728. The system of astronomy based on Heliocentre (sun centred) universe was presented by?
Copernicus
729. The astronomer who presented the system of astronomy based on a geo centric (earth centred) universe?
Ptolemy
730. The first who attempted to measure stellar distances?
James Gregory
731. The length of an Earth day is determined by the time required for approximately one?
Earth rotation
732. The apparent rising and setting of the Sun, as viewed from Earth, is caused by?
Earth’s rotation
733. The apparent daily path of the Sun changes with the seasons because?
Earth's axis is tilted
734. An inter stellar cloud of dust, hydrogen, helium and other ionized gases are called?
Pulsars
735. First pulsar was discovered by?
Jacelyn Bell
736. The pieces of rocks, which move around the sun are called?
Meteoroids
737. The tilt of the Earth on its axis is a cause of the Earth’s?
changing length of day and night
738. Compared to the distances between the planets of our solar system, the distances between stars are usually?
much greater
739. Why does the moon appear to move across the sky during the night?
Earth rotates on its axis.
740. What time of year is the sun farthest from the earth?
Summer in the Northern Hemisphere.
741. As per Microwave Anisotropy Probe (MAP) what is the exact age of the universe?
13.7 billion year after the theoretical Big Bang
742. Name the British astronomer who, told that the Universe was not limited to the solar system, but is much vaster than that?
Sir William Herschel
743. Stars whose brightness increases to 20 magnitude or more due to explosion in the star is called?
Supernovae
744. What is a star?
A star is a gaseous self-luminous body in space
745. What is a parsec?
The word "parsec" is made up of the parts of the words "parallax" and "second". It means the distance from the Earth to a star whose parallax is one second of arc.
746. What does magnitude mean?
Magnitude is the measure of the brightness of a star or of any luminous body in the heaven
747. When the hydrogen in a star is depleted, its outer regions swell and redden such stars are called?