掲載種別：研究論文（学術雑誌）  

DOI： 10.1051/0004-6361/202449449

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Oxford University Press ({OUP})  

<jats:title>ABSTRACT</jats:title>
<jats:p>The characterization of exoplanet atmospheres has proven to be successful using high-resolution spectroscopy. Phase curve observations of hot/ultra-hot Jupiters can reveal their compositions and thermal structures, thereby allowing the detection of molecules and atoms in the planetary atmosphere using the cross-correlation technique. We present pre-eclipse observations of the ultra-hot Jupiter, MASCARA-1b, observed with the recently upgraded CRIRES+ high-resolution infrared spectrograph at the VLT. We report a detection of Fe (≈ 8.3σ) in the K-band and confirm previous detections of CO (&amp;gt;15σ) and H2O (&amp;gt;10σ) in the day-side atmosphere of MASCARA-1b. Using a Bayesian inference framework, we retrieve the abundances of the detected species and constrain planetary orbital velocities, T–P profiles, and the carbon-to-oxygen ratio (C/O). A free retrieval results in an elevated CO abundance ($\log _{10}(\chi _{\rm { { }^{12}CO } }) = -2.85^{+0.57}_{-0.69}$), leading to a supersolar C/O ratio. More realistically, allowing for vertically-varying chemistry in the atmosphere by incorporating a chemical-equilibrium model results in a C/O of $0.68^{+0.12}_{-0.22}$ and a metallicity of $[\rm M/H] = 0.62^{+0.28}_{-0.55}$, both consistent with solar values. Finally, we also report a slight offset of the Fe feature in both Kp and vsys that could be a signature of atmospheric dynamics. Due to the 3D structure of exoplanet atmospheres and the exclusion of time/phase dependence in our 1D forward models, further follow-up observations and analysis are required to confirm or refute this result.</jats:p>

DOI： 10.1093/mnras/stad2476

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掲載種別：研究論文（学術雑誌）  

DOI： 10.3847/1538-3881/acdb75

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掲載種別：研究論文（学術雑誌）  

DOI： 10.3847/1538-3881/acbd39

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Oxford University Press ({OUP})  

<jats:title>ABSTRACT</jats:title>
<jats:p>Recent progress in high-resolution transmission spectroscopy has offered new avenues in which to characterize the atmospheres of transiting exoplanets. High-resolution cross-correlation spectroscopy allows for the unambiguous detection of molecules/atoms. It has also been used to map both atmospheric dynamics and longitudinal variations in the abundance of species across the morning and evening limbs. We present multiple Very Large Telescope (VLT)/Echelle SPectrograph for Rocky Exoplanets and Stable Spectroscopic Observations (ESPRESSO) observations of the ultrahot Jupiter WASP-121b, from which we constrain relative abundances of various neutral metals consistently across all observations, whilst accounting for the distortion of the exoplanet’s signal caused by traditional data processing techniques. We also constrain planetary orbital velocities and T–P profiles. We compare our abundance constraints with previous constraints using VLT/Ultraviolet and Visual Echelle Spectrograph (UVES) transmission spectroscopy of WASP-121b, and find our results to be consistent between observations, and also in agreement with stellar values for species previously detected in the atmosphere of WASP-121b. Our retrieval framework can also be used to identify potential exospheric species, resulting in extended absorption features beyond the transit equivalent Roche limit of WASP-121b (ReqRL ∼ 1.3 Rp). Hα, Fe ii, and Ca ii were found to extend to high altitudes (1.54 ± 0.04 Rp, 1.17 ± 0.01 Rp, and 2.52 ± 0.34 Rp, respectively), which are broadly consistent with literature values. The consistency of our constraints across multiple high-resolution observations is a strong validation of our model filtering and retrieval framework, as well as the stability of the atmosphere over the time-scales of months/years, and could allow for planet formation processes to be inferred from future ground-based observations of exoplanetary atmospheres.</jats:p>

DOI： 10.1093/mnras/stac3388

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Oxford University Press ({OUP})  

<jats:title>Abstract</jats:title>
<jats:p>We report the near-infrared radial velocity (RV) discovery of a super-Earth planet on a 10.77 d orbit around the M4.5 dwarf Ross 508 (Jmag = 9.1). Using precision RVs from the Subaru Telescope IRD (InfraRed Doppler) instrument, we derive a semi-amplitude of $3.92^{+0.60}_{-0.58}\:\mbox{m}\:{\mbox{s}^{-1 } }$, corresponding to a planet with a minimum mass $m \sin i = 4.00^{+0.53}_{-0.55}\, M_{\oplus }$. We find no evidence of significant signals at the detected period in spectroscopic stellar activity indicators or MEarth photometry. The planet, Ross 508 b, has a semi-major axis of $0.05366^{+0.00056}_{-0.00049}\:$au. This gives an orbit-averaged insolation of ≈1.4 times the Earth’s value, placing Ross 508 b near the inner edge of its star’s habitable zone. We have explored the possibility that the planet has a high eccentricity and its host is accompanied by an additional unconfirmed companion on a wide orbit. Our discovery demonstrates that the near-infrared RV search can play a crucial role in finding a low-mass planet around cool M dwarfs like Ross 508.</jats:p>

DOI： 10.1093/pasj/psac044

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：The American Astronomical Society  

DOI： 10.3847/1538-3881/ac5f4d

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Oxford University Press ({OUP})  

<jats:title>ABSTRACT</jats:title>
<jats:p>High-resolution Doppler-resolved spectroscopy has presented new opportunities for studying the atmospheres of exoplanets. While the ‘classical’ cross-correlation approach has proven to be efficient at finding atmospheric species, it is unable to perform direct atmospheric retrievals. Recent work has shown that retrievals are possible using a direct likelihood evaluation or likelihood ‘mappings’. The unique aspect of high-resolution retrievals is that the data-processing methods required to remove the stellar and telluric lines also distort the underlying exoplanet’s signal and therefore the forward model must be pre-processed to match this filtering. This was the key remaining limitation in our previously published framework. This paper directly addresses this by introducing a simple and fast model-filtering technique that can replicate the processing performed by algorithms such as SysRem and PCA. This enables retrievals to be performed without having to perform expensive injection and pre-processing steps for every model. We show that we can reliably constrain quantitative measures of the atmosphere from transmission spectra including the temperature–pressure profile, relative abundances, planetary velocities, and rotational broadening parameters. Finally, we demonstrate our framework using UVES transmission spectroscopy of WASP-121b. We constrain the temperature–pressure profile and relative abundances of Fe, Cr, and V to be log10(χFe/χCr) = 1.66 ± 0.28, log10(χFe/χV) = 3.78 ± 0.29, and log10(χFe/χMg) = −1.26 ± 0.60. The relative abundances are consistent with solar values, with the exception of Fe/Mg, where the large Mg abundance is probably explained by the escaping atmosphere of WASP-121b that is not accounted for in our atmospheric model.</jats:p>

DOI： 10.1093/mnras/stac091

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Oxford University Press ({OUP})  

DOI： 10.1093/mnras/stab1878

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掲載種別：研究論文（学術雑誌）   出版者・発行元：American Astronomical Society  

DOI： 10.3847/1538-3881/abdb25

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：American Astronomical Society  

DOI： 10.3847/2041-8213/abec71

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arXiv

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：EDP Sciences  

DOI： 10.1051/0004-6361/202039135

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IOP Publishing Ltd.  

DOI： 10.3847/2041-8213/aba4b6

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Oxford University Press  

DOI： 10.1093/mnras/staa1459

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arXiv

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：EDP Sciences  

DOI： 10.1051/0004-6361/201937409

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arXiv

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Oxford University Press ({OUP})  

DOI： 10.1093/mnras/staa228

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掲載種別：研究論文（学術雑誌）  

DOI： 10.3847/1538-3881/aa9433

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掲載種別：研究論文（学術雑誌）  

All photometric data reported in this paper were obtained through CCD imaging obtained over more than 50 partial nights comprising a total of more than 20000 useful CCD frames. Table 1 gives the journal of observations. <P />Heliocentric Julian Date, differential magnitudes y_s,b_s,v_s,u_s in the standard system, and instrumental differential magnitudes y_i,b_i,v_i,u_i. <P />(4 data files). <P />...

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掲載種別：研究論文（学術雑誌）  

Based on more than 50 partial nights of CCD monitoring, we derive 118 new times of maximum light of the SX Phoenicis star CY Aquarii. These times support a linear ephemeris for 2013-2015....

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