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We have used the HARPS-North high resolution spectrograph ($\mathcal{R}$=115 000) at TNG to observe one transit of the highly irradiated planet MASCARA-2b/KELT-20b. Using only one transit observation, we are able to clearly resolve the…

We present NLTE abundances and atmospheric parameters for three metal-poor stars ([Fe/H]<-2) in Coma Berenices ultra-faint dwarf galaxy (UFD). The derived results are based on new photometric observations obtained with the 2.5-m telescope…

Solar and Stellar Astrophysics · Physics 2018-12-05 Tatyana Sitnova , Lyudmila Mashonkina , Andrey Tatarnikov , Olga Voziakova , Marina Burlak , Yuriy Pakhomov

We measured the system-integrated thermal emission of the binary Kuiper Belt Object 1999 TC36 at wavelengths near 24 and 70 microns using the Spitzer space telescope. We fit these data and the visual magnitude using both the Standard…

We present a detailed investigation of SBS1150+599A, a close binary star hosted by the planetary nebula PN G135.9+55.9 (TS01, Stasinska et al, 2009). The nebula, located in the Galactic halo, is the most oxygen-poor one known to date and is…

In a well-aimed search based on the recently published Gaia~DR2 radial velocity data and performed with the robotic TIGRE telescope, we have discovered 19 bright ($m_V<7.66$~mag) spectroscopic binary stars. We present the radial velocity…

Solar and Stellar Astrophysics · Physics 2020-10-07 Dennis Jack , Missael Alejandro Hernández Huerta , Klaus-Peter Schröder

Deriving stellar atmospheric parameters and chemical abundances from stellar spectra is crucial for understanding the evolution of the Milky Way. By performing a fitting with MARCS model atmospheric theoretical synthetic spectra combined…

Solar and Stellar Astrophysics · Physics 2023-06-28 Rui Wang , A-Li Luo , Shuo Zhang , Yuan-Sen Ting , Teaghan O'Briain , LAMOST MRS Collaboration

Transmission spectroscopy presents one of the most successful approaches for investigating the atmospheres of exoplanets. We analyzed the near-infrared high-resolution transmission spectrum of a hot Saturn, HD 149026 b, taken using CARMENES…

Earth and Planetary Astrophysics · Physics 2024-07-02 Sayyed A. Rafi , Stevanus K. Nugroho , Motohide Tamura , Lisa Nortmann , Alejandro Sánchez-López

We present follow-up photometry and spectroscopy of ZTF J0328$-$1219 strengthening its status as a white dwarf exhibiting transiting planetary debris. Using TESS and Zwicky Transient Facility photometry, along with follow-up high speed…

A spectroscopic analysis of SDSS J160043.6+074802.9, a binary system containing a pulsating subdwarf-O (sdO) star with a late-type companion, yields Teff = 70 000 +/- 5000 K and log g = 5.25 +/- 0.30, together with a most likely type of K3V…

Solar and Stellar Astrophysics · Physics 2015-05-14 C. Rodríguez-López , A. E. Lynas-Gray , D. Kilkenny , J. MacDonald , A. Moya , C. Koen , P. A. Woudt , D. J. Wium , B. Oruru , E. Zietsman

Eclipsing binaries serve as a valuable source of stellar masses and radii that inform stellar evolutionary models and provide insight into additional astrophysical processes. The exquisite light curves generated by space-based missions such…

Solar and Stellar Astrophysics · Physics 2016-05-25 Rachel A. Matson , Douglas R. Gies , Zhao Guo , Jerome A. Orosz

We obtained a high-resolution VLT-UVES spectrum of the quasar Q2348-011 over a wavelength range that covers most of the prominent metal and molecular absorption lines from the log N(HI)=20.50+-0.10 damped Lyman-alpha system at zabs=2.43.…

Astrophysics · Physics 2009-11-13 P. Noterdaeme , P. Petitjean , R. Srianand , C. Ledoux , F. Le Petit

CONTEXT: Thermal emission from extrasolar planets makes it possible to study important physical processes in their atmospheres and derive more precise orbital elements. AIMS: By using new near infrared and optical data, we examine how these…

Earth and Planetary Astrophysics · Physics 2022-08-10 G. Kovacs , I. Dekany , B. Karamiqucham , G. Chen , G. Zhou , M. Rabus , T. Kovacs

We present techniques for the estimation of stellar atmospheric parameters (Teff,logg,[Fe/H]) for stars from the SDSS/SEGUE survey. The atmospheric parameters are derived from the observed medium-resolution (R=2000) stellar spectra using…

The chemical abundance of the interstellar medium sets the initial conditions for star formation and provides a probe of chemical galaxy evolution models. However, unresolved inhomogeneities in the electron temperature can lead to a…

UVES spectra of the very young (~10^7 years) peculiar B-type star HR 6000 were analyzed in the near-UV and visual spectral regions (3050-9460 A) with the aim to extend to other spectral ranges the study made previously in the UV using IUE…

Astrophysics · Physics 2009-11-13 F. Castelli , S. Hubrig

To search for and study the instabilities in the atmospheres of selected post-AGB stars, we have performed a long-term high-resolution spectroscopy (R=60000) with the spectrograph NES of the 6-meter BTA telescope. Low-amplitude pulsations,…

Solar and Stellar Astrophysics · Physics 2025-02-05 Valentina G. Klochkova , Vladimir E. Panchuk , Nonna S. Tavolzhanskaya , Maksim V. Yushkin

We present the analysis of four new extremely metal poor turn-off stars thanks to high-resolution spectra obtained with the Subaru/HDS spectrograph. We determined the abundances and upper limits of Li, C, Mg, Ca, Sr, and Ba. Metallicities…

Solar and Stellar Astrophysics · Physics 2025-07-01 Takuma Suda , Patrick Francois , Shinya Wanajo , Elisabetta Caffau , Wako Aoki , Piercarlo Bonifacio

M dwarfs are prominent targets of planet search projects, and their chemical composition is crucial to understanding the formation process or interior of orbiting exoplanets. However, measurements of elemental abundances of M dwarfs have…

Solar and Stellar Astrophysics · Physics 2020-12-30 Hiroyuki Tako Ishikawa , Wako Aoki , Takayuki Kotani , Masayuki Kuzuhara , Masashi Omiya , Ansgar Reiners , Mathias Zechmeister

We present constraints on the deuterium to hydrogen ratio (D/H) in the metal-poor gas cloud at redshift $z=0.701$ towards QSO 1718+4807. We use new Keck spectra in addition to Hubble Space Telescope (HST) and International Ultraviolet…

Astrophysics · Physics 2009-10-31 David Tytler , Scott Burles , Limin Lu , Xiao-Ming Fan , Arthur Wolfe , Blair D. Savage