papers

Publications (8)

astro-ph.GA2011

Transformations between WISE, 2MASS, SDSS and BVRI photometric systems: I. Transformation equations for dwarfs

S. Bilir, S. Karaali, S. Ak +5

We present colour transformations for the conversion of the W1 and W2 magnitudes of WISE photometric system to the Johnson-Cousins' BVRI, SDSS (gri), and 2MASS (JHK_s) photometric…

astro-ph.GA2011

Identification of field dwarfs and giants in RAVE

S. Bilir, S. Karaali, S. Ak +3

The second RAdial Velocity Experiment (RAVE) Data Release (DR2) derives log g values but we present a simpler and cleaner method of identifying dwarfs and giants using only magnitu…

astro-ph.GA2011

An Improved Metallicity Calibration with UBV Photometry

S. Karaali, S. Bilir, S. Ak +2

We used the data of 701 stars covering the colour index interval 0.32<B-V<=1.16, with metallicities -1.76<=[Fe/H]<=+0.40 dex, which were taken from PASTEL catalogue and estimated m…

astro-ph.GA2011

Local stellar kinematics from RAVE data: II. Radial Metallicity Gradient

B. Coskunoglu, S. Ak, S. Bilir +5

We investigate radial metallicity gradients for a sample of dwarf stars from the RAdial Velocity Experiment (RAVE) Data Release 3 (DR3). We select a total of approximately 17000 F-…

astro-ph.GA2010

Local Stellar Kinematics from RAVE Data: I. Local Standard of Rest

B. Coskunoglu, S. Ak, S. Bilir +19

We analyze a sample of 82850 stars from the RAVE survey, with well-determined velocities and stellar parameters, to isolate a sample of 18026 high-probability thin-disc dwarfs with…

astro-ph.GA2014

Colour Transformations between BVRc and g'r'i' Photometric Systems for Giant Stars

S. Ak, T. Ak, S. Karaali +9

The transformation equations from to magnitudes and vice versa for the giants were established from a sample of 80 stars collected from Soubiran et al. (2010) with…

astro-ph.GA2013

Local stellar kinematics from RAVE data: IV. Solar neighbourhood age-metallicity relation

S. Duran, S. Ak, S. Bilir +4

We investigated the age-metallicity relation using a sample of 5691 F and G type dwarfs from RAVE DR3 by applying several constraints: i) We selected stars with surface gravities l…

astro-ph.SR2010

Transformations between 2MASS, SDSS and BVI photometric systems for late-type giants

E. Yaz, S. Bilir, S. Karaali +3

We present colour transformations from Two Micron All Sky Survey (2MASS) photometric system to Johnson-Cousins system and to Sloan Digital Sky Survey (SDSS) system for late-type gi…