<em> A. The star must be 29 times larger than Earth's sun, and a supernova explosion must have occurred. </em>
<u>Explanation:</u>
The object has a strong gravitational force. Usually, a black hole has an enormous gas with an overall structure that is present in space. When determining the physical appearance, then it is about 28 times bulky and massive when comparing it with the sun. Therefore energy is pulled by the black hole from the surrounding galaxies.
The black holes are amazing because they have invisible beats that pass through the scatter forming a cosmic object that continues to captivate the explosions.
Formation of black holes occur during the death of massive stars (at least 25 times larger than Earth’s sun). When the fuel of the massive star is exhausted, the star’s nuclear forces are unable to counter the gravitational collapse due to its own weight. The star dies in a supernovae and the remnant is a black hole.
1. The phases of the moon are caused due to the earth's rotations on its axis and the moon rotation around the earth in its elliptical orbit. Certain phases f the moon are caused due to the sun and moon positions about that of the earth on the full moon, new moon and half-moon days. Most of the time we see the same face of the moon.
2. Planet venus show similar properties to that of the moon as both the moon and venus have are made up of same gem material like earth and being a terrestrial planet the venus and both revolve on in the same opposite direction of the earth thus earth sees the same phase of the venus as in the moon.
3. A solar eclipse occurs when the moon blocks the rays id sun and a ring-shaped formations take place when the earth comes in way of the or between the moon and sun the shadows of the earth fall on the moon and hence lunar eclipse takes place.
4. The north star also called the Polaris star seems to change its position for the southern hemisphere, but as for the northern hemisphere, it remains the same as being the north star the equatorial belt the star remains or shows the same side. Due to the rotation and axial tilt of the earth.
5. The cause of sunrise and sunset is mainly due to the sun and the earth's movement around the horizon in the opposite direction and there is 12 hours gap.
