
TY  - JOUR
A1  - D'Amicis, R. 
A1  - Nesci, R. 
A1  - Massaro, E. 
A1  - Maesano, M. 
A1  - Montagni, F. 
A1  - D'Alessio, F. 
T1  - Spectral Variability of BL Lac Objects
JF  - Publications of the Astronomical Society of Australia
JO  - Publ. Astron. Soc.  Aust.
Y1  - 2002
VL  - 19
IS  - 1
SP  - 111
EP  - 113
KW  - BL Lacertae objects: individual (3C 66A, PKS 0422+004, S5 0716+71, OJ 287, ON 231, OQ 530, S5 1803+78, BL Lac)
UR  - https://doi.org/10.1071/AS01113 
N2  - We present the relation between optical luminosity and spectral slope for eight BL Lac objects (3C66A, PKS 0422+00, S5 0716+71, OJ 287, ON 231, OQ 530, S5 1803+78 and BL Lacertae), derived from B, V, R, and I observations spanning a time interval of about 5 years. Four objects show a marked correlation between spectral slope and luminosity, being bluer when brighter, while for the other four the correlation is weaker or absent. Possible explanations are briefly discussed in the framework of current models of the BL Lac phenomenon. 
ER  -

