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Episode 116: Exploring Cosmic Events with Professor Rene Breton at Jodrell Bank Centre for Astrophysics

By Gurbir Dated: June 27, 2024 Leave a Comment

Professor Rene Breton. Deputy head of the Department of Astronomy and Physics at the Jodrell Bank Centre for Astrophysics

Some of the most energetic events in the cosmos are associated with the products left after a star’s violent end. These products are always smaller and denser: a white dwarf (the size of a planet), a Neutron star (the size of a city), or a Black Hole (an object without a size). The bigger the initial mass of a star, the sooner and more energetic its end will be. Our Sun is not all that massive; it will end up as a white dwarf in and out 4.5 billion years from now.

Professor Rene Breton, originally from Quebec, has been working at the Jodrell Bank Centre for Astrophysics for over a decade. We discuss only a small part of his current research, including how Pulsars may one day be used as a GPS for interstellar travel. Other topics include

Credit McGill University
  • Why and how he ended up in Manchester
  • His first impressions of Manchester and comparisons with Quebec in Canada
  • The key role of a high-school teacher, Mr. Gaudreault, setting him on his career in science
  • Stellar evolution – how stars are born and the process by which they end up as white dwarfs, neutron stars and black holes
  • Event Horizon Telescope – imaging the black hole in the centre of our galaxy
  • The ultimate fate of our Sun
  • Quasars are distant galaxies with a Black Hole in the centre,  so distant that they look like stars. 
  • FAST Radio bursts, including Gamma Ray Bursts (GRBs), are from extragalactic distances. Events that last a few seconds or less – a sign of merging neutron stars or evidence of Hypernovae (not novae or supernovae)!
  • Neutron Stars in Binary Systems, accretion discs and “spiders”
  • Neutron Stars as a cosmic GPS for future space travellers
  • Detect Gravitational Waves using neutron stars. Gravitational Wave detectors are not very sensitive, so they can only detect high-energy events, such as the collision of two neutron stars or the formation of black holes. 
  • Space-borne Gravity Wave detectors, such as the Laser Interferometer Space Antenna, which NASA plans to launch in the 2030s, will be able to detect a wider range of cosmological phenomena.
  • Square Kilometer Array’s role in detecting more neutron stars, pulsars and even pulsars orbiting black holes
  • Pulsar Timing Array – a GPS for interstellar travel

Professor Rene Breton. University of Manchester. Jodrell Bank Centre for Astrophysics

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Episode 112 – Brown Dwarfs, Dark Matter and Dark Energy

By Gurbir Dated: March 15, 2024 Leave a Comment

This episode was recorded in Tenerife with Professor Eduardo L Martín who is based at the Instituto de Astrofísica de Canarias. He is working on the European Space Agency’s mission, Euclid.

In time Euclid will shed light on both dark matter and dark energy. It was launched in July 2023 and arrived in its L2 orbit a month later. It has just two instruments which will produce a high-resolution 3-D map of a third of the sky, stretching back 10 billion years during its initial 6-year operational lifetime.

Professor Martín is not part of the Euclid Consortium the around 2500 scientists and engineers from more than a dozen countries who operate the Euclid Mission. He is one of the two Euclid mission Independent Legacy Scientists. Professor Martín is a specialist in substellar bodies, that is celestial bodies with a size about that of Jupiter but with around 50 times its mass. When initially theorised in the 1960s they were called Black Dwarfs but renamed in the 1970s by Jill Tarter as Brown Dwarfs.

Brown Dwarfs generate energy only through gravitational compression, not nuclear fusion. There is an overlap in surface temperature between young brown dwarfs and old very low-mass stars. Martín and his collaborators have developed spectroscopic methods to distinguish brown dwarfs from stars, in particular the Lithium test. More about this interesting role of Lithium in cosmology in Professor Martín’s book published in 2023 by the Institute of Physics, entitled “Lithium Across the Universe“. You can download several free-to-read chapters – here.

Brown Dwarfs emit mostly in the infrared not optical light as our sun. One of the two instruments on Euclid operates in the infrared and can detect these “dark ultracold objects of substellar mass“. Does Professor Martin think Euclid will find Brown Dwarfs? He told me in this recording, “that is what I put in the proposal so we had better do now”. He is supported by a postdoc Marusa Zerjal and a student Diego Martin, funded by the European Research Council.

The first images were released in November 2023. The spacecraft and its instruments are operating well and sending data. More about the Euclid mission, images released so far and a summary of the attributes of Normal Matter, Dark Matter and Dark Energy below.

Episode112 ESA’s Euclid Mission with Professor Eduardo Martin

Perhaps the most pressing question for astrophysicists is what is the cosmos made of. They have known for a long time that visible matter accounts only for the 5%, Dark Matter, 27% and Dark Energy 68%. Currently, most of the attributes of Dark Matter and Dark Energy remain a mystery. Helping to shed some answers to these questions is Euclid’s primary goal.

The visible matter is something we are surrounded by. It responds to all 4 known forces, electromagnetic, gravitation, and the strong and weak nuclear force. Dark matter is not dark, it’s invisible and is only detected through its gravitational influence on the matter we can see. Gravitational lensing is one manifestation.

Whereas gravity is a force of attraction, Dark Energy is repulsive, powering the expansion of the Universe. Its effects are observed by monitoring type 1a supernovae in distant galaxies. Some scientists consider Dark Energy as the Cosmological Constant that Einstein initially added and then removed from his General Theory of Relativity. The Cosmological Constant is now considered by some as the 5th fundamental force, after gravity, electromagnetism, and strong and weak nuclear forces.

  • Horse head Nebula. Credit ESA
  • Globular Cluster NGC6397. Credit ESA
  • Irregular Galaxy NGC6822. Credit ESA
  • Spiral galaxy IC342. Credit ESA Credit ESA
  • Perseus Cluster. Credit ESA

Summary of attributes for Normal Matter, Dark Matter and Dark Energy

AttributeNormal MatterDark MatterDark Energy
Formation TimeShortly after the Big BangLikely formed shortly after the Big BangBelieved to have originated with the expansion of the universe
LocationEverything we can see including Galaxies, stars, planets and the interstellar mediumPrimarily in galactic halos, halos around galactic clusters and permeates the universeHomogeneously distributed throughout space, associated with vacuum energy
Observational EvidenceEmission and absorption spectra, visible light, X-rays, cosmic microwave backgroundGravitational effects on visible matter, galaxy rotation curves; Dark matter inferred from galaxy cluster dynamics by Fritz Zwicky, 1933). Galaxy rotation curves suggest dark matter and the work of Vera Rubin from the 1970s.
Observation of gravitational lensing.
Acceleration of cosmic expansion, distant Type 1a supernova observations by Saul Perlmutter, Brian Schmidt, Adam Riess (1998-1999).
In time, it may turn out to be the 5th fundamental force.
Interaction with Electromagnetic ForceStrong interaction, contributes to various spectra and emissionsWeak or non-existent interactions with light and other EM wavesWeak or non-existent interactions with light and other EM waves
Interaction with Gravitational ForceExperiences gravitational attraction with other matterExperiences gravitational attraction, influencing cosmic structures. Exhibits a repulsive gravitational effect, driving cosmic expansion
Percentage Composition in the Universe~4.6% of the total mass-energy content~26.5% of the total mass-energy content~68.9% of the total mass-energy content
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WEA Online Courses starting in September 2021

By Gurbir Dated: August 6, 2021 Leave a Comment

The two introductory courses below are organised by The Workers’ Educational Association (WEA), UK’s largest voluntary sector provider of adult education in England and Scotland. I will be delivering thee courses via Zoom in September. There is a cost but if you qualify that could be nil.

The New Space Age

The New Space Age

Introductory online course via Zoom. No prerequisite. Fee £64.00 or Nil.

Course dates 07/09/2021 – 09/11/2021
Ten sessions for 2 hrs per session every Tuesday starting at 7pm

Over the ten interactive sessions this course will provide an overview on:

Evolution of the space age from the beginnings with Sputnik to today
Outline the rich sources of services from space that shape society on Earth
The emergence of the private space sector in countries around the world
Space activities in India, China and Africa
Explore the concern of congestion in space from the growing number of spacecraft and the hazards of space debris.
The potential for the militarisation of space.
Humans living and working in Earth orbit. Returning to the Moon and beyond to Mars

Enrol Here


Explorers of the Cosmos

Explorers of the Cosmos

Introductory online course via Zoom. No prerequisite. Fee £64.00 or Nil.

Course dates 09/09/2021 – 11/11/2021.
Ten sessions for 2 hrs per session on Thursdays starting at 5pm

Over ten weeks the course will look at the life and work of the life and work of the following individuals

Nicolaus Copernicus (1473–1543)
Galileo Galilei (1564–1642) 
Isaac Newton (1643–1727)
Henrietta Swann Leavitt (1868–1921)
Albert Einstein (1879-1955)
Edwin Hubble (1899–1953)
Subrahmanyan Chandrasekhar (1910-1995)
Vera Rubin (1928-2016)
Stephen Hawking (1942-2018) 
Jocelyn Bell (1943 – )

Enrol here

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Explorers of the Cosmos – 6 Week Course starting 20 May 2020 online via Zoom

By Gurbir Dated: May 10, 2021 Leave a Comment

By popular demand – its back! Organised by the Workers Educational Association, 2 hours every Thursday between 5pm-7pm over 6 weeks starting on 20/05/2021. The course will examine the lives and contributions of six individuals who have made significant contribution to our understanding of the cosmos. In sequence they are

Henrietta Swan Leavitt 1868-1921
Albert Einstein 1879-1955
Edwin Hubble 1889-1953
Subrahmanyan Chandrasekhar 1910-1995
Stephen Hawking 1942-2018
Jocelyn Bell-Burnell 1943-


There are no prerequisites and no end of course eassessment. As before the course will be run as a Zoom meeting – so lots of interaction in addition to the Q&A at the end. Cost is £38.40 or free – check and signup here

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