Maximizing Telescope Sensitivity: The Importance of Mirror Size

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Discussion Overview

The discussion centers around the relationship between telescope mirror size and sensitivity, particularly in terms of resolution and light collection capabilities. Participants explore how mirror size affects the ability to observe distant and dim celestial objects, including stars and extended objects like nebulae and planets.

Discussion Character

  • Exploratory, Technical explanation, Conceptual clarification

Main Points Raised

  • Some participants propose that a larger mirror increases a telescope's sensitivity by allowing it to collect more light, which could enable the observation of dimmer stars.
  • Others confirm that a bigger mirror correlates with higher resolution, allowing for more detail to be seen at greater distances.
  • A participant mentions that regardless of mirror size, there exists a limiting magnitude for each telescope, indicating a threshold for visibility.
  • One participant provides an example of their telescope's limiting magnitude and compares it to that of the Hubble Space Telescope.
  • There is a distinction made between observing stars and extended objects, with some arguing that the f/number becomes a critical factor for the latter.

Areas of Agreement / Disagreement

Participants generally agree that larger mirrors enhance sensitivity and resolution, but there is a lack of consensus on the implications for different types of celestial observations, particularly between stars and extended objects.

Contextual Notes

Participants mention limiting magnitudes and the importance of the f/number, but these concepts are not fully explored, leaving some assumptions and definitions potentially unresolved.

Erenjaeger
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A telescopes sensitivity, or how much detail it can see is directly related to the size of the mirror area that collects light from the objects being observed. So a bigger mirror means higher resolution so you can see more detail at greater distances right? does it also mean it can collect more light so it will be able to see dimmer stars that wouldn't usually be able to be seen??
 
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Erenjaeger said:
So a bigger mirror means higher resolution so you can see more detail at greater distances right?

yes

Erenjaeger said:
does it also mean it can collect more light so it will be able to see dimmer stars that wouldn't usually be able to be seen??

and again yes, tho regardless of the size of the scope, it will still have a limiting magnitude for that particular size
 
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davenn said:
tho regardless of the size of the scope, it will still have a limiting magnitude for that particular size

for example my 9.25 inch mirror scope has a limiting magnitude of M 14.4
one link on the www told ne that for the Hubble Space Telescope is about M 28Dave
 
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Erenjaeger said:
does it also mean it can collect more light so it will be able to see dimmer stars that wouldn't usually be able to be seen??

If you are talking just about stars, then yes, the size of the mirror is the limiting factor. If you are talking about extended objects (nebula, planets) then the f/number is the important parameter.
 

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