Coronal Polarization Measurements and Associated Observations from the

June, 2001, Solar Eclipse

Roban H. Kramer (roban@sccs.swarthmore.edu)

Swarthmore College 2003

Dr. Jay M. Pasachoff, Williams College

Path of Totality The right place at the right time

Williams College Expedition eclipse image: Kathleen Gibbons, Daniel Seaton, Stephan Martin, and Jay Pasachoff; TXI Rocket image:

Smithsonian Astrophysical Observatory / Leon Golub

Components of the Corona

The three components

K-Corona

E-Corona

F-Corona

From Goulub, Leon and Pasachoff, Jay M. 1997, The Solar Corona. Cambridge University Press, New York

ObservationsLocal time Duration Filter

configuration15:10:23 1s polar 015:10:28 1s polar 015:10:32 1s polar 015:10:36 3s polar 015:10:43 3s polar 0

15:10:50 1s polar 4515:10:54 1s polar 4515:10:59 1s polar 4515:11:03 3s polar 4515:11:10 3s polar 45

15:11:17 1s polar 9015:11:21 1s polar 9015:11:25 1s polar 9015:11:30 3s polar 9015:11:36 3s polar 90

15:11:59 1s Jupiter15:12:03 1s Jupiter15:12:08 3s Jupiter15:12:14 3s Jupiter

The angle of polarization:

ca

cab

II

III

2

2tan

The fraction of polarization:

22 sincos

cap

III

2sin2/)2sin1(

cbp

III

2cos2/)2sin1(

abp

III

Images taken through three polarizing filters oriented at 45 degree intervals can be used to determine the degree of

polarization and the polarization angle.

Maps

Reduction of the 3-second exposures will improve measurements of polarization angle and degree at greater than 2.5 solar radii.

Radiometric calibration will allow

the comparison of photometric results with other observations

as well as improving the precision of our polarization measurements and the separation of the K- and F- coronas.

Further Research

AcknowledgmentsI would like to thank professor Jay Pasachoff for choosing me to

share the incredible experience he organized, R. Lee Hawkins for supervision the experiment, Shoshana Clark for her joyful collaboration, Mike Gioiello for his preparatory work, and the whole 2001 Williams College eclipse team for an extremely enjoyable and productive environment. I'd also like to thank Gabe Brammer, Kate Gibbons, Mike Gioiello, Dan Seaton and Roger Cohen for helping with my work and play all summer. Swarthmore professors Eric Jensen and David Cohen deserve much of the credit for getting me into this project in the first place.

The Keck Northeast Astronomy Consortium provided funding for my participation in this project, for which I am very grateful. Support for the expedition also came from the Atmospheric Sciences Division of the National Science Foundation and the Committee for Research and Exploration of the National Geographic Society.