Open AccessVariable stars in the globular cluster M5: application of the image subtraction method
Author(s) -
Olech A.,
Woźniak P. R.,
Alard C.,
Kaluzny J.,
Thompson I. B.
Publication year - 1999
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.1999.02991.x
Subject(s) - physics , photometry (optics) , globular cluster , astrophysics , variable star , light curve , stars , image subtraction , hubble space telescope , astronomy , image (mathematics) , image processing , binary image , artificial intelligence , computer science
We present V ‐band light curves of 61 variables from the core of the globular cluster M5 obtained using a newly developed image subtraction method (ISM). Four of these variables were previously unknown. Only 26 variables were found in the same field using photometry obtained with dophot software. Fourier parameters of the ISM light curves have relative errors up to 11 times smaller than parameters measured from dophot photometry. We conclude that the new method is very promising for searching for variable stars in the cores of the globular clusters and gives very accurate relative photometry with quality comparable to photometry obtained by the Hubble Space Telescope . We also show that the variable V104 is not an eclipsing star as has been suggested, but is an RRc star showing non‐radial pulsations.