Talk:Astronomical spectroscopy

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Nebulium[edit]

Why does Nebulium get redirected here? -- 222.152.240.178 20:21, 2005 Feb 3

Because it explains what nebulium is -- see the section on nebulae, or search for "nebulium". (It didn't seem to warrant its own article, and fitted better here, as an interim stage in the development of spectroscopy.) -- JTN 20:29, 2005 Feb 3 (UTC)

WikiProject class rating[edit]

This article was automatically assessed because at least one WikiProject had rated the article as start, and the rating on other projects was brought up to start class. BetacommandBot 09:44, 10 November 2007 (UTC)

Only optical[edit]

This article is only about optical spectroscopy. Some info about radio spectroscopy (21 cm line, interstellar molecules, etc) needs to be added. Hobbema (talk) 22:30, 5 April 2012 (UTC)

Agreed (though I don't know enough to do it). Here's a list of important rf spectral lines. —JerryFriedman (Talk) 22:50, 5 April 2012 (UTC)

Major Revisions to this article[edit]

Hello, I'm a 4th-year physics w/ astrophysics student. For my final-year project I've been tasked with bringing a physics-related article on Wikipedia from stub/start class to at least B if not GA class. I have chosen Astronomical spectroscopy as it is one of my primary interests. As I work on the article I may ask for feedback and/or suggestions on improvements. Cheers. Primefac (talk) 16:32, 14 October 2013 (UTC)

Basic Structure
  1. History - from Fraunhofer's first experiments to modern spectroscopy
  2. Underlying Physics - not a full copy of the main spectroscopy page (obviously), but enough to understand what's going on
  3. Uses in astronomy
    • Stars
      • Elements in them
      • Binary Stars (use of Doppler shift to determine size/orbits)
      • Distance/recession velocities of individual stars
      • Link to galaxies (next section)
    • Galaxies
      • Determining their age
      • Determining composition (i.e. type of stars in it)
    • Non-luminous bodies
      • Nebulae
      • Asteroids
      • Comets
      • Planets/planetoids — Preceding unsigned comment added by Primefac (talkcontribs) 11:47, 16 October 2013 (UTC)


My experience is that "History" sections are tough. If you already have a couple good references that you can summarize, I'd stick with that. It's very easy to get bogged down in finding the right balance between accuracy and coverage. I like your idea of presenting the physics of spectroscopy in an astronomical context. The main spectroscopy article had to try and be quite general. It may be possible to make things clearer here by making them specific to astronomical objects. On an administrative note, it's good practice to "sign" posts on talk pages by using four tildes. ronningt (talk) 12:41, 17 October 2013 (UTC)
I once added a paragraph on the mechanism of absorption-line spectra from stars. You can see the last version here—after than someone changed it to disagree with the sources, and later someone removed it. I think I may have overemphasized the difference from ordinary absorption-line spectra, and it's only one part of astronomical spectroscopy, but you may still find it useful.
I think your outline looks good, but in my opinion, a section at the begining on "underlying physics" should be as accessible as possible. A more technical discussion might be good at the end. —JerryFriedman (Talk) 17:16, 18 October 2013 (UTC)

Comments from Modest Genius[edit]

I was asked by Primefac to provide some comments on this article, which is apparently being edited as part of a university project. This isn't (yet) a GA review, but I hope the following points help. I don't have time to read the whole thing in detail and tag up every issue, but here are some general comments:

  • This is a huge topic; as a project I would have chosen something more self-contained!
  • It will be a challenge to cover the topic both comprehensively and accessibly (without getting bogged down in details). It actually does a pretty good job of this. Resist the temptation to add more details to areas which have a decent treatment already, and concentrate on improving the breadth of coverage.
  • Almost every section and/or subsection is going to be covered in more depth elsewhere. So you're going to need more extensive use of summary style. For example, Doppler shift, redshift, Fraunhofer lines etc. already exist; don't duplicate that material, just summarise it in a couple of paragraphs and direct readers to those articles using {{main}} etc.
  • Unfortunately some of the things you need to summarise don't have very good articles on Wikipedia (whilst others do). You should still use summary style in the expectation that those articles will expand and improve, but you won't be able to just grab bits of text out of them.
  • I think it would help to have a further top-level split, above the existing sections. That would be between 1. Theory and background 2. Wavelengths and instruments, and 3. Scientific results / types of object.
  • If you follow the suggestion above, part 3 is currently the best bit, with a good coverage of different types of object and what has been learnt about them from spectroscopy. I suggest a rough size order: solar system, then stars, then ISM, then galaxies. Two areas that are missing, at the opposite ends of the scale, are solar spectroscopy and spectroscopy of the intergalactic medium.
  • Part 1 would hold e.g. the Doppler material, and I think it should have more general background on spectroscopy i.e. describe it as splitting up light into colours, again in summary style. A few paragraphs is all that's needed, but enough to set the scene for the reader. It could then discuss chemical elements, Fraunhofer lines, temperature/luminosity etc.
  • Part 2 needs the most expansion. In particular, I strongly disagree with the statement 'Astronomical spectroscopy can be broken down into three major bands: optical, radio, and x-ray.' That misses out UV, infrared, and sub-mm astronomy entirely. You should add sections on all of those, again in summary style, and fill out the currently blank X-ray section.
  • Part 2 would also benefit from some discussion of particular instruments used. For example, in UV I would expect to see some mention of UV satellites/instruments such as FUSE or STIS (without the jargon acronyms of course). Similarly when discussing optical spectroscopy you could mention the objective prism, echelle spectrograph and integral field spectrograph.
  • The discussion of the ISM is a bit confused. You state that the ISM causes absorption lines (you could add the diffuse interstellar bands here), but then all the following discussion is about molecules found by their radio emission. Molecular astrophysics could also be used.

I'd like to reiterate that this is a very big topic which requires knowledge of a lot of overlapping fields. Many entire textbooks have been written on this! It's a lot to ask of an undergraduate project. If you have access to a university library, useful sources could be Astronomical Spectrographs and their History by Hearnshaw and Astrophysical Techniques by Kitchin. I'll try to take a closer look at some point; good luck! Modest Genius talk 22:16, 2 December 2013 (UTC)

Rotate first photo 90 degrees clockwise (right)[edit]

The Star-Spectroscope of the Lick Observatory in 1898

Is on its side...this photo should be rotated 90 degrees to the right.--James Carlisle (talk) 04:12, 12 May 2014 (UTC)James Carlisle

Wow, surprised I never noticed that. I've put in a request to have the image rotated, should be done in a few hours. Primefac (talk) 08:57, 12 May 2014 (UTC)