Markers of planet migration in the population of planetary cores

Lead Research Organisation: University of Warwick
Department Name: Physics

Abstract

We now know of planets numbering in the thousands. This tells us that planets are common, enough to be a usual occurrence around stars like the sun. However, despite this increasing number of planets, finding out more detail about them is difficult. What are the planets made of, and how did they form and evolve to leave the planets we see? Finding out how other solar systems formed allows us to place our own Solar System in context. Perhaps we are typical, or perhaps unique - this knowledge changes how we think about the Earth and our life upon it.

One way to study how other planets form is to look at their cores. The planetary core shows the environment it began in, with its composition telling us what materials were present at its beginning, before it obtained an envelope of gas. We still do not know any great detail about the cores of Jupiter and Saturn, because their gas envelopes block the core from view, and the same is true of other worlds. But planets close to their host star receive a lot of light and energy, enough to evaporate the gas and reveal the core. By uncovering a new population of these planets, I want to find out the dominant composition of their cores, discovering if they formed differently from others. As such short period planets do not exist in the Solar System, I will be uncovering the evidence of a new type of planetary evolution and history.

Publications

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Armstrong D (2021) Exoplanet validation with machine learning: 50 new validated Kepler planets in Monthly Notices of the Royal Astronomical Society

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Armstrong D (2019) A Gap in the Mass Distribution for Warm Neptune and Terrestrial Planets in The Astrophysical Journal

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Battley M (2020) A search for young exoplanets in Sectors 1-5 of the TESS full-frame images in Monthly Notices of the Royal Astronomical Society

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Boyajian T (2018) The First Post- Kepler Brightness Dips of KIC 8462852 in The Astrophysical Journal

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Bryant E (2020) NGTS-12b: A sub-Saturn mass transiting exoplanet in a 7.53 day orbit in Monthly Notices of the Royal Astronomical Society

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Bryant E (2020) Simultaneous TESS and NGTS transit observations of WASP-166 b in Monthly Notices of the Royal Astronomical Society

 
Title HARPS archival data - NCORES program 
Description Spectroscopic observations of several TESS candidate planets, which are made public on the ESO archive one year after observation. 
Type Of Material Database/Collection of data 
Year Produced 2019 
Provided To Others? Yes  
Impact Ongoing publications and follow-up pf TESS planetary candidates. 
URL http://archive.eso.org/wdb/wdb/adp/phase3_main/form
 
Description Collaboration with Machine Learning research group/Turing Institute 
Organisation Alan Turing Institute
Country United Kingdom 
Sector Academic/University 
PI Contribution Collaborative work whereby by team contributes field-expertise in terms of exoplanets, detection methods and data, and applies jointly developed machine learning techniques to our research
Collaborator Contribution A researcher associated with the Turing contributes expertise on state of the art machine learning techniques which we apply in our research.
Impact Publication - Exoplanet Validation with Machine Learning: 50 new validated Kepler planets (see publications). This was associated with a joint press release. In addition two jointly supervised students, one at 3rd year project level and one at Masters level.
Start Year 2018
 
Description NCORES collaboration 
Organisation Laboratoire d'Astrophysique de Marseile
Country France 
Sector Academic/University 
PI Contribution I am the PI of the collaboration. NCORES exists to coordinate, perform and publish spectroscopic characterisations of planets discovered near the photoevaporation gap, which hence may be exposed planetary cores. I organise the collaboration, PI the large HARPS program which obtains much of the relevant data, and coordinate outputs and publications.
Collaborator Contribution Geneva - The Geneva observatory has significant expertise on the spectrographs used, and lends significant manpower in analysing those data and troubleshooting any issues that arise, as well as performing planetary internal structure calculations. Porto - The team at Porto are experts on stellar characterisation and perform this stage of the analysis for all results LAM - The team at Marseilles perform planetary internal structure calculations and joint Bayesian fitting of datasets.
Impact Publication Outputs: 5 journal articles as detailed in publications section. Public datasets: The HARPS observations which form the backbone of the collaboration are made public after one year and archived by ESO.
Start Year 2018
 
Description NCORES collaboration 
Organisation University of Geneva
Department Geneva Observatory
Country Switzerland 
Sector Academic/University 
PI Contribution I am the PI of the collaboration. NCORES exists to coordinate, perform and publish spectroscopic characterisations of planets discovered near the photoevaporation gap, which hence may be exposed planetary cores. I organise the collaboration, PI the large HARPS program which obtains much of the relevant data, and coordinate outputs and publications.
Collaborator Contribution Geneva - The Geneva observatory has significant expertise on the spectrographs used, and lends significant manpower in analysing those data and troubleshooting any issues that arise, as well as performing planetary internal structure calculations. Porto - The team at Porto are experts on stellar characterisation and perform this stage of the analysis for all results LAM - The team at Marseilles perform planetary internal structure calculations and joint Bayesian fitting of datasets.
Impact Publication Outputs: 5 journal articles as detailed in publications section. Public datasets: The HARPS observations which form the backbone of the collaboration are made public after one year and archived by ESO.
Start Year 2018
 
Description NCORES collaboration 
Organisation University of Porto
Country Portugal 
Sector Academic/University 
PI Contribution I am the PI of the collaboration. NCORES exists to coordinate, perform and publish spectroscopic characterisations of planets discovered near the photoevaporation gap, which hence may be exposed planetary cores. I organise the collaboration, PI the large HARPS program which obtains much of the relevant data, and coordinate outputs and publications.
Collaborator Contribution Geneva - The Geneva observatory has significant expertise on the spectrographs used, and lends significant manpower in analysing those data and troubleshooting any issues that arise, as well as performing planetary internal structure calculations. Porto - The team at Porto are experts on stellar characterisation and perform this stage of the analysis for all results LAM - The team at Marseilles perform planetary internal structure calculations and joint Bayesian fitting of datasets.
Impact Publication Outputs: 5 journal articles as detailed in publications section. Public datasets: The HARPS observations which form the backbone of the collaboration are made public after one year and archived by ESO.
Start Year 2018
 
Description TESS Follow-up Observing Program (TFOP) 
Organisation Massachusetts Institute of Technology
Country United States 
Sector Academic/University 
PI Contribution I am the PI of a HARPS spectrograph program which follows up candidate TESS planets. The results of the follow-up are coordinated with the TFOP collaboration to avoid duplicating observations and maximise the efficiency of the TESS satellite and my HARPS program.
Collaborator Contribution MIT is the site of the TESS science office where TESS data is initially processed. TFOP is actually a wider collaboration involving a large number of institutes around the world, and coordinates follow-up activities to TESS planets. THE main team at MIT contribute to my research by releasing early lists of TESS planet candidates which allows me to save significant time in moving to planet characterisation. The amount of in-kind funding is an estimate but the time saved is substantial, and hence the in-kind funding is likely underestimated if anything.
Impact Publications: Several publications as detailed in the publications section.
Start Year 2019
 
Description BBC Sky at Night interview 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact I was interviewed for the BBC 'Sky at Night' program, with the resulting episode broadcast nationally and available on the BBC's iplayer service after broadcast.
Year(s) Of Engagement Activity 2019
 
Description Business Insider contacted for comment 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact I was contacted by Business Insider to comment on an article related to habitable environments and off-world exploration, and quoted in the resulting article.
Year(s) Of Engagement Activity 2019
 
Description Engagement talk (Local) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Undergraduate students
Results and Impact I gave a talk on the science of 'The Martian' movie from an exoplanet research perspective, linked in with a screening of the film.
Year(s) Of Engagement Activity 2019
 
Description Knowle and Dorridge Astronomy society 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Public/other audiences
Results and Impact I gave an invited talk at a local astronomy society meeting, talking about my research and the exoplanet field.
Year(s) Of Engagement Activity 2019
 
Description Press release - Machine learning for exoplanet discovery 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact We made a press release to accompany a publication in Summer 2020 on the discovery of 50 new planets using machine learning. The interest was significant, appearing in 100s of international news outlets. The press release led directly to an invite to be a main keynote speaker at a major industry data science conference (ODSC Europe 2020), and several contacts offering computing time or expertise.
Year(s) Of Engagement Activity 2020
 
Description Press release, radio and TV interview - Remnant planetary core 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact A significant publication was released in Summer 2020, on the discovery of the remnant core of a giant planet. We made a press release along with the publication, which led to hundreds of news outlets featuring the case, including prominent international and US media. I gave a live interview both on BBC World News (TV) and on BBC Radio 4's PM show, a primetime news show.
Year(s) Of Engagement Activity 2020
 
Description The Times quoted on K2-18 publication 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact I was contacted by The Times to comment on a recent exoplanet paper, and quoted in the resulting article.
Year(s) Of Engagement Activity 2019