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Measurements of the atmospheric carbon (C) and oxygen (O) relative to hydrogen (H) in hot Jupiters (relative to their host stars) provide insight into their formation location and subsequent orbital migration 1 , 2 . Hot Jupiters that form beyond the major volatile (H 2 O/CO/CO 2 ) ice lines and subsequently migrate post disk-dissipation are predicted have atmospheric carbon-to-oxygen ratios (C/O) near 1 and subsolar metallicities 2 , whereas planets that migrate through the disk before dissipation are predicted to be heavily polluted by infalling O-rich icy planetesimals, resulting in C/O < 0.5 and super-solar metallicities 1 , 2 . Previous observations of hot Jupiters have been able to provide bounded constraints on either H 2 O (refs. 3 – 5 ) or CO (refs. 6 , 7 ), but not both for the same planet, leaving uncertain 4 the true elemental C and O inventory and subsequent C/O and metallicity determinations. Here we report spectroscopic observations of a typical transiting hot Jupiter, WASP-77Ab. From these, we determine the atmospheric gas volume mixing ratio constraints on both H 2 O and CO (9.5 × 10 −5 –1.5 × 10 −4 and 1.2 × 10 −4 –2.6 × 10 −4 , respectively). From these bounded constraints, we are able to derive the atmospheric C/H ( 0.35 − 0.10 + 0.17  × solar) and O/H ( 0.32 − 0.08 + 0.12  × solar) abundances and the corresponding atmospheric carbon-to-oxygen ratio (C/O = 0.59 ± 0.08; the solar value is 0.55). The sub-solar (C+O)/H ( 0.33 − 0.09 + 0.13  × solar) is suggestive of a metal-depleted atmosphere relative to what is expected for Jovian-like planets 1 while the near solar value of C/O rules out the disk-free migration/C-rich 2 atmosphere scenario. The C/O ratio of the transiting hot Jupiter WASP-77Ab is measured here and found to be approximately solar, though the (C+O)/H ratio is subsolar.

The formation of galaxies by gradual hierarchical co-assembly of baryons and cold dark matter halos is a fundamental paradigm underpinning modern astrophysics 1 , 2 and predicts a strong decline in the number of massive galaxies at early cosmic times 3 – 5 . Extremely massive quiescent galaxies (stellar masses of more than 10 11   M ⊙ ) have now been observed as early as 1–2 billion years after the Big Bang 6 – 13 . These galaxies are extremely constraining on theoretical models, as they had formed 300–500 Myr earlier, and only some models can form massive galaxies this early 12 , 14 . Here we report on the spectroscopic observations with the JWST of a massive quiescent galaxy ZF-UDS-7329 at redshift 3.205 ± 0.005. It has eluded deep ground-based spectroscopy 8 , it is significantly redder than is typical and its spectrum reveals features typical of much older stellar populations. Detailed modelling shows that its stellar population formed around 1.5 billion years earlier in time ( z ≈ 11) at an epoch when dark matter halos of sufficient hosting mass had not yet assembled in the standard scenario 4 , 5 . This observation may indicate the presence of undetected populations of early galaxies and the possibility of significant gaps in our understanding of early stellar populations, galaxy formation and the nature of dark matter. A massive galaxy observed with the JWST indicates that the bulk of its stars formed within the first 500 million years of the Universe.

Galaxy clusters contain vast amounts of hot ionized gas known as the intracluster medium (ICM). In relaxed cluster cores, the radiative cooling time of the ICM is shorter than the age of the cluster. However, the absence of line emission associated with cooling suggests heating mechanisms that offset the cooling, with feedback from active galactic nuclei (AGNs) being the most likely source 1 , 2 . Turbulence and bulk motions, such as the oscillating (‘sloshing’) motion of the core gas in the cluster potential well, have also been proposed as mechanisms for heat distribution from the outside of the core 3 , 4 . Here we present X-ray spectroscopic observations of the Centaurus galaxy cluster with the X-Ray Imaging and Spectroscopy Mission satellite. We find that the hot gas flows along the line of sight relative to the central galaxy, with velocities from 130 km s −1 to 310 km s −1 within about 30 kpc of the centre. This indicates bulk flow consistent with core gas sloshing. Although the bulk flow may prevent excessive accumulation of cooled gas at the centre, it could distribute the heat injected by the AGN and bring in thermal energy from the surrounding ICM. The velocity dispersion of the gas is found to be only ≲120 km s −1 in the core, even within about 10 kpc of the AGN. This suggests that the influence of the AGN on the surrounding ICM motion is limited in the cluster. X-ray spectroscopic observations of the Centaurus galaxy cluster with the X-Ray Imaging and Spectroscopy Mission satellite show that the hot gas flows along the line of sight relative to the central galaxy.

Studies of micrometeorites in mid-Ordovician limestones and impact craters on Earth indicate that our planet witnessed a massive infall of ordinary L chondrite material about 466 million years ago 1 – 3 that may have been at the origin of an Ordovician ice age and major turnover in biodiversity 4 . The breakup of a large asteroid in the main belt is the likely cause of this massive infall. Currently, material originating from this breakup still dominates meteorite falls (>20% of all falls) 5 . Here we provide spectroscopic observations and dynamical evidence that the Massalia collisional family is the only plausible source of this catastrophic event and the most abundant class of meteorites falling on Earth today. This family of asteroids is suitably located in the inner belt, at low-inclination orbits, which corresponds to the observed distribution of L-chondrite-like near-Earth objects and interplanetary dust concentrated at 1.4° (refs.  6 , 7 ). The Massalia asteroid family is identified as the remnant of the collisional event that gave rise to ordinary L chondrites, the most abundant class of meteorites in our collections.

We present the optical photometric and spectroscopic observations of the nearby Type Ia supernova (SN) 2021hpr. The observations covered the phase of −14.37 to +63.68 days relative to its maximum luminosity in the B band. The evolution of multiband light/color curves of SN 2021hpr is similar to that of normal Type Ia supernovae (SNe Ia) with the exception of some phases, especially a plateau phase that appeared in the V − R color curve before peak luminosity, which resembles that of SN 2017cbv. The first spectrum we observed at t ∼ −14.4 days shows a higher velocity for the Si ii λ 6355 feature (∼21,000 km s −1 ) than that of other normal velocity (NV) SNe Ia at the same phase. Based on the Si ii λ 6355 velocity of ∼12,420 km s −1 around maximum light, we deduce that SN 2021hpr is a transitional object between high velocity (HV) and NV SNe Ia. Meanwhile, the Si ii λ 6355 feature shows a high velocity gradient (HVG) of about 800 km s −1 day −1 from roughly −14.37 to −4.31 days relative to the B -band maximum, which indicates that SN 2021hpr can also be classified as an HVG SN Ia. Despite SN 2021hpr having a higher velocity for the Si ii λ 6355 and Ca ii near-IR (NIR) triplet features in its spectra, its evolution is similar to that of SN 2011fe. Including SN 2021hpr, there have been six supernovae observed in the host galaxy NGC 3147; the supernovae explosion rate in the last 50 yr is slightly higher for SNe Ia, while for SNe Ibc and SNe II it is lower than expected rate from the radio data. Inspecting the spectra, we find that SN 2021hpr has a metal-rich (12 + log(O/H) ≈ 8.648) circumstellar environment, where HV SNe tend to reside. Based on the decline rate of SN 2021hpr in the B band, we determine the distance modulus of the host galaxy NGC 3147 using the Phillips relation to be 33.46 ± 0.21 mag, which is close to that found by previous works.

Scientific Complementary Metal Oxide Semiconductor (sCMOS) sensors are finding increasingly more applications in astronomical observations, thanks to their advantages over charge-coupled devices such as a higher readout frame rate, higher radiation tolerance, and higher working temperature. In this work, we investigate the performance at the individual pixel level of a large-format sCMOS sensor, GSENSE1516BSI, which has 4096 × 4096 pixels, each of 15 μ m in size. To achieve this, three areas on the sCMOS sensor, each consisting of 99 × 99 pixels, are chosen for the experiment. The readout noise, conversion gain and energy resolutions of the individual pixels in these areas are measured from a large number (more than 25,000) of X-ray events accumulated for each of the pixels through long time exposures. The energy resolution of these pixels can reach 140 eV at 6.4 keV at room temperature and shows a significant positive correlation with the readout noise. The accurate gain can also be derived individually for each of the pixels from its X-ray spectrum obtained. Variations of the gain values are found at a level of 0.56% statistically among the 30 thousand pixels in the areas studied. With the gain of each pixel determined accurately, a precise gain correction is performed pixel by pixel in these areas, in contrast to the standardized ensemble gain used in the conventional method. In this way, we could almost completely eliminate the degradation of energy resolutions caused by gain variations among pixels. As a result, the energy resolution at room temperature can be significantly improved to 124.6 eV at 4.5 keV and 140.7 eV at 6.4 keV. This pixel-by-pixel gain correction method can be applied to all kinds of CMOS sensors, and is expected to find interesting applications in X-ray spectroscopic observations in the future.

The results of new low-resolution spectroscopic observations of the short-period system WR 141 (WN5o + O5V–III, ), as well as the results of their comparison with the material of previous studies in order to search for an evolutionary change in the orbital period, are presented. A secular increase in the orbital period of WR 141 with a rate s/yr, corresponding to a mass loss rate /yr with the masses of the stars in the system and , is reported. A correlation between the mass loss rate of WR stars and their mass is discussed.

The first spectroscopic observations of Uranus by the James Webb Space Telescope were obtained in January 2023. Using these observations, we explored the physical properties of the planet's ionosphere through the analysis of near‐infrared H3+ ${\\mathrm{H}}_{3}^{+}$ spectra. We found that both the northern and southern aurora were present; confirmed by localized H3+ ${\\mathrm{H}}_{3}^{+}$ column density enhancements. The median ionospheric temperature across the disk was 415 ± $\\pm $ 13 K, which is at least 300 K lower than measured by Voyager 2 in 1986, making these the lowest temperatures ever recorded. Surprisingly, auroral temperatures are not elevated in the south, and are only enhanced by tens of Kelvin in the north, indicative of limited heating or very efficient transport away from the auroral regions. Significant non‐auroral ionospheric structure is observed, including a dark band aligned with the magnetic dip equator, revealing the first imprints of Uranus's magnetic field on its ionosphere.

3C 273 is a well-studied FSRQ. In order to analyze its spectrum variabilities, we make spectroscopic observations of 3C 273 using the 2.16 m telescope at Xinglong Observatory of the National Astronomical Observatories. Based on these observations and some other spectra from the literature, we study the spectrum variabilities and the physical origin of the optical spectrum. The main results are as follows: (1) The continuum spectrum ( S c ) shows obvious variabilities and displays quasi-periodic properties, P = 3.39 ± 1.13 yr, consistent with the result calculated from photometric observations. (2) The spectral energy distribution (SED) was modeled by a combination of blackbody emission that originated from the accretion disk and the dusty torus, synchrotron emission from the jet, the synchrotron self-Compton (SSC) emission, and the external Compton (EC) emission from the broad-line region, accretion disk, and dusty torus. The SED suggests that the optical continuum is dominated by the thermal emission from the accretion disk. (3) A time delay of τ c H β = 209.42 ± 9.38 days lies between the slope of the continuum spectrum ( S c ) and H β emission line. (4) The relationships between the spectrum and polarization can be explained by the jet model.

The science operations of the spacecraft and remote sensing instruments for the Martian Moon eXploration (MMX) mission are discussed by the mission operation working team. In this paper, we describe the Phobos observations during the first 1.5 years of the spacecraft’s stay around Mars, and the Deimos observations before leaving the Martian system. In the Phobos observation, the spacecraft will be placed in low-altitude quasi-satellite orbits on the equatorial plane of Phobos and will make high-resolution topographic and spectroscopic observations of the Phobos surface from five different altitudes orbits. The spacecraft will also attempt to observe polar regions of Phobos from a three-dimensional quasi-satellite orbit moving out of the equatorial plane of Phobos. From these observations, we will constrain the origin of Phobos and Deimos and select places for landing site candidates for sample collection. For the Deimos observations, the spacecraft will be injected into two resonant orbits and will perform many flybys to observe the surface of Deimos over as large an area as possible.