Most modern telescopes are reflectors, with the primary element being a very large mirror.
The first era was ancient observations (such as with the naked eye), before the invention of the modern telescopes.
The modern optical (uses visible light) telescope is still more advanced.
Most modern professional telescopes use a guide star.
Our modern high-tech telescopes with higher resolution now confirm their view.
In 1996, it was decommissioned due to its age and lack of sensitivity compared with modern telescopes.
Using his modern telescope he succeeded in subdividing the nebula into different stars.
The real disks of stars are generally too tiny to be seen even with the best of modern telescopes.
This method is used in the manufacture of almost all large mirrors for modern telescopes.
M51 is visible through binoculars under dark sky conditions and can be resolved in detail with modern amateur telescopes.