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Heartbeat stars (HBSs) with tidally excited oscillations (TEOs) are ideal astrophysical laboratories for studying the internal properties of the systems. In this paper, five new HBSs exhibiting TEOs are discovered using TESS photometric data. The orbital parameters are derived using a corrected version of Kumar et al.'s model based on the Markov Chain Monte Carlo method. The TEOs in these objects are examined, and their pulsation phases and modes are identified. The pulsation phases of the TEOs in TIC 266809405, TIC 266894805, and TIC 412881444 are consistent with the dominant l = 2, m = 0, or ±2 spherical harmonic. For TIC 11619404, although the TEO phase is close to the m = +2 mode, the m = 0 mode cannot be excluded because of the low inclination in this system. The TEO phase in TIC 447927324 shows a large deviation (>2 σ ) from the adiabatic expectations, suggesting that it is expected to be a traveling wave or that the pulsations are nonadiabatic. In addition, these TEOs occur at relatively low orbital harmonics, and we cautiously suggest that this may be an observational bias. These objects are valuable sources for studying the structure and evolution of eccentricity orbit binaries and extending the TESS HBS catalog with TEOs.

Asteroseismology offers a profound window into stellar interiors and has emerged as a pivotal technique in exoplanetary research. This study harnesses the Transiting Exoplanet Survey Satellite observations to reveal, for the first time, the asteroseismic oscillations of four exoplanet-hosting stars. Through meticulous analysis, we extracted their asteroseismic signatures, enabling the precise determination of stellar masses, radii, luminosities, and surface gravities. These parameters exhibit markedly reduced uncertainties compared to those derived from spectroscopic methods. Crucially, the exoplanets orbiting these stars were initially identified via radial velocity measurements. The refinement of host stellar masses necessitates a corresponding adjustment in planetary characteristics. Employing asteroseismology, we recalibrated the exoplanets’ minimum masses and semimajor axes—a novel approach in the field. For instance, the exoplanet HD 5608 b's minimum mass, denoted as $M\sin i$ , was ascertained to be 1.421 ± 0.091 M _J through the integration of asteroseismic and radial velocity data. Similarly, two planets within the 7 CMa system yielded $M\sin i$ values of 1.940 ± 0.064 M _J and 0.912 ± 0.067 M _J , respectively. Two planets in the HD 33844 system presented $M\sin i$ figures of 1.726 ± 0.145 M _J and 1.541 ± 0.182 M _J , while the HIP 67851 system's planets registered $M\sin i$ at 1.243 ± 0.139 M _J and a notably higher 5.387 ± 0.699 M _J . This investigation extends beyond mere parameter refinement, it underscores the synergy between asteroseismology and exoplanetology, yielding unprecedented precision in system metrics. Focusing on a quartet of K-type giants in advanced evolutionary phases, our work positions these systems as invaluable astrophysical laboratories, offering insights into the potential trajectory of our own solar system's fate.

TV Col is a long-period eclipsing intermediate polar (IP) prototype star for the negative superhump (NSH) system. We investigate the eclipse minima, eclipse depth, and NSH amplitude based on TESS photometry. Using the same analytical method as for SDSS J081256.85+191157.8, we find periodic variations of O − C for eclipse minima and NSH amplitudes with periods of 3.939(25) days and 3.907(30) days, respectively. The periodic variation of the NSH amplitude of TV Col confirms that periodic changes in NSH amplitude in response to the tilted disk precession may be universal, which is further evidence that the origin of the NSHs is related to the tilted disk precession. We suggest that the variation in NSH amplitude may be similar to the superorbital signal, coming from the periodic change in visual brightness of the energy released by streams touching the tilted disk with tilted disk precession. Finally, we find for the first time that the eclipse depth exhibits biperiodic variations with periods of P _1 = 3.905(11) days and P _2 = 1.953(4) days, respectively. P _2 is about half of P _1 and the disk precession period ( P _1 ≈ P _prec ≈ 2 × P _2 ). We suggest that P _1 may come from the periodic change in the brightness of the eclipse center due to tilted disk precession, while P _2 may come from two accretion curtains precessing together with the tilted disk, but more verification and discussion are necessary. The discovery of biperiodic variations in eclipse depth provides a new window for studying IPs and tilted disk precession.

Negative superhumps (NSHs) are signals a few percent shorter than the orbital period of a binary star and are considered to originate from the reverse precession of the tilted disk. Based on TESS photometry, we find nine new cataclysmic variable stars with NSHs. Three (ASAS J1420, TZ Per, and V392 Hya) of these stars similar to AH Her still have NSHs during dwarf nova outbursts, and the NSH amplitude varies with the outburst. The variation in the radius of the accretion disk partially explains this phenomenon. However, it does not explain the rebound of the NSH amplitude after the peak of the outburst and the fact that the NSH amplitude of the quiescence is sometimes not the largest, and it is necessary to include the disk instability model (DIM) and add other ingredients. Therefore, we suggest that the variation of NSH amplitude with outburst can be an important basis for studying the origin of NSHs and improving the DIM. The six (ASASSN-V J1137, ASASSN-V J0611, 2MASS J0715, LAMOST J0925, ASASSN-17qj, and ZTF 18acakuxo) remaining stars have been poorly studied, and for the first time we determine their orbital periods, NSHs, and superorbital signal (SOR) periods. The NSH periods and amplitudes of ASASSN-V J1137 and ASASSN-17qj vary with the SOR, and based on the comparison of the observations with the theory, we suggest that a single change in tilted disk angle does not explain the observations of the SOR and that other ingredients need to be considered as well.

Heartbeat stars (HBSs) with tidally excited oscillations (TEOs) are ideal laboratories for studying the effect of equilibrium and dynamical tides. However, studies of TEOs in Kepler HBSs are rare due to the need for better modeling of the equilibrium tide in light curves. We revisit the HBSs in our previous work and study the TEOs in these HBSs based on the derived orbital parameters that could express the equilibrium tide. We also compile a set of analytic procedures to examine the harmonic and anharmonic TEOs in their Fourier spectra. The TEOs of 21 HBSs have been newly analyzed and presented. Twelve of these HBSs show prominent TEOs (signal-to-noise ratio of the harmonics S/N ≥ 10). The relation between the orbital eccentricities and the harmonic number of the TEOs shows a positive correlation. The relation between the orbital periods and the harmonic number also shows a positive correlation. Furthermore, the distribution of HBSs with TEOs in the Hertzsprung–Russell diagram shows that TEOs are more visible in hot stars with surface effective temperatures T ≳ 6500 K. These samples may also be valuable targets for future studies of the effect of tidal action in eccentric orbits.

Massive contact binaries refer to the close binary systems in which the components have filled their respective Roche lobes and share a common envelope with early-type spectra. Twin binaries are a special type of binary system characterized by two components with nearly equal masses. The Magellanic Cloud, comprising the Large Magellanic Cloud (LMC) and the Small Magellanic Cloud, is a fascinating galaxy that is distinct from the Milky Way. With its low metallicity, it serves as an ideal test bed for studying the formation and evolution of massive binaries and testing theoretical models. In this work, based on long-term observations with Optical Gravitational Lensing Experiment and MAssive Compact Halo Object in the LMC, we identified and performed comprehensive analyses of five massive twin contact binaries via the method of the light travel time effect and Wilson–Devinney code. The results show that all of these twin binaries are accompanied by low-mass third bodies. The third bodies have minimum masses ranging from 0.33 to 1.46 M _⊙ . Their orbital periods range from 4.34 to 12.03 yr. The maximum distances between the third bodies and the central binary systems range from 6.7 to 11.4 au. Remarkably, four out of the five massive twins have evolved into deep-contact binaries, which indicates that all of them may have originated from Case A mass transfer. These results strongly suggest the significant influence of the third body in the formation and evolution of massive contact binaries and may hold the key to unraveling the origins of massive binaries.

Heartbeat stars (HBSs) are astrophysical laboratories for studying binaries with eccentric orbits. A catalog of 173 Kepler HBSs was reported by Kirk et al., and we have modeled 153 of them by using a corrected version of Kumar et al.'s model based on the Markov Chain Monte Carlo method. The orbital parameters, including orbital period, eccentricity, orbital inclination, the argument of periastron, and epoch of the periastron passage of these HBSs, have been determined and are presented. Orbital parameters of more than 100 systems are obtained for the first time. After comparing the parameters of 38 overlapping systems with previous works, it is shown that the orbital parameters of HBSs can be reliably derived using this method. These samples can also be valuable targets for future studies of the structures and evolution of HBSs. The eccentricity–period (e–P) relation also reveals the existence of orbital circularization in HBSs. We then propose an empirical equation for the relationship between the upper limit of eccentricity and the orbital period in systems with orbital periods less than 10 days based on the e–P relation. In addition, it is possible that seven systems in the catalog with eccentricity less than 0.02 should be excluded from the HBS candidates.