Ground-based CCD astrometry with wide-field imagers - II. A star catalog for M 67: WFI@2.2 m MPG/ESO astrometry, FLAMES@VLT radial velocities

By R. S. Yadav, L. Bedin, G. Piotto, J. Anderson, Santi Cassisi, S. Villanova, I. Platais, L. Pasquini, Y. Momany, R. S. U. Padova and 7 more. 2008

189 citations recorded by the source corpus.

Context. The solar-age open cluster M 67 (C0847+120, NGC 2682) is a touchstone in studies of the old Galactic disk. Despite its outstanding role, the census of cluster membership for M 67 at fainter magnitudes and their properties are not well-established. Aims. Using proprietary and archival ESO data, we have obtained astrometric, photometric, and radial velocities of stars in a $34\times33$ arcmin 2 field centered on the old open cluster M 67. Methods. The two-epoch archival observations separated by 4 years and acquired with the Wide-Field Imager at the 2.2 m MPG/ESO telescope were reduced with our new astrometric techniques, as described in the first paper in this series. The same observations served to derive calibrated BVI photometry in M 67. Radial velocities were measured using the archival and new spectroscopic data obtained at the VLT. Results. We have determined relative proper motions and membership probabilities for ~2400 stars. The precision of proper motions for optimally exposed stars is 1.9 mas yr -1 , gradually degrading down to ~5 mas yr -1 at $V=20$. Our relatively precise proper motions at $V>16$ were first obtained in this magnitude range for M 67. Radial velocities were measured for 211 stars in the same field. We also present a detailed comparison with recent theoretical isochrones from several independent groups. Conclusions. For the M 67 area, we provide positions, calibrated BVI photometry, relative proper motions, membership probabilities, and radial velocities. We demonstrate that ground-based CCD mosaic observations just a few years apart are producing proper motions, allowing reliable membership determination. We have produced a catalog that is electronically available to the astronomical community.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/e812b8e4d4fb778c2e12095eea6088bfde158aba

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. Martin Asplund
2. Jay Anderson
3. G. Piotto
4. A. Renzini
5. F. D’Antona
6. R. Gratton
7. A. Milone
8. E. Carretta

In Instrumentation

1. F. D’Antona
2. E. Carretta
3. R. Gratton
4. G. Piotto
5. A. Bragaglia
6. A. Milone
7. Jay Anderson
8. L. Bedin

Citations in the corpus

• Lithium depletion in solar-like stars: no planet connection (2010, background): “The age for M67 is taken from VandenBerg et al. (2007) and Yadav et al. (2008), the lithium abundances for M67 stars are from Castro et al. (2010).”
• The Gaia-ESO Survey: the analysis of high-resolution UVES spectra of FGK-type stars (2014, background): “17 Star NGC 2682 YBP 1194 with identification number from Yadav et al. (2008).”
• Improving PARSEC models for very low mass stars (2014, methodology): “Top panel: The M 67 data from Yadav et al. (2008), in the V vs.”
• Astrometry and Photometry with HST WFC3. II. Improved Geometric-Distortion Corrections for 10 Filters of the UVIS Channel (2011, methodology): “This result is evenmore astonishing if we consider that we did not use local transformations (see, e.g., Bedin et al. 2003; Anderson et al. 2006b; Anderson & van der Marel 2010), which would further reduce systematic residuals in the GD solution, as well as any correction for breathing (which can…”
• Stellar Proper Motions in the Galactic Bulge from Deep Hubble Space Telescope ACS WFC Photometry (2008, background): “We do not include the target star itself in the transformation (see Anderson et al. 2006) and are careful to ensure that tracer stars only on the same chip as the target star are used, to guard against any trends over time in the distortion of the two chips relative to each other.”
• A WFC3/HST VIEW OF THE THREE STELLAR POPULATIONS IN THE GLOBULAR CLUSTER NGC 6752 (2013, methodology): “Photometry and relative positions of stars in HST/WFC3 images were extracted with the software tools described in Bellini et al. (2011), mostly based on the software described in Anderson et al. (2006).”
• Chemical abundance analysis of the open clusters Cr 110, NGC 2099 (M 37), NGC 2420, NGC 7789, and M 67 (NGC 2682) (2009, background): “Since the first pioneering studies at the beginning ofXX century, we have a few hundred papers published to date (see Burstein et al., 1986; Carraro et al., 1996; Yadav et al., 2008, for more references).”
• The Multiplicity of the Subgiant Branch of ω Centauri: Evidence for Prolonged Star Formation (2007, methodology): “The images were reduced using img2xym_WFI, software developed specifically for the WFI camera and described in Anderson et al. (2006).”
• MULTIPLE STELLAR POPULATIONS IN 47 Tucanae (2011, methodology): “Star positions and fluxes in the WFC3 images were measured with software that is mostly based on img2xym_WFI (Anderson et al. 2006); this will be presented in a separate paper.”