Related papers: Proper-Motion Membership Tests for Four Planetary …

In the course of a search for common proper motion binaries, in the Jones & Walker (JW) catalogue of proper motions in the Orion Nebula Cluster, we came across several faint stars with proper motions larger than one arcsecond per century…

We present medium- and broad-band Hubble Space Telescope (HST) photometry of a sample of 35 central stars (CSs) of Planetary Nebulae (PNs) in the Large Magellanic Cloud (LMC). The observations were made with the WFPC2 and STIS instruments…

We present an astrometric study of the proper motions (PMs) in the core of the globular cluster NGC 6441. The core of this cluster has a high density and observations with current instrumentation are very challenging. We combine…

About 3,500 planetary nebulae (PNe) are currently known in the Milky Way, which shows a great discrepancy with the expected number for these objects, regardless of the reference used, $33-59 \times 10^{3}$. The same holds for symbiotic…

We computed proper motions of a selected sample of globular clusters projected on the central bulge, employing CCD images gathered along the last 25 years at the ESO-NTT, ESO-Danish and HST telescopes. We presented a method to derive their…

We surveyed the central 4 x 4 degrees of the Galactic center for planetary nebulae in the light of [S III] 9532 A and found 94 PNe that were not previously known, plus 3 that were previously identified as possible candidates. For 63 of…

We have measured the absolute proper motions of four low-latitude, inner-Galaxy globular clusters. These clusters are: NGC 6266 (M62), NGC 6304, NGC 6316 and NGC 6723. The proper motions are on the Hipparcos system, as no background…

Extragalactic Planetary Nebulae (PNe) are not only useful as distance signposts or as tracers of the dark-matter content of their host galaxies, but constitute also good indicators of the main properties of their parent stellar populations.…

Planetary nebulae (PNe) are strong H$\alpha$ line-emitters and a lot of new PNe discoveries have been made by the SuperCOSMOS AAO/UKST H$\alpha$ Survey (SHS) and the Isaac Newton Telescope Photometric H$\alpha$ Survey (IPHAS). However, the…

We have obtained multi-wavelength observations of compact Galactic planetary nebulae (PNe) to probe post-Asymptotic Giant Branch (AGB) evolution from the onset of nebular ejection. We analyze new observations from HST to derive the masses…

We have undertaken a long term program to measure high precision proper motions of nearby Galactic globular cluster (GC) stars using multi-epoch observations with the WFPC2 and the ACS cameras on-board the Hubble Space Telescope. The proper…

This paper presents a deep investigation of two open clusters, Haffner 22 and Melotte 71, using astrometric and photometric data from Gaia EDR3. We identified 382 and 597 most probable cluster members with membership probability higher than…

In this paper we report a new estimate of the absolute proper motion (PM) of the globular cluster NGC 5139 ($\omega$ Cen) as part of the HST large program GO-14118+14662. We analyzed a field 17 arcmin South-West of the center of $\omega$…

Membership identification is the first step to determine the properties of a star cluster. Low-mass members in particular could be used to trace the dynamical history, such as mass segregation, stellar evaporation, or tidal stripping, of a…

We have obtained observations of the planetary nebula K648 in the Galactic globular cluster M15 with the Hubble Space Telescope's WFPC2 camera, covering an interval of 7 days. The frames provide both time-sampled broad-band photometry of…

Context. There are more than 3000 true and probable known Galactic Planetary Nebulae (PNe), but only for 13% of them there is central star spectroscopic information available. Aims. To contribute to the knowledge of central stars of…

In this paper, I review some of the basic properties of the pulsar population in globular clusters (GCs) and compare it with the the Galactic disk population. The neutron stars (NSs) in GCs were likely formed - and appear to continue…

Planetary nebulae (PNe) consist of an ionized envelope surrounding a hot central star (CSPN) that emits mostly at ultraviolet (UV) wavelengths. Ultraviolet observations, therefore, provide important information on both the CSPN and the…

We present results of fully self-consistent N-body simulations of the motion of four globular clusters moving in the inner region of their parent galaxy. With regard to previous simplified simulations, we confirm merging and formation of an…

Close binary central stars of planetary nebulae (PNe) must have formed through a common envelope evolution during the giant phase experienced by one of the stars. Transfer of the angular momentum from the binary system to the envelope leads…