2009BaltA..18...53A

The behavior of DY Per during the latest deep decline event is studied on the basis of BVRIJHKLM photometry, low resolution near-infrared spectra and long-term photographic monitoring in red light. The relation of DY Per to RCB-type stars and to DY Per-like stars is discussed from the viewpoint of properties of their light variations. The spectral energy distribution of DY Per in the wavelength range 0.44-5.0 µm can be approximated by the sum of two blackbody distributions of T = 2400 K and 1700 K at light minimum of the deep decline event in 2004, and of T = 2700 K and 1100 K at light maximum. In the near infrared spectra at minimum light, CO bands at 1.6 µm and 2.3 µm have been identified. The long-term (∼30 yr) photometric monitoring suggests that the depth of the regular light declines is modulated in time by a wavy function with a cycle length of ∼13 years.