Search Publications
Fundamental effective temperature measurements for eclipsing binary stars - III. SPIRou near-infrared spectroscopy and CHEOPS photometry of the benchmark G0V star EBLM J0113+31
Alonso, R.; Deleuil, M.; Erikson, A. +74 more
EBLM J0113+31 is a moderately bright (V = 10.1), metal-poor ([Fe/H] ≈-0.3) G0V star with a much fainter M dwarf companion on a wide, eccentric orbit (= 14.3 d). We have used near-infrared spectroscopy obtained with the SPIRou spectrograph to measure the semi-amplitude of the M dwarf's spectroscopic orbit, and high-precision photometry of the eclip…
Stellar kinematics of dwarf galaxies from multi-epoch spectroscopy: application to Triangulum II
Caldwell, Nelson; Martin, Nicolas F.; Mateo, Mario +9 more
We present new MMT/Hectochelle spectroscopic measurements for 257 stars observed along the line of sight to the ultrafaint dwarf galaxy Triangulum II (Tri II). Combining results from previous Keck/DEIMOS spectroscopy, we obtain a sample that includes 16 likely members of Tri II, with up to 10 independent redshift measurements per star. To this mul…
Can we reveal the core-chemical composition of ultra-massive white dwarfs through their magnetic fields?
Córsico, Alejandro H.; Rebassa-Mansergas, Alberto; Althaus, Leandro G. +5 more
Ultra-massive white dwarfs ($1.05\, \rm M_\odot \lesssim M_{WD}$) are particularly interesting objects that allow us to study extreme astrophysical phenomena such as type Ia supernovae explosions and merger events. Traditionally, ultra-massive white dwarfs are thought to harbour oxygen-neon (ONe) cores. However, recent theoretical studies and new …
The peculiar chemical abundance of the transitional millisecond pulsar PSR J1023+0038 - Li enhancement
Breton, R. P.; Kennedy, M. R.; Mata Sánchez, D. +3 more
Using high-resolution optical spectroscopy we determine the chemical abundance of the secondary star in the binary millisecond pulsar PSR J1023+0038. We measure a metallicity of [Fe/H] = 0.48 ± 0.04 which is higher than the Solar value and in general find that the element abundances are different compared to the secondary stars in X-ray binaries a…
The search for gas in debris discs: ALMA detection of CO gas in HD 36546
Henning, Thomas; Villaver, Eva; Rivière-Marichalar, Pablo +9 more
Debris discs represent the last stages of planet formation and as such are expected to be depleted of primordial gas. None the less, in the last few years the presence of cold gas has been reported in ~20 debris discs from far-infrared to (sub-)mm observations and hot gas has been observed in the optical spectra of debris discs for decades. While …
A census of post-AGB stars in Gaia DR3: evidence for a substantial population of Galactic post-RGB stars
Oudmaijer, René D.; Jones, Emma R. M.; Vioque, Miguel
This paper presents the first census of Galactic post-asymptotic giant branch (post-AGB) stars in the Hertzsprung-Russell (HR) diagram. We combined Gaia DR3 parallax-based distances with extinction corrected integrated fluxes and derived luminosities for a sample of 185 stars that had been proposed to be post-AGB stars in the literature. The lumin…
Asteroid phase curves using sparse Gaia DR2 data and differential dense light curves
Shevchenko, V.; Kwiatkowski, T.; Oszkiewicz, D. +10 more
The amount of sparse asteroid photometry being gathered by both space- and ground-based surveys is growing exponentially. This large volume of data poses a computational challenge owing to both the large amount of information to be processed and the new methods needed to combine data from different sources (e.g. obtained by different techniques, i…
The thermal and non-thermal components within and between galaxy clusters Abell 399 and Abell 401
Sarazin, Craig L.; Hilton, Matt; Sifón, Cristóbal +28 more
We measure the local correlation between radio emission and Compton-y signal across two galaxy clusters, Abell 399 and Abell 401, using maps from the Low Frequency Array and the Atacama Cosmology Telescope + Planck. These data sets allow us to make the first measurement of this kind at ~arcmin resolution. We find that the radio brightness scales a…
The morphology of the ejecta of SN 1987A at 31 yr from 1150 to 10 000 Å
Larsson, J.; Sollerman, J.; Lundqvist, P. +7 more
We present spectroscopy of the ejecta of SN 1987A in 2017 and 2018 from the Hubble Space Telescope and the Very Large Telescope, covering the wavelength range between 1150 and $10\, 000$ Å. At 31 yr, this is the first epoch with coverage over the ultraviolet-to-near-infrared range since 1995. We create velocity maps of the ejecta in the H α, Mg II…
The Hot Neptune WASP-166 b with ESPRESSO - I. Refining the planetary architecture and stellar variability
Lafarga, M.; Lendl, M.; Lovis, C. +24 more
In this paper, we present high-resolution spectroscopic transit observations from ESPRESSO of the super-Neptune WASP-166 b. In addition to spectroscopic ESPRESSO data, we analyse photometric data from TESS of six WASP-166 b transits along with simultaneous NGTS observations of the ESPRESSO runs. These observations were used to fit for the planetar…