Related papers: Resolving the 47 Tucanae Distance Problem
New estimate of the distances of 36 nearby galaxies is presented. It is based on the calibration of the V- and I-band Period-Lumi- nosity relations for galactic Cepheids measured by the HIPPARCOS mission. The distance moduli are obtained in…
We review seven methods of measuring the absolute magnitude M_V of RR Lyrae stars in light of the Hipparcos mission and other recent developments. We focus on identifying possible systematic errors and rank the methods by relative immunity…
We present linear polarization in the V band for 77 stars in the field of the globular cluster 47 Tucanae (NGC 104), and for 14 bright-star-free regions, located along an elliptical isophotal contour of the cluster, as well as UBVRI…
We present further arguments that the Hipparcos parallaxes for some of the clusters and associations represented in the Hipparcos catalog should be used with caution in the study of the Galactic structure. It has been already shown that the…
The open clusters NGC 2323 and NGC 2539 have been analysed using CCD UBV(RI)KC photometric data, observed at the San Pedro Martir Observatory. Cluster memberships have been determined with the proper motion and parallax measures from the…
We exploit the large number of archival HST images of 47 Tuc to examine its subgiant branch (SGB) and main sequence (MS) for signs of multiple populations. In the cluster core, we find that the cluster's SGB exhibits a clear spread in…
The CCD UBV(RI)KC photometry of the poorly studied open clusters Juchert 9 (Juc 9) and Berkeley 97 (Be 97), which are observed with the 0.84 m telescope at the San Pedro M\'artir National Observatory, M\'exico has been analysed. For the…
We derive the basic properties of seven Galactic open clusters containing Cepheids and construct their period-luminosity (P-L) relations. For our cluster main-sequence fitting we extend previous Hyades-based empirical color-temperature…
We use images collected with the near-infrared camera (NIRCam) on board the James Webb Space Telescope and with the Hubble Space Telescope (HST) to investigate multiple populations at the bottom of the main sequence (MS) of 47 Tucanae. The…
We present new large field-of-view ($\sim$1\deg$\times$1\deg) Ca-CN photometry of the prototypical metal-rich globular cluster 47 Tucanae (NGC 104). Our results are the following. (1) The populational number ratios of the red giant branch…
We use near-infrared observations obtained as part of the {\sl Visible and Infrared Survey Telescope for Astronomy} (VISTA) Survey of the Magellanic Clouds (VMC), as well as two complementary {\sl Hubble Space Telescope} ({\sl HST}) data…
The paper investigates the properties of the dust mass loss in stars populating the giant branch of the globular cluster 47 Tuc, by combining ISOCAM and DENIS data. Raster maps of 5 fields covering areas ranging from 4 x 4 to 15 x 15…
We present the results of photometric measurements from images of the LMC cluster ESO 121-SC03 taken with HST/ACS. Our resulting CMD reaches 3 magnitudes below the main-sequence turn-off, representing the deepest observation of this cluster…
Precision uvbyCaHbeta photometry of the nearby old open cluster, NGC 752, is presented. The mosaic of CCD fields covers an area ~42' on a side with internal precision at the 0.005 to 0.010 mag level for the majority of stars down to V~15.…
In a recent paper Brown et al. (2018) analyze the spectral properties of the globular cluster 47 Tucanae (47 Tuc) using 9 years of Fermi-LAT data. Brown et al. (2018) argue that the emission from 47 Tuc cannot be explained by millisecond…
NGC 5822 is a richly populated, moderately nearby, intermediate-age open cluster covering an area larger than the full moon on the sky. A CCD survey of the cluster on the UBVI and uvbyCaHbeta systems shows that the cluster is superposed…
We analyse a sample of 236 Cepheids from the Hipparcos catalog, using the method of ``reduced parallaxes'' in V, I, K and the reddening-free ``Wesenheit-index''. We compare our sample to those considered by Feast & Catchpole (1997) and…
High precision trigonometric parallaxes from the HIPPARCOS satellite and accurate metal abundances ([Fe/H], [O/Fe], and [alpha/Fe]) from high resolution spectroscopy for about 30 local subdwarfs have been used to derive distances and ages…
We present high-quality BVRI photometric data in the field of globular cluster NGC 6496 obtained with the SOAR Telescope Adaptive Module (SAM). Our observations were collected as part of the ongoing SAM commissioning. The distance modulus…
A globular cluster distance scale based on Hipparcos parallaxes of subdwarfs has been used to derive estimates of M_K for cluster Miras, including one in the SMC globular cluster NGC121. These lead to a zero-point of the Mira infrared…