AB and Vega Magnitudes, Fλ and Fν
The Table below summarises wavelength, frequency and flux reference data for Johnson V, Sloan Survey ugriz and Mauna Kea Observatories YJHK′KsKL′M′ optical and infrared filters. The information is taken from Tokunaga & Vacca 2005 and Hewett et al. 2006. Please refer to the original publications for further details on definitions etc. For some fluxes the values from these two sources differed by ~1% and the average is given in the Table. The fluxes are for Vega, defined to be zero magnitude at all wavelengths (see however the discussion in Tokunaga & Vacca 2005). Note that the isophotal and effective wavelengths and frequencies in the Table are valid only for A0 stars.
Readers may also find this tool for converting between magnitudes and fluxes useful.
| Filter | Effective Wavelength µm |
Isophotal Wavelength µm |
Isophotal Frequency 1014 Hz |
Flux Wm-2µm-1 |
Flux Jansky |
AB Mag |
| V | 0.545 | 5.490 | 3.68E-08 | 3630 | 0.026 | |
| u | 0.355 | 3.66E-08 | 1545 | 0.927 | ||
| g | 0.467 | 5.41E-08 | 3991 | -0.103 | ||
| r | 0.616 | 2.50E-08 | 3174 | 0.146 | ||
| i | 0.747 | 1.39E-08 | 2593 | 0.366 | ||
| z | 0.892 | 8.32E-09 | 2222 | 0.533 | ||
| Y | 1.031 | 5.71E-09 | 2026 | 0.634 | ||
| J | 1.248 | 1.250 | 2.394 | 2.98E-09 | 1545 | 0.940 |
| H | 1.631 | 1.644 | 1.802 | 1.16E-09 | 1030 | 1.38 |
| K′ | 2.121 | 1.413 | 4.57E-10 | 686 | 1.84 | |
| Ks | 2.149 | 1.395 | 4.35E-10 | 670 | 1.86 | |
| K | 2.201 | 2.198 | 1.364 | 3.95E-10 | 638 | 1.90 |
| L′ | 3.764 | 0.798 | 5.31E-11 | 249 | 2.93 | |
| M′ | 4.702 | 0.635 | 2.22E-11 | 163 | 3.40 |