相关论文: Palomar 13's Last Stand

Using wide-field photometric data from the Sloan Digital Sky Survey (SDSS) we recently showed that the Galactic globular cluster Palomar 5 is in the process of being tidally disrupted. Its tidal tails were initially detected in a 2.5 degree…

We have measured the absolute proper motions of globular clusters NGC 2808, 3201, 4372, 4833, 5927 and 5986. The proper motions are on the Hipparcos system and they are the first determinations ever made for these low Galactic latitude…

NGC 1851 is an intriguing Galactic globular cluster, with multiple stellar evolutionary sequences, light and heavy element abundance variations and indications of a surrounding stellar halo. We present the first results of a spectroscopic…

The Milky Way halo is one of the few galactic haloes that provides a unique insight into galaxy formation by resolved stellar populations. Here, we present a catalogue of $\sim$47 million halo stars selected independent of parallax and…

We report the discovery of PM J13420-3415, a faint (V=17) white dwarf with a very high proper motion mu = 2.55 arcsec/yr. The star was found in the southern sky extension of the SUPERBLINK proper motion survey. A red spectrum shows the…

Using astrometric techniques developed by Anderson et al., we determine proper motions (PMs) in 14.60 arcmin X 16.53 arcmin area of the kinematically "thick-disk" globular cluster M12. The cluster's proximity and sparse nature makes it a…

Using the high-resolution observations obtained by the Hubble Space Telescope, we analyzed the blue straggler stars (BSSs) in the Large Magellanic Cloud cluster NGC 2213. We found that the radial distribution of BSSs is consistent with that…

We present a proper motion measurement for the halo globular cluster Pyxis, using HST/ACS data as the first epoch, and GeMS/GSAOI Adaptive Optics data as the second, separated by a baseline of about 5 years. This is both the first…

We present a timing and scintillation study of the young Galactic halo pulsar PSR J1740+1000 using observations from the Nanshan, FAST, and Parkes radio telescopes. From timing analysis, we measure the pulsar's proper motion for the first…

Blue stragglers are anomalously luminous core hydrogen-burning stars formed through mass-transfer in binary/triple systems and stellar collisions. Their physical and evolutionary properties are largely unknown and unconstrained. Here we…

This work employs high-quality {\em Hubble Space Telescope} ({\em HST}) Advanced Camera for Surveys (ACS) F606W and F814W photometry to correct for the differential reddening affecting the colour-magnitude diagram (CMD) of the…

Globular clusters in the Galactic bulge are difficult to study due to high extinction and severe crowding. VVV-CL001 is an old, metal-poor, and fast cluster in the inner bulge, whose extreme properties make it a key probe of the early…

The globular cluster Palomar 5 (Pal 5) is in the process of being tidally shredded as it orbits the Milky Way. Its core is currently at a heliocentric distance of ~21 kpc, near apogalacticon (~18 kpc), and it reaches ~5-7 kpc at…

A proper motion study of a field of 20' x 20' inside Plaut's low extinction window (l,b)=(0 deg,-8 deg), has been completed. Relative proper motions and photographic BV photometry have been derived for ~21,000 stars reaching to V~20.5 mag,…

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…

We present the stellar population, using {\it Gaia}\,DR2 parallax, kinematics, and photometry, of the young ($\sim 100$~Myr), nearby ($\sim 230$~pc) open cluster, Blanco1. A total of 644 member candidates are identified via the unsupervised…

The Gaia HR diagram shows the presence of apparently young stars at high tangential velocities. Using a simple analytical model I show that these stars are likely to be blue stragglers. Once normalized to red giant stars, the fraction of…

Palomar 1 is a peculiar galactic globular cluster, suspected to be younger than the bulk of the Galactic halo objects. However, such a low age can be confirmed only after a reliable determination of the metallicity. In the present paper, we…

(Abridged) We use the largest set of globular cluster velocities obtained so far of any elliptical galaxy to revise and extend the previous investigations of the dynamics of NGC 1399, the central dominant galaxy of the nearby Fornax cluster…

Blue straggler stars have been proposeed as powerful indicators to measure the dynamical state of Galactic globular clusters. Here we examine for the first time if this framework of blue straggler stars as dynamical clocks, which was…