<p>No, for your so-called “non-traditional” definition. The <a href="https://glast.sites.stanford.edu/about" rel="noreferrer">Large Area Telescope</a> (note the name ) on board of the <a href="https://en.wikipedia.org/wiki/Fermi_Gamma-ray_Space_Telescope" rel="noreferrer">Fermi Gamma-ray Space Telescope</a> alone has an energy range from 20 MeV to 300 GeV, a factor of 15000. If you also count the Gamma-ray Burst Monitor (8 keV to 30 MeV) it is nearly forty million.</p>
<p>I think this is a large range for gamma-ray telescopes but others are comparable. See for example this <a href="https://www.researchgate.net/figure/Point-source-continuum-differential-sensitivity-of-different-X-and-g-ray-instruments-The_fig1_317589179" rel="noreferrer">figure</a>:
<a href="https://i.sstatic.net/FLS3r.png" rel="noreferrer"><img src="https://i.sstatic.net/FLS3r.png" alt="The e-ASTROGAM mission (exploring the extreme Universe with gamma rays in the MeV-GeV range)" /></a>
<a href="https://arxiv.org/abs/1611.02232" rel="noreferrer">The e-ASTROGAM mission (exploring the extreme Universe with gamma rays in the MeV-GeV range)</a> by <a href="https://orcid.org/0000-0002-3288-2517" rel="noreferrer">Alessandro De Angelis</a> et al. is licensed under <a href="https://creativecommons.org/licenses/by-sa/4.0/" rel="noreferrer">CC BY-SA 4.0</a></p>

CC BY-SA 4.0
2022-10-28T06:32:36.770Z
I was going to mention Swift, but this wins.
James K
CC BY-SA 4.0
2022-10-28T09:34:56.743Z
@JamesK does Swift work for the "traditional" telescope (using refraction or reflection)?
uhoh
CC BY-SA 4.0
2022-10-28T09:47:53.273Z
It has a traditional telescope, but it also has a (soft) gamma-ray detector.  You could well argue that these are two separate telescopes that happen to be on the same spacecraft.
James K
CC BY-SA 4.0
2022-10-28T19:49:34.997Z
@JamesK Oh I see [...Swift...is a NASA three-telescope space observatory...](https://en.wikipedia.org/wiki/Neil_Gehrels_Swift_Observatory)
uhoh
CC BY-SA 4.0
2022-10-28T06:29:22.613Z
2022-10-28T17:01:10.053Z
2022-10-28T17:01:10.053Z
Karsten Kretschmer
<p>If the longest and shortest wavelengths that JWST can focus are 28.3 and 0.6 microns respectively, then it has a bandwidth (max/min) of a factor of about 47.</p>
<p>That's a lot, and of course it needs several different instruments for different wavelength ranges to make use of all of that.</p>
<p>But let's only talk about the entire system as &quot;the telescope&quot;.</p>
<p>Is this the widest range?</p>
<p>For example if it were radio this might be 21 GHz to 1 THz or 10 meters to 20 centimeters.</p>
<p>The hard part about answering this question is the definition of &quot;telescope&quot;. I suppose one could answer based on traditional instruments using reflection or refraction, and another might be anything that can resolve direction (e.g. <a href="https://en.wikipedia.org/wiki/IceCube_Neutrino_Observatory" rel="nofollow noreferrer">IceCube Neutrino Observatory</a> or one or other of the two <a href="https://en.wikipedia.org/wiki/Square_Kilometre_Array" rel="nofollow noreferrer">Square Kilometer Arrays</a> (Africa or Australia)</p>
<p>So answers can cite a winner for each definition if they like and resolve in each case if JWST has the largest bandwidth of any telescope.</p>

<observational-astronomy><telescope><observatory>
Does JWST have the largest bandwidth of any telescope?
uhoh
# Does JWST have the largest bandwidth of any telescope?

(Asked by: username_0 on 2022-10-28)

If the longest and shortest wavelengths that JWST can focus are 28.3 and 0.6 microns respectively, then it has a bandwidth (max/min) of a factor of about 47.

That's a lot, and of course it needs several different instruments for different wavelength ranges to make use of all of that.

But let's only talk about the entire system as "the telescope".

Is this the widest range?

For example if it were radio this might be 21 GHz to 1 THz or 10 meters to 20 centimeters.

The hard part about answering this question is the definition of "telescope". I suppose one could answer based on traditional instruments using reflection or refraction, and another might be anything that can resolve direction (e.g. [IceCube Neutrino Observatory](https://en.wikipedia.org/wiki/IceCube_Neutrino_Observatory) or one or other of the two [Square Kilometer Arrays](https://en.wikipedia.org/wiki/Square_Kilometre_Array) (Africa or Australia)

So answers can cite a winner for each definition if they like and resolve in each case if JWST has the largest bandwidth of any telescope.

**Tags:** observational-astronomy, telescope, observatory


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## 1 answers

### Answer by username_1 on 2022-10-28. Score: 8 | Accepted answer

No, for your so-called “non-traditional” definition. The [Large Area Telescope](https://glast.sites.stanford.edu/about) (note the name ) on board of the [Fermi Gamma-ray Space Telescope](https://en.wikipedia.org/wiki/Fermi_Gamma-ray_Space_Telescope) alone has an energy range from 20 MeV to 300 GeV, a factor of 15000. If you also count the Gamma-ray Burst Monitor (8 keV to 30 MeV) it is nearly forty million.

I think this is a large range for gamma-ray telescopes but others are comparable. See for example this [figure](https://www.researchgate.net/figure/Point-source-continuum-differential-sensitivity-of-different-X-and-g-ray-instruments-The_fig1_317589179):
[![The e-ASTROGAM mission (exploring the extreme Universe with gamma rays in the MeV-GeV range)](https://i.sstatic.net/FLS3r.png)](https://i.sstatic.net/FLS3r.png)
[The e-ASTROGAM mission (exploring the extreme Universe with gamma rays in the MeV-GeV range)](https://arxiv.org/abs/1611.02232) by [Alessandro De Angelis](https://orcid.org/0000-0002-3288-2517) et al. is licensed under [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0/)

> **Comments:**
> **username_2**: I was going to mention Swift, but this wins.  
> **username_0**: @username_2 does Swift work for the "traditional" telescope (using refraction or reflection)?  
> **username_2**: It has a traditional telescope, but it also has a (soft) gamma-ray detector.  You could well argue that these are two separate telescopes that happen to be on the same spacecraft.  
> **username_0**: @username_2 Oh I see [...Swift...is a NASA three-telescope space observatory...](https://en.wikipedia.org/wiki/Neil_Gehrels_Swift_Observatory)  

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