Jagdev Singh/India Experiments

jsingh@iiap.ernet.in

(i) High frequency photometry of the solar corona using photomultiplier tubes :

We plan to use a 12-inch coelostat and 8-inch objective of 10 feet focus to form the image of the sun/corona. A 3-inch prism kept near the focus diverts eastern part of the image in the perpendicular direction and western part in the other direction. Six fibers each of 250- micron size will be mounted on the eastern part of the image at 1.2 solar radii and 1.5 solar radii. The light from these fibers will be fed to six photo- multiplier, R 647 HAMAMATSU, tubes. An interference filter of 5 A pass- band centered around 5303 A, Fe XIV line will be mounted before the fibers. The intensity at six locations will be recorded using photon counting system at the rate of 20 Hz. The dead time for the system is 10 nano-second. The data obtained during the eclipse will be used to study the high frequency oscillations in the solar corona.

(ii) Two dimensional photometry of the solar corona using CCD:

A Peltier cooled CCD camera from Photometrics will be mounted on a 10-inch Meade Telescope having a focal length of 100-inch. A broadband filter will be kept before the CCD camera. A suitable region on some streamer structure will be choosen. The size of the coronal region will be restricted to 200 by 1000 arcsec to obtain the images at faster rate. The pixel size of 24-microns will provide an image scale of 2 arcsec per pixel. THe data will be obtained at 1.5 Hz. The two dimensional data obtained will be used to investgate the existence and nature of waves in the solar corona, if any.

Location of site:

Chadegan

Chadegan is site about 15 Km south of the totality path. This place is about 100 km from Isfahan in Iran. The site is close to a big lake at an altitude of about 2800 m. It is expected to provide clear sky with good transpareny during the eclipse.