IANAO operates the 2-m Ritchey-Chrétien (RC), the 60-cm Cassegrain, and the 50/70-cm Schmidt telescopes at the Rozhen NAO and the 60-cm Cassegrain telescope at the Belogradchik AO. The following foci and observing modes are currently (August 2019) available to the observers:
The 2-m RC telescope
▶ RC focus, CCD mode: it uses a 2048×2048 Andor iKon-L CCD camera attached at the f/8 RC focus of the telescope resulting in a pixel size of 0.174 arcsec. The FoV is about 6×6 arcmin. This mode could be used only for direct imaging. An autoguiding unit is available upon observer’s request. The telescope-focus combination to be used in naming the filled in application form is 2mRC.
▶ RC focus, FoReRo2 mode: it uses the two-channel focal reducer FoReRo2 attached at the f/8 RC focus of the telescope reducing the focal ratio to f/2.8. The reducer feeds two 2048x2048 Andor iKon-L CCD cameras attached at the blue and red channels. The resulting pixel size is 0.497 arcsec and the FoV is about 17×17 arcmin. The observers are requested to cite the paper 2000KFNTS...3..262J (local copy) using this mode. This mode could be used for direct imaging, low-dispersion spectroscopy, and polarimetry (imaging and spectro using a Wollaston prism and a half-wave plate). An improved slit unit (allowing guiding) could be used along with the original one. The telescope-focus combination to be used in naming the filled in application form is 2mRC.
▶ RC focus, Photometer mode: it uses a high-speed single-channel photometer attached at the f/8 RC focus of the telescope. The papers to be cited if one uses this mode are: 2001bmya.meet..226A (local copy) and/or 2006BlgAJ...8..117B. The telescope-focus combination to be used in naming the filled in application form is 2mRC.
▶ RC focus, ESpeRo mode: it uses the high-dispersion eshelle spectrograph ESpeRo which is fiber-fed from the f/8 RC focus of the telescope. The spectrograph is mounted in a separate room. The light detector is 2048×2048 Andor iKon-L CCD camera. The observers are requested to cite the paper 2017BlgAJ..26...67B using this mode. Note that the observing proposals for the high-dispersion spectral modes of the 2-m telescope are evaluated by TAC together despite the different foci being used. By reason of this the telescope-focus combination to be used in naming the filled in application form is 2mCoude.
▶ Coudé focus, Coudé mode: it uses a high-dispersion grating spectrograph mounted at the f/36 Coudé focus of the telescope. The spectrograph is mounted in a separate room. The light detector is 2048×512 Andor iKon-L CCD camera. The telescope-focus combination to be used in naming the filled in application form is 2mCoude.
The 60-cm Cassegrain telescope
▶ CCD mode: it uses a FLI PL09000 CCD camera attached at the f/12.5 Cassegrain focus of the telescope. The telescope-focus combination to be used in naming the filled in application form is 60Nao.
The 50/70-cm Schmidt telescope
▶ CCD mode: it uses a 4096×4096 FLI PL16803 CCD camera attached at the f/3.44 prime focus of the telescope. The resulting pixel size is 1.079 arcsec and the FoV is about 73.7×73.7 arcmin. The telescope-focus combination to be used in naming the filled in application form is Schmidt.
The 60-cm Cassegrain telescope
▶ CCD mode: it uses a FLI PL09000 CCD camera attached at the f/12.5 Cassegrain focus of the telescope. The paper to be cited if one uses this mode is: 2011BlgAJ..16..144S. The telescope-focus combination to be used in naming the filled in application form is 60Bel.
▶ Photometer mode: it uses a high-speed single-channel photometer attached at the f/12.5 Cassegrain focus of the telescope. The papers to be cited if one uses this mode are: 2001bmya.meet..226A (local copy) and/or 2006BlgAJ...8..117B. The telescope-focus combination to be used in naming the filled in application form is 60Bel.