Abstract Details
| Name: Ankala RajaBayanna Affiliation: PRL, Ahmedabad Conference ID: ASI2019_360 Title : Fizeau Mask Interferometry of Solar Features using the Multi Application Solar Telescope at the Udaipur Solar Observatory Authors and Co-Authors : R. Sridharan P. Venkatakrishnan S. K. Mathew Abstract Type : Oral Abstract Category : Instrumentation and Techniques Abstract : Efforts are made to demonstrate high-resolution observations of the solar atmosphere using spatial interferometry. Covering the telescope pupil with a Fizeau mask consisting of two small circular apertures separated by a vector distance known as baseline is the first step towards interferometric imaging. Two apertures of 7 cm in diameter separated by a distance of 19 cm are placed in the re-imaged pupil of the Multi-application solar telescope at Udaipur solar observatory. Fringe pattern observed in the image plane signifies the presence of solar structures with sizes smaller than the fringe period of 0.5 arcsec, which is well known by now from the observations obtained from various high-resolution telescopes. The study is extended by using Fizeau masks with increase in base-line to 29 cm and 38 cm. It is observed that, increase of the base-line causes the reduction in the fringe period and the fringe contrast. Observations were obtained in two spectral lines (656.3 nm and 820.0 nm) using filters of bandwidth 1 nm and 400 nm, respectively. It is also observed that the larger bandwidth causes reduction in the fringe contrast. |