We present JWST NIRSpec/PRISM IFU time-resolved observations of 2M1207 A and b (TWA 27), a $\sim 10$ Myr binary system consisting of a $\sim 2500$ K sub-stellar primary hosting a $\sim 1300$ K companion. Our data provide 20 time-resolved spectra over an observation spanning 12.56 hours. We provide an empirical characterization for the spectra of both objects across time. For 2M1207 A, non-linear trend models are statistically favored within the ranges 0.6-2.3 $\mu$m and 3.8-5.3 $\mu$m. However, most of the periods constrained from sinusoidal models exceed the observing window, setting a lower limit of 12.56 hours. We find the data at H$\alpha$ and beyond 4.35 $\mu$m show a moderate time correlation, as well as a pair of light curves at 0.73-0.80 $\mu$m and 3.36-3.38 $\mu$m. For 2M1207 b, light curves integrated across 0.86-1.77 $\mu$m and 3.29-4.34 $\mu$m support linear trend models. Following the interpretation of Zhang et. al. (2025), we model the 2M1207 b data with two 1D atmospheric components, both with silicate and iron condensates. The model of time variability as changes to the cloud filling factor shows broad consistency with the variability amplitudes derived from our data. Our amplitudes, however, disagree with the models at $\approx$0.86-1 $\mu$m. While an additional model component such as rainout chemistry may be considered here, our analysis is limited by a low signal-to-noise ratio. Our results demonstrate the capability of JWST to simultaneously monitor the spectral variability of a planetary-mass companion and host at low contrast.

We present the discovery of a large gradual apparent fading event in optical and near-infrared wavelengths in a quasar at z=1.767 by a factor of 20-30 (in optical) over a period of ~20 years in the observed frame. This pronounced fading trend in brightness was first identified by comparing the magnitudes measured in the Subaru/Hyper Suprime-Cam (HSC) images with those in the Sloan Digital Sky Survey (SDSS) images for ~3x10^4 quasars spectroscopically identified by SDSS. We performed follow-up observations, including optical imaging and spectroscopy as well as near-infrared imaging, with >4m-class telescopes such as Subaru, GTC, Keck, and SOAR telescopes. We combine these new data with the archival data to examine the variability behavior over ~20 years in detail and even the longer-term trend of the variability over ~70 years in the observed frame. We find that (i) the AGN component likely faded by a factor of ~50 from the early 2000s to 2023 and (ii) the observed brightness decline is best explained by a substantial decrease in accretion rate rather than time-varying line-of-sight dust obscuration. These findings are derived from multi-component (time-varying AGN + constant galaxy) spectral energy distribution fitting over multi-epochs, which is well consistent with the optical spectra. The Eddington ratio decreases by a factor of ~50, from ~0.4 to ~0.008 if we use the black hole mass measured with the SDSS spectrum, which could be highly uncertain because of the very large variability. The total brightness is dominated by the host galaxy in the rest-frame optical wavelength rather than the AGN as of 2023.

We report the discovery of two binary systems, each consisting of a slightly bloated G-type main-sequence star and an unseen companion, identified through photometric data from TESS and radial velocity variation from Gaia. High-resolution spectroscopy confirms orbital periods of 1.37 and 2.67 days with circular orbits. The visible components have masses of $\sim 0.9\,M_\odot$, while the minimum masses of the unseen companions are $1.073^{+0.058}_{-0.060} M_\odot$ and $0.919^{+0.049}_{-0.051} M_\odot$, respectively. Assuming tidal synchronization, we estimate the companion masses to be $1.12^{+0.10}_{-0.08} M_\odot$ and $1.02^{+0.15}_{-0.10} M_\odot$. The absence of detectable spectral features from the companions rules out main-sequence stars of these masses, suggesting that the unseen companions are likely O/Ne or C/O massive white dwarfs. The short orbital periods imply that these systems are post-common envelope binaries. Their subsequent evolution is uncertain, with possible outcomes including cataclysmic variables, Type Ia supernovae, or accretion-induced collapse, depending on the nature of future mass transfer.

The ``Neptunian ridge'' is a recently identified peak in the frequency of planets with sizes between that of Neptune and Saturn orbiting their host stars with periods between 3 and 6 days (A. Castro-González et al. 2024). These planets may have formed similarly to their larger, hot Jupiter counterparts in the ``three-day pile-up'', through a dynamically excited migration pathway. The distribution of stellar obliquities in hot Neptune systems may therefore provide a vital clue as to their origin. We report a new stellar obliquity measurement for TOI-2374\,b, a planet in the Neptunian ridge ($P = 4.31$ days, $R_p = 7.5 R_\oplus$). We observed a spectroscopic transit of TOI-2374 b with the Keck Planet Finder, detecting the Rossiter-McLaughlin (RM) anomaly with an amplitude of 3 m/s, and measured a sky-projected obliquity of $\lambda = {81^\circ}^{+23^\circ}_{-22^\circ}$, indicating an orbit significantly misaligned with the spin axis of its host star. A reloaded RM analysis of the cross-correlation functions confirms this misalignment, measuring $\lambda = {65^\circ}^{+32^\circ}_{-24^\circ}$. Additionally, we measured a stellar rotation period of $P_\mathrm{rot} = 26.4^{+0.9}_{-0.8}$ days with photometry from the Tierras observatory, allowing us to deduce the three-dimensional stellar obliquity of $\psi = {85.9^\circ}^{+8.6^\circ}_{-9.2^\circ}$. TOI-2374 b joins a growing number of hot Neptunes on polar orbits. The high frequency of misaligned orbits for Neptunian ridge and desert planets, compared with their longer period counterparts, is reminiscent of patterns seen for the giant planets and may suggest a similar formation mechanism.

Aligning light spots into arbitrary shapes is a fundamental challenge in holography, leading to various applications across diverse fields in science and engineering. However, as the spot interval approaches the wavelength of light, interference effects among the spots become prominent, which complicates the generation of a distortion-free alignment. Herein, we introduce a hologram design method based on the optimisation of a nonlinear cost function using a holographic phase pattern as the optimisation parameter. We confirmed a spot interval of 0.952(1) $\mu$m in a $5 \times 5$ multispot pattern on the focal plane of a high-numerical-aperture (0.75) objective by observing the near-infrared (wavelength: 820 nm) holographic output light from a spatial light modulator device, a result which overcomes the limitation of a few micrometres under similar conditions. Furthermore, the definition of the Rayleigh diffraction limit is refined by considering the separation of spots and the spot interval, thereby concluding the achievement of "super-resolution." The proposed method is expected to advance laser fabrication, scanning laser microscopy, and cold atom physics, among other fields.

Characterizing the atmospheres of exoplanets and brown dwarfs is crucial for understanding their atmospheric physics and chemistry, searching for biosignatures, and investigating their formation histories. Recent advances in observational techniques, combining adaptive optics with high-resolution spectrographs, have enabled detailed spectroscopic analysis for directly imaged faint companions. In this paper, we report an atmospheric retrieval on the L-type brown dwarf HR 7672 B using a near-infrared high-contrast high-resolution spectrograph, REACH (Y, J, H band, $R\sim100,000$), which combines SCExAO with IRD at the Subaru Telescope. Our model, developed based on the ExoJAX spectrum code, simultaneously accounts for several factors, including the presence of clouds in the L dwarf's atmosphere as well as contamination from the host star's light and telluric absorption lines in the observed spectra. Our analysis identified H2O and FeH as the primary absorbers in the observed J- and H-band spectra. Additionally, the observed features were reproduced with a model that includes cloud opacity, assuming an optically thick cloud at the pressure $P_\mathrm{top}$. The resulting temperature at the cloud top pressure suggests the potential formation of clouds composed of TiO2, Al2O3, or Fe. This study is the first science demonstration for faint spectra obtained by REACH, providing a foundation for future investigations into the atmospheres of exoplanets and brown dwarfs.

We report the discovery of a new directly-imaged brown dwarf companion with Keck/NIRC2+pyWFS around a nearby mid-type M~dwarf LSPM~J1446+4633 (hereafter J1446). The $L'$-band contrast ($4.5\times10^{-3}$) is consistent with a $\sim20-60\ M_{\rm Jup}$ object at 1--10~Gyr and our two-epoch NIRC2 data suggest a $\sim30\%$ ($\sim3.1\sigma)$ variability in its $L'$-band flux. We incorporated Gaia DR3 non-single-star catalog into the orbital fitting by combining the Subaru/IRD RV monitoring results, NIRC2 direct imaging results, and Gaia proper motion acceleration. As a result, we derive ${59.8}_{-1.4}^{+1.5}\ M_{\rm Jup}$ and $\approx4.3~{\rm au}$ for the dynamical mass and the semi-major axis of the companion J1446B, respectively. J1446B is one of the intriguing late-T~dwarfs showing variability at $L'$-band for future atmospheric studies with the constrained dynamical mass. Because the J1446 system is accessible with various observation techniques such as astrometry, direct imaging, and high-resolution spectroscopy including radial velocity measurement, it has a potential as a great benchmark system to improve our understanding for cool dwarfs.

We present laboratory results from supercritical, magnetized collisionless shock experiments ($M_A \lesssim 10$, $\beta\sim 1$). We report the first observation of fully-developed shocks ($R=4$ compression ratio and a downstream region decoupled from the piston) after seven upstream ion gyration periods. A foot ahead of the shock exhibits super-adiabatic electron and ion heating. We measure the electron temperature $T_e = 115$ eV and ion temperature $T_i = 15$ eV upstream of the shock; whereas, downstream, we measure $T_e=390$ eV and infer $T_i=340$ eV, consistent with both Thomson scattering ion-acoustic wave spectral broadening and Rankine-Hugoniot conditions. The downstream electron temperature has a $30$-percent excess from adiabatic and collisional electron-ion heating, implying significant collisionless anomalous electron heating. Furthermore, downstream electrons and ions are in equipartition, with a unity electron-ion temperature ratio $T_e/T_i = 1.2$.

The V1298 Tau system (20-30Myr), is a benchmark young multi-planet system that provides the opportunity to perform comparative exoplanetology between planets orbiting the same star right after their formation. We present the first atmospheric comparison between two planets in the same transiting system: V1298 Tau b and V1298 Tau c. We derive constraints on the mass of planet b and c (<20M$_\oplus$ at 3$\sigma$ confidence level and $17_{-6}^{+13} M_{\oplus}$ respectively) and atmospheric metallicity (logZ/Z$_\odot$=-2.04$_{-0.59}^{0.69}$, -0.16$_{-0.94}^{1.15}$ respectively) from atmospheric retrievals. The V1298 Tau planets, are likely to be similar in terms of mass at the current age, implying that both planets are potential sub-Neptune/super-Earth progenitors. However, planet c is expected to lose a higher fraction of its mass compared to planet b given its close proximity to the host star. Alternatively, the observed spectrum of planet c can be explained by atmospheric hazes, which is in contrast to planet b where efficient haze formation can be ruled out. Higher haze formation efficiency in planet c could be due to differences in atmospheric composition, temperature and higher UV flux incident compared to planet b.

Japan Astrometry Satellite Mission for INfrared Exploration (JASMINE) is a planned M-class science space mission by the Institute of Space and Astronautical Science, the Japan Aerospace Exploration Agency. JASMINE has two main science goals. One is the Galactic archaeology with Galactic Center Survey, which aims to reveal the Milky Way's central core structure and formation history from Gaia-level (~25 $\mu$as) astrometry in the Near-Infrared (NIR) Hw-band (1.0-1.6 $\mu$m). The other is the Exoplanet Survey, which aims to discover transiting Earth-like exoplanets in the habitable zone from NIR time-series photometry of M dwarfs when the Galactic center is not accessible. We introduce the mission, review many science objectives, and present the instrument concept. JASMINE will be the first dedicated NIR astrometry space mission and provide precise astrometric information of the stars in the Galactic center, taking advantage of the significantly lower extinction in the NIR. The precise astrometry is obtained by taking many short-exposure images. Hence, the JASMINE Galactic center survey data will be valuable for studies of exoplanet transits, asteroseismology, variable stars and microlensing studies, including discovery of (intermediate mass) black holes. We highlight a swath of such potential science, and also describe synergies with other missions.

Despite the wide range of planet-star (mis)alignments in the mature population of transiting exoplanets, the small number of known young transiting planets are nearly all aligned with the rotation axes of their host stars, as determined by the sky-projected obliquity angle. The small number of young systems with measured obliquities limits statistical conclusions. Here we determine the sky-projected obliquity ($\lambda$) of the 3 Myr transiting planet with a misaligned outer protoplanetary disk, TIDYE-1 b (IRAS 04125+2902 b), using the Rossiter-McLaughlin (RM) effect. Our dataset lacks a pre-transit baseline and ingress, complicating a blind RM fit. Instead, we use contemporaneous spectra and photometry from a mass-measurement campaign to model the stellar activity trend across the transit and provide an external prior on the velocity baseline. We determine $|\lambda|=11.8^{+5.9\,\circ}_{-5.0}$. Combined with the published rotational velocity of the star, we find a true three-dimensional obliquity of $\psi=15.2^{+7.3\,\circ}_{-5.7}$. Our result is consistent with an aligned orbit, suggesting the planet remains aligned to its star even though the outer disk is misaligned, though additional RM observations are needed to exclude the low-probability tail of misaligned ($>30^{\circ}$) scenarios present in our posterior.

During cosmic noon ($z\sim1-3$), when both star formation and black hole growth peaked, galaxy mergers are predicted to trigger dual active galactic nuclei (AGN) that eventually coalesce as supermassive black hole (SMBH) binaries. However, observations of dual quasars with sub-5 kpc separations-the critical phase preceding final coalescence-have remained elusive due to angular resolution limitations. We present the discovery and confirmation of two sub-arcsecond dual quasars at $z>1$, selected from 59,025 SDSS quasars, which fall within the footprint of the Hyper Suprime-Cam Survey. Using high-resolution Hubble Space Telescope (HST) imaging and slitless spectroscopy, we confirmed SDSS J1625+4309 ($z=1.647$, separation 0.55"/4.7 kpc) and SDSS J0229$-$0514 ($z=3.174$, separation 0.42"/3.2 kpc), probing the sub-5 kpc separation regime. Through novel combination of WFC3/IR direct imaging (F140W) and grism spectroscopy (G141), we resolve both components morphologically and spectroscopically confirm their dual nature via detection of H$\beta$+[OIII] and MgII emission lines in each nucleus. Two-dimensional image decomposition reveals distinct host galaxy morphologies: J1625+4309 shows an extended, disturbed structure ($R_e$=4.7 kpc) indicative of an ongoing major merger, while J0229$-$0514 exhibits a compact host ($R_e$=1.4 kpc) suggesting an advanced coalescence stage. Black hole mass estimates based on virial relations yield M$_{\mathrm{BH}} \sim 10^{8.1}-10^{8.7} M_\odot$ with line-of-sight velocity offsets of $(0.7\pm0.1)\times10^{3}$ km s$^{-1}$ and $(1.0\pm0.2)\times10^{3}$ km s$^{-1}$, respectively. These confirmations directly constrain the frequency and properties of close dual quasars, opening new avenues for studying SMBH mergers at cosmic noon.

The different spatial distributions of N-bearing and O-bearing species, as is well known towards Orion~KL, is one of the long-lasting mysteries. We conducted a survey observation and chemical modeling study to investigate if the different distributions of O- and N-bearing species are widely recognized in general star-forming regions. First, we report our observational results of complex organic molecules (COMs) with the 45~m radio telescope at the Nobeyama Radio Observatory towards eight star-forming regions. Through our spectral survey ranging from 80 to 108~GHz, we detected CH$_3$OH, HCOOCH$_3$, CH$_3$OCH$_3$, (CH$_3$)$_2$CO, CH$_3$CHO, CH$_3$CH$_2$CN, CH$_2$CHCN, and NH$_2$CHO. Their molecular abundances were derived via the rotation diagram and the least squares methods. We found that N-bearing molecules, tend to show stronger correlations with other N-bearing molecules rather than O-bearing molecules. While G10.47+0.03 showed high fractional abundances of N-bearing species, those in NGC6334F were not so rich, being less than 0.01 compared to CH$_3$OH. Then, the molecular abundances towards these sources were evaluated by chemical modeling with NAUTILUS three-phase gas-grain chemical code. Through the simulations of time evolutions for the abundances of COMs, we suggest that observed correlations of fractional abundances between COMs can be explained by the combination of the different temperature structures inside the hot cores and the different evolutionary phase. Since our modeling could not fully explain the observed excitation temperatures, it is important to investigate the efficiency of grain surface reactions and their activation barriers, and the binding energy of COMs to further promote our understanding.

We present a detailed analysis of HARPS-N radial velocity observations of K2-100, a young and active star in the Praesepe cluster, which hosts a transiting planet with a period of 1.7 days. We model the activity-induced radial velocity variations of the host star with a multi-dimensional Gaussian Process framework and detect a planetary signal of $10.6 \pm 3.0 {\rm m\,s^{-1}}$, which matches the transit ephemeris, and translates to a planet mass of $21.8 \pm 6.2 M_\oplus$. We perform a suite of validation tests to confirm that our detected signal is genuine. This is the first mass measurement for a transiting planet in a young open cluster. The relatively low density of the planet, $2.04^{+0.66}_{-0.61} {\rm g\,cm^{-3}}$, implies that K2-100b retains a significant volatile envelope. We estimate that the planet is losing its atmosphere at a rate of $10^{11}-10^{12}\,{\rm g\,s^{-1}}$ due to the high level of radiation it receives from its host star.

We propose and implement a protocol to measure the state-dependent motion of Rydberg atoms induced by dipole-dipole interactions. Our setup enables simultaneous readout of both the atomic internal state and position on a one-dimensional array of optical tweezers. We benchmark the protocol using two atoms in the same Rydberg state, which experience van der Waals repulsion, and measure velocities in agreement with theoretical predictions. When preparing the atoms in a different pair state, we observe an oscillatory dynamics that we attribute to the proximity of a macrodimer bound state. Finally, we perform a Stern-Gerlach-like experiment in which a superposition of the two previous pair states results in the separation of the atomic wavepacket into two macroscopically distinct trajectories, thereby demonstrating spin-motion coupling mediated by the interactions.