UNTIL FURTHER NOTICE DUE TO THE COVID-19 SITUATION MEETINGS WILL BE STREAMED ONLINE TO SIGMA AND AFFILIATED CLUB MEMBERS. MEETINGS WILL RESUME IN DUE COURSE AT LHANBRYDE.
Meetings are held on the first Friday* of every month
Doors open at 7pm for a 7.30pm start.
Non-members are always welcome – please contact us.
* Please note that the January meeting may be held later in the month.
Friday, 7 January 2022
Echo-mapping of Supermassive Black Holes
Dr Juan Santisteban, University of St Andrews
Super-massive black holes inhabit the cores of every galaxy in our Universe. In many cases, material can reach very close to them forming a flat, thin disc of hot material producing one of the most energetic and bright sources in the sky, observable all the way back to the formation of the first galaxies. As material spirals into the black hole it causes changes in the brightness that propagates outwards to the disc. As light travels further away from the black hole, it echoes at larger distances in the surrounding disc. From the Earth, we observe these “echoes” of the inner parts of the disc at different colours of the electromagnetic spectrum shifted in time. This “echo mapping” of black holes is a fantastic technique that allows us to probe this otherwise inaccessible environment, enabling us to measure the size of the disc and the mass of the black hole. In this talk Dr Santisteban will present what we can learn about the extreme conditions around supermassive black holes and how he uses a worldwide robotic network of telescopes to unravel the many puzzles that are left to solve.
Friday, 4 February 2022
From Clouds to Crust – How can we investigate the surface of rocky exoplanets without seeing them directly?
Oliver Herbort, University of St Andrews
Within the last two decades a large variety of planets around stars other than our own Sun have been detected. Measurements of diameter and mass of these planets suggests that an increasing number of these planets are indeed somehow of a rocky nature, similar to Earth, Mars, Venus, but also larger in size. One of the main questions is what the surface of these planets looks like, what kind of rock is there, are there continents and ultimately the question of potential life on those worlds. Observations in the foreseeable future will provide insights to the atmospheric composition of these planets, but the view onto their surface will remain obscured. Therefore a good understanding of the link between the higher parts of the planetary atmosphere and the surface of the planets becomes necessary. In this talk, Oliver will present his current work as part of his PhD studies at the University of St Andrews and the Institute for Space Science in Graz, Austria.
Friday, 4 March 2022
Maarten De Vries, SIGMA
White dwarf stars are the most common type of stellar object in our galaxy, possibly the whole universe and yet by the start of the 20th century we had discovered only a handful of them, and by the end of the century not more than a few thousand. In his talk Maarten will explain how white dwarf stars were discovered and why they puzzled astronomers so much at the time. He will talk about how the advances in quantum mechanics eventually helped put together workable models, which were later refined to a high degree of correlation with observations by the introduction of computers. He will also look at how in recent years our understanding of white dwarf stars has been expanded through the discovery of many more white dwarfs by the GAIA mission. White dwarfs are fascinating objects that are not only responsible for some of the biggest explosions in the universe, but they have also helped us learn a lot about how our galaxy and the whole universe has evolved.
Friday, 1 April 2022
Earth Observation – Foundations and the Future
With the launch of Landsat 9, NASA marked the continuation of the Landsat programme – the longest running satellite imagery mission with nearly 40 years of eyes on the Earth. Landsat was one of the first, but decades later the Earth Observation industry is still growing and innovating. How do these satellites work? What can we do with all this imagery? And what will the future look like?
Friday, 6 May 2022
Messages from Mercury: Discovering the Innermost Planet
Prof. Keith Nicholson, Caithness Astronomy Group
Looking at the history of observing Mercury and data from the Messenger mission.
Friday, 1 July 2022
Exploring Cosmic Dawn with the James Webb Space Telescope
Prof. Jim Dunlop, Royal Observatory Edinburgh
Prof. Dunlop will review the huge progress (made with both ground-based and space-based observatories) over the last ~2 decades to advance our understanding of early galaxy formation. He will then discuss the revolutionary power of the James Webb Space Telescope (JWST) to transform our understanding of cosmic dawn – the creation of the first stars and galaxies in the wake of the Big Bang. Launched Christmas Day 2021, by the time of this talk it should be in position at Lagrangian Point 2 and about to start science operations. Prof. Dunlop is Principal Investigator of the largest “Galaxies” JWST program scheduled for observing in JWST Cycle 1, and so will focus in particular about what this transformative major new infrared imaging survey should/could reveal about the early evolution of our Universe.
Friday, 5 August 2022
Synchronized Swinging: The (simplified) story of polaritons
Dr Kristin Arnardottir, University of St Andrews
Theoretical physics is about solving equations to explain how physical phenomena behave. The world can be a complicated place, and most of the time solving these equations becomes an insurmountable task. Therefore, we spend most of our time trying to come up with good approximations for the physical phenomena we are interested in. One thing we know is that many phenomena can be approximated to behave like the simple swinging of pendulums (if you don‘t push it too hard!). Electromagnetic wave? Pendulum. The behaviour of an electron in crystal structures? Pendulum. Now, what will happen if we make the electromagnetic wave interact with the electrons? When two pendulums interact, they can swing synchronously. But what does that mean for the analogous system?
Friday, 2 September 2022
A billion years of stargazing
Dr Michael Petersen, Royal Observatory Edinburgh
When we look up at the sky from Earth today, we see familiar constellations in what appears to be a static, unchanging sky. However, if we had lived a few thousand years ago, or a few million years ago, or a billion years ago, the sky would look different – at some point, unrecognisably so. We’ll learn about some of the timescales for the motions of stars in the galaxy, and focus on the biggest changes in the sky in the last billion years: smaller galaxies that our Milky Way galaxy has dragged in with its gravitational pull and caused to fall apart. We’ll review current research trying to construct a timeline of the Milky Way history, as well as what astronomers might hope to learn in the next few years.
Friday, 7 October 2022
The Life of a Planetary System
Dr Tom Wilson, University of St Andrews
Planets, moons, asteroids, and comets have fascinated professional and amateur astronomers alike for millennia. Observations by astronomers such as Galileo Galilei, Johannes Kepler, and Edmund Halley revealed substantial knowledge about the current state of the Solar System, but it has only been over the past half a century that astrophysicists have been able to probe the complete life of a planetary system thanks to the development of space- and ground-based telescopes. In this talk Dr. Wilson will discuss the current state of knowledge in answering questions such as; How do planetary systems form? Are there Earth-like exoplanets? What happens to planetary systems when their stars die? By highlighting key missions and telescopes this talk will go through the life of a planetary system. From how ALMA observations of dust and gas teach us about planet formation, to how Kepler has expanded the zoo of known exoplanets by over 100 times, to how the Hubble and Spitzer space telescopes have revealed the end state of planetary systems including our own Solar System. Finally, it will highlight some upcoming missions and telescopes that will provide further valuable insight into the life of planetary systems.
Friday, 2 December 2022
SIGMA Members and your Families
Bring along the family for a night of fun, questions and mince pies to end the year. There will also be the usual Christmas raffle.
The SIGMA Leaflet 2022 is available to download (pdf).