Questions about the measurement of light waves whereby the wavelength is classified by its position in the electromagnetic spectrum.
Questions tagged [spectroscopy]
263 questions
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Finding the Uncertainty in a Spectral Line
Currently, I am doing a lab in school on atomic spectroscopy. After taking readings of strong emission lines of various elements, I have fit the data using a Voigt Profile function from lmfit. The function minimizes the reduced chi-squared and…
ahayes24
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3
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2 answers
Any cheap (<100 euro) tools for observing the lines in solar spectrum?
I am now reading the book ''The story of Helium and the Birth of Astrophysics''.
I really want to observe the lines (dark or bright) in the solar spectrum.
Any easily available tools for an amateur?
wdlang
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3
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How are we identifying chemicals in space?
How do we identify chemicals in space? For example, how did we find the cloud of methyl alcohol (aka methanol) in W3 (OH) which is 6500 light years away. I can understand a scope being able to tell something is there, but I don't see how they…
Bookaholic
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3
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Choosing a diffraction grating
I am interested in doing some solar spectroscopy on my own for fun. How do I go about choosing the appropriate diffraction grating?
okarin
- 183
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3
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1 answer
Integral Field Spectroscopy vs Fabry-Perot Interferometry
Why are Fabry-Perot Interferometers (FPIs) and Fourier Transform Spectrographs (FTSs less common than Integral Field Spectrographs (IFS) nowadays? My understanding is that:
With FPIs and FTSs you have to scan your spectral range over time. This (A)…
AstrOne
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Can spectroscopes identify minerals?
Could a spectrometer on a probe or space telescope identify minerals, not only elements and molecules, from the spectral lines? Is there any technology for identifying minerals remotely?
LocalFluff
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Spectographically determine surface composition of exoplanet
We can determine the surface composition of a star by studying its spectrograph. If a exoplanet transits the star, then there is a slight change to the spectrograph, which lets us determine the composition of the planet's atmosphere.
When the planet…
CSM
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How do we know that the mass ratio of hydrogen and helium in the sun is approximately 3:1?
From what I learnt, we can find what elements are in the sun by analysing spectrums since each elements has same emission spectrum, and when you look at the sun's spectrum, you can see absorption spectrum missing some lines which is the…
Pizzaroot
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2
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1 answer
Delete key does not always work in IRAF's xgterm on Mac
Sometimes it does not let me delete text in an xgterm terminal and outputs ^H instead.
Example:
Run IRAF:
xgterm -e cl
It opens the xgterm, there I type:
splot black_hole.fits[0]
Image line/aperture to plot (0:) (12): 192
Then I realise I made a…
Evgenii
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vote
1 answer
Thermal Doppler broadening
How to plot Doppler profile corresponding to the spectral line? The spectral line was plotted from data: flux with respect to wavelenght and I know the temperature.
These two function are Doppler profile? What should I substitue for $\Delta…
Arrara
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vote
2 answers
How to estimate uncertainty of measurements of equivalent widths?
I'm measuring equivalent widths of absorption lines using a spectrum of a star. I make two or three measurements of each line by making reasonable gaussian fits of the line with IRAF's splot tool. Then I calculate the mean of the measurements, which…
Evgenii
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1
vote
1 answer
What spectral feature was used to confirm that S0-2 is "single and available"? What is Brγ?
The Phys.org article Astronomers discover S0-2 star is single and ready for big Einstein test describes the results of a careful analysis of radial velocity measurements of the star S0-2, which orbits the supermassive black hole at the center of our…
uhoh
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Spectroscopy of Exoplanets
How is accurate spectral analysis of a planets atmosphere achieved, bearing in mind that its host star's resultant light emission is not a full spectrum?
user21951
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How does glass affect taking solar spectra?
In this case I'm using a CCD camera mounted telescope pointed at the clouds to take solar spectra and was wondering how the telescope being pointed at the clouds through a double gazing (two layer) glass window would affect the spectra, if at all?
Peter C
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vote
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Infrared Astronomy for non transiting objects?
I understand how infrared spectroscopy works for determining molecules in the atmosphere of a transiting object (like Venus from Earth). But how does this work for objects that don't pass between us and the sun? If the IR spectra is an absorption…
NotSoSN
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