<p>I am looking for a credible source (or even the original sources) that describe point sources and/or point spread functions (PSFs) on astronomy.</p>
<p>Unfortunately, the Wikipedia pages (<a href="https://en.wikipedia.org/wiki/Point_source" rel="nofollow noreferrer">point source</a>, <a href="https://en.wikipedia.org/wiki/Point_spread_function" rel="nofollow noreferrer">PSF</a>) leave much to be desired regarding their references.</p>
<p>I am familiar with the terms (at least on a basic level), so I am not so much looking for definitions. I already found plenty of books and articles in that regard. But I am not really happy with citing some arbitrary reference just because it was the first one that popped up during my research. I would rather like to give proper credit to the original sources.</p>
<p>But for some reason, they are very hard to find. Sources that I found that explain these terms often don't cite any prior work.</p>
<p>I have now also asked the question in the <a href="https://hsm.stackexchange.com/q/15245/18187">History of Science and Mathematics SE</a>. While there I am interested in the very first descriptions of the concepts, here I am also happy with just a credible/typically cited astronomical source.</p>

CC BY-SA 4.0
2023-03-28T13:58:19.493Z
I'm not sure I understand your question. What kind of reference do you look for? For one, a point source is a concept which can nicely be described theoretically by means of the wave function of light. The airy disk it transforms to in any optics is one of the results. On the other hand: (nearly) every star is a point source except the ~dozen largest and nearest ones to the largest interferometric telescopes.
planetmaker
CC BY-SA 4.0
2023-03-28T19:24:04.453Z
Hi @planetmaker, that's a very good question. I guess I was a little bit naive in my expectations. So here's what I think: obviously people have known stars to be tiny dots in the sky for millenia. The first person to discover that must have been the first one to look up during the night. But when did they realize that no matter how hard they try, the will never be able to resolve those dots? That might be the origin of the point source concept (not sure if there was ever anyting else in nature that reselbled a point source). And who was then the first to realize that they have PSFs? Airy?
mapf
CC BY-SA 4.0
2023-04-04T18:40:52.057Z
Bessel was the first to measure the parallax of a star, 61 Cygnus in 1838.  Assuming it was about the size of the sun, it would be clear that it could not be resolved.  But others would already know this from their lower limits on distances.
eshaya
CC BY-SA 4.0
2023-04-04T20:00:41.530Z
@eshaya indeed! [Resolving long-standing mysteries about the first parallaxes in astronomy](https://phys.org/news/2020-11-long-standing-mysteries-parallaxes-astronomy.html)
uhoh
<history><resource-request><image-processing>
Credible description of point sources and point spread functions in astronomy
mapf
# Credible description of point sources and point spread functions in astronomy

(Asked by: username_0 on 2023-03-22)

I am looking for a credible source (or even the original sources) that describe point sources and/or point spread functions (PSFs) on astronomy.

Unfortunately, the Wikipedia pages ([point source](https://en.wikipedia.org/wiki/Point_source), [PSF](https://en.wikipedia.org/wiki/Point_spread_function)) leave much to be desired regarding their references.

I am familiar with the terms (at least on a basic level), so I am not so much looking for definitions. I already found plenty of books and articles in that regard. But I am not really happy with citing some arbitrary reference just because it was the first one that popped up during my research. I would rather like to give proper credit to the original sources.

But for some reason, they are very hard to find. Sources that I found that explain these terms often don't cite any prior work.

I have now also asked the question in the [History of Science and Mathematics SE](https://hsm.stackexchange.com/q/15245/18187). While there I am interested in the very first descriptions of the concepts, here I am also happy with just a credible/typically cited astronomical source.

**Tags:** history, resource-request, image-processing

> **Comments:**
> **username_1**: I'm not sure I understand your question. What kind of reference do you look for? For one, a point source is a concept which can nicely be described theoretically by means of the wave function of light. The airy disk it transforms to in any optics is one of the results. On the other hand: (nearly) every star is a point source except the ~dozen largest and nearest ones to the largest interferometric telescopes.  
> **username_0**: Hi @username_1, that's a very good question. I guess I was a little bit naive in my expectations. So here's what I think: obviously people have known stars to be tiny dots in the sky for millenia. The first person to discover that must have been the first one to look up during the night. But when did they realize that no matter how hard they try, the will never be able to resolve those dots? That might be the origin of the point source concept (not sure if there was ever anyting else in nature that reselbled a point source). And who was then the first to realize that they have PSFs? Airy?  
> **username_2**: Bessel was the first to measure the parallax of a star, 61 Cygnus in 1838.  Assuming it was about the size of the sun, it would be clear that it could not be resolved.  But others would already know this from their lower limits on distances.  
> **username_3**: @username_2 indeed! [Resolving long-standing mysteries about the first parallaxes in astronomy](https://phys.org/news/2020-11-long-standing-mysteries-parallaxes-astronomy.html)  

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## 0 answers

