Helen Giles
CHEOPS PhD StudentObservatoire de Genève
About Me

Originally from a town in the North West of England, I was fascinated with astronomy from a young age.
After attending a summer space school for three years, I independently studied for a GCSE in Astronomy during the last four months of my final year of high school.
Two years later, I achieved the necessary grades to attend the University of St Andrews in Scotland to study Astrophysics.
In St Andrews, I opted to enter into the second year - taking each astronomy course possible.
During the course of my degree I undertook two summer internships in exoplanet atmospheres and detection, with Christiane Helling in St Andrews and Chas Beichman in Pasadena.
Then for my final year Masters project, studying starspot lifetimes from Kepler data, was supervised by Raphaëlle Haywood and Andrew Collier Cameron.
After earning an integrated Masters degree in Astrophysics (1st class with Honours), I secured a PhD position at the Observatoire de Genève in Switzerland where I have continued my stellar activity work and further exoplanet discovery.
My Research
Starspots
Whilst we understand sunspots extremely well, our knowledge of these magnetic regions on other stars is limited. And given we can't resolve stellar surfaces to the same degree as we can observe the solar surface, we need to extrapolate information from another source.
For my Masters' project (and now as part of my PhD) I successfully determined the lifetimes of starspots from photometry obtained from the Kepler mission, and how they depend on the stellar spectral type in collaboration with Raphaëlle Haywood and Andrew Collier Cameron.
For details, see the paper available on arXiv.
Exoplanet Discovery & Characterisation
In my role as the CHEOPS PhD student, I conduct the exoplanet discovery and radial velocity follow-up from publicly released data from the K2 mission - in collaboration with Exoplanet groups around Europe, the USA and Chile. Currently this has resulted in three planet discoveries (one from a summer internship, two during my PhD where one is still in the pipeline).
These tools and methods will be applied to the TESS mission when it releases its first set of data.
For details, see the papers for Kepler-1654 b, K2-140 b and EPIC248847494b available on arXiv.
Publications
Total Publications: 10 | Total Refereed: 9 | First Author: 3 | h-index: 5
Transiting planet candidate from K2 with the longest period
H.A.C. Giles, H.P. Osborn, S. Blanco-Cuaresma, C. Lovis, D. Bayliss, P. Eggenberger, A. Collier Cameron, M.H. Kristiansen, O. Turner, F. Bouchy, and S. Udry
Accepted to Astronomy & Astrophysics
An Earth-sized exoplanet with a Mercury-like composition
Santerne, A.; Brugger, B.; Armstrong, D.J.; Adibekyan, V.; Lillo-Box, J.; Gosselin, H.; Aguichine, A.; Almenara, J.-M.; Barrado, D.; Barros, S.C.C.; Bayliss, D.; Boisse, I.; Bonomo, A.S.; Bouchy, F.; Brown, D.J.A.; Deleuil, M.; Delgado Mena, E.; Demangeon, O.; Díaz, R.F.; Doyle, A.; Dumusque, X.; Faedi, F.; Faria, J. P.; Figueira, P.; Foxell, E.; Giles, H.A.C.; Hébrard, G.; Hojjatpanah, S.; Hobson, M.; Jackman, J.; King, G.; Kirk, J.; Lam, K.W.F.; Ligi, R.; Lovis, C.; Louden, T.; McCormac, J.; Mousis, O.; Neal, J.J.; Osborn, H.P.; Pepe, F.; Pollacco, D.; Santos, N.C.; Sousa, S.G.; Udry, S.; Vigan, A.
Nature Astronomy, Volume 2, 393-400 (2018)
An Accurate Mass Determination for Kepler-1655b, a Moderately Irradiated World with a Significant Volatile Envelope
Haywood, R.D.; Vanderburg, A.; Mortier, A.; Giles, H.A.C.; López-Morales, M.; Lopez, E.D.; Malavolta, L.; Charbonneau, D.; Collier Cameron, A.; Coughlin, J.L.; Dressing, C.D.; Nava, C.; Latham, D.W.; Dumusque, X.; Lovis, C.; Molinari, E.; Pepe, F.; Sozzetti, A.; Udry, S.; Bouchy, F.; Johnson, J.A.; Mayor, M.; Micela, G.; Phillips, D.; Piotto, G.; Rice, K.; Sasselov, D.; Ségransan, D.; Watson, C.; Affer, L.; Bonomo, A.S.; Buchhave, L.A.; Ciardi, D.R.; Fiorenzano, A.F.; Harutyunyan, A.
The Astronomical Journal, Volume 155, Issue 5, 203 (2018)
K2-140b - an eccentric 6.57 d transiting hot Jupiter in Virgo
Giles, H.A.C.; Bayliss, D.; Espinoza, N.; Brahm, R.; Blanco-Cuaresma, S.; Shporer, A.; Armstrong, D.; Lovis, C.; Udry, S.; Bouchy, F.; Marmier, M.; Jordán, A.; Bento, J.; Collier Cameron, A.; Sefako, R.; Cochran, W. D.; Rojas, F.; Rabus, M.; Jenkins, J.S.; Jones, M.; Pantoja, B.; Soto, M.; Jensen-Clem, R.; Duev, D.A.; Salama, M.; Riddle, R.; Baranec, C.; Law, N.M.
Monthly Notices of the Royal Astronomical Society, Volume 475:2, 1809-1818 (2018)
Validation and Initial Characterization of the Long-period Planet Kepler-1654 b
Beichman, C.A.; Giles, H.A.C.; Akeson, R.; Ciardi, D.; Christiansen, J.; Isaacson, H.; Marcy, G.M.; Sinukoff, E.; Greene, T.; Fortney, J.J.; Crossfield, I.; Hu, R.; Howard, A. W.; Petigura, E. A.; Knutson, H.A.
The Astronomical Journal, Volume 155, Issue 4, 158, 11, (2018)
Understanding Stellar Contamination in Exoplanet Transmission Spectra as an Essential Step in Small Planet Characterization
Apai, D.; Rackham, B.V.; Giampapa, M.S.; Angerhausen, D.; Teske, J.; Barstow, J.; Carone, L.; Cegla, H.; Domagal-Goldman, S.D.; Espinoza, N.; Giles, H.A.C.; Gully-Santiago, M.; Haywood, R.; Hu, R.; Jordan, A.; Kreidberg, L.; Line, M.; Llama, J.; López-Morales, M.; Marley, M.S.; de Wit, J.
White paper submitted to the NAS Committee on Exoplanet Science Strategy
A Kepler study of starspot lifetimes with respect to light-curve amplitude and spectral type
Giles, H.A.C.; Collier Cameron, A.; Haywood, R.D.
Monthly Notices of the Royal Astronomical Society, Volume 472:2, 1618-1627 (2017)
Ground-based photometry of the 21-day Neptune HD 106315c
Lendl, M.; Ehrenreich, D.; Turner, O. D.; Bayliss, D.; Blanco-Cuaresma, S.; Giles, H.; Bouchy, F.; Marmier, M.; Udry, S.
Astronomy & Astrophysics, Volume 603, L5 (2017)
Kepler-21b: A Rocky Planet Around a V = 8.25 Magnitude Star
López-Morales, M.; Haywood, R.D.; Coughlin, J.L.; Zeng, L.; Buchhave, L.A.; Giles, H.A.C.; Affer, L.; Bonomo, A.S.; Charbonneau, D.; Collier Cameron, A.; Consentino, R.; Dressing, C.D.; Dumusque, X.; Figueira, P.; Fiorenzano, A.F.M.; Harutyunyan, A.; Johnson, J.A.; Latham, D.W.; Lopez, E.D.; Lovis, C.; Malavolta, L.; Mayor, M.; Micela, G.; Molinari, E.; Mortier, A.; Motalebi, F.; Nascimbeni, V.; Pepe, F.; Phillips, D.F.; Piotto, G.; Pollacco, D.; Queloz, D.; Rice, K.; Sasselov, D.; Segransan, D.; Sozzetti, A.; Udry, S.; Vanderburg, A.; Watson, C.
The Astronomical Journal, Volume 152, Issue 6, 204 (2016)
Dust in brown dwarfs and extra-solar planets.
IV. Assessing TiO2 and SiO nucleation for cloud formation modelling
Lee, G.; Helling, Ch.; Giles, H.A.C.; Bromley, S.T.
Astronomy & Astrophysics, Volume 575, A11 (2015)
Talks & Posters
Cool Stars 20
31 July 2018
Starspots and Their Longer Lives on Cool Stars
An invited talk given at the 'Know thy Starspot, Know thy Star' splinter session at the 20th Cambridge Workshop on Cool Stars in Boston, Massachusetts (USA).
Exoplanets II
2 July 2018
The Longest Period Transiting Planet Candidate from K2
A poster presented at the Exoplanets II conference in Cambridge, UK.
Know thy Star, Know thy Planet
12 October 2017
Determining Starspot Lifetimes from Photometry to Feed Models of Stellar Activity in Exoplanet RV Surveys
A talk given at the Know thy Star, Know thy Planet conference in Pasadena, California (USA).
CHEOPS 5th Science Workshop
24 July 2017
K2 Discoveries as Precursors for CHEOPS Follow-Up Candidates
A talk given at the 5th CHEOPS Science Workshop in Schloss Seggau, Austria.
Transiting Exoplanets
17 July 2017
EPIC 228735255b - A tale of an eccentric transiting hot Jupiter
A poster presented at the Transiting Exoplanet conference in Keele, UK.
UK Exoplanet Meeting 2017
16 March 2017
A Transit-Searching Pipeline for CHEOPS Candidates from Campaign 10 of K2
A poster presented at the 2017 UK Exoplanet Meeting in St Andrews, Scotland.
UK Exoplanet Meeting 2017
16 March 2017
Determining starspot lifetimes from photometry to feed models of stellar activity in exoplanet RV surveys
A talk given at the 2017 UK Exoplanet Meeting in St Andrews, Scotland.
CHEOPS 4th Science Workshop
23 June 2016
“What's eating those starspots?” - Determining a Relationship Between Starspot Size and Their Decay Timescale With Respect to Stellar Spectral Type
A talk given at the 4th CHEOPS Science Workshop in Geneva, Switzerland.
Cool Stars 19
7 June 2016
“What's eating those starspots?” - Determining a Relationship Between Starspot Size and Their Decay Timescale With Respect to Stellar Spectral Type
A plenary talk given at the 19th Cambridge Workshop on Cool Stars in Uppsala, Sweden.
Contact Me
If you want to get in touch, I’d love to hear from you!
You can either send me an email (helen.giles[at]unige.ch) or use the contact form below!