Astronomers use a system of magnitudes to indicate how bright a stellar object is. An object is said to have a certain numerical magnitude. The larger the magnitude number, the fainter the object. Each object with an increased single number is approximately 2.5 times fainter. The faintest star you can see with your naked unaided eye is about 6th magnitude whereas the brightest stars are negative number magnitude.
The skies and any instrument mentioned are at the best condition.
