Sample spectra?

[acey]

I'm looking for samples of below-atmosphere visible-light stellar spectra in table format (intensity versus wavelength), preferably in a format like Excel rather than Fits, preferably at intervals of about 1nm, and preferably from observatory data. I'd like to have samples from classes O to M. Can anyone suggest a link?

[robin_astro]

Hi Acey,

How about the Miles database  at 2.5A resolution?

http://miles.iac.es/

These are actual spectra taken from the ground but like most published spectra, they have been corrected for atmospheric extinction and the telluric lines have been removed.

Here is  a link to a spreadsheet which allows the spectra to be extracted (corrected and uncorrected for interstellar extinction) in dat format ready to import into Excel etc.

http://www.spectro-aras.com/forum/viewtopic.php?f=6&t=207&start=30#p2162

(Incidentally, 1D fits spectra can  easily  be converted to dat files using eg Visual Spec or ISIS and then imported into Excel)

Cheers

Robin

[Merlin66]

+1 from me.

BASS Project also converts to dat files/ Excel.

[acey]

Many thanks to both. These do seem to be above-atmosphere spectra, though - I'm looking for the ground-level data before correction, i.e. subject to atmospheric scattering and absorption (the way we actually see them). I can find something that does it for the Sun so maybe I'll stick with that.

[robin_astro]

HI Acey,

What is you application? The problem is what you want would vary dependent on the specific  atmospheric conditions and the altitude of the object in the sky at the time  which is why spectra  are corrected. If you know what degree of atmospheric extinction you are aiming at, you could do the reverse and "uncorrect" the corrected spectra to some specific atmospheric conditions.  See here for example for information on calculation of atmospheric extinction from Christian Buil. ( In French but Google translates reasonably well)

http://www.astrosurf.com/buil/extinction/calcul.htm

Cheers

Robin