SIMBAD references

Photographic monitoring in the I(0.81), R(0.63), v, b and u passbands with the Baldone Schmidt telescope in 1975-2002, the infrared J, H, K, L and M photometry carried out in 1995-2002 with the 0.7 m telescope of the Crimean Astrophysical Observatory and with the 1.25 m telescope of the Crimean Station of the Sternberg Astronomical Institute, as well as photovisual magnitude estimates on the Sonneberg Observatory Patrol plate archive of 1963-1980 are used to study the photometric behavior of DY Per, an unusual carbon star. The characteristics of light variations of DY Per are compared with those of long period variables, RCB stars and LMC DY Per-like stars.