Approximate wavelengths for filters accepted for the AAVSO International Database
The filters listed below are used in the AAVSO International Database. For your reference, the approximate effective wavelength is given as well as the Full Width Half Maximum. These filters may be used when submitting observations to the AAVSO via WebObs.
Numbers are in Ångstroms unless otherwise indicated. FWHM = Full Width Half Maximum (gives the approximate width of the coverage; e.g., Johnson U is approximately 650 Ångstroms wide centered on 3663 Å; equivalent to the 50% transmission value)
| Filter |
AID |
Effective |
FWHM (Å) |
|---|---|---|---|
| Johnson U | U | 3663 | 650 |
| Johnson B | B | 4361 | 890 |
| Johnson V | V | 5448 | 840 |
| Johnson R | RJ | 7000 | 2200 |
| Johnson I | IJ | 9000 | 2400 |
| Cousins R | R | 6407 | 1580 |
| Cousins I | I | 7980 | 1540 |
| Near-Infrared J | J | 1.2 microns | 0.32 micron |
| Near-Infrared H | H | 1.6 microns | 0.36 micron |
| Near-Infrared K | K | 2.2 microns | 0.37 micron |
| Sloan u | SU | 3543 | 650 |
| Sloan g | SG | 4770 | 1490 |
| Sloan r | SR | 6231 | 1400 |
| Sloan i | SI | 7625 | 1300 |
| Sloan z | SZ | 9097 | 1370 |
| Stromgren u | STU | 3520 | 314 |
| Stromgren v | STV | 4100 | 170 |
| Stromgren b | STB | 4688 | 185 |
| Stromgren y | STY | 5480 | 226 |
| Stromgren Hbw | STHBW | 4890 | 150 |
| Stromgren Hbn | STHBN | 4860 | 30 |
| Optec Wing A | MA | 7120 | 110 |
| Optec Wing B | MB | 7540 | 110 |
| Optec Wing C (or Wing I) | MI | 10240 | 420 |
| PanSTARRS z-short (APASS) | ZS | 8730 | 940 |
| PanSTARRS Y (APASS) | Y | 10004 | 1080 |
| DSLR Blue | TB | differs by camera | |
| DSLR Green | TG | differs by camera | |
| DSLR Red | TR | differs by camera | |
| Clear (unfiltered) reduced to V sequence | CV | differs by camera | |
| Clear (unfiltered) reduced to R sequence | CR | differs by camera | |
| Clear with blue-blocking | CBB | differs by camera | |
| Halpha | HA | 6563 | |
| Halpha_continuum | HAC | 5400 | 60 |
| Blue visual filter | Blue-vis. | historical data only; do not use | |
| Green visual filter | Green-vis. | historical data only; do not use | |
| Red visual filter | Red-vis. | historical data only; do not use | |
| Orange filter | Orange | historical data only; do not use | |
| Yellow visual filter | Yellow-vis. | historical data only; do not use | |
| Visual | Vis. | human eye; ~5500 | |
| Other | O | filter not listed above, must describe in Comments |
Note: The effective wavelength values for the Sloan filters are from the SDSS filters table. The Sloan FWHM values are from the Astrodon filters information table.
References
Johnson UBV: Bessell, Ann. Rev. Astron. Astrophys., 43 (2005)
Cousins RI: Bessell, Ann. Rev. Astron. Astrophys., 43 (2005)
JHK: JHK filter table on Marco Gullieuszik webpage on ESO work (http://web.oapd.inaf.it/gullieuszik/research.php)
Sloan zugri: Astrodon Sloan filters table; SDSS camera and filters publication (http://www.astro.princeton.edu/PBOOK/camera/camera.htm)
Stromgren uvby: Bessell, Ann. Rev. Astron. Astrophys., 43 (2005)
Wing ABC/I: Wing, JAAVSO, 21, 1, 42 (1992)
PanSTARRS zs and y: Tonry et al., Astrophy. J., 750 (2012)
Halpha_continuum: Baader Solar Continuum Filter information
Clear with blue-blocking filter: http://www.astrodon.com/store/p9/Exo-Planet_Filter.html