Related papers: Two planetary nebulae in the Sagittarius Dwarf Gal…
We report the discovery of a planetary nebula centered on the poorly studied symbiotic binary star DT Ser. In a few other symbiotic stars spatially resolved nebulae have been discovered: however, only one of them might be a genuine…
Suggestions have appeared in the literature that the following five pairs of Milky Way and Andromeda satellite galaxies are gravitationally bound: Draco and Ursa Minor, Leo IV and V, Andromeda I and III, NGC 147 and 185, and the Magellanic…
We use Hubble Space Telescope imaging to show that the nearby dwarf starburst galaxy NGC 4449 has an unusual abundance of luminous red star clusters. Joint constraints from integrated photometry, low-resolution spectroscopy, dynamical…
The morphological properties of the Carina, Sculptor and Fornax dwarfs are investigated using new wide field data with a total area of 29 square degrees. The stellar density maps are derived, hinting that Sculptor possesses tidal tails…
Binaries in the cores of globular clusters are known to prevent the gravitational collapse of the cluster, and simulations predict that the core of NGC 6397 contains a large number of white dwarfs (WDs), of which many are expected to be…
We have imaged the recently discovered stellar overdensity located approximately one core radius from the center of the Fornax dwarf spheroidal galaxy using the Magellan Clay 6.5m telescope with the Magellan Instant Camera (MagIC). Superb…
Recent studies show the possibility of the formation of fairly regular and global spiral patterns in dwarf galaxies (dS type). Our sample of observed dwarf objects of this class also includes galaxies with a central stellar bar. The…
We report the detection of $\sim$ 1500 RR Lyrae of Bailey type ab located in the Sagittarius dwarf galaxy (Sgr). These variables have been detected on two ESO Schmidt fields centred on (l,b)=(3.1 deg,-7.1 deg) and (6.6 deg, -10.8 deg),…
Based on the large number of elliptical planetary nebulae I argue that about 55 per cent of all progenitors of planetary nebulae have planets around them. The planets spin up the stars when the later evolve along the red giant branch or…
This paper discusses the location of a sample of planetary nebulae on the HR diagram. We determine the internal velocity fields of 14 planetary nebulae from high-resolution echelle spectroscopy, with the help of photoionization models. The…
Recent spectroscopic and morphological observational studies of galaxies around NGC 1399 in the Fornax Cluster (Drinkwater et al. 2000b) have discovered several `ultra-compact dwarf' galaxies with intrinsic sizes of $\sim$ 100 pc and…
We use Sloan Digital Sky Survey (SDSS) Data Release 5 (DR5) u,g,r,i,z photometry to study Milky Way halo substructure in the area around the North Galactic Cap. A simple color cut (g-r < 0.4) reveals the tidal stream of the Sagittarius…
The kinematic structure of a sample of planetary nebulae, consisting of 23 [WR] central stars, 21 weak emission line stars (wels) and 57 non-emission line central stars, is studied. The [WR] stars are shown to be surrounded by turbulent…
While there has been significant progress in our understanding of the origin and evolu-tion of planetary nebulae in the last 50 years, there remain several unsolved problems. These include the true 3D morphological structure of the nebulae,…
We present an analysis of the asymmetries in the population of Galactic M-giant stars present in the 2MASS All Sky catalogue. Several large-scale asymmetries are detected, the most significant of which is a strong elliptical-shaped stellar…
The destiny of planetary systems through the late evolution of their host stars is very uncertain. We report a metal-rich gas disk around a moderately hot and young white dwarf. A dynamical model of the double-peaked emission lines…
Stellar halo substructures were identified using statistical photometric parallax of blue main sequence turnoff stars from fourteen Sloan Digital Sky Survey stripes in the north Galactic cap. Four structures are consistent with previous…
We present new radial velocity results for 176 stars in the Fornax dwarf spheroidal galaxy, of which at least 156 are probable Fornax members. We combine with previously published data to obtain a radial velocity sample with 206 stars, of…
We present a comprehensive and detailed study of the stellar populations of the Fornax dwarf spheroidal galaxy. We analyse their spatial distributions along the main body of the galaxy, obtaining their surface density maps, together with…
The Fornax dwarf spheroidal galaxy is well known for its very high globular cluster specific frequency, SN=26. Furthermore, while the field star metallicity distribution peaks at [Fe/H]=-1, four of the five GCs have [Fe/H]<-2. Only about 5…