منابع مشابه
CCD 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 کاملA 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 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...
متن کاملStellar Photometry with CCD Sub - Pixel SensitivityVariationsA
The variation of sensitivity within a pixel of a CCD can be substantial and also substantially the same for each pixel of the CCD. Variations of the order of 10%, now being found for CCDs, can lead to errors in stellar photometry on the order of a few percent, dependent on the size of the stellar image and the position of its center within the pixel. An enhanced version of Starman, a proole tti...
متن کاملGlobular Cluster Ages and Strömgren CCD Photometry
Strömgren uvby CCD photometry can be used in a variety of ways to constrain the absolute and relative ages of globular clusters. The reddening corrected v−y, c1 diagram offers the means to derive ages that are completely independent of distance. Very precise differential ages for clusters of the same chemical composition may also be determined from such 2–color plots, or from measurements of th...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Symposium - International Astronomical Union
سال: 1995
ISSN: 0074-1809
DOI: 10.1017/s0074180900056370