Ya. V. Pavlenko
YOU?
Author Swipe
View article: Infrared spectroscopy of V838 Monocerotis in 2015 and 2022
Infrared spectroscopy of V838 Monocerotis in 2015 and 2022 Open
We report medium-resolution 0.85–2.45 $\mu$m spectroscopy obtained in 2015 and 2022 and high-resolution 2.27–2.39 $\mu$m and 4.59–4.77 $\mu$m spectroscopy obtained in 2015 of V838 Monocerotis (V838 Mon), along with modelling of the 0.85–2.…
View article: Detection of Methane in the Closest Extreme Metal-poor T Dwarf WISEA J181006.18−101000.5*
Detection of Methane in the Closest Extreme Metal-poor T Dwarf WISEA J181006.18−101000.5* Open
WISEA J181006.18−101000.5 (WISE1810) is the nearest metal-poor ultracool dwarf to the Sun. It has a low effective temperature and has been classified as an extreme early-T subdwarf. However, methane, the characteristic molecule of the spec…
View article: Detection of Methane in the Closest Extreme Metal-poor T Dwarf WISEA J181006.18-101000.5
Detection of Methane in the Closest Extreme Metal-poor T Dwarf WISEA J181006.18-101000.5 Open
WISEA J181006.18-101000.5 (WISE1810) is the nearest metal-poor ultracool dwarf to the Sun. It has a low effective temperature and has been classified as extreme early-T subdwarf. However, methane, the characteristic molecule of the spectra…
View article: Optical constraints on the coldest metal-poor population
Optical constraints on the coldest metal-poor population Open
The coldest metal-poor population made of T and Y dwarfs are archaeological tracers of our Galaxy because they are very old and have kept the pristine material. The optical properties of these objects are important to characterise their at…
View article: INVESTIGATION OF THE RADIOACTIVE PROMETHIUM LINES IN STELLAR SPECTRA
INVESTIGATION OF THE RADIOACTIVE PROMETHIUM LINES IN STELLAR SPECTRA Open
Eleven lines of promethium Pm II in the spectra of the magnetic peculiar A0 V star HD 25354 were analysed thoroughly in order to obtain information about how the short-lived element lines behave in spectra acquired on different observation…
View article: The Radioactive Elements in the Atmosphere of HD25354—Are They the Result of the Symmetric Decay of the Chemical Elements of the Island of Stability?
The Radioactive Elements in the Atmosphere of HD25354—Are They the Result of the Symmetric Decay of the Chemical Elements of the Island of Stability? Open
In this research, we investigated the observed spectra of the hot peculiar star HD25354 with an effective temperature Teff = 12,800 K, identified the lines of radioactive chemical elements, including the elements with short decay time, and…
View article: Primeval very low-mass stars and brown dwarfs – VIII. The first age benchmark L subdwarf, a wide companion to a halo white dwarf
Primeval very low-mass stars and brown dwarfs – VIII. The first age benchmark L subdwarf, a wide companion to a halo white dwarf Open
We report the discovery of five white dwarf + ultracool dwarf systems identified as common proper motion wide binaries in the Gaia Catalogue of Nearby Stars. The discoveries include a white dwarf + L subdwarf binary, VVV 1256−62AB, a gravi…
View article: Numerical simulations of exocomet transits: Insights from \{beta} Pic and KIC 3542116
Numerical simulations of exocomet transits: Insights from \{beta} Pic and KIC 3542116 Open
In recent years, the topic of existence and exploration of exocomets has been gaining increasing attention. The asymmetrical decrease in the stellar brightness due to the passage of a comet-like object in front of the star was successfully…
View article: Numerical simulations of exocomet transits: Insights from <i>β</i> Pic and KIC 3542116
Numerical simulations of exocomet transits: Insights from <i>β</i> Pic and KIC 3542116 Open
In recent years, the topic of existence and exploration of exocomets has been gaining increasing attention. The asymmetrical decrease in the star’s brightness due to the passage of a comet-like object in front of the star was successfully …
View article: Optical properties of Y dwarfs observed with the Gran Telescopio Canarias
Optical properties of Y dwarfs observed with the Gran Telescopio Canarias Open
Observations of five Y dwarfs with three optical and near-infrared instruments at the 10.4 m Gran Telescopio Canarias are reported. Deep images of the five targets and a low-resolution far-red optical spectrum for one of the targets were o…
View article: Optical properties of Y dwarfs observed with the Gran Telescopio Canarias
Optical properties of Y dwarfs observed with the Gran Telescopio Canarias Open
Aims . Our science goals are to characterise the optical properties of Y dwarfs and to study their consistency with theoretical models. Methods . A sample of five Y dwarfs was observed with three optical and near-infrared instruments at th…
View article: ExoMol line lists -- LIV: Empirical line lists for AlH and AlD and experimental emission spectroscopy of AlD in $A$ $^1Π$ ($v=0, 1, 2$)
ExoMol line lists -- LIV: Empirical line lists for AlH and AlD and experimental emission spectroscopy of AlD in $A$ $^1Π$ ($v=0, 1, 2$) Open
New ExoMol line lists AloHa for AlH and AlD are presented improving the previous line lists WYLLoT (Yurchenko et al., MNRAS 479, 1401 (2018)). The revision is motivated by the recent experimental measurements and astrophysical findings inv…
View article: ExoMol line lists – LIV. Empirical line lists for AlH and AlD and experimental emission spectroscopy of AlD in A1Π (<i>v</i> = 0, 1, 2)
ExoMol line lists – LIV. Empirical line lists for AlH and AlD and experimental emission spectroscopy of AlD in A1Π (<i>v</i> = 0, 1, 2) Open
New ExoMol line lists AloHa for aluminium hydride (AlH and AlD) are presented improving the previous line lists WYLLoT. The revision is motivated by the recent experimental measurements and astrophysical findings involving the highly excit…
View article: Hunting for exocomet transits in the TESS database using the Random Forest method
Hunting for exocomet transits in the TESS database using the Random Forest method Open
This study introduces an approach to detecting exocomet transits in the dataset of the Transiting Exoplanet Survey Satellite (TESS), specifically within its Sector 1. Given the limited number of exocomet transits detected in the observed l…
View article: ExoMol line lists – LI. Molecular line lists for lithium hydroxide (LiOH)
ExoMol line lists – LI. Molecular line lists for lithium hydroxide (LiOH) Open
New molecular line lists for lithium hydroxide (6Li16O1H and 7Li16O1H isotopologues) covering wavelengths λ > 1 $\mu$m (0–10 000 cm−1 range) are presented. Each line list contains around 300 million transitions between rotation–vibratio…
View article: ExoMol line lists -- LI. Molecular line list for lithium hydroxide (LiOH)
ExoMol line lists -- LI. Molecular line list for lithium hydroxide (LiOH) Open
A new molecular line list for lithium hydroxide ($^{7}$Li$^{16}$O$^{1}$H) covering wavelengths $λ> 1 μ$m (the 0-10000 cm$^{-1}$ range) is presented. The OYT7 line list contains over 331 million transitions between rotation-vibration energy…
View article: A blue depression in the optical spectra of M dwarfs
A blue depression in the optical spectra of M dwarfs Open
A blue depression is found in the spectra of M dwarfs from 4000 to 4500 Å. This depression shows an increase towards lower temperatures, though it is particularly sensitive to gravity and metallicity. It is the single strongest and most se…
View article: A blue depression in the optical spectra of M dwarfs
A blue depression in the optical spectra of M dwarfs Open
A blue depression is found in the spectra of M dwarfs from 4000 to 4500A. This depression shows an increase toward lower temperatures though is particularly sensitive to gravity and metallicity. It is the single most sensitive feature in t…
View article: COMPARATIVE ANALYSIS OF OBSERVATIONS OF THE SELECTED EXOPLANET TRANSITS OBTAINED AT THE KYIV COMET STATION WITH THE DATABASE OF THE ORBITAL TELESCOPES TESS AND KEPLER
COMPARATIVE ANALYSIS OF OBSERVATIONS OF THE SELECTED EXOPLANET TRANSITS OBTAINED AT THE KYIV COMET STATION WITH THE DATABASE OF THE ORBITAL TELESCOPES TESS AND KEPLER Open
We present a comparative analysis of observations of the selected exoplanet transits obtained at the Kyiv Comet station with the database of the TESS (Transiting Exoplanet Survey Satellite) and Kepler space telescopes. The light curves obt…
View article: Rise and fall of silicate dust in RS Ophiuchi following the 2006 eruption
Rise and fall of silicate dust in RS Ophiuchi following the 2006 eruption Open
We present an analysis of archival Spitzer InfraRed Spectrograph (IRS) observations of the recurrent nova RS Ophiuchi obtained on several occasions, beginning about 7 months after the outburst in 2006. These data show atomic emission lines…
View article: Rise and fall of silicate dust in RS Ophiuchi following the 2006 eruption
Rise and fall of silicate dust in RS Ophiuchi following the 2006 eruption Open
We present an analysis of archival Spitzer InfraRed Spectrograph (IRS) observations of the recurrent nova RS Ophiuchi obtained on several occasions, beginning about 7 months after the outburst in 2006. These data show atomic emission lines…
View article: AlH lines in the blue spectrum of Proxima Centauri
AlH lines in the blue spectrum of Proxima Centauri Open
The recently computed ExoMol line lists for isotopologues of AlH are used to analyse the blue spectrum (4000–4500 Å) of Proxima Cen (M5.5 V). Comparison of the observed and computed spectra enables the identification of a large number of 2…
View article: AlH lines in the blue spectrum of Proxima Centauri
AlH lines in the blue spectrum of Proxima Centauri Open
The recently-computed ExoMol line lists for isotopologues of AlH are used to analyse the blue spectrum (4000-4500 Å) of Proxima Cen (M5.5 V). Comparison of the observed and computed spectra enables the identification of a large number of 2…
View article: The recurrent nova V3890 Sgr: a near-infrared and optical study of the red giant component and its environment
The recurrent nova V3890 Sgr: a near-infrared and optical study of the red giant component and its environment Open
We present an analysis of the red giant component of the recurrent nova V3890 Sgr, using data obtained before and after its 2019 eruption. Its effective temperature is Teff = 3050 ± 200 K for log g = 0.7, although there are modest changes …
View article: The recurrent nova V3890~Sgr: a near-infrared and optical study of the red giant component and its environment
The recurrent nova V3890~Sgr: a near-infrared and optical study of the red giant component and its environment Open
We present an analysis of the red giant component of the recurrent nova V3890 Sgr, using data obtained before and after its 2019 eruption. Its effective temperature is $T_{\rm eff}=3050\pm$200 K for $\log{g}=0.7$, although there are modest…
View article: New exocomets of β Pic
New exocomets of β Pic Open
Aims. The aim of our work is to analyze the light curves of β Pic which were recently observed by the Transiting Exoplanet Survey Satellite (TESS) in sectors 32, 33, and 34 by searching for the signatures of exocomet transits. Methods. We …
View article: ACTINIUM ABUNDANCES IN STELLAR ATMOSPHERES
ACTINIUM ABUNDANCES IN STELLAR ATMOSPHERES Open
This paper presents a study of radioactive actinium in the atmospheres of stars located in galaxies with different chemical evolution history – namely, Przybylski's Star (HD 101065) in the Milky Way and the red supergiant PMMR27 in the Sma…