam and Dr Andrzej Piascik worked with Bovornpratch Vijarnwannaluk and Pathompong Butpan from NARIT, to compare the efficiency of an ES search engine to that of a conventional relational database.
In the final week, Dr Utane Sawangwit from NARIT also joined us to conclude the project. This entailed the production of a complete prototype web front end for the demonstrator archives. A poster paper describing the work was presented in the Software Session of the European Week of Astronomy and Space Science 2018. A joint research paper will also be presented at the June SPIE 2018 Astronomical Telescopes conference in Austin, Texas.
LJMU staff were joined by representatives from the Instituto de Astrofísica de Canarias, the National Astronomical Research Institute of Thailand, and by videolink the National Astronomical Observatory of China.
On the first day, following a tour of the Astrophysics Research Institute, the focus was on the new science the telescope will enable, with a series of presentations covering all of the major topics within the NRT science case. This was followed by a workshop dinner. As well as the delegates, the dinner was attended by Prof. Ahmed Al-Shamma'a, the Dean of the Faculty of Engineering and Technology; and Prof. Robin Leatherbarrow, the Pro Vice-Chancellor for Research.
On day two, the focus was on the new technologies needed to build the telescope. Each group presented an overview of their technical capabilities, and then a lively debate was held over the various parameters of the NRT design. The meeting concluded with a round table discussion on the building and formalising of the funding consortium. This was an extremely fruitful exercise, being the first time the partners and current prospective partners have come together to discuss a way forward for the project, rather than meeting individually.
With the Lead Engineer and Project Manager for the NRT joining the LT group, and further project office recruitments underway in both Liverpool and Spain, this is an exciting time for us all as we move closer towards realising the goal of building the world's largest robotic telescope!