How do you calculate the ultimate magnitude of a telescope?

Limit magnitude refers to the brightness of the faintest celestial object that the telescope can see, which is one of the important indicators to measure the ability of the telescope, mainly determined by the aperture of the telescope, the larger the aperture, the larger the limit magnitude value, which means that the fainter the celestial objects can be seen, and the more the number of celestial objects. Of course, extreme magnitudes are also affected by other factors such as atmospheric transparency, atmospheric tranquility, clouds, and so on.

If the magnitude difference is one magnitude, the brightness of the celestial body will be doubled, that is, the 1st magnitude star is twice brighter than the 2nd magnitude star, so the 12th magnitude is brighter than the 1st magnitude, so you can see the 12th magnitude, which is already very powerful. In fact, within the Earth's atmosphere, this is close to the limit.

However, the brightness of a star does not directly reflect its distance from the earth, some stars are larger in size, and some stars have a strong luminous ability and greater luminosity, even if they are far away, they may look brighter. Some stars may be dwarfs, which are relatively small and not very bright even if they are close. For example, Proxima Centauri, which we are familiar with, is only light-years away, but it is a red dwarf, very faint and faint, with an apparent magnitude of only 11.

So the ultimate magnitude indicates how faint it can be seen, not how far it can be seen.

This is a base 10 logarithm, also known as a common logarithm. The most commonly used base number in logarithms is 10, and the mathematical constant e sum, which represents a base number of 10 (commonly used logarithms), such as lg 10=1. If 10 y=x then y is the common logarithm of x:

y=lgx In addition, on the 3rd floor, the natural logarithm is ln, which is based on e. Also, m = is just an empirical formula, d is the effective aperture of the objective, measured in centimeters.

LG is logarithmic and D is the effective aperture of the objective in centimeters.

Telescope limit sight refers to the faintest magnitude that a telescope can observe. Generally speaking, the ultimate apparent magnitude of a telescope is determined by the telescope's type, aperture, optical system, noise immunity, observation environment, and other factors.

For telescopes, the ultimate apparent magnitude is limited by the telescope's aperture, and generally speaking, the larger the telescope's aperture, the lower the ultimate apparent magnitude. In addition, the optical system of the telescope also affects the ultimate apparent magnitude, and the better the telescope's optical system, the lower the ultimate apparent magnitude. In addition, the observation environment will also affect the ultimate visual magnitude, and in the case of a poor observation environment, the ultimate visual magnitude will also be affected.

Generally speaking, the ultimate apparent magnitude of a telescope is above the equal, you can observe the fainter magnitude, and the telescope's ultimate magnitude is above the equal, you can observe the fainter magnitude, and the telescope's ultimate magnitude is above the equal, you can observe the fainter star macro Soxiang and so on, and the telescope's ultimate magnitude is above the equal, you can observe the fainter magnitude.

Generally, the limit apparent magnitude of telescopes is 18, which can also be adjusted appropriately according to the actual situation.

1. The magnification configuration of the telescope should be reasonable: the telescope has a larger field of view at low magnification, and can see fainter celestial objects and finer details at high magnification. In order to make full use of the light from the objective lens, the minimum magnification of the telescope should not be less than a multiple of the number of centimeters in aperture.

2. The bracket should be stable: the astronomical telescope is larger and heavier, and the magnification is higher, so a stable bracket is needed to give full play to its optical performance. The instability of the bracket seriously affects the use, especially when using eyepieces with higher magnification, and in many cases it is not possible to place the object to be observed in the field of view due to the narrow field of view.

3. The interface of the focuser should be standard: in order to give full play to the potential of the telescope, it is best to choose a telescope with a focuser diameter equal to or greater than millimeters.

Extreme magnitude (m): The faintest magnitude that can be seen by a telescope is called an extreme magnitude.

Different telescopes have different limit magnitudes, as far as a telescope is concerned, it is not possible to increase the limit magnitude of the stars we see with the naked eye is 6 magnitude, and the limit magnitude is 12, which means that the highest star of 12 magnitude can be seen, which is 6 magnitude more than we can see with the naked eye (almost 100 times more), which should be a better astronomical telescope.

Hope it helps.

In layman's terms, it is the faintest star that the telescope can theoretically see, and this indicator reflects the telescope's ability to collect light, and has nothing to do with "how far it can see". It is a fixed indicator of the telescope and cannot be increased.

Supplement upstairs. The larger the aperture, the larger the clear area, which means that more photons can be received, and the fainter the star can be seen. Using this equation, d refers to the aperture of the telescope

m = The aperture of the telescope cannot be changed, and the only way to increase it is to change to a larger telescope.

Simply paying attention to the multiple of the telescope is a national misunderstanding, and it is also the most vulnerable place for businesses to exploit loopholes. The system magnification of the telescope is equal to the focal length of the objective lens divided by the focal length of the eyepiece, and if the imaging quality is not considered, the focal length of the eyepiece should be shortened as much as possible (the cost of a short focal length is much lower than that of a long focal length for an eyepiece of the same quality), and a baro lens can be added if it is not enough. In the past, many toy telescopes with millimeter aperture dared to mark multiples to multiples, and this is the reason.

Although the amateur-grade astronomical telescope is basically a toy, it is a toy that is very demanding for players.

In fact, 150 times is very high, and the wood grain Wood Guard or something can be seen very clearly.

If you want to see the nebula, it is enough to see less than 100 times, and 150 times you can't see anything.

So what multiples are the real astronomical telescopes? 50-150 times for civilian will do.

The most important factor in the magnification factor is the caliber, and the theoretical multiple is not clear no matter how large the caliber is.

For refraction, the magnification can reach a maximum of 2 times the aperture value (in mm), and the reflection can only be equal to the aperture value.

If the telescope aperture that the landlord fancies is less than 75mm, it means that the landlord has been deceived.

Pictured below, Jupiter and Europin in a 150x telescope.

The telescope's limit magnitude is related to many factors, the most important of which is the aperture of the telescope objective, if the telescope's ultimate magnitude is m, the telescope's objective lens aperture is d, and the rough estimate is: m=

Where: d is measured in millimeters.

For example: d = 100 (i.e. the telescope objective aperture is 10 cm), then the limit magnitude (m) is the town of the tomb, if d = 200 mm, then m =

Hope LZ is satisfied

Astronomical telescopes are generally purchased.

It was purchased by looking at the aperture of the astronomical telescope. Because the magnification of the astronomical telescope can be adjusted by replacing the eyepiece and adding a magnifier. For example, compare an astronomical telescope used by beginners:

Boguan 80 900The multiplier is = focal length of the eyepiece focal length. That is, when using a 20mm eyepiece.

, the multiplier is =900 20=45x. Such a multiplier allows the full surface of the moon to be clearly seen, and the surface of the moon is clearly visible. If you add a 2x extender, the magnification is 90x. Such a multiple allows you to see the crater of the moon clearly.

Take the moon sea. If using a 9mm eyepiece. The multiplier is 100 times. Add 2x the extender, and it's 200x. Such multiples, look at the stripes of Jupiter, the rings of Saturn.

Wait, it's all enough.

In fact, astronomical telescopes recommend magnification that is twice the aperture. It's relatively clear, and if you zoom in, the effect will be worse. Therefore, when you buy an astronomical telescope, you buy it by looking at the aperture.

ps: If you need to buy an astronomical telescope, you can contact Mr. Zeng of the Shenzhen Astronomical Association, "Shenzhen Telescope."