Difference imaging photometry of blended gravitational microlensing events with a numerical kernel

M. D. Albrow, K. Horne, D. M. Bramich, P. Fouqué, V. R. Miller, J. P. Beaulieu, C. Coutures, J. Menzies, A. Williams, V. Batista, D. P. Bennett, S. Brillant, A. Cassan, S. Dieters, D. Dominis Prester, J. Donatowicz, J. Greenhill, N. Kains, S. R. Kane, D. KubasJ. B. Marquette, K. R. Pollard, K. C. Sahu, Y. Tsapras, J. Wambsganss, M. Zub

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94 Citations (Scopus)


The numerical kernel approach to difference imaging has been implemented and applied to gravitational microlensing events observed by the PLANET collaboration. The effect of an error in the source-star coordinates is explored and a new algorithm is presented for determining the precise coordinates of the microlens in blended events, essential for accurate photometry of difference images. It is shown how the photometric reference flux need not be measured directly from the reference image but can be obtained from measurements of the difference images combined with the knowledge of the statistical flux uncertainties. The improved performance of the new algorithm, relative to isis2, is demonstrated.

Original languageEnglish
Pages (from-to)2099-2105
Number of pages7
JournalMonthly Notices of the Royal Astronomical Society
Issue number4
Publication statusPublished - 1 Aug 2009
Externally publishedYes



  • Methods: statistical
  • Techniques: image processing
  • Techniques: photometric

ASJC Scopus subject areas

  • Space and Planetary Science
  • Astronomy and Astrophysics

Cite this

Albrow, M. D., Horne, K., Bramich, D. M., Fouqué, P., Miller, V. R., Beaulieu, J. P., Coutures, C., Menzies, J., Williams, A., Batista, V., Bennett, D. P., Brillant, S., Cassan, A., Dieters, S., Prester, D. D., Donatowicz, J., Greenhill, J., Kains, N., Kane, S. R., ... Zub, M. (2009). Difference imaging photometry of blended gravitational microlensing events with a numerical kernel. Monthly Notices of the Royal Astronomical Society, 397(4), 2099-2105. https://doi.org/10.1111/j.1365-2966.2009.15098.x