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juansebastianl edited this page Apr 18, 2018 · 2 revisions

Below is a list of the stellar parameters provided by astroML when loading the SEGUE dataset

Parameter meaning
ra Right ascension of fiber, J2000 (https://en.wikipedia.org/wiki/Right_ascension)
dec Declination of fiber, J2000 (https://en.wikipedia.org/wiki/Declination)
Ar
upsf The magnitude of the U-band photo input, characterized by light centered 365 nm, with a width of 66 nm.(see https://astronomy.stackexchange.com/questions/18986/what-is-the-ugriz-magnitude-system and https://en.wikipedia.org/wiki/Photometric_system) It is not clear is SDSS uses ugirz or u'g'i'r'z' (see: http://www.phys.lsu.edu/~jclem/publications/phd.pdf)
uErr The uncertiny in upfs
gpsf The magnitude of the G-band photo input, characterized by light centered 464 nm, with a width of 128 nm. (see upfs)
gErr The uncertiny in gpfs
rpsf The magnitude of the R-band photo input, characterized by light centered 658 nm, with a width of 138 nm. (see upfs)
rErr The uncertiny in rpfs
ipsf The magnitude of the I-band photo input, characterized by light centered 806 nm, with a width of 149 nm. (see upfs)
iErr The uncertiny in ipfs
zpsf The magnitude of the Z-band photo input, characterized by light centered 900 nm, with a width of ?? nm. (see upfs)
zErr The uncertiny in zpfs
pmL
pmB
pmErr
mjd MJD (Modified Julien Date) of observation. Used along with plate & fiber to form the unique triple (plate , mjd , fiber)
plate Plate number of observation. Used along with MJD & fiber to form the unique triple (plate , mjd , fiber)
fiber Fiber number of observation. Used along with plate & MJD to form the unique triple (plate , mjd , fiber)
SNR
FeH [Fe/H] ratio, [Fe/H] = log((Fe/H)/(Fe/H)_sun) (see: http://icc.dur.ac.uk/~tt/Lectures/Galaxies/TeX/lec/node27.html)
FeHErr Uncertainty in [Fe/H]
Teff Effective temperature, a temperature estimate which oomes from luminosity L and black body radiation, given by L = (4πR^2)σT^4_eff, where σ is the Stefan-Boltzman constant. (see https://www.astro.princeton.edu/~gk/A403/constants.pdf)
TeffErr Uncertainty in T_eff
logg Log of surface gravitational constant g.
loggErr Uncertainty in g
alphFe [\alpha/Fe] ratio, or the log of the ratio of Ne, Mg, Si, S, Ar, Ca or Ti to Fe relative to the sun. (see https://physics.stackexchange.com/questions/205873/what-is-the-definition-of-alpha-rm-h and https://en.wikipedia.org/wiki/Alpha_process)
alphFeErr Uncertainty in alphaFe
radVel Radial Velocity
radVelErr Uncertainty in radial velocity

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