June 2024 : The CMB and it's B-modes

Episode Audio

The CMB and it's B-modes. In this episode, Kammy and Jonathan interview Dr William Coulton from the Centre of Computational Astronomy in New York and they discuss early universe cosmology and the detection of CMB B-modes. Bijas and Phoebe discuss the discovery of a protoplanetary disk around a nearby star, new insights into one of the most distant and luminous galaxies ever observed and the possible environments on exoplanets. Jessy interviews Oli Dodge in this month’s Jodbite.This month we had issues with the audio quality when recording. We tried to mitigate them in post but it mostly affects the jodbite (24:45 - 35:27).

The News

Young stars and their protoplanets

Recently, the largest known batch of the building blocks for forming planets has been found circling a young star. The star is about 1,000 light years away and was first spotted in 2016 but recent observations have shown it to be surrounded by a disc of gas and dust, known as a proto-planetary disc, that has a diameter of over 3000 times the distance between the Earth and the Sun, making it almost double the size of the previously largest known disc.

The observations were made by telescopes in Hawaii. The Submillimeter Array captured the thermal emission from the dust and carbon monoxide gas present in the disc, and the Panoramic Survey Telescope and Rapid Response System, known as Pan-STARRS, captured optical light.

This disc has been nicknamed ‘Dracula’s Chivito’ after a similar disc discovered in 1987 which was named ‘Gomez’ Hamburger’, and it has two dusty strips resembling a fang like structure.

More information on this exciting new discovery can be found in these papers: Monsch et. al (2024) and Berghea et. al (2024)

Insights into GN-z11

In an astonishing discovery this month, the James Webb Space Telescope (JWST) has provided new insights into one of the most distant and luminous galaxies ever observed, GN-z11. Located about 13.4 billion light-years away, this galaxy dates back to when the universe was only 430 million years old. This breakthrough offers a glimpse into the early universe, revealing both a supermassive black hole and pristine gas clumps, which could significantly impact our understanding of cosmic evolution.

The discovery was made using the Near-Infrared Camera (NIRCam) and Near-Infrared Spectrograph (NIRSpec) aboard the JWST. These instruments allow astronomers to capture and analyse light from extremely distant objects, far beyond the capabilities of previous telescopes. NIRCam's sensitivity to infrared light enables it to peer through cosmic dust and reveal the underlying structures of early galaxies. NIRSpec provides detailed spectra, allowing researchers to identify chemical elements and their ionisation states in these distant celestial bodies.

GN-z11 hosts a supermassive black hole, making it the most distant known black hole to date. This finding challenges current models of black hole formation and growth in the early universe. The identification of a helium-dominated gas clump supports the existence of primordial gas pockets, providing a potential site for the formation of Population III stars. These stars are crucial for understanding the reionisation epoch and the subsequent evolution of galaxies. The detection of ionised elements and high-velocity winds around the black hole offers new insights into the energetic environments of early galaxies, which played a vital role in shaping the universe's structure.

Interview with William Coulton

This month, we are delving into our catalogue and bringing you an unaired interview from our hiatus. In this interview from 2022, Dr William Coulton (from the Centre of Computational Astronomy in New York) talks to Kammy & Jonathan about understanding early universe cosmology by tracking the positions of galaxies. A brief yet interesting discussion on the CMB and current and future projects being undertaken to detect the infamous B-modes!


Our Jodbite series continues with Oli Dodge, a final year PhD student studying spider pulsars. Jessy Marin speaks with him about finishing his PhD at JBCA and what’s next in the field of pulsars.

Odds and Ends

This month we are reading and discussing the paper ‘A Perfect Tidal Storm: HD 104067 Planetary Architecture Creating an Incandescent World’

As we are finding new planetary systems we are discovering a wide variety of the composition and environments on these planets with many unlike anything within our own solar system. The system in this paper was previously known and thought to consist only of a bright K dwarf host star and a giant planet completing an orbit of the star every 55 days. This paper reveals the discovery of two additional planets in this system: one with a mass similar to Uranus which has an orbital period of 14 days, and a terrestrial sized planet with a very short 2.2 day orbital period. The two outer planets have eccentric orbits, meaning that they have an oval orbital path, and these orbits tidally influence the innermost planet causing it to have surface temperatures of about 2600K, nearly 3000 degrees Celsius! These temperatures mean that this terrestrial planet could be caught in a tidal storm causing its surface to radiate light at optical wavelengths - it’s a shiny planet!

The discovery was made using data from NASA's Transiting Exoplanet Survey Satellite (TESS). Photometric analysis revealed consistent periodic variability showing the star's rotation and the planet's transit, allowing the authors to infer the extreme environmental conditions on the planet.

There were two techniques used to detect these new planets: Analysis of TESS photometry data and radial velocity (RV) measurements. The primary technique used for detecting the planets was transit photometry, which involves measuring the light from a star and looking for periodic dips in brightness. These dips occur when a planet passes (or transits) in front of the star, temporarily blocking a small fraction of the star's light. To complement the transit photometry data, radial velocity measurements were used to detect the gravitational influence of the planets on their host star. The Keck Observatory's High-Resolution Echelle Spectrometer (HIRES) was utilised to obtain high-precision spectra of the system. Radial velocity measurements detect the star's wobble caused by the gravitational pull of orbiting planets, providing additional confirmation of the planet's presence and helping to estimate its mass.

Show Credits

News : Phoebe Ryder, Bijas Najimudeen
Interview : Dr William Coulton Kammy Bogue and Jonathan Wong
Presenters : Phoebe Ryder, Bijas Najimudeen, Jessy Marin, Kammy Bogue and Jonathan Wong
Editors : Louisa Mason and Lily Correa Magnus
Website : Lily Correa Magnus and Jessy Marin
Producer : Lily Correa Magnus and Jessy Marin
Cover Art :CREDIT:ESA/Plank Collaboration