Limiting Magnitude | British Astronomical Association
Most ways of counting and measuring things work logically. When the thing that you're measuring increases, the number gets bigger. When you gain weight, after all, the scale doesn't tell you a smaller number of pounds or kilograms. But things are not so sensible in astronomy — at least not when it comes to the brightnesses of stars.
This page has a variety of suggestions for beginning amateur astronomers who wish to observe the sky with only the unaided eye. It is a common misconception that you need to have a telescope to do astronomy; this simply is not true. A wide variety of objects can be seen with the naked eye: from planets and stars, to nebulae and galaxies. While you can usually see more detail if you use a telescope or binoculars and you can usually see more objects of a given type if you use a telescope or binoculars ; the same types of objects that can be seen with a telescope can be seen without a telescope.
In astronomy , limiting magnitude is the faintest apparent magnitude of a celestial body that is detectable or detected by a given instrument. In some cases, limiting magnitude refers to the upper threshold of detection. In more formal uses, limiting magnitude is specified along with the strength of the signal e. Sometimes limiting magnitude is qualified by the purpose of the instrument e.