Journal of Earth Science, Astronomy and Space

A Study for Orbital Period Variation of Eclipsing Binary System V2821 Orionis

Ronnachai Lakhom — 2026-06-21

This research aims to investigate the orbital period variation of the eclipsing binary system V2821 Orionis, which is classified as a β Lyrae-type semi-detached system. The light curve of the system exhibits continuous variations, indicating that both stellar components are orbiting around a common center of mass. The observations were carried out using a 1-meter reflecting telescope equipped with an Andor iKon-L CCD camera (2048 × 2048 pixels) through B, V, and Rc filters based. Data were collected at the National Observatory, Chiang Mai, on December 10–11, 2024, January 17, 2025, and January 19, 2025. All CCD images were calibrated and analyzed using the Differential Photometry technique with MaxIm DL Pro Version 6 to obtain the standard magnitudes. The orbital period analysis was performed using an Observed minus Calculated (O–C) diagram, which revealed a downward parabolic trend, indicating a decrease in the orbital period. The results show that V2821 Orionis has an orbital period of 0.377661 ± 0.0000007 days approximately 9.0639 hours and an orbital period decrease rate of (-7.23 ± 0.0013) × 10^–2 seconds per year. This decrease may be attributed to mass transfer between the two stars when one component expands to fill its Roche lobe, or to angular momentum loss through magnetic braking-both of which play crucial roles in the evolution of close binary systems. Therefore, the findings of this study provide valuable insights into the long-term orbital period evolution of eclipsing binary systems.

Coastal Line Change Analysis of Samila Beach, Songkhla Province, (2025) using Geoinformatics Technology

Luksika Nuankaew — 2026-06-21

A study on the changes in the coastal conditions of Samila Beach, Songkhla Province. The study area starts from the Golden Mermaid statue to the breakwater at the mouth of the Songkhla Lake channel, covering a distance of 2,720 meters. The objective was to study the change in the coastal area and to prepare a map showing the coastline changes in the Samila Beach area, Songkhla Province. The coastline position was recorded using a Geographic Positioning System, with the time of the highest tide taken from the tide tables. Data was recorded 2 a month, every month, continuously for one year in 2025 A.D. The data was then analyzed to calculate the area of Samila Beach using the Quantum GIS 3.4.12 It was found that the coastal area of Samila Beach is continuously undergoing depositional change at a rate of 3,612.09 square meters per month, or 43,345.08 square meters per year. The average beach area throughout the year in 2025 A.D. will be equal to 1,150,039.85 square meters. When compared to the Samila beach area from data collected in 2018 A.D., which had an average beach area throughout the year of 1,092,286.62 square meters, it shows that over a period of 8 years, the coastal area of Samila Beach has increased due to deposition by 57,753.23 square meters, or an increase of 7,219.15 square meters per year. The coastline is experiencing sedimentation at a rate of 2.65 meters per year. The map indicates that deposition occurred more significantly in the upper and middle sections of the coast than in the lower section.

Model of the Binary System V392 Orion

Supat Sairattanain — 2026-06-21

The purpose of this research is to construct a model of a binary star system V392 Orion (V392 Ori). The data of the light curve was observed by the satellite TESS, NASA. The physical parameters were analyzed in red (R) wavelength by Wilson-Devinney software. The results show that the mass ratio of this binary system is about 0.23 and the effective temperature both are 8170 and 5389 K.

Product Development of Semi-processed Chamuang Curry Powder

Watcharee Waratchareeyakul — 2026-06-21

This research aimed to develop a semi-processed Chamuang curry powder, evaluate its sensory quality and consumer acceptance, analyze its nutritional value, shelf life, and determine the total phenolic content of Chamuang leaves and the developed product. The standard formula of Chamuang curry powder comprised lemongrass, galangal, shallot, garlic, dried chili and Chamuang leaves, which were dried and roasted in a hot air oven at 60°C for 6 hours before being ground into fine powder. Consumer acceptane testing (n=100) revealed an overall mean liking score of 4.50±0.66 out of 5 (90.00%). The characteristics of colour, aroma, taste, texture, and overall acceptability were not significantly different statistically (p > 0.05). The product exhibited a water activity value of 0.48, sufficient to inhibit microbial growth and no microbial contamination was detected throughout the storage period. Total phenolic content analysis by the Folin-Ciocalteu method revealed that the aqueous extract of Chamuang leaves contained the highest phenolic concentration (74.55 ± 4.45 mg GAE/g extract), whereas the semi-processed Chamuang curry powder showed a lower phenolic content (24.91 ± 0.89 mg GAE/g extract) due to processing effects such as drying and roasting. In conclusion, the developed semi-processed Chamuang curry powder demonstrated good sensory acceptance, microbiological safety, and potential for commercial development, while also promoting the value of local herbal resources.

Development of a Prototype Sunscreen Cream Enhanced with Chitosan Microgel Encapsulating α-Mangostin from Garcinia mangostana L. Pericarp

Watcharee Waratchareeyakul — 2026-06-21

This study aimed to extract, isolate and identify bioactive compounds from mangosteen (Garcinia mangostana L.) pericarp, evaluate their antioxidant activity, and develop chitosan microgels for encapsulation with potential application in sunscreen formulations. Successive solvent extraction revealed that the methanol extract yielded the highest amount and allowed the isolation of -mangostin, whose structure was confirmed by spectroscopic techniques. Antioxidant activity evaluated by the DPPH assay showed IC₅₀ values of 10.251 ± 2.458 µg/ml for vitamin C and 16.879 ± 2.291 µg/ml for BHT, whereas the crude ethanol extract of mangosteen peel exhibited an IC₅₀ of 59.181 ± 4.051 µg/ml, indicating lower antioxidant activity compared to standards. FTIR analysis confirmed successful encapsulation of the extract within chitosan microgels while preserving phenolic functional groups, which enhanced antioxidant activity and stability. However, sunscreen prototypes containing -mangostin at 1%, 3%, and 5% concentrations did not yield measurable IC₅₀ values, antioxidant activity could not be reliably determined by DPPH assay in cream matrix due to formulation interference, suggesting the need for alternative methods such as ORAC or cell-based assays. In conclusion, chitosan microgels effectively improve its efficacy and stability, though further optimization is needed for practical application in sunscreen products to ensure quality and safety.

Assessment of Potential Evapotranspiration in the Future over Northern Thailand

Pakpoom Ratjiranukool — 2026-06-21

In this research, potential evapotranspiration (PET) changes across northern Thailand were estimated using the Thornthwaite method. The Weather Research and Forecasting (WRF) model was driven by the Community Earth System Model (CESM) during the baseline period (2000-2004) and the projected period (2050-2054) under the Coupled Model Intercomparison Project 5 (CMIP5). The results reveal that the simulated monthly mean temperatures were underestimated relative to the observed data across all stations, with root mean square errors (RMSE) ranging from 0.73 to 3.14°C and correlation coefficients (R) ranging from 0.72 to 0.89. The monthly potential evapotranspiration over northern Thailand peaks in April, corresponding to the summer months, a pattern consistent across both current climate conditions and future projections. Specifically, the lower northern region shows higher monthly potential evapotranspiration during the summer compared to other provinces in the region. Future projections under the RCP8.5 scenario indicate a consistent increase in monthly potential evapotranspiration across all study stations, implying an elevated risk of drought conditions relative to the current climate.