ARCSAT ID NUMBER: AS04

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: 

We only want to apply for one week: 
March 16, 2014 - March 23, 2015 (First Choice)

If we aren't able to be accommodated for this week then the following
dates also work:
March 23 - March 30, 2015 (Second 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. 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