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The expression of therapeutic genes is critical for the efficacy of gene therapy products. However, existing methods such as immunological analysis at the protein level or reverse-transcription PCR at the RNA level are unable to accurately quantify the expression activity of the target gene. Herein, an in vitro RNA editing-based reporter assay was developed to detect specific mRNA. The designed sensor RNA could specifically identify the target mRNA, and the reporter gene was activated in a dose-dependent manner because of RNA editing mediated by endogenous adenosine deaminases acting on RNA. Of note, all sensors that targeted different regions, including the gene of interest, tag sequence, and 3′ untranslated region, showed a dose-dependent response pattern. The sensor reporter assay, which was used for quantifying the transcriptional activity of recombinant adeno-associated virus-based gene therapy products, revealed excellent performance in terms of assay specificity, precision (inter-assay relative standard deviation < 15%), accuracy (90–115% recovery), and linearity (R2 > 0.99). The reporter assay could also be employed for other gene therapy vectors, including mRNA and recombinant lentivirus. Thus, a robust and reliable platform was developed for assessing the transcriptional activity of therapeutic genes, thereby offering a powerful tool for the quality control of gene therapy products.

KIC 6362386 is an eclipsing binary system that exhibits both γ Doradus ( γ Dor)–type pulsations and starspots. In this study, we investigated this binary system using the Kepler photometry and the spectroscopic data from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope. After employing the PHOEBE program for light-curve and radial-velocity-curve synthesis, analyses reveal that the binary is a circle ( e ∼ 0.0006), has a small mass ratio ( q ∼ 0.311), and is a detached system consisting of an F-type primary star and an M-type secondary star with masses and radii of M _1 = 1.43 ± 0.13 M _⊙ , R _1 = 1.68 ± 0.08 R _⊙ and M _2 = 0.44 ± 0.18 M _⊙ , R _2 = 0.46 ± 0.06 R _⊙ , respectively. Utilizing the Padova isochrone, we estimate the age of the binary system to be ${1.58}_{-0.13}^{+0.15}$ Gyr. By analyzing the out-of-eclipse residuals, we identify variations in the residuals attributed to both starspots and stellar pulsations. The autocorrelation function analysis indicates the decay time of starspots is approximately 37 days with the rotation period aligning with the orbital period. Considering the masses, radii, and positions of the two components on the Hertzsprung–Russell diagram, we deduce that the γ Dor–type g-mode pulsations came from the primary star where the main frequency is 0.1642c/d. Consequently, KIC 6362386 becomes a valuable target for the investigation of γ Dor–type pulsations and asteroseismology in a binary system.

Accurate determination of the stellar atmospheric parameters of RR Lyrae stars (RRLs) requires short individual exposures of the spectra to mitigate pulsation effects. We present improved template-matching methods to determine the stellar atmospheric parameters of RRLs from single-epoch spectra of the Large Sky Area Multi-Object Fiber Spectroscopic Telescope, also known as the Guoshoujing Telescope (LAMOST). We determine the radial velocities and stellar atmospheric parameters (effective temperature T _eff , surface gravity $\mathrm{log}\,g$ , and metallicity [M/H]) of 10,486 and 1027 RRLs from 42,729 LAMOST low-resolution spectra (LRS) and 7064 LAMOST medium-resolution spectra (MRS), respectively. Our results are in good agreement with the parameters of other databases, where the external uncertainties of T _eff , $\mathrm{log}\,g$ , and [M/H] for LRS/MRS are estimated to be 207/142 K, 0.21/0.16 dex, and 0.24/0.18 dex, respectively. We conclude with the variation characteristics of the radial velocities (RV) and stellar atmospheric parameters for RRLs during the pulsation phase. There is a significant difference of 28 ± 21 km s ^−1 between the peak-to-peak amplitude ( A _ptp ) of RV from the H α line (RV _H _α ) and from metal lines (RV _metal ) for RRab, whereas it is only 4 ± 17 km s ^−1 for RRc. The A _ptp of T _eff is 930 ± 456 and 409 ± 375 K for RRab and RRc, respectively. The $\mathrm{log}\,g$ of RRab shows a mild variation of approximately 0.22 ± 0.42 dex near the phase of φ = 0.9, while that of RRc almost remains constant. The [M/H] of RRab and RRc show a minor variation of about 0.25 ± 0.50 and 0.28 ± 0.55 dex, respectively, near the phase of φ = 0.9. We expect that the determined stellar atmospheric parameters would shed new light on the study of stellar evolution and pulsation, the structure of the Milky Way, as well as other research fields.

We present a comprehensive analysis of oscillations of the helium-rich white dwarf DBV star EPIC 248705247 (SDSS J102106.69+082724.8). We extract the light curves from 79.7 days of K2 Campaign 14 data and identify 21 independent frequencies, including three complete and three incomplete dipole modes, with an average frequency splitting of 20.37 ± 0.40 μ Hz. Our analyses reveal a rotation period of EPIC 248705247 of approximately 6.82 ± 0.07 hr, making it one of the most rapidly rotating DBV stars currently known. We utilize the White Dwarf Evolution Code ( WDEC ) to compute models to look for the seismic best-fitted model, yielding the following stellar parameters: M / M _⊙ = 0.650 ± 0.003, T _eff = 23,660 ± 68 K, $\mathrm{log}({M}_{\mathrm{env}}/{M}_{* })=-2.01\pm 0.01$ and $\mathrm{log}({M}_{\mathrm{He}}/{M}_{* })\,=-4.90\pm 0.05$ . We also explore the phenomenon of mode trapping, as well as the potential influence of a weak magnetic field. We find that this star is located near the red edge of the theoretical instability strip of DBVs. Hence, our asteroseismological analysis of EPIC 248705247 provides the properties and behaviors of a rapidly rotating DBV.

We revisited the short-period (∼1.5 days) binary system KIC 5444392, which shows quasi-period modulated light variations. Previous studies indicated that these variations might be caused by stellar pulsations. In our work, we used the PHOEBE program, which revealed that this binary is an almost circular (e ≈0.007) detached system with two G-type stars. The masses and radii of the primary and secondary stars were obtained as M1=1.21±0.06M⊙, R1=1.69±0.09R⊙ and M2=1.27±0.06M⊙, R2=1.69±0.09R⊙, respectively. Based on these parameters, the isochrone fitting showed that this system consists of a subgiant and a main-sequence star, whose ages are 3.89−0.34+0.37 Gyr. Neither the primary nor the secondary star is in the mass range of Cepheid and Gamma Dor. Fourier analysis showed that the fitting residuals varied stochastically in a frequency around the orbital frequency, which means that the quasi-periodic signals resulted from starspots rather than stellar pulsation. Similar stellar parameters of both components of KIC 5444392 and the frequency analysis lead us to believe that starspots are in both stars. The autocorrelation analysis on the residuals indicates that the decay timescale of the starspots is about 53 days, and the rotational periods of both stars are very close to the orbital period of the binary. This result adheres to the trend that the decay timescale increases following the rotational frequency. Thus, studying this binary could increase our understanding of the light variations in the binary system.

We report the detection of gravity ( g ) and Rossby ( r ) mode pulsations of four short-period eclipsing binaries, KIC 5439790, KIC 7501230, KIC 9350889, and KIC 9453192 based on the 4 yr Kepler high-precision photometry. Light-curve modeling reveals that the four binaries are all contact systems with small mass ratios. We study the short-term variability of the light-curve residuals after the removal of the binary model and attribute them to the g- and r -mode pulsations that stem from the primary stars. By introducing a new criterion, we attempt to identify period-spacing patterns in the Fourier spectra, which refers to the determination of the rotation rates of stellar interior and envelope as well as the asymptotic period spacings of the pulsating stars. It is interesting to find that the rotation rates of the stellar envelopes are all nearly equal to the orbits. The near-core rotations, however, are significantly slower by about 10%. Based on the derived asymptotic period spacings, stellar parameters were constrained from asteroseismology models. The pulsators are revealed to be evolved main-sequence stars with high metallicities.

We present a sample of 2700 Ap stars in the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) DR9 catalog. The candidates are first selected to be in a temperature range typical of Ap stars by using the BP − RP color index from Gaia DR3. Then the 5200 Å flux depression features characteristic of Ap stars are visually checked in LAMOST DR9 spectra. The detailed spectral features are given by applying a modified spectral classification program, MKCLASS. The stellar parameters of these Ap stars, such as the T _eff , $\mathrm{log}g$ , [Fe/H], [Si/H], and $v\sin i$ , are either extracted from a hot star catalog or derived through empirical relations and then a statistical analysis is carried out. The evolutionary stages are also discussed. Finally, we discuss the rotation and pulsation features of those that have TESS or Kepler light curves. Among these Ap stars, we find seven new rotation variables, one new roAp star, and a new δ Scuti pulsation of a previously known roAp star.

Superflares are large explosive events on stellar surfaces, much larger than solar flares, but it remains unclear whether they share the same origin. Here, the authors analysed 48 superflare stars and determine the relation between their chromospheric activity and the occurrence of superflares.

Observations for the δ Scuti star AN Lyn have been made between 2008 and 2016 with the 85- cm telescope at Xinglong station of National Astronomical Observatories of China, the 84-cm telescope at SPM Observatory of Mexico and the Nanshan One metre Wide field Telescope of Xinjiang Observatory of China. Data in V in 50 nights and in R in 34 nights are obtained in total. The bi-site observations from both Xinglong Station and SPM Observatory in 2014 are analysed with Fourier Decomposition to detect pulsation frequencies. Two independent frequencies are resolved, including one non-radial mode. A number of stellar model tracks are constructed with the MESA code and the fit of frequencies leads to the best-fitting model with the stellar mass of M = 1.70 ±0.05M☉, the metallicity abundance of Z = 0.020 ±0.001, the age of 1.33 ±0.01 billion years and the period change rate 1/P · dP/dt = 1.06×10-9 yr-1, locating the star at the evolutionary stage close to the terminal age main sequence. The O--C diagram provides the period change rate of (1/P)(dP/dt) = 4.5(8)×10-7 yr-1. However, the period change rate calculated from the models is smaller in two orders than the one derived from the O--C diagram. Together with the sinusoidal function signature, the period variations are regarded to be dominated by the light-travel time effect of the orbitalmotion of a three-body system with two low-luminosity components, rather than the stellar evolutionary effect. [ABSTRACT FROM AUTHOR]

The nearly circular (mean eccentricity e0.06) and coplanar (mean mutual inclination (i ≈3°) orbits of the solar system planets motivated Kant and Laplace to hypothesize that planets are formed in disks, which has developed into the widely accepted theory of planet formation. The first several hundred extrasolar planets (mostly Jovian) discovered using the radial velocity (RV) technique are commonly on eccentric orbits (e≈0.3). This raises a fundamental question: Are the solar system and its formation special? The Kepler mission has found thousands of transiting planets dominated by sub-Neptunes, but most of their orbital eccentricities remain unknown. By using the precise spectroscopic host star parameters from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) observations, we measure the eccentricity distributions for a large (698) and homogeneous Kepler planet sample with transit duration statistics. Nearly half of the planets are in systems with single transiting planets (singles), whereas the other half are multiple transiting planets (multiples). We find an eccentricity dichotomy: on average, Kepler singles are on eccentric orbits with e≈ 0.3, whereas the multiples are on nearly circular (e=0.04-0.04+0.03) and coplanar (i =1.4-1.1+0.8 degree) orbits similar to those of the solar system planets. Our results are consistent with previous studies of smaller samples and individual systems. We also show that Kepler multiples and solar system objects follow a common relation [e≈(1-2)?i] between mean eccentricities and mutual inclinations. The prevalence of circular orbits and the common relation may imply that the solar system is not so atypical in the galaxy after all. [ABSTRACT FROM AUTHOR]

Stellar fundamental parameters are important in the asteroseismic study of Kepler light curves. However, the most used estimates in the Kepler Input Catalog (KIC) are not accurate enough for hot stars. Using a sample of B stars from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) spectral survey, we confirmed the systematic underestimation in the KIC effective temperature and overestimation in KIC surface gravity. The good agreement between LAMOST and other follow-up observations proved the accuracy of effective temperature and surface gravity of B stars derived from LAMOST low-resolution spectra. By searching through LAMOST data, we found four misclassified main-sequence B stars in the Kepler field, which had been previously classified as A-type variables. We present spectroscopic and detailed frequency analysis of these four stars based on LAMOST spectra and Kepler photometry. [ABSTRACT FROM AUTHOR]

The variability of young stellar objects is mostly driven by star–disk interactions. In long-term photometric monitoring of the accreting T Tauri star GI Tau, we detect extinction events with typical depths of mag that last for days to months and often appear to occur stochastically. In 2014–2015, extinctions that repeated with a quasi-period of 21 days over several months are the first empirical evidence of slow warps predicted by magnetohydrodynamic simulations to form at a few stellar radii away from the central star. The reddening is consistent with and, along with an absence of diffuse interstellar bands, indicates that some dust processing has occurred in the disk. The 2015–2016 multiband light curve includes variations in spot coverage, extinction, and accretion, each of which results in different traces in color–magnitude diagrams. This light curve is initially dominated by a month-long extinction event and a return to the unocculted brightness. The subsequent light curve then features spot modulation with a 7.03 day period, punctuated by brief, randomly spaced extinction events. The accretion rate measured from U-band photometry ranges from to M⊙ yr−1 (excluding the highest and lowest 5% of high- and low- accretion rate outliers), with an average of M⊙ yr−1. A total of 50% of the mass is accreted during bursts of M⊙ yr, which indicates limitations on analyses of disk evolution using single-epoch accretion rates. [ABSTRACT FROM AUTHOR]

The spectroscopic sky survey carried out by the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) provides the largest stellar spectra library in the world to date. A large number of new DA white dwarfs had been identified based on the LAMOST spectra. The effective temperature () and surface gravity () of most DA white dwarfs were determined and published in the catalogs. We selected ZZ Ceti candidates from the published catalogs by considering whether their are situated in the ZZ Ceti instability strip. The follow-up time-series photometric observations for the candidates were performed in 2015 and 2016. Four stars: LAMOST J004628.31+343319.90, LAMOST J062159.49+252335.9, LAMOST J010302.46+433756.2, and LAMOST J013033.90+273757.9 are finally confirmed to be new ZZ Ceti stars. They show dominant peaks with amplitudes rising above the 99.9% confidence level in the amplitude spectra. As LAMOST J004628.31+343319.90 has an estimated mass of ∼0.40 , and LAMOST J013033.90+273757.9 has a mass of ∼0.45 derived from their values, these two stars are inferred to be potential helium-core white dwarfs. [ABSTRACT FROM AUTHOR]