Page 3 (data 61 to 77 of 77) | Displayed ini 30 data/page
<< PREV 1 2 3

61	Public Outreach, Education, and Popularization of Astronomy	ABS-77
Unlocking Educational Potential for The Introduction of Astronomy Through The Planetarium of UIN Walisongo Semarang Muhammad Fajri Kholili Zain (a*), Inayah (b) a) Jember Astronomy Club *fajrikholili082[at]gmail.com b) Walisongo Islamic State University, Semarang Abstract This study aims to explore the educational potential of introducing astronomy through the use of the Planetarium at UIN Walisongo Semarang. Using a qualitative approach and field observation methods, the research directly examines how the planetarium function as an interactive and engaging learning medium. The findings indicate that the planetarium plays a significant role in enhancing students^ interest and understanding of basic astronomical concepts. Furthermore, the immersive learning environment and visual presentation contribute to a more enjoyable and meaningful educational experience. This study recommends the development of planetarium-based educational programs as an effective alternative for introducing science, particularly astronomy, across various levels of education. Keywords: Study, Astronomy, Planetarium. Share Link | Plain Format | Corresponding Author (Muhammad Fajri Kholili Zain)

62	Public Outreach, Education, and Popularization of Astronomy	ABS-81
Galaksi:Bridging Astronomy and Public Curiosity Through Edutainment Television Show Amirul Hazim Kamarulzaman (1), Mohd Syafiq Nasrudin (2), Iskandar Jebat (2), Arief Mohd Kharib (2)(3) (1) East Coast Environmental Research Institute, Universiti Sultan Zainal Abidin (2) Paper Screen Pictures Sdn. Bhd. (3) KCP Studios San. Bhd. Abstract Innovative approaches to public astronomy outreach are essential in fostering lifelong curiosity and scientific literacy among diverse communities. This abstract presents the concept and development of a family-oriented astronomy television program called Galaksi. The show was designed as a unique blend of education and entertainment (edutainment) to make astronomy accessible, engaging, and enjoyable for audiences of all ages. The show also includes simple experiments that families can do at home, inspiring interviews with astronomers and visits to observatories that offer viewers a closer look at how science works in real life. By working closely with experienced television producers, Galaksi is crafted to be visually engaging and educational to connect with viewers on a personal level. Through creative visuals, expert insights and interactive segments, the show encourages learning together as a family and brings the wonders of the universe right into the living room. This initiative aims to complement formal science education, broaden public engagement and strengthen community appreciation for the universe. Even in this social media world, mainstream television shows still give an impact to the public as a whole. Keywords: Edutainment, Television Show, Astronomy Education, Family Share Link | Plain Format | Corresponding Author (Amirul Hazim Kamarulzaman)

63	Public Outreach, Education, and Popularization of Astronomy	ABS-83
Light Pollution Awareness Through Elementary Education: An Astronomy Public Outreach Program by Bosscha Observatory Nadila Fitriyani (a*), Hesti Retno Tri Wulandari (a,b), Kiki Vierdayanti (a,b), Dian Rosleine (c), Aprilia (a,b), Yatny Yulianty (b), Luthfiandari (b), Windy Talitha Azura (a), Manalu Firdaus Orvin Dwifauja (a), Adinda Putri Jannatul Firdaus (a), Isnanda Amatul Huda (a), Hakim Al Ikhsan (a), Amandaru Taruna Mandala (a), Gendhis Pangesti Sekartaji (a), Bayu Septiadi (a), Va Syarif (a), Kiki Citra Wati (a) Abstract Light pollution has become a growing concern for astronomical observations and the surrounding ecosystem. In response, a public outreach program titled ^Lawan Polusi Cahaya Bersama Observatorium Bosscha^ (Combating Light Pollution with Bosscha Observatory) was initiated by Bosscha Observatory, with a focus on elementary schools located near the observatory in Lembang, Indonesia. The program included a series of school visits and observatory tours, combining educational presentations, interactive hands-on activities, and science exhibitions focused on the impacts of light pollution. Presentations were adapted to the understanding levels of elementary school students, utilizing visual-rich slides, animated videos, and gamified quizzes to maintain engagement. The initiative concluded with the selection of ^Light Pollution Ambassadors^ based on creative student-submitted worksheets. Through this outreach project, the program successfully fostered awareness among young learners, teachers, and the local community, while strengthening relationships between the observatory and its surrounding schools. This outreach program contributes to the advancement of public science education and shows the potential for similar outreach models to be applied in other Southeast Asian regions with access to astronomical resources. Keywords: Share Link | Plain Format | Corresponding Author (Nadila Fitriyani)

64	Public Outreach, Education, and Popularization of Astronomy	ABS-86
Youth Engagement in Astronomy Outreach: A Case Study of Sidorejo, Kulon Progo Muhammad Maulidan (a*), Yudhiakto Pramudya (a), Sri Wahyuni (a), Ami Lia Calista (a) (a) Center for Astronomical Studies, Ahmad Dahlan Yogyakarta University Jl. Ringroad Selatan, Tamanan, Banguntapan, Bantul 55191 Indonesia muhammad1900014043[at]webmail.uad.ac.id Abstract Astronomy outreach plays a vital role in fostering scientific literacy and inspiring public engagement, particularly among younger generations. However, sustaining youth interest remains a challenge, especially in contexts where access to astronomical facilities is limited. This study aims to document and evaluate astronomy outreach initiatives conducted in Sidorejo Village, Kulon Progo, Indonesia, in collaboration with the Center for Astronomical Studies, Universitas Ahmad Dahlan, during the period 2023-2025. The activities included AstroCamp, the astronomy-themed Kafe Palintangan, and cultural integration programs introducing traditional Javanese systems such as pranata mangsa and wuku. Data were collected through participant surveys (n = 30) and descriptive documentation of program implementation. The results demonstrate a significant increase in participation across three years, influenced by improved promotional strategies and more diverse activities. Survey findings indicate that the majority of youth respondents preferred the informal cafe-based setting, highlighting the effectiveness of socially embedded and accessible approaches. Furthermore, Instagram and TikTok emerged as the most promising platforms for future promotion, reflecting broader digital trends among Generation Z. The integration of cultural heritage with modern astronomy was also shown to enhance relevance and acceptance within the community. These findings suggest that Sidorejo Village holds strong potential as a model for astronomy tourism and community-based science outreach, providing valuable insights for the development of sustainable and culturally rooted public engagement strategies. Keywords: Astronomy Outreach, Sidorejo Village, Youth engagement Share Link | Plain Format | Corresponding Author (Muhammad Maulidan)

65	Stellar Physics	ABS-8
Bayesian Nested Sampling for Robust Model Selection and Validation of Lunar Occultation Light Curves Agus Triono Puri Jatmiko Bosscha Observatory, ITB Abstract Bayesian Nested Sampling (NS) offers a powerful framework for model selection and validation in astrophysical data analysis. This study applies NS to analyze lunar occultation (LO) light curves, enabling robust sampling of the posterior distribution for model selection and validation purposes. However, model selection for these light curves is challenging due to complex noise structures and parameter degeneracies. We implement a Bayesian approach to model the LO light curves, incorporating multi-level priors to account for uncertainties in noise models and physical parameters. NS is employed to compute the Bayesian evidence, facilitating the comparison of competing models, such as single-star, binary, or multiple-stars configurations. Our methodology leverages NS^s ability to efficiently explore high-dimensional parameter spaces and marginalize over nuisance parameters, ensuring accurate model ranking and parameter estimation. We validate our approach using synthetic LO light curves generated from known stellar configurations. Our next step is incorporating this method as part of our lunar occultation pipeline to ensure the proper selection of the model. Keywords: bayesian, occultation, model selection Share Link | Plain Format | Corresponding Author (Agus Triono Puri Jatmiko)

66	Stellar Physics	ABS-22
X-ray Timing Study of Galactic Pulsating Ultraluminous X-ray Sources with NICER Bryant Randolph (1*), Kiki Vierdayanti(2), Tiara Andamari Saraswati(2) 1) Astronomy Studi Program, Faculty of Mathematics and Natural Science, Institut Teknologi Bandung *bryantrandolph03[at]gmail.com 2) Astronomy Research Group, Faculty of Mathematics and Natural Science, Institut Teknologi Bandung Abstract Ultraluminous X-ray Sources (ULXs) are accreting compact objects that are observed to be extremely luminous at the X-ray range, significantly exceeding the Eddington luminosity, indicating a potential new regime of accretion process. While majority of ULXs are extragalactic objects, recent studies have discovered such objects also within our own Galaxy which offered opportunity for a more in-depth study of ULXs. In this work, we performed timing study on two Galactic sources, Swift J0243.6+6124 and RX J0209.6-7427, during their super-Eddington outbursts observed using the Neutron Star Interior Composition ExploreR (NICER). Our timing analysis tracks the evolution of their Power Spectral Density (PSD), showing the presence of pulsation, Quasi Periodic Oscillations (QPOs) and time lags that correlates with the change in luminosity throughout the outburst, indicating significant structural change in the accretion disk. Additionally, spectral analysis was also performed with complementary data from NuSTAR mission to reach a wider energy range to provide a more detailed view on the super-Eddington accretion disk structure. Keywords: ULX- accretion- outburst- super-Eddington- timing analysis- NICER Share Link | Plain Format | Corresponding Author (Bryant Randolph)

67	Stellar Physics	ABS-23
Analysis Of The Colour-Magnitude Diagram Of The Open Cluster NGC 5822 Based On Observations Using The Itera Robotic Telescope Ahmad Habibi Syah (a), Hakim L. Malasan (b), Muhammad Isnaenda Ikhsan (a*)(b) a) Department of Atmospheric and Planetary Science, Institut Teknologi Sumatera, Jalan Ters. Ryacudu, Lampung Selatan, Indonesia *isnaenda.ikhsan[at]sap.itera.ac.id b) Department of Astronomy, Bandung Institute of Technology Jalan Ganesha 10, Bandung 40132, Indonesia Abstract Star clusters, groups of stars formed from a common nebular cloud, offer key insights into star formation, evolution, and properties like age, distance, and metallicity. In this research, a Colour-Magnitude Diagram (CMD) was constructed from observations using the ITERA Robotic Telescope (IRT) with Bessel B and V filters. Isochrone fitting was then applied to the CMD, producing a theoretical curve that represents the evolutionary stages of stars in the cluster and enables the extraction of key physical parameters. The target of this study is the open cluster NGC 5822, notable for its relatively young age and moderately high metallicity, characteristics that make it especially interesting for stellar and planetary formation studies. Based on the results of the isochrone fitting, the metallicity of NGC 5822 is found to be 0.013 \pm 0.001 ([Fe/H] = -0.137). Referring to the study by Debra A. Fischer and Jeff Valenti on the relationship between metallicity and exoplanet occurrence, clusters with a metallicity similar to NGC 5822 are estimated to have approximately 2\% of their stars hosting exoplanets. Isochrone fitting indicates that NGC 5822 lies at a distance of 529.91 \pm 18.07 parsecs, with a log(age) of 9.098 \pm 0.009, corresponding to an age of 1.256 billion years, and an interstellar extinction of 0.19 \pm 0.138. Keywords: Stars, Open Cluster, NGC 5822, Colour-Magnitude Diagram (CMD), Isochrone Share Link | Plain Format | Corresponding Author (Muhammad Isnaenda Ikhsan)

68	Stellar Physics	ABS-26
Multifrequency Methanol Maser Observations with the Ibaraki 32-m Radio Telescopes Sahlan Ramadhan(1), Yukika Murata(1), Ren Moriizumi(1), Yoshihiro Tanabe(2), Yoshinori Yonekura(1) (1)Ibaraki University (2)Yamaguchi University Abstract Methanol maser observation is one of the ways to study the formation processes of massive stars. Ibaraki University, using its Hitachi-32m and Takahagi-32m radio telescopes, routinely conducting daily monitoring observation of the variability of Class-II methanol masers. Hitachi-32m is observing at frequencies of 6.67 and 12.18 GHz, while Takahagi-32m is observing at frequencies of 19.97 and 23.12 GHz. Recently, Takahagi-32m detected rare emission from the object ID: 133.94+1.04 [other names: IRAS 02232+6138, also known as W3(OH)]. This report will discuss the correlation between these maser frequencies and their implications on star forming regions. Keywords: radio astronomy, methanol maser, star forming region Share Link | Plain Format | Corresponding Author (Sahlan Ramadhan)

69	Stellar Physics	ABS-31
Measurements of Visual Double Stars Orbit Satrio Fatkhusalma, Taufieq Zannata Ramadha, Hakim Al-Ikhsan, Muhammad Harits Al-Akbar, Fatimah Zahra Bosscha Observatory Astronomy Study Program, ITB Abstract Visual binary stars (commonly are called as double stars) are stellar pairs whose it^s component can be resolved through telescopic imaging. Study of these kind objects is fundamental topic in astronomy, due to it^s role as direct method for determining the most important properties of stellar physics, i.e. it^s mass. High-precision astrometric and photometric measurements which are obtained via CCD imaging, combined with data provided by Washington Double Star Catalog (WDS) enable us to calculate the orbit accurately. In this work, we report the result of double stars observations in 2025 using 8 inch (20 cm) Schmidt-Cassegrain telescope at Bosscha Observatory, Lembang. Observed objects were selected from WDS catalog. We carried position angle and separation angle calculation based on data we obtained from our observation using photutils.centroids in python mainly using 2 degree Gaussian and center of mass fitting function. Based on available WDS data and our data, we prioritize objects with \theta \leq 10 10 over the epoch from the first observation to 2025 to further calculate the orbit of each of these pairs. Throughout 2025, 182 binaries were selected and observed. Data points are fitted with least-square method, then we configurate the orbit using Danby^s Newton-Raphson for Kepler^s equation solution, thus we obtained the result presented here. Keywords: Visual double stars, Astrometric observation, Orbital fitting Share Link | Plain Format | Corresponding Author (Satrio Fatkhusalma)

70	Stellar Physics	ABS-32
Modeling the Equation of State of Ellipsoidal Neutron Stars with a Deep Learning Approach 1. Hasanain Arrosyid Alfiansyah (a*,b) - 2. Muhamad Irfan Hakim (a,b) - 3. Mochamad Ikbal Arifyanto (a,b) a) Department of Astronomy, Bandung Institute of Technology *arrosyidnumber4[at]gmail.com b) Bosscha Observatory, Bandung Institute of Technology Abstract Neutron star has extremely high density that makes particles in various unusual quantum state able to exist. It makes neutron star an important natural laboratory for stellar structure study and particle physics in general. In order to study the structure and composition of neutron star, the most essential equation is the equation of state, which is a function of pressure (P) vs density (\(\rho\)). Determining it is not easy because the incomplete theory and lack of observational data which espescially true for the innermost part. Various approaches have been done, including computational approaches using deep learning, as in the study by Yuki F et al. (2019). Here, we adapts and further explores the methods used in that study by incorporating ellipticity factor that were not previously accounted for. It is because some compact stars, including neutron star, may have significant ellipticity that can affect its structure. In this study, we built deep learning that map observational data, mass and radius, to the parameters of the equation of state, \(c_s^2 = dP/d\rho\), for various ellipticities. The prediction results are then compared to observational data to determine the most suitable model. This model is then used to map observational data to get the equation of state and mass-radius curve for each ellipticities. We concluded that the most suitable model is the one with perfectly spherical shape, as in Yuki F et al. (2019). This model produces equations of state that are consistent with previous theoretical models. Furthermore, a consistent trend was found in the mass-radius curve, where a 10% increase in ellipticity causes approximately 15% and 10% increases in the mass and radius of the star, respectively, in line with the study by Zubairi, O., et al. (2015). As such, the implication that multiple mass-radius curves can occur from a single equation of state could be a key in understanding observational data that has increasingly wide range of masses. Keywords: neutron star, equation of state, deep learning, ellipticity, mass-radius curve Share Link | Plain Format | Corresponding Author (Hasanain Arrosyid Alfiansyah)

71	Stellar Physics	ABS-36
The Observation of AM CVn type star SDSS J080449.49+161624.8 Chatief Kunjaya (a,b,c*), Keisuke Isogai (d,e), Daisaku Nogami (d), Rafa N. Akilah (a), Tian A. Bayuadri (a), Sahabista A. Armantara (a), Kiki Vierdayanti (a,c), Fumihide Iwamuro (d), Anton T. Jaelani (a,c), Putra Mahasena (a,c), Yusuke Tampo (f,g) a) FMIPA, Intitut Teknologi Bandung, Jl. Ganesa 10, Bandung 40132, Indonesia *kunjaya[at]itb.ac.id b) University Center of Excellence for Space Science Technology and Innovation, Jl. Ganesa 10, Bandung 40132, Indonesia c) Bosscha Observatory, Jl. Peneropongan Bintang 1, Lembang 40391, Indonesia d) Department of Astronomy, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto-shi, Kyoto 606-8502, Japan e) Okayama Observatory, Kyoto University, 3037-5 Honjo, Kamogata-cho, Asakuchi-shi, Okayama 719-0232, Japan f) South African Astronomical Observatory, PO Box 9, Observatory, 7935, Cape Town, South Africa g) Department of Astronomy, University of Cape Town, Private Bag X3, Rondebosch 7701, South Africa Abstract AM CVn type stars are ultra short period binary below the minimum period of Cataclysmic Variables. The components are very close to each other so that their hydrogen was stripped off during second common envelope phase, resulting in little or no hydrogen lines in their spectra. It is expected that it evolves from Cataclysmic Variables with angular momentum losses by magnetic braking and/or gravitational wave radiation. SDSS J080449.49+161624.8 is an AM CVn type cataclysmic variable which has 44.5 minutes orbital period. We observed the star in February 2024 using Seimei 3.8m Telescope at Okayama Astrophysical Observatory. The spectra showed several elements dominated by neutral and ionized Helium, other elements detected are NII and SiII. This indicates a high temperature system with Helium as dominant material without Hydrogen. Keywords: Stars: individual : SDSS J080449.49+161624.8, Stars: variables: AM CVn, Cataclysmic Variables Share Link | Plain Format | Corresponding Author (Chatief Kunjaya)

72	Stellar Physics	ABS-41
A Study of the Circumstellar Envelopes of \(\delta\) Centauri and \(\eta\) Centauri Based on H\(\alpha\) Line and Geometric Modeling Amandaru Taruna Mandala, Hakim L. Malasan Institut Teknologi Bandung Abstract This study investigates the envelope dynamics of two southern Be stars, \(\delta\) Centauri and \(\eta\) Centauri, using observational data from the Bosscha Observatory and the BeSS database. \(\delta\) Centauri was identified as a binary star in 2008 via spectro-interferometry, while \(\eta\) Centauri exhibits rapid photometric and spectroscopic variability on timescales of hours to days. The findings of this study present an initial interpretation of the complex physical mechanisms involved, including possible binary interaction driving the variability in \(\delta\) Centauri and pulsation-driven mass ejections in \(\eta\) Centauri. High-resolution analysis of the H\(\alpha\) line reveals complex and distinct envelope dynamics in both stars. In \(\delta\) Centauri, a temporary profile change from a double-peak to a single-peak was observed, which is hypothesized to be a consequence of a polar mass ejection triggered by Non-Radial Pulsations (NRPs). The presence of perturbations on the line peaks also indicates a likely interaction with the companion star. For \(\eta\) Centauri, an increase in absorption strength, correlated with the E/C ratio, signifies a new injection of matter into the envelope. Supported by additional photometric data, this variability is consistent with a beat cycle mechanism (0.035 c/d) driven by NRPs, causing periodic mass ejections and the observed expansion of the gaseous disk. To support future studies, a preliminary qualitative 3D model depicting the geometry of the Be star^s circumstellar envelope has also been successfully developed. Keywords: Be Star, Spectroscopy, H\(\alpha\), Modeling, Envelope, Binary, NRP Share Link | Plain Format | Corresponding Author (Amandaru Taruna Mandala)

73	Stellar Physics	ABS-43
The Study of Solar Proton Events Characteristics in Solar Cycle 24 Using Principal Component Analysis Firshanda Alvyanita (a*), Dhani Herdiwijaya (a), Santana Despon Solina (a), Lingga Hanum (a) a) Faculty of Mathematics and Natural Science, Bandung Institute of Technology Jalan Ganesha 10, Bandung 40132, Indonesia *firshandaalvyanita[at]gmail.com Abstract Solar Proton Events (SPEs) are marked by flux increases from protons in energetic solar particles (SEPs). Energetic solar particles are produced through acceleration mechanisms. In existing studies, these acceleration mechanisms of energetic solar particles are thought to be associated with eruptive phenomena on the Sun, specifically solar flares and coronal mass ejections (CMEs). SPEs have a significant impact on space weather, potentially causing geomagnetic storms on Earth. Therefore, it is necessary to study the parameters of flares and CMEs that can influence SPEs. This can be used to understand the origin of energetic particles, their acceleration mechanisms, and their propagation in interplanetary space towards Earth. In this study, an SPE dataset from solar cycle 24 (2009-2019) consisting of 99 SPEs with a maximum proton flux greater than 1 pfu was used. This dataset includes both SPE parameter data and phenomena associated with SPEs (flares and CMEs). From that, a statistical analysis was carried out using Principal Component Analysis (PCA) on the parameters of solar flares and coronal mass ejections (CMEs) to investigate their correlation with the parameter of SPEs. The solar flares and CMEs parameters used in this study consist of six variables: flare soft X-ray flux, flare duration, flare longitude, CME speed, CME angular width, and CME position angle. The results of this study showed that CME speed is the parameter most correlated with SPE parameters, especially the maximum proton flux. Keywords: Solar Proton Events- Flares- Coronal Mass Ejections- Principal Component Analysis Share Link | Plain Format | Corresponding Author (Firshanda Alvyanita)

74	Stellar Physics	ABS-46
Unveiling Oxygen Past with Subaru/IRD: Oxygen Abundance of Very Metal-Poor Stars Bakuh Danang Setyo Budi (1,2*), Wako Aoki (1,2), Nick Storm (3), Miho Ishigaki (2), Tadafumi Matsuno (4) (1) Astronomical Science Program, The Graduate University for Advanced Studies, SOKENDAI, Mitaka, Tokyo, Japan *danang.budi[at]grad.nao.ac.jp (2) National Astronomical Observatory of Japan, Mitaka, Tokyo, Japan (3) MPIA, Heidelberg, Germany (4) Heidelberg University Abstract Oxygen, the third most abundant element in the universe, is mainly synthesized in massive stars by carbon-alpha capture reaction. Determining oxygen abundances in very metal-poor (VMP) stars ([Fe/H] < -3.0 ) is very challenging due to the weak and telluric-contaminated [OI] 630.03 nm forbidden line, the most reliable O indicator. It is widely known for O overabundance in VMP stars ([O/Fe] ~ 0.5), identifying stars with lower oxygen content requires alternative tracers. This study assesses the reliability of near-infrared OH vibration-rotation lines as oxygen indicators where the [OI] line is inaccessible. We analyse high-resolution Subaru/IRD spectra (R = 70,000), covering first-overtone OH lines in the H-band (1500-1700 nm), to derive oxygen abundances for 35 VMP stars using 1D/LTE model atmospheres. Comparing the O abundance from near-IR OH lines with optical [OI] line reveals OH abundances are very sensitive to the input stellar parameters, especially effective temperature and surface gravity. Significant scatter founds in the [O(OH)/Fe] versus [Fe/H] relation, notably in cooler or hotter red giants, where OH abundances are much lower or higher than [OI] abundances. In contrast, [O([OI])/Fe] values show less scatter, aligning with Galactic Chemical Evolution models. Future work will include 3D/LTE effects to enhance [OI] line abundance accuracy and address discrepancies between indicators. This study highlights limitations of OH lines for oxygen abundance determination with 1D/LTE methods. In the end of presentation, we will give a brief report progress on another project of Radial Velocity monitoring of VMP spectroscopic binaries with Seimei/GAOES-RV, with aims to determine chemical abundance pattern including lithium and neutron-capture element abundance for each component in the metal-poor binaries. This research may give some insight of potential studies with the new 3.8m telescope at Timau National Observatory. Keywords: Stellar abundances - Nucleosynthesis - Galaxy chemical evolution - Population III stars Share Link | Plain Format | Corresponding Author (Bakuh Danang Setyo Budi)

75	Stellar Physics	ABS-73
From early universe to current universe : The impact of massive stars throughout the cosmic time Norhasliza Yusof Department of Physics, Universiti Malaya Abstract In this talk, I will present our latest work where we exploit the large grid of GENEC models, covering initial masses from 9 to 500 M&#8857- and metallicities ranging from Z = 0 to 0.02, to determine the impact of rotation on their fate across cosmic times. We identify the fate of the stars based on the production of carbon-oxygen core mass and studied the impact of the fate to the supernova and it^s remnants. We also explored the location of pair instability mass gap where is important in the gravitational wave detection. Keywords: massive stars Share Link | Plain Format | Corresponding Author (Norhasliza Yusof)

76	Stellar Physics	ABS-78
Photometric Observation of Dwarf Nova IP Pegasii Using CAT-ITB Telescope N. F. Nurindra, C. Kunjaya, H. L. Malasan, M. Putra, M. Z. Aprianizar Institut Teknologi Bandung Abstract Cataclysmic binaries are a type of star system in which mass transfer from one star to its companion occurs. One type of cataclysmic binary is dwarf nova. Photometric observations of the dwarf nova IP Pegasii were done to determine the characteristics of the dwarf nova light curve using a small telescope in a city with light pollution. Observations were made using the CAT-ITB telescope at the ITB Astronomy Study Program. The light curve obtained through image processing has a shape and trend similar to the light curve in previous observations but does not clearly show the egress profile of the white dwarf and hotspot. Through comparison of the time of minima between two nights of observation, a period of 3.79200 hours was obtained. There is a difference of \(\sim 4.5\) seconds with the period taken from previous studies. From the calculation of the accretion disk radius, it was found that the accretion disk radius on September 28th 2024 was \( R_{D}/R_1 = 0.76915 \) and on September 30th 2024 was \( R_{D}/R_1 = 0.83609 \). Both values are in the range of \( R_{D}/R_1 \) IP Pegasii taken from previous studies. Keywords: stars: cataclysmic variables, stars: dwarf novae, binaries: eclipsing, stars: individual: IP Pegasii Share Link | Plain Format | Corresponding Author (Naufal Farras Nurindra)

77	Stellar Physics	ABS-88
Time of Minima Analysis of Eclipsing Binaries MV Car, V0604 Car, AD CnC, MQ CnC, and KV Gem E. I. Akbar(a*), A. T. Mandala(a), N. F. Nurindra(a), F. A. Firmansyah(a), A.S. Chandradewani(a), H. L. Malasan(a,b), B. D. S. Budi (c), P. Irawati (d) a) Astronomy Study Program, Institut Teknologi Bandung, Indonesia *evan[at]itb.ac.id b) Bosscha Observatory, Indonesia c) The Graduate University for Advanced Studies, SOKENDAI, Japan d) National Astronomical Research Institute of Thailand, Thailand Abstract We present 30 times of minima for five short-period eclipsing binaries. The observational data were collected using the Thai Robotic Telescope (TRT) network between January and April 2024. The times of minima were calculated using the Kwee-van Woerden method. We also used data from ASAS, TESS, and the AAVSO^s Bob Nelson O-C database to perform O-C analysis and determine the orbital periods of these systems. The O-C diagram for KV Gem shows a changing period in a cyclic phenomenon, suggesting mass transfer between the stars, apsidal motion, or the presence of a third body. The O-C diagram for MQ CnC and AD CnC shows a straight line going downward, indicating shorter period change. As for the V0604 Car and MV Car, there were no times of minima reported before, so further analysis cannot be done. This work is part of the BIMA project, a collaborative effort between Bosscha Observatory and the National Astronomical Research Institute of Thailand (NARIT). Keywords: eclipsing binary, time of minima, O-C diagram Share Link | Plain Format | Corresponding Author (Evan I Akbar)

Page 3 (data 61 to 77 of 77) | Displayed ini 30 data/page
<< PREV 1 2 3

Powered By Konfrenzi Ultimate 1.832M-Build8 © 2007-2026 All Rights Reserved