Bibcode
Díaz-Sánchez, Anastasio; Pérez-Garrido, Antonio; Villó, Isidro; Rebolo, R.; Pérez-Prieto, J. A.; Oscoz, A.; Hildebrandt, S. R.; López, R. L.; Rodríguez, L. F.
Bibliographical reference
Monthly Notices of the Royal Astronomical Society, Volume 423, Issue 3, pp. 2260-2269.
Advertised on:
7
2012
Citations
6
Refereed citations
6
Description
We present high-resolution I-band imaging of the core of the globular
cluster M15 obtained at the 2.5-m Nordic Optical Telescope with FastCam,
a low readout noise L3CCD-based instrument. Short exposure times (30 ms)
were used to record 200 000 images (512 × 512 pixels each) over a
period of 2 h and 43 min. The lucky imaging technique was then applied
to generate a final image of the cluster centre with full width at
half-maximum ˜0.1 arcsec and 13 × 13 arcsec2
field of view. We obtained a catalogue of objects in this region with a
limiting magnitude of I= 19.5. I-band photometry and astrometry are
reported for 1181 stars. This is the deepest I-band observation of the
M15 core at this spatial resolution. Simulations show that crowding is
limiting the completeness of the catalogue. At shorter wavelengths, a
similar number of objects have been reported using Hubble Space
Telescope (HST)/Wide Field Planetary Camera observations of the same
field. The cross-match with the available HST catalogues allowed us to
produce colour-magnitude diagrams where we identify new blue straggler
star candidates and previously known stars of this class.
Related projects
Very Low Mass Stars, Brown Dwarfs and Planets
Our goal is to study the processes that lead to the formation of low mass stars, brown dwarfs and planets and to characterize the physical properties of these objects in various evolutionary stages. Low mass stars and brown dwarfs are likely the most numerous type of objects in our Galaxy but due to their low intrinsic luminosity they are not so
Rafael
Rebolo López