Related papers: Internal Proper-Motions in the Eskimo Nebula

Extragalactic proper motions can reveal a variety of cosmological and local phenomena over a range of angular scales. These include observer-induced proper motions, such as the secular aberration drift caused by the solar acceleration about…

It has been suggested that the Crab pulsar's proper motion is well aligned with the symmetry axis of the pulsar wind nebula. We have re-visited this question, examining over 6 years of F547M WFPC2 chip 3 images to obtain a best-fit value of…

The Orion Nebula Cluster (ONC) is the nearest site of ongoing massive star formation, which allows us to study the kinematics and dynamics of the region in detail and constrain star formation theories. Using HST ACS/WFPC2/WFC3IR and Keck II…

As the first step to determine disk mass-to-light ratios for normal spiral galaxies, we present the results of an imaging survey for planetary nebulae (PNe) in six nearby, face-on systems: IC 342, M74 (NGC 628), M83 (NGC 5236), M94 (NGC…

We have measured astrometry for members of the Orion Nebula Cluster with images obtained in 2015 with the Wide Field Camera 3 on board the Hubble Space Telescope. By comparing those data to previous measurements with NICMOS on Hubble in…

We present the first study of high-precision internal proper motions (PMs) in a large sample of globular clusters, based on Hubble Space Telescope (HST) data obtained over the past decade with the ACS/WFC, ACS/HRC, and WFC3/UVIS…

We present a measurement of the Hubble constant made using geometric distance measurements to megamaser-hosting galaxies. We have applied an improved approach for fitting maser data and obtained better distance estimates for four galaxies…

We have measured the absolute proper motion of the Draco dwarf spheroidal galaxy using Subaru Suprime-Cam images taken at three epochs, with time baselines of 4.4 and 7 years. The magnitude limit of the proper-motion study is i=25, thus…

Using all the HST WFC/WFPC2 images of the field collected so far, we have performed an accurate relative astrometry analysis to re-assess the value of the Vela pulsar proper motion. Although covering a much shorter time span, our…

Spatially resolved profiles of the Halpha and [NII] lines have been obtained at unprecendented signal--to--noise ratios over the outflowing lobes of the high--excitation, poly--polar planetary nebula NGC~6302. A deep image in the light of…

The optical expansion parallax of NGC 6543 has been detected and measured using two epochs of HST images separated by a time baseline of only three years. We have utilized three separate methods of deriving the angular expansion of bright…

We have measured the expansion velocities and proper motion of the ansae in NGC7009 using high dispersion echelle spectra and archive narrow band HST images. Assuming that the ansae are moving at equal and opposite velocities from the…

The ouflowing proper motions of fifteen knots in the dominant northwestern lobe of the high-excitation poly-polar planetary nebula NGC 6302 have been determined by comparing their positions relative to those of faint stars in an image taken…

We use two 4.5micron Spitzer (IRAC) maps of the NGC 1333 region taken over approx. 7 yr interval to determine proper motions of its associated outflows. This is a first, successful attempt at obtaining proper motions of stellars outflow…

This work describes the modelling of the 3D structure and position-velocity (P-V) diagrams of NGC 2440, a well known planetary nebula, aiming to describe the morphology of this object, specially its core. We have used high resolution…

In this paper, we report on high angular resolution radio observations of the planetary nebula NGC 6881 obtained with the Very Large Array at a wavelength of 6 cm. The emission appears to be the superposition of a roundish core and a…

The comparison of the proper motions constructed from positions spanning a short (Hipparcos) or long time (Tycho-2) makes it possible to uncover binaries with periods of the order of or somewhat larger than the short time span, since the…

Relative proper motions and cluster membership probabilities of 30 stars within an area of 14' of diameter centered in the open cluster NGC1662 (\alpha=04^{\rm h}48^{\rm m}, \delta=+10^{\rm o}56') are determined by combining positions of…

Images from the High Resolution Camera on the Chandra X-ray Observatory were used to measure the proper motion of the neutron star in Cassiopeia A over a baseline of 10 years (1999-2009). One background source and 13 quasi-stationary…

We derive relative proper motions of stars in the fields of the globular clusters M12, NGC 6362, M4, M55, M22, NGC 6752, NGC 3201, M30, M10, NGC 362, M5, and 47 Tucanae based on data collected between 1997 and 2015 with the 1-m Swope…