Variable stars in the SuperWASP all sky survey

Lead Research Organisation: Open University
Department Name: Faculty of Sci, Tech, Eng & Maths (STEM)


The SuperWASP all sky photometric survey (Pollacco et al. 2006) is the most successful ground based search for transiting exoplanets, having discovered more than 150 hot Jupiters. In 10 years of operation, it has also produced an archive of more than 30 million high cadence lightcurves comprising over 500 billion individual measurements of bright stars.
In recent years we have exploited this photometric archive to address aspects of stellar evolution, focussing on eclipsing binaries and stellar multiplicity (Lohr et al. 2012; 2013a; 2013b; 2014a; 2014b; 2015a; 2015b) and on stellar pulsations (Norton et al. 2016; Holdsworth et al. 2014; Smalley et al. 2011; 2017). Much of this work was inspired by our initial work on identifying new periodic variable stars coincident with ROSAT X-ray sources (Norton et al. 2007). That initial cross-correlation was performed on only the first few years of SuperWASP data but yielded hundreds of matches for new variable objects.
Following a 50 CPU-year run on our linux cluster, we are nearing completion of a new search for periodic variability in the entire SuperWASP archive of 30 million stellar lightcurves. Up to a million objects are detectably periodically variable on timescales from hours to years. An initial aim of this PhD project will be to carry out a similar analysis to that of Norton et al. (2007) but cross-correlating against the full SuperWASP archive and a much larger X-ray catalogue, such as the 2XMMi-DR3 catalogue of almost 300,000 X-ray point sources (Watson et al 2009), so yielding an order of magnitude increase in the resulting catalogue. Following publication of the results from this work, the PhD candidate appointed will explore further aspects of stellar variability, multiplicity, pulsation, and rotation, which may include searches for stellar mergers, pulsating stars in eclipsing binaries, and other rare systems.
Holdsworth, D.L. et al. 2014, MNRAS, 439, 2078
Lohr, M.E., Norton, A.J., Kolb, U.C., et al. 2012, A&A, 542, 124
Lohr, M.E., Norton, A.J., Kolb, U.C., et al. 2013a, A&A, 549, 86
Lohr, M.E., Norton, A.J., Kolb, U.C., Boyd, D., 2013b, A&A, 558, 71
Lohr, M.E., Hodgkin, S., Norton, A.J., Kolb, U.C., 2014a, A&A, 563, 34
Lohr, M.E., Norton, A.J., Kolb, U.C., et al., 2014b, A&A, 566, 128
Lohr, M.E., Norton, A.J., Kolb, U.C., et al., 2015a, A&A, 578, 103
Lohr, M.E., Norton, A.J., et al., 2015b, A&A, 578, 136
Norton, A.J., et al. 2007, A&A, 467, 785
Norton, A.J., Lohr, M.E., et al., 2016, A&A, 587, 54
Pollacco, D. et al., 2006, PASP, 118, 1407-1418
Smalley, B., et al. 2011, A&A, 535, 3
Smalley, B., et al. 2017, MNRAS, 465, 2662
Watson, M.G., et al. 2009, A&A, 493, 339


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Thiemann H (2021) SuperWASP variable stars: classifying light curves using citizen science in Monthly Notices of the Royal Astronomical Society

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Thiemann H (2020) The stellar rotation-activity relation for a sample of SuperWASP and ASAS-SN field stars in Publications of the Astronomical Society of Australia

Studentship Projects

Project Reference Relationship Related To Start End Student Name
ST/P006760/1 01/10/2017 30/09/2024
1994202 Studentship ST/P006760/1 01/10/2017 30/11/2021 Heidi Thiemann
Description E. A. Milne Travelling Fellowships
Amount £1,000 (GBP)
Organisation Royal Astronomical Society 
Sector Academic/University
Country United Kingdom
Description Public Engagement Grant
Amount £50 (GBP)
Organisation Institute of Physics (IOP) 
Sector Learned Society
Country United Kingdom
Description I'm A Scientist 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Schools
Results and Impact "I'm a Scientist, Get me out of here" is an online STEM engagement competition that gets people from all areas and roles in science talking with curious school students. It's a competition between scientists, where students are the judges. Students challenge the scientists over fast-paced online text-based live chats. They ask the scientists anything they want, and vote for their favourite scientist to win a prize of £500 to communicate their work with the public.
I was part of the "Electromagnetic Zone" supported by STFC. 555 secondary school students took part in this activity from 13 schools across the country. The percentage of students who were engaged was 94%, asking over 800 questions across 2 weeks. Students sent 7681 lines of chat over 24 live chat sessions. Students were able to find out more about what its like to be a scientist, and understand different paths into science.
Year(s) Of Engagement Activity 2019
Description Soapbox Science 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Public/other audiences
Results and Impact Soapbox Science is a novel public outreach platform for promoting women scientists and the science they do. Soapbox Science events transform public areas into an arena for public learning and scientific debate. I spoke about my research in Milton Keynes shopping centre for 1 hour to the general public, and engaged with discussion around the formation of the solar system, telescopes, and how to become an astronomer. Up to 50 members of the general public attended my talk.
Year(s) Of Engagement Activity 2019
Description Space Speaker in Your Classroom/Space Goes to School 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Schools
Results and Impact Spoke to 8 primary and secondary schools in the Republic of Ireland about careers in astronomy. At least 100 students were engaged.
Year(s) Of Engagement Activity 2020