Abstract:
The solar observational facilities at ARIES (erstwhile U.P.
State Observatory, UPSO), Nainital, began in the sixties with the acquisition
of two moderate sized (25 cm, f/66 off-axis Skew Cassegrain and 15 cm,
f/15 refractor) telescopes. Both these systems receive sunlight through
a 45 cm and 25 cm coelostat respectively. The backend instruments to
these systems comprised of a single pass grating spectrograph for spectroscopic study of the Sun and a Bernhard–Halle H α filter, coupled with
a Robot recorder camera for solar patrolling in H α respectively. With
the advancement in solar observing techniques with high temporal and
spatial resolution in H α and other wavelengths, it became inevitable to
acquire sophisticated instrumentation for data acquisition. In view of that,
the above facilities were upgraded, owing to which the conventional pho-
tographic techniques were replaced by the CCD camera systems attached
with two 15 cm, f/15 Coude refractor telescopes. These CCD systems
include the Peltier cooled CCD camera and photometrics PXL high speed
modular CCD camera which provide high temporal and spatial resolution
of ∼ 25 ms and ∼ 1.3 arcsec respectively.
