Starspots

Our knowledge of spots on the Sun (known as sunspots) is very good, especially when compared to our knowledge of the same phenomena on other stars. This is because we can easily make out features on the solar surface and study them, but we can’t easily resolve stellar surfaces (unless they have quite extreme surface features). So, if we want to know something about starspots then we need to extrapolate that information from other sources!

My collaborators and I have successfully determined the lifetimes of starspots using Kepler mission light curves for a sample of 2000+ stars. We also determined how they changed given the kind of stellar spectral type. This work has also been used for other scenarios, measuring the starspot lifetime for individual stars, where this knowledge can significantly help other studies such as exoplanet detection and characterisation.

Key Publications

Below are a handful of key publications where I contributed with my stellar activity experience:

  • A Kepler study of starspot lifetimes with respect to light-curve amplitude and spectral type
    Giles, Helen A. C.; Collier Cameron, Andrew; Haywood, Raphaëlle D. (2017)
    Monthly Notices of the Royal Astronomical Society, Volume 472, Issue 2, p.1618-1627 [ADS]

  • An Accurate Mass Determination for Kepler-1655b, a Moderately Irradiated World with a Significant Volatile Envelope
    Haywood, Raphaëlle D.; Vanderburg, Andrew; Mortier, Annelies; Giles, Helen A. C.; López-Morales, Mercedes; Lopez, Eric D.; Malavolta, Luca; Charbonneau, David; Collier Cameron, Andrew; Coughlin, Jeffrey L.; Dressing, Courtney D.; Nava, Chantanelle; Latham, David W.; Dumusque, Xavier; Lovis, Christophe; Molinari, Emilio; Pepe, Francesco; Sozzetti, Alessandro; Udry, Stéphane; Bouchy, François Johnson, John A.; Mayor, Michel; Micela, Giusi; Phillips, David; Piotto, Giampaolo; Rice, Ken; Sasselov, Dimitar; Ségransan, Damien; Watson, Chris; Affer, Laura; Bonomo, Aldo S.; Buchhave, Lars A.; Ciardi, David R.; Fiorenzano, Aldo F.; Harutyunyan, Avet (2018)
    The Astronomical Journal, Volume 155, Issue 5, article id. 203 [ADS]

  • The solar benchmark: rotational modulation of the Sun reconstructed from archival sunspot records
    Morris, Brett M.; Davenport, James R. A.; Giles, Helen A. C.; Hebb, Leslie; Hawley, Suzanne L.; Angus, Ruth; Gilman, Peter A.; Agol, Eric (2019)
    Monthly Notices of the Royal Astronomical Society, Volume 484, Issue 3, p.3244-3250 [ADS]

  • Using HARPS-N to characterize the long-period planets in the PH-2 and Kepler-103 systems
    Dubber, Sophie C.; Mortier, Annelies; Rice, Ken; Nava, Chantanelle; Malavolta, Luca; Giles, Helen; Coffinet, Adrien; Charbonneau, David; Vanderburg, Andrew; Bonomo, Aldo S.; Boschin, Walter; Buchhave, Lars A.; Collier Cameron, Andrew; Cosentino, Rosario; Dumusque, Xavier; Ghedina, Adriano; Harutyunyan, Avet; Haywood, Raphaëlle D.; Latham, David; López-Morales, Mercedes Micela, Giusi; Molinari, Emilio; Pepe, Francesco A.; Phillips, David; Piotto, Giampaolo; Poretti, Ennio; Sasselov, Dimitar; Sozzetti, Alessandro; Udry, Stéphane (2019)
    Monthly Notices of the Royal Astronomical Society, Volume 490, Issue 4, p.5103-5121 [ADS]

  • Exoplanet Imitators: A Test of Stellar Activity Behavior in Radial Velocity Signals
    Nava, Chantanelle; López-Morales, Mercedes; Haywood, Raphaëlle D.; Giles, Helen A. C. (2020)
    The Astronomical Journal, Volume 159, Issue 1, article id. 23 [ADS]