Spectroscopy Links

Astronomical Spectroscopy

  • Learning from Light is a set of pages tackling how we use light to learn about the Universe. Sections include how to measure a spectrum, spectroscopy in space and spectroscopy as a tool of astronomers. It is part of the outreach material developed for the FUSE UV space-based telescope program.
  • Planck curve is an effective one-page article with a diagram explaining the concept of black body radiation.
  • Spectra is an excellent site written by Prof James Kaler, author of classic books on stellar spectroscopy and stars. There are thirty subsections each of an effective length and easily found.
  • Stellar Spectra is part of Gene Smith's Astronomy Tutorial from University of California, San Diego. The concise explanations are supported by clear and effective diagrams. You can follow links to explanations about thermal radiation and blackbodies.
  • Stellar Spectra is a short, simple set of pages explaining how spectral lines are formed, giving astronomical examples.
  • Stellar Spectra and the Secrets of Starlight provides some excellent explanations and clear diagrams of features of spectral lines including the Doppler effect, line intensity profiles, temperature and composition, rotation and pressure broadening.
  • Stellar Spectroscopy is a set of four slides from Armagh Observatory that provide a basic, visual introduction.
  • Stellar Spectroscopy - STARBASE is part of the Surrey Teachers' Astrophysics Resources and provides a concise set of notes with links on stellar spectroscopy. The sections on the shapes of spectral lines and radial velocity are useful.
  • The Atom and Spectroscopy is a visual page of lecture notes emphasising how spectral lines are produced. It also discusses the Doppler effect and provides a simulation for it.
  • The Classification of Stellar Spectra is a handy page from NASA with details on the different spectral classes including subtypes and peculiar stars.
  • What is Spectrum? is a concise and clear set of pages explaining astronomical spectra, colour and wavebands.

Catalogs and Sources of Spectra

  • A library of stellar spectra is an online version of the 1984 paper from Astrophysical Journal Supplement Series of 161 O-M stars. This is a professional 25-page paper with numerous references, data tables and plots of the spectra.
  • An Atlas of Stellar Spectra is a very detailed site with archived photographic plates of the spectral standard stars.
  • BASS2000 Solar Spectrum is a quereable database on the solar spectrum and related solar studies from the Paris Observatory. It also has links to live solar webcams in different wavebands.
  • SkyServer SDSS is the public and education site for the Sloan Digital Sky Survey. It has provides spectra of stars, galaxies and quasars together with a range of educational projects and informative articles. Data on over 88 million objects can be accessed online.
  • The 2dF Galaxy Redshift Survey provides access to over 250,000 galaxy spectra obtained in this survey. The site also has a lot of useful images of the 2dF instrument and other material. It is aimed at professional astronomers.
  • The 2dF QSO Redshift Survey provides spectra , field images and other information on 25,000 QSOs gathered using the 2dF instrument on the AAT. The "Non-astronomer's guide to redshift surveys" is an effective introduction to the role of redshift surveys in modern cosmology.

Applets, Activities and Software

  • Absorption Spectroscopy uses Macromedia Shockwave in a web browser to simulate spectra from discharge tubes of different elements. You can produce different absorption lines and try and identify an unknown lamp.
  • Applet: Spectrum is a simple but effective Java applet that shows the frequency, wavelength and energy of any region of the em spectrum as you drag a mouse across it. It also shows sources of the different wavebands, how we detect them and some uses of each.
  • BlackBody Physlet is an effective Java applet that allows you to see the Planck curve and colour for stars of different temperatures.
  • black body Radiation Exercises: Planck Law Radiation Distributions is a Java applet that allows you to plot up to 10 Planck curves for temperatures from 3,000 to 30,000 K and compare them. It was used to produce some of the images used in this site. It also has links to applets for Wien's Law and black body: The Game where you have to try and determine the temperature of an unknown object to match a given Planck curve.
  • Color Science is an excellent site with links to many detailed pages on the science of colour. It also provides Fortran and C code for several programs that can generate spectra, and colour diagrams.
  • Diffraction Grating – The Study of Color & Light is a lesson plan using diffraction gratings, lights and diffraction glasses to study colour and spectra.
  • doppler is a simple applet demonstrating the production of circular wavefronts and how a stationary observer seems them propagate from a moving source.
  • Elemental Spectra allows you to see absorption and emission spectra for every element as a photogrpahic colour spectrum.
  • Hydrogen Energy Levels is a simple applet demonstrating the use of the Bohr equation to calculate the energy levels of a hydrogen atom. It shows an energy level diagram vertically from infinity to the ground state.
  • Hydrogen Recombination Spectrum Applet simulates absorption of photons from a continuum source such as found in stellar atmospheres. Uisng hydrogen it shows the possible spectral lines that can form for different energy transitions.
  • HyperPhysics hydrogen energies and spectrum has a handy applet that calculates the wavelength for different transitions in hydrogen. The page also has useful energy level diagrams.
  • IMSA Astrophysics: Stellar Spectra and Planck black body Radiation is an excellent resource with detailed theory, clear diagrams and an Excel spreadsheet where you can model Planck curves and analyse data.
  • Mini Spectroscopy "is a simplified version of the Harvard-Smithsonian Center for Astrophysics full-featured spectroscopy software called Virtual Spectroscope." The Java applet allows you produce a spectrum from a fluorescent lamp, the Sun, a red LED, Hydrogen and three galaxies. They appear as photographic and intensity plots against a reference spectrum.
  • NOVA: Origins: Decoding Cosmic Spectra is an interactive site, part of the a new TV series on the origin of the Universe, stars, planets and life. In this section you can examine spectra from a star, galaxy, planet and nebula to identify lines.
  • Photon Emission Applet shows how photon transitions occur, how they are related to atomic energy levels and how the Balmer series for hydrogen can be produced.
  • Project CLEA The Classification of Stellar Spectra is an excellent free simulation for Win PCs. You can download the software, a User's Guide, pre and post tests and a comprehensive Student Manual free from the CLEA site. The simulation allows you to control a telescope and spectrograph to take spectra of a large number of stars. You can then attempt to identify them by comparing with spectral standard reference stars. It includes stars of different luminosity classes. Spectra can be examined as photographic or intensity plots. This is worth spending time with. The student manual is comprehensive and a handy resource. You can use this for classroom activities or even as a practical assessment task with some prior exposure.
  • SkyServer SDSS has an excellent activity/project leading you through the classification of stellar spectra, Spectral Types using actual Sloan Digital Sky Survey data. It is accompanied by detailed instructions and relevant theory. Highly recommended. Other activities and projects can also be found by following the links from the home page.
  • Spectroscopy of Supernova Remnants Lesson Plan is one of the set of units developed by teachers and NASA educators for years 9-12. In this unit, "Students will read and write about the chemistry and spectroscopy of stars and supernova remnants, as well as understand their relevance and impact on human life. Students will also learn about cutting edge technology that will help us to build better instruments with which to study the Universe." The focus is on high-energy astrophysics including X-ray obervations. Extensive resources and background material.
  • Thermal Radiation Curves Applet allows you to specifiy a temperature or a peak wavelength for a star and view the corresponding Planck curve with a simulated visible spectrum superimposed on it.