Related papers: The Most Distant Stars in the Milky Way
We report the discovery of SDSSJ1049+5103, an overdensity of resolved blue stars at (\alpha_{2000}, \delta_{2000}) = (162.343, 51.051). This object appears to be an old, metal-poor stellar system at a distance of 45 +/- 10 kpc, with a…
We increase the number of remote halo tracers by using blue horizontal branch (BHB) stars out to Galactocentric distances of 130 kpc. We use SDSS EDR photometry and the VLT to detect 16 BHB stars at Galactocentric distances 70 < r < 130,…
RR Lyr stars are ideal massless tracers that can be used to study the total mass and dark matter content of the outer halo of the Milky Way. This is because they are easy to find in the light curve databases of large stellar surveys and…
We report here the discovery of an apparent excess of 2MASS M giant candidates with dereddened 0.85 < J-K_S < 1.2 spanning a considerably large area of the celestial sphere between, at least, $100\degr < l < 150\degr$ and $-20\degr > b >…
In this Letter, we report the discovery of a new dwarf satellite to the Milky Way, located at ($\alpha_{2000}, \delta_{2000}$) $=$ (158.72,51.92) in the constellation of Ursa Major. This object was detected as an overdensity of red,…
We report the discovery of a new, low luminosity star cluster in the outer halo of the Milky Way. High quality $gr$ photometry is presented, from which a color-magnitude diagram is constructed, and estimates of age, [Fe/H], [$\alpha$/Fe],…
Abridged: We estimate the distances to ~48 million stars detected by the Sloan Digital Sky Survey and map their 3D number density distribution in 100 < D < 20 kpc range over 6,500 deg^2 of sky. The data show strong evidence for a Galaxy…
We identify new structures in the halo of the Milky Way Galaxy from positions, colors and magnitudes of five million stars detected in the Sloan Digital Sky Survey. Most of these stars are within 1.26 degrees of the celestial equator. We…
We report the discovery of the molecular cloud whose kinematic distance is the largest in the Galaxy at the present moment, named G213.042$+$0.003, at $l =$ 213.042$^\circ$ and $b =$ 0.003$^\circ$ in the $^{12}$CO($J =$ 1-0) line using the…
While massive stars are known to shape galactic ecosystems, their formation has long been assumed to require the high-density environments of inner galactic disks. This paradigm is challenged by mounting evidence of young massive stars in…
We present initial results from our study of the outer halo of the Milky Way using a large sample of RR Lyr(ab) variables datamined from the archives of the Palomar Transient Facility. Of the 464 RR Lyr in our sample with distances…
Runaway stars ejected from the Galactic disk populate the halo of the Milky Way. To predict the spatial and kinematic properties of runaways, we inject stars into a Galactic potential, compute their trajectories through the Galaxy, and…
We present a method for isolating a clean sample of red giant stars in the outerregions of the Andromeda spiral galaxy (M31) from an ongoing spectroscopic survey using the DEIMOS instrument on the Keck 10-m telescope. The survey aims to…
We present the discovery of Ursa Major III/UNIONS 1, the least luminous known satellite of the Milky Way, which is estimated to have an absolute V-band magnitude of $+2.2^{+0.4}_{-0.3}$ mag, equivalent to a total stellar mass of…
We present the discovery of five new unbound hypervelocity stars (HVSs) in the outer Milky Way halo. Using a conservative estimate of Galactic escape velocity, our targeted spectroscopic survey has now identified 16 unbound HVSs as well as…
A recently discovered young, high-velocity giant star J01020100-7122208 is a good candidate of hypervelocity star ejected from the Galactic center, although it has a bound orbit. If we assume that this star was ejected from the Galactic…
We present "augustus", a catalog of distance, extinction, and stellar parameter estimates to 170 million stars from $14\,{\rm mag} < r < 20\,{\rm mag}$ and with $|b| > 10^\circ$ drawing on a combination of optical to near-IR photometry from…
We measure proper motions with the Hubble Space Telescope for 16 extreme radial velocity stars, mostly unbound B stars in the Milky Way halo. Twelve of these stars have proper motions statistically consistent with zero, and thus have radial…
A wealth of recent studies have shown that the LMC is likely massive, with a halo mass $>10^{11} M_\odot$. One consequence of having such a nearby and massive neighbour is that the inner Milky Way is expected to be accelerated with respect…
RR Lyrae stars are standard candles with characteristic photometric variability and serve as powerful tracers of Galactic structure, substructure, accretion history, and dark matter content. Here we report the discovery of distant RR Lyrae…