We intend to study a modified version of the planar Circular Restricted Three-Body Problem (CRTBP) by incorporating several perturbing parameters. We consider the bigger primary as an oblate spheroid and emitting radiation while the small primary has an elongated body. We also consider the perturbation from a disk-like structure encompassing this three-body system. First, we develop a mathematical model of this modified CRTBP. We have found there exist five equilibrium points in this modified CRTBP model, where three of them are collinear and the other two are non-collinear. Second, we apply our modified CRTBP model to the Sun–Haumea system by considering several values of each perturbing parameter. Through our numerical investigation, we have discovered that the incorporation of perturbing parameters has resulted in a shift in the equilibrium point positions of the Sun–Haumea system compared to their positions in the classical CRTBP. The stability of equilibrium points is investigated. We have shown that the collinear equilibrium points are unstable and the stability of non-collinear equilibrium points depends on the mass parameter μ of the system. Unlike the classical case, non-collinear equilibrium points have both a maximum and minimum limit of μ for achieving stability. We remark that the stability range of μ in non-collinear equilibrium points depends on the perturbing parameters. In the context of the Sun–Haumea system, we have found that the non-collinear equilibrium points are stable.

Massive quiescent galaxies at high redshift show significantly more compact morphology than their local counterparts. To examine their internal structure across a wide redshift range and investigate potential redshift dependence, we performed spatially resolved spectral energy distribution fitting using piXedfit software on massive ( log ( M * / M ⊙ ) ∼ 11 ) quiescent galaxies at 0 < z < 4 with public James Webb Space Telescope and Hubble Space Telescope imaging data from the Public Release Imaging for Extragalactic Research and the Cosmic Evolution Early Release Science Survey. We find that at z ∼ 3.5 the half-mass radius is about 5.4 times smaller than at z ∼ 0.5. This growth is driven by stellar mass buildup in the outskirts ( r > 4 kpc), while the central regions ( r ∼ 1 kpc) remain largely unchanged, with stellar mass surface density similar to local quiescent galaxies. The estimated star formation rates are too low to explain the stellar mass growth, indicating that an additional stellar mass accumulation process, such as mergers, is necessary. We parameterize the size–mass relation of the most massive galaxies in our sample as log ( R e , mass ) ∝ α log ( M * ) and find α = 2.6 7 − 1.17 + 1.14 for z ⪅ 2, consistent with growth dominated by minor mergers, and α = 0.9 1 − 0.16 + 0.20 for z ⪆ 2, consistent with growth dominated by major mergers. These results indicate that massive quiescent galaxies originate from compact quenched systems and grow through combinations of minor and major mergers.

"The importance of radio telescopes for astronomy, geodesy, and other disciplines has been demonstrated by the growing number of radio telescopes worldwide, including in South-East Asia. Timau National Observatory has also considered a radiotelescope development program, which is expected to contribute both on a national and global scale. The diameter for the single dish is planned to be around 20-meter with a frequency range of 1-50 GHz. This paper outlines potential research for the planned radio telescope as a single dish as well as a part of future interferometer/VLBI collaboration. We collected several studies conducted with single antenna with a diameter of around 20-meter as a comparison to study its potential use as a single dish. As it is also essential to consider using an interferometer network, we also examined its capability as a part of VLBI, including the UV coverage and object simulation. Finally, it can be concluded that many studies can be conducted using the 20-m radio telescope as a single dish. Its location slightly below the equator can also play an important role in completing the global VLBI network."

"In the near future, four radio telescopes will be installed in Indonesia. Besides the astronomical purposes, these telescopes are expected to support the ground station for tracking the Artificial Earth Satellites (AES). In this study, we focus on the development of AES simulation software, named AESSIMS, that can be used to aid Indonesian radio telescope engineers in tracking the AES. This software is interactive and web-based. It can track the AES position in real time as well as predict the position for the near future. This software provides information about when a satellite signal can be acquired and lost, which can be beneficial for radio telescopes to establish communication with the satellite. We visualize the use of this software by conducting a simulation of satellite tracking by Indonesian future radio telescopes. Three Indonesian satellites named LAPAN-A1/TUBSAT, LAPAN-A2/ORARI, and LAPAN-A3/IPB are considered in the simulation. This study demonstrates that AESSIMS simulation results for Indonesian satellites and radio telescopes are consistent with the results obtained from already existing satellite tracking simulation software."