Related papers: Discovery of A candidate Hypervelocity star origin…
We present the serendipitous discovery of a late T-type brown dwarf candidate in JWST NIRCam observations of the Early Release Science Abell 2744 parallel field. The discovery was enabled by the sensitivity of JWST at 4~$\mu$m wavelengths…
As part of the Selected Areas Starcount Survey (SASS), a CCD survey to V>21, we have obtained VI photometry of two fields at b=+-40 aligned roughly with an extrapolation of the major axis of the Sagittarius (Sgr) dwarf spheroidal galaxy.…
Herschel/HIFI observations have revealed the presence of widespread absorption by hydrogen fluoride (HF) J = 1-0 rotational transition, toward a number of Galactic sources. We present observations of HF J = 1-0 toward the high-mass…
M giants recovered from the Two Micron All-Sky Survey (2MASS) have recently been used to map the position and velocity distributions of tidal debris from the Sagittarius (Sgr) dwarf spheroidal galaxy entirely around the Galaxy. We compare…
We report the discovery of an eclipsing binary -- PTF1 J072456$+$125301-- composed of a subdwarf B (sdB) star ($g'=17.2^m$) with a faint companion. Subdwarf B stars are core helium-burning stars, which can be found on the extreme horizontal…
Hypervelocity stars (HVS) traverse the Galaxy from the central black hole to the outer halo. We show that the Galactic potential within 200 pc acts as a high pass filter preventing low velocity HVS from reaching the halo. To trace the…
In this study, spectral, age, kinematic, and orbital dynamical analyses were conducted on metal-poor and high proper-motion (HPM) stars, HD 8724 and HD 195633, selected from the Solar neighborhood. This analysis combines detailed abundance…
We use the fundamental-mode RR Lyr-type variable stars (RRab) from OGLE-IV survey to draw a 3D picture of the central part of the tidally disrupted Sagittarius Dwarf Spheroidal (Sgr dSph) galaxy. We estimate the line-of-sight thickness of…
A significant percentage of OB stars are runaways, so we should expect a similar percentage of their evolved descendants to also be runaways. However, recognizing such stars presents its own set of challenges, as these older, more evolved…
We present high-contrast Magellan adaptive optics (MagAO) images of HD 7449, a Sun-like star with one planet and a long-term radial velocity (RV) trend. We unambiguously detect the source of the long-term trend from 0.6-2.15 \microns ~at a…
SDSS J1507+52 is an eclipsing cataclysmic variable consisting of a cool, non-radially pulsating white dwarf and an unusually small sub-stellar secondary. The system has a high space velocity and a very short orbital period of about 67…
We present results from simultaneous modeling of 2D (projected along the line of sight) position, proper motion and line-of-sight velocity for \textit{Gaia}- and APOGEE-observed stars near the centre of the Sagittarius (Sgr) dwarf…
The supergiant fast X-ray transient IGR J08408-4503 was discovered by INTEGRAL on May 15, 2006, during a bright flare. The source shows sporadic recurrent short bright flares, reaching a peak luminosity of 10^36 erg s^-1 within less than…
We report the discovery of NGC 253-dw2, a dwarf spheroidal (dSph) galaxy candidate undergoing tidal disruption around a nearby spiral galaxy, NGC 253 in the Sculptor group: the first such event identified beyond the Local Group. The dwarf…
We present a new precision radial velocity dataset that reveals a multi-planet system orbiting the G0V star HD 34445. Our 18-year span consists of 333 precision radial velocity observations, 56 of which were previously published, and 277…
Within the SECCO survey we identified a candidate stellar counterpart to the Ultra Compact High Velocity Cloud (UCHVC) HVC274.68+74.70-123, that was suggested by Adams et al. (2013) as a possible mini-halo within the Local Group of…
We present the first 3D spectroscopic observations of a nearby HI detected poststarburst, or E+A, galaxy, SDSS J230743.41+152558.4, obtained with the VIMOS IFU spectrograph at ESO VLT. Using the NBursts full spectral fitting technique, we…
We have obtained deep photometric data in 24 fields along the southeast extension of the major axis of the Sagittarius dwarf spheroidal (Sgr dSph) galaxy, and in four fields along the northwest extension. Using star counts at the expected…
We present the chemical composition of a sample of 37 red giant branch (RGB) stars belonging to the main body of the remnant of the Sagittarius (Sgr) dwarf spheroidal galaxy. All stars were observed with the FLAMES-UVES high-resolution…
Hypervelocity stars (HVSs) are produced by the Hills mechanism when a stellar binary is disrupted by a supermassive black hole (SMBH). The HVS Survey detected 21 unbound B-type main-sequence stars in the Milky Way's outer halo that are…