This paper presents a table with estimates of the absolute magnitude of the Sun and the conversions from vegamag to the AB and ST systems for several wide-band filters used in ground and space-based observatories .
These estimates use the dustless spectral energy distribution ( SED ) of Vega , calibrated absolutely using the SED of Sirius , to set the vegamag zero-points and a composite spectrum of the Sun that coadds space-based observations from the ultra-violet to the near infrared with models of the Solar atmosphere .
The uncertainty of the absolute magnitudes is estimated comparing the synthetic colors with photometric measurements of solar analogs and is found to be \sim 0.02 magnitudes .
Combined with the uncertainty of \sim 2 % in the calibration of the Vega SED , the errors of these absolute magnitudes are \sim 3–4 % .
Using these SEDs , for the three of the most utilized filters in extragalactic work the estimated absolute magnitudes of the Sun are M _ { B } = 5.44 , M _ { V } = 4.81 and M _ { K } = 3.27 mag \added in the vegamag system and M _ { B } = 5.31 , M _ { V } = 4.80 and M _ { K } = 5.08 mag in AB .