Guildford Astronomical Society

Meetings

The 2020-2021 season is a bit different due to the ongoing Covid-19 issues & being able to keep socially distant.
The University Lecture theatres are not accessible, so we are planning Zoom talks for our members.
Joining details of each meeting will be sent out prior to each talk.

Below are our current guest speakers.


The 2020-2021 Session

Subject to change

DateTalk/Presentation TitleSpeaker
3 Sep 2020A Zoom talk:- Crowd and the CosmosProf. Chris Lintott
1 Oct 2020A Zoom talk: Recent findings of a possible neutron star in Supernova 1987A.Dr Mikako Matsuura
5 Nov 2020A Zoom talk: Radio Astronomy for AmateursAndrew Thomas
3 Dec 2020A Zoom talk: Remote Observing - Remote Telescopes for Public and Educational usePete Williamson
7 Jan 2021A Zoom talk: The latest news of Lunar ExplorationProf. Neil Bowles
4 Feb 2021A Zoom Talk: Supernova NeutrinosDr Susan Cartwright
18 Feb 2021A Zoom Talk : The music of stars reveals their deep interiorsDr Giovanni Mirouh
4 Mar 2021A Zoom Talk: The History of the TelescopeDr David Arditti
18 Mar 2021A Zoom Talk: Accreting white dwarf binary systems which result in nova outburstsArman Aryaeipour
1 Apr 2021A Zoom Talk: Professional Radio AstronomyDr Alasdair Thomson
15 Apr 2021A Zoom Talk: The creation of gravitational waves and what the observations could tell us about the progenitor systems

In this talk I will give an overview on the topic of gravitational waves. After a short introduction I will cover the theory of gravitational waves and show which systems and phenomena would emit gravitational waves.
I will then talk about show the history the different observation methods, the current (and future) detectors and the first observations of gravitational waves.
Gravitational wave observations give us a new way of observing the universe, and, as such, also new opportunities to narrow down the uncertainties we have within stellar evolution, or even confirm or reject different possible scenarios. In the last part of this talk I will zoom in on the science we do with the observations of gravitational waves, specifically the use of synthetic populations that are matched to the observations. Several assumptions for e.g. the supernova kick velocity or the common envelope ejection efficiency are used as input for these synthetic populations of stars, and it has been shown that some of these can significantly affect the merger rate. By evolving populations of stars we can estimate these merger rates for different types of binary systems, and compare that to the observed merger rate, allowing us to infer the input values that best match the observations.

David Hendriks
Surrey University Department of Astrophysics
7 May 2021A Zoom Talk: Megaconstellations

The impact of satellite megaconstellations on amateur & professional astronomy

Dr Paul A Daniels
VP Astronomy RAS
20 May 2021A Zoom Talk: AGB (Asymptotic giant branch) stars : thermal pulses, third dredge-up and binary interactions

The asymptotic giant branch (AGB) is a late stage in the evolution of intermediate mass stars. These stars are extremely luminous, with outer layers that are cool and expanded, causing them to be found in the upper right portion of the Hertzsprung-Russell diagram.
By this point in the star’s lifetime, helium has been exhausted in the core leading to a carbon and oxygen rich core surrounded by separate helium and hydrogen burning shells. The double shell burning results in dramatic thermal pulses when helium ignites under degenerate conditions in a thin shell.
The pulses give rise to the phenomena of third dredge-up where material from the core (primarily carbon) is mixed all the way up to the surface, where it can be detected by observers.
AGB stars are also thought to be the location of the slow-neutron capture process (s-process) which produces heavy elements such as barium and lead, making them important contributors to the galactic chemical evolution.
In addition, AGB stars are also likely to interact with a binary companion due to their large size and strong stellar winds, resulting in mass transfer and potentially even common envelope evolution.
This talk will investigate all of these processes and how they lead to a variety of different observed stars including carbon stars, nitrogen-rich stars, S stars, barium stars, cataclysmic variables and red stragglers.

Natalie Rees
Surrey University Department of Astrophysics
3 Jun 2021A Zoom Talk: Outflow from Super-Massive and Wolf-Rayet starsProf. Raman Prinja
UCL
Aug 2021Note: There is no meeting in August 

Click here to see the profiles of past and forthcoming speakers.

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