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Exoplanets that receive stellar irradiance of approximately Earth's or less have been discovered and many are suitable for spectral characterization. Here we focus on the temperate planets that have massive H2-dominated atmospheres, and…

Earth and Planetary Astrophysics · Physics 2021-11-03 Renyu Hu

Using the Green Bank 100 m telescope and the Nobeyama 45 m telescope, we have observed the rotational emission lines of the three 13C isotopic species of HC3N in the 3 and 7 mm bands toward the low-mass star-forming region L1527 in order to…

Solar and Stellar Astrophysics · Physics 2016-12-28 Mitsunori Araki , Shuro Takano , Nami Sakai , Satoshi Yamamoto , Takahiro Oyama , Nobuhiko Kuze , Koichi Tsukiyama

The variations of elemental abundance and their ratios along the Galactocentric radius result from the chemical evolution of the Milky Way disks. The $\rm ^{12}C/^{13}C$ ratio in particular is often used as a proxy to determine other…

Hot giant exoplanets are very exotic objects with no equivalent in the Solar System that allow us to study the behavior of atmospheres under extreme conditions. Their thermal and chemical day--night dichotomies associated with extreme wind…

Earth and Planetary Astrophysics · Physics 2023-01-31 William Pluriel

The gas and solid-state C/O ratios provide context to potentially link the atmospheric composition of planets to that of the natal disk. We provide a synthesis of extant estimates of the gaseous C/O and C/H ratios in planet-forming disks…

Earth and Planetary Astrophysics · Physics 2024-06-19 Edwin A. Bergin , Richard A. Booth , Maria Jose Colmenares , John D. Ilee

T-type brown dwarfs present an opportunity to explore atmospheres teeming with molecules such as H2O, CH4 and NH3, which exhibit a wealth of absorption features in the mid-infrared. With JWST, we can finally explore this chemistry in…

Detections of extragalactic $^{15}$N are reported from observations of the rare hydrogen cyanide isotope HC$^{15}$N toward the Large Magellanic Cloud (LMC) and the core of the (post-) starburst galaxy NGC 4945. Accounting for optical depth…

Astrophysics · Physics 2009-10-31 Yi-nan Chin , Christian Henkel , Norbert Langer , Rainer Mauersberger

Atmospheric temperature and planetary gravity are thought to be the main parameters affecting cloud formation in giant exoplanet atmospheres. Recent attempts to understand cloud formation have explored wide regions of the equilibrium…

Carbon containing molecules in cold molecular clouds show various levels of isotopic fractionation through multiple observations. To understand such effects, we have developed a new gas-grain chemical model with updated 13C fractionation…

Astrophysics of Galaxies · Physics 2020-10-07 Jean-Christophe Loison , Valentine Wakelam , Pierre Gratier , Kevin M. Hickson

High-resolution spectroscopy (HRS) has grown into one of the main techniques to characterise the atmospheres of extrasolar planets. High spectral resolving power allows for the efficient removal of telluric and host-star contamination.…

Earth and Planetary Astrophysics · Physics 2025-05-15 Ignas Snellen

This White Paper describes the opportunities for discovery of Jupiter-mass objects with 300K atmospheres. The discovery and characterization of such cold objects is vital for understanding the low-mass terminus of the initial mass function…

We present a detailed study of the physical properties of the nebular material in four star-forming knots of the blue compact dwarf galaxy Haro 15. Using long-slit and echelle spectroscopy obtained at Las Campanas Observatory, we study the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Guillermo F. Hagele , Veronica Firpo , Guillermo Bosch , Angeles I. Diaz , Nidia Morrell

Measuring the chemical and isotopic compositions of gas giants and brown dwarfs provides insights into their formation pathways and birth environments. 2MASS J0249-0557 c is an L2-type planetary mass companion ($\sim 12 M_{\mathrm{Jup}}$)…

Earth and Planetary Astrophysics · Physics 2026-05-05 Yurou Liu , Yapeng Zhang , Jerry W. Xuan , Dimitri Mawet , Ignas Snellen , Rico Landman , Tomas Stolker , Sam de Regt , Aurora Kesseli , Malena Rice

With four giant planets ($m\sim5-10~M_{\rm Jup}$, $T_\rm{eff}\sim900-1200$ K) orbiting between 15-70 au, HR 8799 provides an unparalleled testbed for studying giant planet formation and probing compositional trends across the protoplanetary…

In this work we present the main atmospheric parameters, carbon, nitrogen and oxygen abundances, and 12C/13C ratios determined in a sample of 28 Galactic clump stars. Abundances of carbon were studied using the C2 band at 5086.2 {\AA}. The…

Astrophysics of Galaxies · Physics 2013-04-17 G. Tautvaišienė , G. Barisevičius , Y. Chorniy , I. Ilyin , E. Puzeras

Precise measurements of the fundamental properties of low-mass stars and brown dwarfs are key to understanding the physics underlying their formation and evolution. While there has been great progress over the last decade in studying the…

We present here the analysis of 30 gaseous extrasolar planets, with temperatures between 600 and 2400 K and radii between 0.35 and 1.9 $R_\mathrm{Jup}$. The quality of the HST/WFC3 spatially scanned data combined with our specialized…

Earth and Planetary Astrophysics · Physics 2018-03-20 A. Tsiaras , I. P. Waldmann , T. Zingales , M. Rocchetto , G. Morello , M. Damiano , K. Karpouzas , G. Tinetti , L. K. McKemmish , J. Tennyson , S. N. Yurchenko

Mass, radius, and age are three of the most fundamental parameters for celestial objects, enabling studies of the evolution and internal physics of stars, brown dwarfs, and planets. Brown dwarfs are hydrogen-rich objects that are unable to…

We present the results of a study aimed at determining the 12C/13C ratio in two samples of planetary nebulae (PNe) by means of millimeter wave observations of 12CO and 13CO. The first group includes six PNe which have been observed in the…

Astrophysics · Physics 2007-05-23 F. Palla , R. Bachiller , L. Stanghellini , M. Tosi , D. Galli

Despite a rich observational background, few spectroscopic studies have dealt with the measurement of the carbon isotopic ratio in giant stars. However, it is a key element in understanding the mixing mechanisms that occur in the interiors…

Solar and Stellar Astrophysics · Physics 2023-12-14 N. Lagarde , R. Minkeviciute , A. Drazdauskas , G. Tautvaisiene , C. Charbonnel , C. Reylé , A. Miglio , T. Kushwahaa , B. Bale
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