The DDO photometric system

Basic Reference

McClure R.D. 1976, AJ 81, 182


Extensive photometry for 285 stars to be used as photometric standards has been completed on the David Dunlap Observatory (DDO) system. The magnitudes and colors given in Table IV define the standard system. Most of the northern stars originally observed by McClure and van den Bergh (1968, AJ 73, 313) are included in the list; however, a large number of stars at declination within 10d of the equator were added. This addition results in a list of 151 standards in the equatorial zone that can be used at southern hemisphere observatories. The matching of filter sets to the DDO system is discussed.


Access to the data and references

Asiago Database on Photometric System (ADPS)

Indices and Parameters

V48, C48-51, C45-48, C42-45, C41-42, C38-41, C35-38


 Filter  Name                                 wavelength  Width
                                                  [Å]       [Å]
    35 : 8 mm Schott UG11 + 1 mm Schott WG345     3460      383
    38 : 5 mm Corning 7-51 + 2 mm Schott GG375    3815      330
    41 : Interference                             4166       83
    42 : Interference                             4257       73
    45 : Interference                             4517       76
    48 : Interference                             4886      186

Transmission curves


RCA 1P21


Several calibrations have been published.

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Last update: 13 September 2002