Search Publications
Collision of two stellar associations in the nearby Gum Nebula
White, Russel J.; Yep, Alexandra C.
Based on Gaia DR2 data and new CHIRON radial velocities, we have discovered that two nearby stellar associations UPK 535 (318.08 ± 0.29 pc, $25^{+15}_{-10}$ Myr, 174 stars) and Yep 3 (339.54 ± 0.25 pc, $45^{+55}_{-20}$ Myr, 297 stars) in the Gum Nebula have recently collided. We project stars' current positions, motions, and measurement uncertaint…
H I in and behind the Hubble Frontier Field clusters: a deep MeerKAT pilot search out to z ∼ 0.5
Obreschkow, Danail; Heywood, Ian; Deane, Roger +2 more
The Hubble Frontier Fields (HFF) are a selection of well-studied galaxy clusters used to probe dense environments and distant gravitationally lensed galaxies. We explore the 21cm neutral hydrogen (H I) content of galaxies in three of the HFF clusters, Abell 2744 (z = 0.308), Abell S1063 (z = 0.346), and Abell 370 (z = 0.375), to investigate the ev…
Two years of optical and NIR observations of the superluminous supernova UID 30901 discovered by the UltraVISTA SN survey
Milvang-Jensen, B.; Fynbo, J. P. U.; Anderson, J. P. +6 more
We present deep optical and near-infrared photometry of UID 30901, a superluminous supernova (SLSN) discovered during the UltraVISTA survey. The observations were obtained with VIRCAM (YJHKs) mounted on the VISTA telescope, DECam (griz) on the Blanco telescope, and SUBARU Hyper Suprime-Cam (HSC; grizy). These multiband observations comp…
Estimating accurate reddening values of LAMOST M dwarfs
Chen, B. -Q.; Yuan, H. -B.; Sun, W. -X. +3 more
M dwarfs are the dominating type of stars in the solar neighbourhood. They serve as excellent tracers for the study of the distribution and properties of the nearby interstellar dust. In this work, we aim to obtain high accuracy reddening values of M dwarf stars from the Large Sky Area Multi-Object Fibre Spectroscopic Telescope (LAMOST) Data Relea…
Approach of the Hyades star cluster to the Solar system
Vereshchagin, S. V.; Sizova, M. D.; Emel'yanenko, V. V.
We present the results of calculations of the motion of the Hyades open cluster in the gravitational field of the Galaxy in the recent past. Our calculations show that the recent close passage of Hyades by the Solar system could cause a noticeable shift of the perihelion distances q of comets. The shift is negligible from q = 3 au to 2.6 au for th…
Survey for distant solar twins (SDST) - II. Design, observations, and data
Kos, Janez; Martell, Sarah L.; Murphy, Michael T. +5 more
Studies of solar twins have key impacts on the astronomical community, but only ~100-200 nearby solar twins (<1 kpc) have been reliably identified over the last few decades. The aim of our survey (SDST) is to identify ~150-200 distant solar twins and analogues (up to ≲4 kpc) closer to the Galactic Centre. We took advantage of the precise Gaia a…
Scattering and sublimation: a multiscale view of µm-sized dust in the inclined disc of HD 145718
Monnier, John D.; Schaefer, Gail H.; Lanthermann, Cyprien +16 more
We present multi-instrument observations of the disc around the Herbig Ae star, HD 145718, employing geometric and Monte Carlo radiative transfer models to explore the disc orientation, the vertical and radial extent of the near-infrared (NIR) scattering surface, and the properties of the dust in the disc surface and sublimation rim. The disc appe…
Assessment of the accuracy of measures in the 1829 southern double star catalogue of James Dunlop
Letchford, Roderick R.; White, Graeme L.; Brown, Carolyn J.
In 1829 James Dunlop published the first southern double star catalogue of some 253 double stars. The accuracy of this catalogue has been determined by using Aladin to cross-match them with Gaia DR2 and estimate their positional (right ascension, declination, position angle, and separation) and magnitude accuracy. Seven per cent could not be ident…
Fragmented atomic shell around S187 H II region and its interaction with molecular and ionized gas
Ghosh, Swarna K.; Dewangan, Lokesh K.; Ojha, Devendra K. +6 more
The environment of S187, a nearby H II region (1.4 ± 0.3 kpc), is analyzed. A surrounding shell has been studied in the H I line, molecular lines, and also in infrared and radio continua. We report the first evidence of a clumpy H I environment in its photodissociation region. A background radio galaxy enables the estimation of the properties of c…
η Geminorum: an eclipsing semiregular variable star orbited by a companion surrounded by an extended disc
Torres, Guillermo; Sakano, Kristy
We report 11 yr of spectroscopic monitoring of the M-type asymptotic giant branch star η Gem, a semiregular variable and a known spectroscopic binary with a period of 8.2 yr. We combine our radial velocities with others from the literature to provide an improved spectroscopic orbital solution, giving a period of 2979 d, which we then use to predic…