Unified Pretraining Target Based Video-music Retrieval With Music Rhythm And Video Optical Flow Information

Background music (BGM) can enhance the video's emotion. However, selecting an appropriate BGM often requires domain knowledge. This has led to the development of video-music retrieval techniques. Most existing approaches utilize pretrained video/music feature extractors trained with different target sets to obtain average video/music-level embeddings. The drawbacks are two-fold. One is that different target sets for video/music pretraining may cause the generated embeddings difficult to match. The second is that the underlying temporal correlation between video and music is ignored. In this paper, our proposed approach leverages a unified target set to perform video/music pretraining and produces clip-level embeddings to preserve temporal information. The downstream cross-modal matching is based on the clip-level features with embedded music rhythm and optical flow information. Experiments demonstrate that our proposed method can achieve superior performance over the state-of-the-art methods by a significant margin

TESS Discovery of an ultra-short-period planet around the nearby M dwarf LHS 3844

Data from the newly-commissioned \textit{Transiting Exoplanet Survey Satellite} (TESS) has revealed a "hot Earth" around LHS 3844, an M dwarf located 15 pc away. The planet has a radius of $1.32\pm 0.02$ $R_\oplus$ and orbits the star every 11 hours. Although the existence of an atmosphere around such a strongly irradiated planet is questionable, the star is bright enough ($I=11.9$, $K=9.1$) for this possibility to be investigated with transit and occultation spectroscopy. The star's brightness and the planet's short period will also facilitate the measurement of the planet's mass through Doppler spectroscopy.Comment: 10 pages, 4 figures. Submitted to ApJ Letters. This letter makes use of the TESS Alert data, which is currently in a beta test phase, using data from the pipelines at the TESS Science Office and at the TESS Science Processing Operations Cente

A massive hot Jupiter orbiting a metal-rich early-M star discovered in the TESS full frame images

Observations and statistical studies have shown that giant planets are rare around M dwarfs compared with Sun-like stars. The formation mechanism of these extreme systems remains under debate for decades. With the help of the TESS mission and ground based follow-up observations, we report the discovery of TOI-4201b, the most massive and densest hot Jupiter around an M dwarf known so far with a radius of $1.22\pm 0.04\ R_J$ and a mass of $2.48\pm0.09\ M_J$, about 5 times heavier than most other giant planets around M dwarfs. It also has the highest planet-to-star mass ratio ($q\sim 4\times 10^{-3}$) among such systems. The host star is an early-M dwarf with a mass of $0.61\pm0.02\ M_{\odot}$and a radius of$0.63\pm0.02\ R_{\odot}$. It has significant super-solar iron abundance ([Fe/H]=$0.52\pm 0.08$ dex). However, interior structure modeling suggests that its planet TOI-4201b is metal-poor, which challenges the classical core-accretion correlation of stellar-planet metallicity, unless the planet is inflated by additional energy sources. Building on the detection of this planet, we compare the stellar metallicity distribution of four planetary groups: hot/warm Jupiters around G/M dwarfs. We find that hot/warm Jupiters show a similar metallicity dependence around G-type stars. For M dwarf host stars, the occurrence of hot Jupiters shows a much stronger correlation with iron abundance, while warm Jupiters display a weaker preference, indicating possible different formation histories.Comment: 21 pages, 11 figures, 4 tables, submitted to A

Three low-mass companions around aged stars discovered by TESS

We report the discovery of three transiting low-mass companions to aged stars: a brown dwarf (TOI-2336b) and two objects near the hydrogen burning mass limit (TOI-1608b and TOI-2521b). These three systems were first identified using data from the Transiting Exoplanet Survey Satellite (TESS). TOI-2336b has a radius of $1.05\pm 0.04\ R_J$, a mass of $69.9\pm 2.3\ M_J$ and an orbital period of 7.71 days. TOI-1608b has a radius of $1.21\pm 0.06\ R_J$, a mass of $90.7\pm 3.7\ M_J$ and an orbital period of 2.47 days. TOI-2521b has a radius of $1.01\pm 0.04\ R_J$, a mass of $77.5\pm 3.3\ M_J$ and an orbital period of 5.56 days. We found all these low-mass companions are inflated. We fitted a relation between radius, mass and incident flux using the sample of known transiting brown dwarfs and low-mass M dwarfs. We found a positive correlation between the flux and the radius for brown dwarfs and for low-mass stars that is weaker than the correlation observed for giant planets.Comment: 20 pages, 13 figures; submitted to MNRA

Revisiting the HD 21749 planetary system with stellar activity modelling

HD 21749 is a bright (V = 8.1 mag) K dwarf at 16 pc known to host an inner terrestrial planet HD 21749c as well as an outer sub-Neptune HD 21749b, both delivered by Transiting Exoplanet Survey Satellite (TESS). Follow-up spectroscopic observations measured the mass of HD 21749b to be 22.7 ± 2.2 M with a density of 7.0^{+1.6}_{-1.3} g cm-3, making it one of the densest sub-Neptunes. However, the mass measurement was suspected to be influenced by stellar rotation. Here, we present new high-cadence PFS RV data to disentangle the stellar activity signal from the planetary signal. We find that HD 21749 has a similar rotational time-scale as the planet's orbital period, and the amplitude of the planetary orbital RV signal is estimated to be similar to that of the stellar activity signal. We perform Gaussian process regression on the photometry and RVs from HARPS and PFS to model the stellar activity signal. Our new models reveal that HD 21749b has a radius of 2.86 ± 0.20 R, an orbital period of 35.6133 ± 0.0005 d with a mass of Mb = 20.0 ± 2.7 M and a density of 4.8^{+2.0}_{-1.4} g cm-3 on an eccentric orbit with e = 0.16 ± 0.06, which is consistent with the most recent values published for this system. HD 21749c has an orbital period of 7.7902 ± 0.0006 d, a radius of 1.13 ± 0.10 R, and a 3σ mass upper limit of 3.5 M. Our Monte Carlo simulations confirm that without properly taking stellar activity signals into account, the mass measurement of HD 21749b is likely to arrive at a significantly underestimated error bar

LHS 1815b: The First Thick-disk Planet Detected by TESS

We report the first discovery of a thick-disk planet, LHS 1815b (TOI-704b, TIC 260004324), detected in the Transiting Exoplanet Survey Satellite (TESS) survey. LHS 1815b transits a bright (V = 12.19 mag, K = 7.99 mag) and quiet M dwarf located 29.87 ± 0.02 pc away with a mass of 0.502 ± 0.015 M o˙ and a radius of 0.501 ± 0.030 R o˙. We validate the planet by combining space- and ground-based photometry, spectroscopy, and imaging. The planet has a radius of 1.088 ± 0.064 R ⊕ with a 3σ mass upper limit of 8.7 M ⊕. We analyze the galactic kinematics and orbit of the host star LHS 1815 and find that it has a large probability (P thick/P thin = 6482) to be in the thick disk with a much higher expected maximal height (Z max = 1.8 kpc) above the Galactic plane compared with other TESS planet host stars. Future studies of the interior structure and atmospheric properties of planets in such systems using, for example, the upcoming James Webb Space Telescope, can investigate the differences in formation efficiency and evolution for planetary systems between different Galactic components (thick disks, thin disks, and halo)

TESS discovery of a sub-Neptune orbiting a mid-M dwarf TOI-2136

peer reviewedWe present the discovery of TOI-2136b, a sub-Neptune planet transiting every 7.85 days a nearby M4.5V-type star, identified through photometric measurements from the TESS mission. The host star is located $33$ pc away with a radius of $R_{\ast} = 0.34\pm0.02\ R_{\odot}$, a mass of $0.34\pm0.02\ M_{\odot}$ and an effective temperature of $\rm 3342\pm100\ K$. We estimate its stellar rotation period to be $75\pm5$ days based on archival long-term photometry. We confirm and characterize the planet based on a series of ground-based multi-wavelength photometry, high-angular-resolution imaging observations, and precise radial velocities from CFHT/SPIRou. Our joint analysis reveals that the planet has a radius of $2.19\pm0.17\ R_{\oplus}$, and a mass measurement of $6.4\pm2.4\ M_{\oplus}$. The mass and radius of TOI2136b is consistent with a broad range of compositions, from water-ice to gas-dominated worlds. TOI-2136b falls close to the radius valley for low-mass stars predicted by the thermally driven atmospheric mass loss models, making it an interesting target for future studies of its interior structure and atmospheric properties

TESS Discovery of an Ultra-short-period Planet around the Nearby M Dwarf LHS 3844

Data from the newly commissioned Transiting Exoplanet Survey Satellite has revealed a 'hot Earth' around LHS 3844, an M dwarf located 15 pc away. The planet has a radius of R ⊕ and orbits the star every 11 hr. Although the existence of an atmosphere around such a strongly irradiated planet is questionable, the star is bright enough (I = 11.9, K = 9.1) for this possibility to be investigated with transit and occultation spectroscopy. The star's brightness and the planet's short period will also facilitate the measurement of the planet's mass through Doppler spectroscopy