Search Publications

A survey for variable young stars with small telescopes: II - mapping a protoplanetary disc with stable structures at 0.15 au
DOI: 10.1093/mnras/staa158 Bibcode: 2020MNRAS.493..184E

Scholz, Aleks; Eislöffel, Jochen; Dvorak, Shawn +57 more

The HOYS citizen science project conducts long-term, multifilter, high-cadence monitoring of large YSO samples with a wide variety of professional and amateur telescopes. We present the analysis of the light curve of V1490 Cyg in the Pelican Nebula. We show that colour terms in the diverse photometric data can be calibrated out to achieve a median…

2020 Monthly Notices of the Royal Astronomical Society
Gaia 12
Seismic solar models from Ledoux discriminant inversions
DOI: 10.1051/0004-6361/202037980 Bibcode: 2020A&A...642A..36B

Buldgen, G.; Eggenberger, P.; Christensen-Dalsgaard, J. +6 more

Context. The Sun constitutes an excellent laboratory of fundamental physics. With the advent of helioseismology, we were able to probe its internal layers with unprecendented precision and thoroughness. However, the current state of solar modelling is still stained by tedious issues. One of these central problems is related to the disagreement bet…

2020 Astronomy and Astrophysics
SOHO 12
How faculae and network relate to sunspots, and the implications for solar and stellar brightness variations
DOI: 10.1051/0004-6361/202037739 Bibcode: 2020A&A...639A.139Y

Solanki, S. K.; Yeo, K. L.; Krivova, N. A.

Context. How global faculae and network coverage relates to that of sunspots is relevant to the brightness variations of the Sun and Sun-like stars.
Aims: We aim to extend and improve on earlier studies that established that the facular-to-sunspot-area ratio diminishes with total sunspot coverage.
Methods: Chromospheric indices and the t…

2020 Astronomy and Astrophysics
SOHO 12
An eclipsing M-dwarf close to the hydrogen burning limit from NGTS
DOI: 10.1093/mnras/staa2513 Bibcode: 2020MNRAS.498.3115A

Wheatley, Peter J.; Bayliss, Daniel; Moyano, Maximiliano +20 more

We present the discovery of NGTS J0930-18, an extreme mass ratio eclipsing M-dwarf binary system with an early M-dwarf primary and a late M-dwarf secondary close to the hydrogen burning limit. Global modelling of photometry and radial velocities reveals that the secondary component (NGTS J0930-18 B) has a mass of M* = $0.0818 ^{+0.0040}…

2020 Monthly Notices of the Royal Astronomical Society
Gaia 12
Two new nova shells associated with V4362 Sagittarii and DO Aquilae
DOI: 10.1093/mnras/staa2896 Bibcode: 2020MNRAS.499.2959H

Boumis, P.; Derlopa, S.; Akras, S. +8 more

A classical nova is an eruption on the surface of a white dwarf in an accreting binary system. The material ejected from the white dwarf surface generally forms an axisymmetric shell. The shaping mechanisms of nova shells are probes of the processes that take place at energy scales between planetary nebulae and supernova remnants. We report on the…

2020 Monthly Notices of the Royal Astronomical Society
Gaia 12
Optical Transmission Spectra of Hot Jupiters: Effects of Scattering
DOI: 10.3847/1538-4357/ab6592 Bibcode: 2020ApJ...889..181S

Tinetti, Giovanna; Sengupta, Sujan; Chakrabarty, Aritra

We present new grids of transmission spectra for hot Jupiters by solving the multiple-scattering radiative transfer equations with non-zero scattering albedo instead of using the Beer-Bouguer-Lambert law for the change in the transmitted stellar intensity. The diffused reflection and transmission due to scattering increase the transmitted stellar …

2020 The Astrophysical Journal
eHST 12
Stellar wind models of central stars of planetary nebulae
DOI: 10.1051/0004-6361/201937150 Bibcode: 2020A&A...635A.173K

Krtička, J.; Kubát, J.; Krtičková, I.

Context. Fast line-driven stellar winds play an important role in the evolution of planetary nebulae, even though they are relatively weak.
Aims: We provide global (unified) hot star wind models of central stars of planetary nebulae. The models predict wind structure including the mass-loss rates, terminal velocities, and emergent fluxes from…

2020 Astronomy and Astrophysics
Gaia IUE 12
First L band detection of hot exozodiacal dust with VLTI/MATISSE
DOI: 10.1093/mnrasl/slaa156 Bibcode: 2020MNRAS.499L..47K

Kirchschlager, Florian; Ertel, Steve; Matter, Alexis +2 more

For the first time, we observed the emission of hot exozodiacal dust in L band. We used the new instrument MATISSE at the Very Large Telescope Interferometer to detect the hot dust around κ Tuc with a significance of 3σ to 6σ at wavelengths between 3.37 and $3.85\, {\mu {\rm m}}$ and a dust-to-star flux ratio of 5 to $7{{{\ \rm per\ cent}}}$ . We …

2020 Monthly Notices of the Royal Astronomical Society
Gaia 12
First discovery of trans-iron elements in a DAO-type white dwarf (BD-22°3467)
DOI: 10.1093/mnras/stz3247 Bibcode: 2020MNRAS.492..528L

Rauch, T.; Werner, K.; Kruk, J. W. +4 more

We have identified 484 lines of the trans-iron elements (TIEs) Zn, Ga, Ge, Se, Br, Kr, Sr, Zr, Mo, In, Te, I, Xe, and Ba, for the first time in the ultraviolet spectrum of a DAO-type WD, namely BD-22°3467, surrounded by the ionized nebula Abell 35. Our TIE abundance determination shows extremely high overabundances of up to five dex - a…

2020 Monthly Notices of the Royal Astronomical Society
Gaia eHST 12
Colour-magnitude diagrams of transiting exoplanets - III. A public code, nine strange planets, and the role of phosphine
DOI: 10.1093/mnras/staa2350 Bibcode: 2020MNRAS.499..505D

Triaud, Amaury H. M. J.; Dransfield, Georgina

Colour-magnitude diagrams provide a convenient way of comparing populations of similar objects. When well populated with precise measurements, they allow quick inferences to be made about the bulk properties of an astronomic object simply from its proximity on a diagram to other objects. We present here a PYTHON toolkit that allows a user to produ…

2020 Monthly Notices of the Royal Astronomical Society
Gaia eHST 12