Four Oke-Gunn (OG) standards, HD 19445, HD 84937, BD+26 2606 and BD+17 4708 are used as standard stars for flux calibration in the BATC project. They are also widely used in the visual wavelength region in many other ...Four Oke-Gunn (OG) standards, HD 19445, HD 84937, BD+26 2606 and BD+17 4708 are used as standard stars for flux calibration in the BATC project. They are also widely used in the visual wavelength region in many other photometric projects. Over the years we have observed on 58 good photometric nights, and the data obtained are used for flux calibration. Normally two or three OG standards are observed in every photometric night. The data are used for getting the atmospheric extinction coefficients and instrumental magnitude zero point. We also use these data to make inter-comparisons among the magnitudes of these standard stars. As a result, we found the magnitudes of HD 19445, HD 84937 and BD+17 4708 to agree well with those estimated in previous work to within 0.03 magnitude. However, BD+26 2606 shows a larger deviation especially at short wavebands. Possible reasons are analyzed and the revised magnitudes are obtained for these standards. It is shown that the quality of flux calibration of the BATC fields is significantly approved by applying the new magnitudes.展开更多
A 2 channel photometer was upgraded to a Whole Earth Telescope (WET) high speed 3 channel photometer at Beijing Astronomical Observatory (BAO). The structure and functions of the photometer are discussed. The data obt...A 2 channel photometer was upgraded to a Whole Earth Telescope (WET) high speed 3 channel photometer at Beijing Astronomical Observatory (BAO). The structure and functions of the photometer are discussed. The data obtained by attaching the photometer to the 85cm reflector at BAO are presented.展开更多
We present here a design of fiber fed 4000 object low resolution spectroscopy of LAMOST. And some related problems are discussed briefly. LAMOST is a 4m aperture 5° FOV telescope. 4000 object low resolution spect...We present here a design of fiber fed 4000 object low resolution spectroscopy of LAMOST. And some related problems are discussed briefly. LAMOST is a 4m aperture 5° FOV telescope. 4000 object low resolution spectroscopic observation is its main observation mode. The LAMOST instrument is mainly a multi-object spectroscopy system including 4000 independent fiber positioners, fiber optics, 14 spectrographs and 28 CCD cameras. 4000 fiber is a great challenge to present multi-fiber spectroscopy. And positioning 4000 fiber is one of the two technological difficulties for LAMOST project.展开更多
文摘Four Oke-Gunn (OG) standards, HD 19445, HD 84937, BD+26 2606 and BD+17 4708 are used as standard stars for flux calibration in the BATC project. They are also widely used in the visual wavelength region in many other photometric projects. Over the years we have observed on 58 good photometric nights, and the data obtained are used for flux calibration. Normally two or three OG standards are observed in every photometric night. The data are used for getting the atmospheric extinction coefficients and instrumental magnitude zero point. We also use these data to make inter-comparisons among the magnitudes of these standard stars. As a result, we found the magnitudes of HD 19445, HD 84937 and BD+17 4708 to agree well with those estimated in previous work to within 0.03 magnitude. However, BD+26 2606 shows a larger deviation especially at short wavebands. Possible reasons are analyzed and the revised magnitudes are obtained for these standards. It is shown that the quality of flux calibration of the BATC fields is significantly approved by applying the new magnitudes.
文摘A 2 channel photometer was upgraded to a Whole Earth Telescope (WET) high speed 3 channel photometer at Beijing Astronomical Observatory (BAO). The structure and functions of the photometer are discussed. The data obtained by attaching the photometer to the 85cm reflector at BAO are presented.
文摘We present here a design of fiber fed 4000 object low resolution spectroscopy of LAMOST. And some related problems are discussed briefly. LAMOST is a 4m aperture 5° FOV telescope. 4000 object low resolution spectroscopic observation is its main observation mode. The LAMOST instrument is mainly a multi-object spectroscopy system including 4000 independent fiber positioners, fiber optics, 14 spectrographs and 28 CCD cameras. 4000 fiber is a great challenge to present multi-fiber spectroscopy. And positioning 4000 fiber is one of the two technological difficulties for LAMOST project.
