USTMís First Capture of an
Astronomical Event by Astronoscope-I
25th August, 2017, USTM : Astronomical
events like solar eclipse and lunar eclipse are
very exciting natural events which repeat after
long duration. During a solar and a lunar
eclipse the sun and the moon, respectively
disappears for few hours partially or totally.
People eagerly wait to witness such events while
scientist performs different experiments under
the condition of such eclipses. Seizing the
opportunity of Lunar Eclipse that occurred on
7th August 2017, visible from all the parts of
India, the Department of Physics at
University of Science and Technology, Meghalaya
(USTM), had conducted a scientific
experimentation on Lunar Eclipse.
A group of M.Sc. Physics students, Mr. Mrinmoi
K. Bora, Mr. Ariful Alom, Mr. Rakesh G. Chetry
and Mr. Ikbal Farid Ali have developed USTMís
first optical telescope, ďAstronoscope-IĒ
(Newtonian Reflector Type), under the
supervision of Mr. Nitu Borgohain, Assistant
Professor, Department of Physics. Astronoscope-I
initially has the maximum magnification 450X,
which will be increased in the upgraded versions
of this telescope series. During the time of the
eclipse students and faculties of different
departments gathered to witness the event but
due to heavy cloud the initial phases of the
eclipse have missed. After 5 hours of wait few
windows of partially clear sky for 2-3 minutes
have been found, which were not to let go in
vain and finally, the lunar eclipse has been
captured successfully at 11:45PM.
How Astronoscope-I was made?
The major parts of Astronoscope-I are the
Telescope Tube and the Mount. The Telescope Tube
contains a convex primary mirror of aperture
diameter 4.5 inch and focal length 900 mm at the
bottom end, an oval structured flat secondary
mirror near the open tube end and a focuser that
holds the eyepieces mount outside the tube, near
the secondary mirror. These mirrors are bought
from a Mumbai based company which costs are
around Rs. 5000 only. The telescope tube is made
from a 1 meter long PVC pipe of diameter 5.5
inch. The holder clamps of the tube are made
from scrap iron bars available in the RIST
workshop. The mount that has been developed is a
modified Dobsonian type which suspends the
telescope with the help of nut-bolt. A scrap
revolving chair is used for this purpose where
the seat has been replaced with a plywood mount
made by the students.
How Astronoscope-I works?
Light enters the open end of the tube, travels
down to the primary mirror. The focused image
then reflects back to the small secondary mirror
which is placed at an angle of 450 with the
primary mirror. Secondary mirror reflects the
image out through the side of the tube to the
eyepiece where it enlarged the object.
Magnification power of Astronoscope-I:
Magnification power of this type of telescope is
given by the ratio of focal lengths of the
primary mirror to the eyepieces. We have 3
different eyepieces viz. 20 mm, 12 mm and 4 mm,
for which corresponding magnifications with a 2X
Barlow lens are 90X, 150X and 450X (maximum).
Thus with the help of Astronoscope-I, any
distant object in the night sky can be viewed
maximum 450 times closer then they appear.
What Astronoscope-I can gaze in the night
The whole universe could be viewed in the night
sky. Moon is the easiest target to find at
night. The craters and mountains of the moon can
be studied in much details with Astronoscope-I.
Other planets of the solar system such as Venus,
Mars, and Jupiter can also be viewed. Rings of
Saturn may be spectacular to be observed too.
Astronoscope-I also can be used for gazing the
galaxies, nebulae and star clusters abound in
the deep sky and study their formations.
Future Developments to Astronoscope-I:
Currently, Astronoscope-I has to be operated
manually for targeting an object in the sky. In
the nearest future, this discrepancy is to be
removed with a digital orientation system. A
tuneable eyepiece system attached with a HD
camera also to be developed soon.
Department of Physics acknowledges the
financial support from Mr. M. Hoque, Chancellor,