The JHKLMN photometric system

Basic Reference

Johnson H.L. 1963, Tonantzintla Tacubaya 3, 305


The infrared program that was begun in 1959 has been continued and the time has come for a fairly extensive report on the progress of the work. This paper is divided into several sections, as follows:

Observations. Photometric observations in ten wavelength bands, U, B, V, R, I, J, K, L, M, and N, have been made. Some of hese observations were made with the 82-inch and 36-inch telescopes of the McDonald Observatory and other were made by B. Iriarte with the 40-inch telescope of the Observatorio Astrp`onomico Nacional of the University of Mexico but the majority were made with the 21-inch and 28-inch photometric telescope of the Lunar and Planetary Laboratory (University of Arizona).
Data for a total of 256 stars are given in this paper; of these 241 have complete onservations in U, B, V, R, I, J, and K. Observations in L, M, and N are given for a number of the brighter stars. For the R, I, J, K, L, M, and N systems, the data here should be regarded as the standard values for additional photometric work.

Intrinsic coulors of stars. The data that are now available proved to be sufficient for the derivation of the intrinsic colors of many types of stars. These are giants of luminosity class II from G8 to M5, supergiants, from O to M5 and main-sequence stars from O to K7. The intrinsic color-indices U-V, B-V, V-R, V-I, V-J, and V-K were derived for most types of stars within these ranges; in addition, V-L, V-M and V-N were derived for the ranges of spectral types and luminosity class for which data are available.

Absolute intensities and bolometric corrections. An absolute calibration procedure has made possible the derivation of the total energy output and these data were used to obtain the bolometric corrections for many types of stars for which intrinsic colors were derived.

Effective temperatures. The computed total energies have also been used, in comjunction with the apparent diameter measures that are available for ten stars,to derive the effective temperature of many of the types of stars for which intrinsic colors are given.


Access to the data and references

Asiago Database on Photometric System (ADPS)

Indices and Parameters

J, H, K, L, M, N


Effective lambda (microns)1.201.622.203.505.00 9.00


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Last update: 2 April 1998