VizieR Online Data Catalog: Variable stars in M4 primary field (Nascimbeni+, 2014)

The full GO-12911 data set was gathered during 120 HST orbits, arranged in 12 epochs made of 10 HST visits each, where each visit is one orbit. Each orbit is filled with five 392-396s exposures in the blue filter F467M (except for 11 isolated frames for which the F467M exposure time was set to 366s), and one additional 20s exposure through a red F775W filter at the beginning of the orbit.

The first visit occurred on 2012 Oct 9, followed by a 100 d gap and then by 11 other visits regularly spaced at an ~24d cadence. In this work, we will focus on a homogeneous subset of 589 'deep' (392-396s) F467M images, in order to take advantage of a denser sampling and smaller flux contamination from giants.

(2 data files).