Jelaskan Sumber dari Indeks warna

Johnson, H. L. and Morgan, ApJ 117, 313 (1953)

Cousins, A. W. J., MNRAS 166, 711 (1974)

Cousins, A. W. J., MNASSA 33, 149 (1974)

Bessell, M. S., PASP 102, 1181 (1990)

The Simbad Astronomical Database' Rigel page

David F. Gray (1992), The Inferred Color Index of the Sun, Publications of the Astronomical Society of the Pacific, vol. 104, no. 681, pp. 1035-1038 (November 1992)

Michael S. Bessell (1990), UBVRI passbands, Astronomical Society of the Pacific, Publications (ISSN 0004-6280), vol. 102, Oct. 1990, p. 1181-1199