ARCSAT ID NUMBER: AS02

DESCRIPTIVE TITLE: 
Constraining the magnetic fields of transiting exoplanets through ground-based near-UV observations

PI: Jake Turner

OBSERVER(S): Jake Turner (Graduate Student: University of Virginia)
	     Apurva Oza  (Graduate Student: University of Virginia)
	     Robin Leiter (Undergraduate Student: University of Virginia)

UNCERTIFIED/UNTRAINED OBSERVERS: Jake Turner, Apurva Oza, Robin Leiter

COLLABORATORS: Kyle Pearson (University of Arizona)
 
CONTACT INFORMATION: jt6an@virginia.edu, 719-251-3263

TIME REQUESTED: (give weeks from Mon night - Sun night, e.g. May 5-11.  Put in 
full weeks even if you only want to use a day or two.  You are responsible for 
figuring out moon phase, making sure time doesn't conflict with your travel schedule, etc.  You may ask for up to 3 separate weeks with this form.  All observing is assumed to be remote unless you specify on-site in COMMENTS below.)

We only want to apply for one week: 
May 11, 2014 - May 17, 2015 (First Choice)

If we aren't able to be accommodated for this week then the following dates also work:
May 18 - May 24, 2015 (Second Choice)
July 13- July 19, 2015 (Third Choice)
June 1 - June 7, 2015 (Fourth Choice)

INSTRUMENT: FlareCam

FILTERS: ugri 

COMMENTS: (any special requests we need to be aware of about your run)

BRIEF SCIENCE JUSTIFICATION:  (restrict yourself to 1-2 paragraphs)
We propose to observe the primary transits of several exoplanets in the near-UV and optical bands in an attempt to detect their magnetic fields and update their planetary parameters. The magnetic field of a transiting exoplanet can be constrained by observing asymmetries in their near-UV light curves (Vidotto, Jardine & Helling 2011a; Vidotto et al. 2011; Llama et al. 2011, 2013). Specifically, a transiting exoplanet with a magnetic field should show an earlier transit ingress in the near-UV than in the optical, while the transit egress times would be the same. This phenomenon is caused by the presence of a bow-shock in front of the planet formed by interactions between the stellar coronal material and the planetтАЩs magnetosphere. The material in the shocked region will absorb starlight and cause an early ingress in the near-UV light curve (Vidotto, Jardine & Helling 2011a). The difference between ingress times in different wavelength bands can be used to constrain the planetтАЩs magnetic field. Studying the magnetic fields of exoplanets will allow for the investigation of their rotation periods, interior structure, atmospheric retention, and the presence of extrasolar moons (Lazio et al. 2010). Additionally, it has been suggested that the magnetic field of Earth helps contribute to its habitability by deflecting stellar wind particles and cosmic rays (Grie†Яmeier et al. 2005); exoplanets may also exhibit this characteristic (Lazio et al. 2010). Therefore, studying the magnetic fields of hot Jupiters will help lay the foundation for the characterization of magnetic fields around Earth-like planets, and consequently, it will aid in the search for life outside our solar system. 

We have already begun a campaign to observe this effect on hot Jupiters from the 1.5 meter Kuiper telescope on Mt. Bigelow in the near-UV and on ARCSAT in the optical. Vidotto, Jardine & Helling (2011a) predicted that near-UV ingress asymmetries should be common in transiting exoplanets and compiled a list of 142 planets that should exhibit this effect. In addition, in our work in Turner et al. (2013) and Pearson, Turner & Sagan (2014) we concluded that the timing difference for a hot Jupiter should be between 10-30 minutes, within reach for ground-based telescopes. We have already developed a data reduction pipeline called ExoDERPL and a transit modeling package called EXOMOP for this research. Both the ExoDERPL and EXOMOP have successfully been implemented in Turner et al. (2013), Teske et al. (2013), and Pearson, Turner & Sagan (2014). We hope to detect and study the magnetic fields of exoplanets by utilizing a multi-wavelength and multiple platform approach and conduct a unique survey of hot Jupiters. We hope to not only detect the magnetic fields of these exoplanets but also constrain some of their other properties.

REFERENCES 
Grie†Яmeier J.-M., Stadelmann A., Motschmann U., Belisheva N. K., Lammer H., Biernat H. K., 2005, Astrobiology, 5, 587 

Lazio T. J. W., Carmichael S., Clark J., Elkins E., Gudmundsen P., Mott Z., Szwajkowski M., Hennig L. A., 2010, AJ, 139, 96 

Llama J., Vidotto A. A., Jardine M., Wood K., Fares R., Gombosi T. I., 2013, MNRAS 

Llama J., Wood K., Jardine M., Vidotto A. A., Helling C., Fossati L., Haswell C. A., 2011, MNRAS, 416, L41
 
Pearson K. A., Turner J. D., Sagan T. G., 2014, New A, 27, 102 

Teske J. K., Turner J. D., Mueller M., GriтАвth C. A., 2013, MNRAS, 431, 1669 Turner J. D. et al., 2013, MNRAS, 428, 678
 
Vidotto A. A., Jardine M., Helling C., 2011a, MNRAS, 411, L46 Vidotto A. A., Jardine M., Helling C., 2011a, MNRAS, 414, 1573
 
Vidotto A. A., Llama J., Jardine M., Helling C., Wood K., 2011, Astronomische Nachrichten, 332, 1055