Stellar Photometry with CCD Sub - Pixel SensitivityVariationsA

نویسنده

  • George H. Jacoby
چکیده

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 tting stellar photometry package, has been used to analyze the eeect of such variations. When the seeing drops below one pixel FWHM, photometry errors can rise to the 1{5 percent levels, depending on the nature of the sub-pixel variations. By using suitable software which allows for the sub-pixel pattern, the measuring errors can be reduced to the millimag level.

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Stellar Photometry and Astrometry with Discrete Point Spread Functions

The key features of the MATPHOT algorithm for precise and accurate stellar photometry and astrometry using discrete Point Spread Functions are described. A discrete Point Spread Function (PSF) is a sampled version of a continuous PSF which describes the two-dimensional probability distribution of photons from a point source (star) just above the detector. The shape information about the photon ...

متن کامل

The Stellar Populations of Pixels and Frames

Derived from first physical principles, a few simple rules are presented that can help in both the planning and interpretation of CCD and IR-array camera observations of resolvable stellar populations. These rules concern the overall size of the population sampled by a frame as measured by its total luminosity, and allow to estimate the number of stars (in all evolutionary stages) that are incl...

متن کامل

SkyMapper and the Southern Sky Survey: a valuable resource for stellar astrophysics

The Australian National University’s SkyMapper telescope is amongst the first of a new generation of dedicated wide-field survey telescopes. Featuring a 5.7 deg field-of-view Cassegrain imager and 268 Mega-pixel CCD array, its primary goal will be to undertake the Southern Sky Survey: a six color (uvgriz), six-epoch digital record of the entire southern sky. The survey will provide photometry f...

متن کامل

CCD photometry of young MC clusters I : NGC 2172 ?

We present a new CCD photometry for the young LMC cluster NGC 2172, giving B, V, I magnitudes for more than 600 stars within 70 ′′ from the cluster center, down to approximatelyV = 21 mag. After correction for completeness and field stars contamination, we discuss the cluster HR diagram and the MS luminosity function in the light of current evolutionary theories and in connection with the probl...

متن کامل

Sub-pixel Response Measurement of Near-infrared Sensors

Wide-field survey instruments are used to efficiently observe large regions of the sky. To achieve the necessary field of view, and to provide a higher signal-to-noise ratio for faint sources, many modern instruments are undersampled. However, precision photometry with undersampled imagers requires a detailed understanding of the sensitivity variations on a scale much smaller than a pixel. To a...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2007