166 citations · 1.4k across the 32 of their papers we have counts for
32 papers
Radial velocity precision of ESPRESSO through the analysis of the solar twin HIP 11915
Yuri Netto, Diego Lorenzo-Oliveira, Jorge Meléndez +4
Different stellar phenomena affect radial velocities (RVs), causing variations large enough to make it difficult to identify planet signals from the stellar variability. RV variati…
HD 183579b: A Warm Sub-Neptune Transiting a Solar Twin Detected by TESS
Tianjun Gan, Megan Bedell, Sharon Xuesong Wang +48
We report the discovery and characterization of a transiting warm sub-Neptune planet around the nearby bright ( mag, mag) solar twin HD 183579, delivered by the Tr…
Gemini/Phoenix H-band analysis of the globular cluster AL3
B. Barbuy, H. Ernandes, S. O. Souza +9
The globular cluster AL~3 is old and located in the inner bulge. Three individual stars were observed with the Phoenix spectrograph at the Gemini South telescope. The wavelength re…
Explosive nucleosynthesis of a metal-deficient star as the source of a distinct odd-even effect in the solar twin HIP 11915
Jhon Yana Galarza, Jorge Meléndez, Amanda I. Karakas +2
The abundance patterns observed in the Sun and in metal-poor stars show a clear odd-even effect. An important question is whether the odd-even effect in solar-metallicity stars is…
Search for helium in the upper atmosphere of the hot Jupiter WASP-127 b using Gemini/Phoenix
Leonardo A. dos Santos, David Ehrenreich, Vincent Bourrier +8
Large-scale exoplanet search surveys have shown evidence that atmospheric escape is a ubiquitous process that shapes the evolution and demographics of planets. However, we lack a d…
How magnetic activity alters what we learn from stellar spectra
Lorenzo Spina, Thomas Nordlander, Andrew R. Casey +8
Magnetic fields and stellar spots can alter the equivalent widths of absorption lines in stellar spectra, varying during the activity cycle. This also influences the information th…
The ancient main-sequence solar proxy HIP 102152 unveils the activity and rotational fate of our Sun
Diego Lorenzo-Oliveira, Jorge Meléndez, Geisa Ponte +1
We present a detailed analysis of the possible future Sun's rotational evolution scenario based on the 8 Gyr-old solar twin HIP 102152. Using HARPS high-cadence observations (and T…
The effect of stellar activity on the spectroscopic stellar parameters of the young solar twin HIP 36515
Jhon Yana Galarza, Jorge Meléndez, Diego Lorenzo-Oliveira +7
Spectroscopic equilibrium allows us to obtain precise stellar parameters in Sun-like stars. It relies on the assumption of the iron excitation and ionization equilibrium. However,…
Non-LTE analysis of K I in late-type stars
Henrique Reggiani, Anish M. Amarsi, Karin Lind +7
Older GCE models predict [K/Fe] ratios as much as 1 dex lower than those inferred from stellar observations. Abundances of potassium are mainly based on analyses of the 7698 re…
Revisiting the 16 Cygni planet host at unprecedented precision and exploring automated tools for precise abundances
M. Tucci Maia, J. Meléndez, D. Lorenzo-Oliveira +2
The binary system 16 Cygni is key in studies of the planet-star chemical composition connection, as only one of the stars is known to host a planet. This allows us to better assess…
Constraining the evolution of stellar rotation using solar twins
Diego Lorenzo-Oliveira, Jorge Meléndez, Jhon Yana Galarza +7
The stellar Rotation Age relation is commonly considered as a useful tool to derive reliable ages for Sun-like stars. However, in the light of \kepler\ data, the presence of…
Chemical inhomogeneities in the Pleiades: signatures of rocky-forming material in stellar atmospheres
Lorenzo Spina, Jorge Meléndez, Andrew R. Casey +2
The aim of Galactic archaeology is to recover the history of our Galaxy through the information encoded in stars. An unprobed assumption of this field is that the chemical composit…
The Solar Twin Planet Search: The age - chromospheric activity relation
Diego Lorenzo-Oliveira, Fabrício C. Freitas, Jorge Meléndez +8
It is well known that the magnetic activity of solar type stars decreases with age, but it is widely debated in the literature whether there is a smooth decline or if there is an e…
Evidences of extragalactic origin and planet engulfment in the metal-poor twin pair HD 134439/HD 134440
Henrique Reggiani, Jorge Meléndez
Recent studies of chemical abundances in metal-poor Halo stars show the existence of different populations, which is important for studies of Galaxy formation and evolution. Here w…
The temporal evolution of neutron-capture elements in the Galactic discs
Lorenzo Spina, Jorge Meléndez, Amanda I. Karakas +8
Important insights into the formation and evolution of the Galactic disc(s) are contained in the chemical compositions of stars. We analysed high-resolution and high signal to nois…
Constraining cosmic scatter in the Galactic halo through a differential analysis of metal-poor stars
Henrique Reggiani, Jorge Meléndez, Chiaki Kobayashi +2
We present the abundances of Li, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Co, Ni, Zn, Sr, Y, Zr, and Ba in a wide metallicity range ( [Fe/H] ). Using the differen…
Spectroscopic binaries in the Solar Twin Planet Search program: from substellar-mass to M dwarf companions
Leonardo A. dos Santos, Jorge Meléndez, Megan Bedell +6
Previous studies on the rotation of Sun-like stars revealed that the rotational rates of young stars converge towards a well-defined evolution that follows a power-law decay. It se…
How much can we trust high-resolution spectroscopic stellar chemical abundances?
S. Blanco-Cuaresma, T. Nordlander, U. Heiter +8
To study stellar populations, it is common to combine chemical abundances from different spectroscopic surveys/studies where different setups were used. These inhomogeneities can l…
How much can we trust high-resolution spectroscopic stellar atmospheric parameters?
S. Blanco-Cuaresma, T. Nordlander, U. Heiter +8
The determination of atmospheric parameters depends on the use of radiative transfer codes (among other elements such as model atmospheres) to compute synthetic spectra and/or deri…
The Solar Twin Planet Search: IV. The Sun as a typical rotator and evidence for a new rotational braking law for Sun-like stars
Leonardo A. dos Santos, Jorge Meléndez, José-Dias do Nascimento +8
It is still unclear how common the Sun is when compared to other similar stars in regards to some of its physical properties, such as rotation. Considering that gyrochronology rela…
High precision analysis of the solar twin HIP 100963
Jhon Yana Galarza, Jorge Meléndez, Ivan Ramírez +3
Methods. We used the HIRES spectrograph on the Keck I telescope to acquire high-resolution (R 70000) spectra with a high signal-to-noise ratio (S/N 400 - 650 pe…
Serendipitous discovery of the faint solar twin Inti 1
Jhon Yana Galarza, Jorge Meléndez, Judith G. Cohen
Methods. We determine the atmospheric parameters and differential abundances using high-resolution (), high signal-to-noise (S/N 110 - 240 per pixel) Ke…
The first high precision differential abundance analysis of Extremely Metal Poor stars
Henrique Reggiani, Jorge Meléndez, David Yong +2
Context: Studies of extremely metal-poor stars indicate that chemical abundance ratios [X/Fe] have an rms scatter as low as 0.05 dex (12 \%). It remains unclear whether this reflec…
Planet signatures and effect of the chemical evolution of the Galactic thin-disk stars
Lorenzo Spina, Jorge Meléndez, Ivan Ramírez
Context: Studies based on high-precision abundance determinations revealed that chemical patterns of solar twins are characterised by the correlation between the differential abund…