<p><a href="https://astronomy.stackexchange.com/a/33765/7982">This answer</a> to <em>How will microshutter arrays be used in the James Webb and future space telescopes?</em> explains how multiple objects can be selected so that the throughput of a spectrometer can be enhanced (with some compromises somewhere) by recording spectra of more than one object at a time. The answer is worth a read if you haven't read it yet.</p>
<p>Another technique to get multiple spectra from a single telescope is to place (and sometimes articulate) high quality optical fibers at may locations at the focal plane. These days the number of fibers and objects can number in the thousands, so the output of several fibers can be lined up along the slit one spectrometer, and multiple spectrometers can also be used.</p>
<p>But here I'd like to look back in time to understand the beginnings of this technology.</p>
<p><strong>Question:</strong> How were &quot;microshutters&quot; or other multiplexed or multi-object techniques first used in Astronomical spectroscopy <em><strong>to capture spectra from multiple object?</strong></em></p>
<hr />
<p>Related:</p>
<ul>
<li><a href="https://astronomy.stackexchange.com/q/33757/7982">How will microshutter arrays be used in the James Webb and future space telescopes?</a></li>
<li><a href="https://astronomy.stackexchange.com/q/33758/7982">What is an &quot;Off Rowland-circle Telescope&quot;? Are there &quot;On Rowland-circle Telescope&quot; as well?</a></li>
</ul>

CC BY-SA 4.0
2021-08-21T08:30:12.740Z
Do prism plates count? Taking images through a prism gives you a spectrum of every object in the field.
ProfRob
CC BY-SA 4.0
2021-08-21T10:24:10.313Z
@ProfRob that is such a notable first that it really should be an answer here. I'm also interested in when the first micro-shutters or multiple objects with fibers were done, maybe I can keep this question general (and thus the prism plate would almost certainly be the right answer) and ask separately about those other two. Does that sounds like a good way to proceed?
uhoh
CC BY-SA 4.0
2021-12-31T19:53:58.767Z
@ProfRob prisms still count!
uhoh
CC BY-SA 4.0
2022-01-03T17:01:04.577Z
@uhoh Do you mean the multi-object observing technique in your question ? Looks like I misunderstood the question
Kavin Ishwaran
CC BY-SA 4.0
2022-01-03T19:39:28.990Z
@KavinIshwaran yes, the use of "multiple" in the first sentence of the first and second paragraph does indicate that, but I will edit the question to add "multiple" to the third paragraph as well. That's what microshutters do and that's what multiplexing is; multiple signals through a single path (in this case through a telescope) such that they can be separated later.
uhoh
CC BY-SA 4.0
2022-01-04T21:53:30.377Z
Microshutters and fibers give spectra of selected targets. I'm not sure but I think slit-masks may have been the first technique used for selective multi-object spectroscopy, like in DEIMOS where plates of metal were cut to match a specific field: https://www2.keck.hawaii.edu/inst/deimos/
giardia
CC BY-SA 4.0
2022-01-04T22:18:04.230Z
@giardia Thanks! Here's a [paper](https://escholarship.org/uc/item/84m7z4h6) and it seems [IMACS is similar](http://instrumentation.obs.carnegiescience.edu/imacs/). I would guess that these modern instruments are not the first ever uses of slit masks in astronomical history, and I think just putting a prism in front of a telescope to record the spectra of dozens of stars at the same time certainly counts as multiplexing, so now that I think about it we're looking for something either hundreds of years old (visually) or soon after photographic plates started to be used for spectrometry.
uhoh
<observational-astronomy><history><spectroscopy><instruments>
How were "microshutters" or other multiplexed or multi-object techniques first used in Astronomical spectroscopy?
uhoh
# How were "microshutters" or other multiplexed or multi-object techniques first used in Astronomical spectroscopy?

(Asked by: username_0 on 2020-09-13)

[This answer](https://astronomy.stackexchange.com/a/33765/7982) to *How will microshutter arrays be used in the James Webb and future space telescopes?* explains how multiple objects can be selected so that the throughput of a spectrometer can be enhanced (with some compromises somewhere) by recording spectra of more than one object at a time. The answer is worth a read if you haven't read it yet.

Another technique to get multiple spectra from a single telescope is to place (and sometimes articulate) high quality optical fibers at may locations at the focal plane. These days the number of fibers and objects can number in the thousands, so the output of several fibers can be lined up along the slit one spectrometer, and multiple spectrometers can also be used.

But here I'd like to look back in time to understand the beginnings of this technology.

**Question:** How were "microshutters" or other multiplexed or multi-object techniques first used in Astronomical spectroscopy ***to capture spectra from multiple object?***

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Related:

* [How will microshutter arrays be used in the James Webb and future space telescopes?](https://astronomy.stackexchange.com/q/33757/7982)
* [What is an "Off Rowland-circle Telescope"? Are there "On Rowland-circle Telescope" as well?](https://astronomy.stackexchange.com/q/33758/7982)

**Tags:** observational-astronomy, history, spectroscopy, instruments

> **Comments:**
> **username_1**: Do prism plates count? Taking images through a prism gives you a spectrum of every object in the field.  
> **username_0**: @username_1 that is such a notable first that it really should be an answer here. I'm also interested in when the first micro-shutters or multiple objects with fibers were done, maybe I can keep this question general (and thus the prism plate would almost certainly be the right answer) and ask separately about those other two. Does that sounds like a good way to proceed?  
> **username_0**: @username_1 prisms still count!  
> **username_2**: @username_0 Do you mean the multi-object observing technique in your question ? Looks like I misunderstood the question  
> **username_0**: @username_2 yes, the use of "multiple" in the first sentence of the first and second paragraph does indicate that, but I will edit the question to add "multiple" to the third paragraph as well. That's what microshutters do and that's what multiplexing is; multiple signals through a single path (in this case through a telescope) such that they can be separated later.  
> **username_3**: Microshutters and fibers give spectra of selected targets. I'm not sure but I think slit-masks may have been the first technique used for selective multi-object spectroscopy, like in DEIMOS where plates of metal were cut to match a specific field: https://www2.keck.hawaii.edu/inst/deimos/  
> **username_0**: @username_3 Thanks! Here's a [paper](https://escholarship.org/uc/item/84m7z4h6) and it seems [IMACS is similar](http://instrumentation.obs.carnegiescience.edu/imacs/). I would guess that these modern instruments are not the first ever uses of slit masks in astronomical history, and I think just putting a prism in front of a telescope to record the spectra of dozens of stars at the same time certainly counts as multiplexing, so now that I think about it we're looking for something either hundreds of years old (visually) or soon after photographic plates started to be used for spectrometry.  

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## 0 answers

