منابع مشابه
A Technique for Ultrahigh-Precision CCD Photometry
We present techniques for wide-field ultrahigh-precision time-sampled CCD photometry. Representing a survey of field stars, our data consist of UBVRI photometry and a V-band time series of exposures on 5 consecutive nights covering 11,500 stars in a ∼1 deg field. The resulting light curves reach precisions of 0.0020 mag per exposure in the brightest stars ( ). Light curves binned and averaged o...
متن کاملDifferential Time-Series CCD Photometry of BL Camelopardalis Revisited
New differential time-series observations of BL Camelopardalis were secured using B and V filters. It was confirmed that BL Cam is an optical double star. Differential magnitudes were obtained through a photometric profile reduction procedure to eliminate the influence of a faint adjacent star. Variations in values O C for light maxima were investigated. We found that the parabolic period varia...
متن کاملCCD photometry of distant comets
While it is apparent that many comets are active beyond the canonical distance of 3 AU, few surveys of cometary activity have been performed in this region previously. Such a survey enables a more accurate determination of the proportion of comets that exhibit little or no outgassing at these distances. Results are presented of CCD observations of comets in the region of 3 AU ≤ Rh ≤ 6 AU obtain...
متن کاملVAPHOT - A Package for Precision Differential Aperture Photometry
The aperture photometry package ‘vaphot’ was developed to perform reliable and precise time-series photometry of uncrowded fields. This package works within the IRAF environment and is built upon the standard aperture photometry task ‘phot’ from IRAF. The design goal of ‘vaphot’ was a simple-to-use photometry task with relatively few input parameters that performs precise aperture photometry, u...
متن کاملNarrowband CCD Photometry of Giant HII Regions
We have obtained accurate CCD narrow band Hβ and Hα photometry of Giant HII Regions in M 33, NGC 6822 and M 101. Comparison with previous determinations of emission line fluxes show large discrepancies; their probable origins are discussed. Combining our new photometric data with global velocity dispersion (σ) derived from emission line widths we have reviewed the L(Hβ)) − σ relation. A reanaly...
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ژورنال
عنوان ژورنال: Symposium - International Astronomical Union
سال: 1995
ISSN: 0074-1809
DOI: 10.1017/s0074180900056436