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All Journal Jurnal Matematika & Sains Journal of Mathematical and Fundamental Sciences Religio : Jurnal Studi Agama-agama Gravity : Jurnal Ilmiah Penelitian dan Pembelajaran Fisika Jurnal Otomasi Kontrol dan Instrumentasi Mutawatir : Jurnal Keilmuan Tafsir Hadith Journal of Multidisciplinary Applied Natural Science Prosiding Seminar Nasional Sains Teknologi dan Inovasi Indonesia (Senastindo) Indonesian Journal of Physics (IJP) Equator Science Journal (ESJ) Sunan Kalijaga Journal of Physics
Dhani Herdiwijaya
Institut Teknologi Bandung
Religion Agriculture, Biological Sciences & Forestry Humanities Astronomy Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Computer Science & IT Control & Systems Engineering Earth & Planetary Sciences Education Electrical & Electronics Engineering Energy Engineering Environmental Science Immunology & microbiology Industrial & Manufacturing Engineering Materials Science & Nanotechnology Mathematics Mechanical Engineering Physics Social Sciences Other

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The Probability of Flare Occurrences Based on Sunspot Group and Magnetic Configurations Dhani Herdiwijaya; Sherly Imelda
Jurnal Matematika & Sains Vol 11, No 2 (2006)
Publisher : Institut Teknologi Bandung

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Abstract

We study the probability of flare occurrences observed in Hα and X-ray based on the classification and evolution of sunspot group and the magnetic structure within period 1994 to 2001. We found that there was a strong correlation between flare occurrences with the morphology and configuration of sunspot group and the magnetic structure. We also found that simple sunspot groups move more slowly before flare event, whereas complex groups move faster. On the other hand we did not find correlation between maximum area of sunspot group and the intensity of solar flare.
Interpretasi Global Hadis Rukyat Hilal Rusmin, Pranoto Hidaya; Rohman, Arief Syaichu; Herdiwijaya, Dhani; Khaerani, Izzah Faizah Siti Rusydati; Pahlevi, Reza; Darmawan, Dadang
Mutawatir : Jurnal Keilmuan Tafsir Hadith Vol 7 No 1 (2017): JUNI
Publisher : Program Studi Perbandingan Agama, Fakultas Ushuluddin dan Filsafat, Universitas Islam Negeri (UIN) Sunan Ampel Surabaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (619.584 KB) | DOI: 10.15642/mutawatir.2017.7.1.50-75

Abstract

Before Islamic Calendar begins, Muslims were used to wait for the earliest visible crescent (hilâl), which marks the beginning of Ramadan. The determination of the beginning of Ramadan is based on the rukyat al-hilâl hadith. Because the hilâl visibility on the earth surface is not the same, it results the differences on the beginning of Ramadan fasting. In addition, the sighting hilâl method can only determine the next 29 days, it cannot reach for the next month and even for the next year. These are the main reasons for re-interpretation of the rukyat al-hilâl hadith from global perspective. From this study, it is found that the context in the Qur’an, related to the Ramadan fasting, is fasting in one full month, 29 or 30 days, according to the duration of the lunar synodic cycle. However, the condition of the people and the science at that time has not developed yet, which is the cause of calculation (h}isâb) verses in the Qur’an cannot be used. When they have developed, the calculation verses in the Qur’an can be used to determine the number of days in a calendar month. This will produce a global calendar for mankind.
INTERPRETASI GLOBAL HADIS RUKYAT HILAL Rusmin, Pranoto Hidaya; Rohman, Arief Syaichu; Herdiwijaya, Dhani; Khaerani, Izzah Faizah Siti Rusydati; Pahlevi, Reza; Darmawan, Dadang
Mutawatir : Jurnal Keilmuan Tafsir Hadith Vol. 7 No. 1 (2017): JUNI
Publisher : Program Studi Perbandingan Agama, Fakultas Ushuluddin dan Filsafat, Universitas Islam Negeri (UIN) Sunan Ampel Surabaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (619.584 KB) | DOI: 10.15642/mutawatir.2017.7.1.50-75

Abstract

Before Islamic Calendar begins, Muslims were used to wait for the earliest visible crescent (hilâl), which marks the beginning of Ramadan. The determination of the beginning of Ramadan is based on the rukyat al-hilâl hadith. Because the hilâl visibility on the earth surface is not the same, it results the differences on the beginning of Ramadan fasting. In addition, the sighting hilâl method can only determine the next 29 days, it cannot reach for the next month and even for the next year. These are the main reasons for re-interpretation of the rukyat al-hilâl hadith from global perspective. From this study, it is found that the context in the Qur?an, related to the Ramadan fasting, is fasting in one full month, 29 or 30 days, according to the duration of the lunar synodic cycle. However, the condition of the people and the science at that time has not developed yet, which is the cause of calculation (h}isâb) verses in the Qur?an cannot be used. When they have developed, the calculation verses in the Qur?an can be used to determine the number of days in a calendar month. This will produce a global calendar for mankind.
Multi-wavelength Fibril Dynamics and Oscillations above Sunspot-II Wave Propagation Signature Emanuel Sungging Mumpuni; Dhani Herdiwijaya; Mitra Djamal; Thomas Djamaluddin
Journal of Mathematical and Fundamental Sciences Vol. 50 No. 3 (2018)
Publisher : Institute for Research and Community Services (LPPM) ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.math.fund.sci.2018.50.3.4

Abstract

In this work, the dynamics of one particular fibril were investigated through high-resolution multi-wavelength images with high cadence obtained from the Dutch Open Telescope. Based on exceptional observation data of Active Region 10789, 13th July 2005, we investigated the alternating fibril pattern using tomography of the multi-wavelength band, consisting of the hydrogen alpha line center and also the blue wing, the calcium II H line, and the G-band. Phase difference and coherence analyses were conducted for several points along the fibril and (k, ω) analysis was conducted to understand the wave interaction and its mechanism in the propagation process. Our findings suggest short- to long-period transitions along the fibril with coherence in 10-min oscillations in the penumbra.
Design of Mobile and Robotic Observing System with Special Telescope Baffle for Searching Young Lunar Crescent Dhani Herdiwijaya; Mitra Djamal; Hendra Gunawan
Jurnal Otomasi Kontrol dan Instrumentasi Vol 4 No 1 (2012): Jurnal Otomasi Kontrol dan Instrumentasi
Publisher : Pusat Teknologi Instrumentasi dan Otomasi (PTIO) - Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/joki.2012.4.1.1

Abstract

The visibility of very young lunar crescent near the Sun at western horizon after sunset are indispensable important factor in determining important religious Islamic calendar. One can see it at horizon after the sunset as this is the less stringent condition However, in an advanced scientific and technological based, the observation of lunar crescent near the Sun can be undertaken in broad daylight before sunset. The research project will study and develop some additional observing tools, image acquisition and image processing procedures for mobile and robotic observing system that one enable to search the very young crescent in broad daylight. The main problem is how to minimize the atmospheric and instrumental stray light that can obscure the information from the very young crescent image from the daylight background. We have developed and tested a simple extended telescope baffle that can reduce the incoming stray light from the sky and environment. Hence, it will increase the contrast of the lunar crescent. Some requirements and optimization have been applied for the robotic observing system (telescope and its mounting), image acquisition and image processing procedures. The free software and digital camera are used. The observational main constraint was the cloudy sky on the first day of lunar calendar. The progresses will be reported
Fraktal dan Variabilitas dalam Siklus Bintik Matahari Dhani Herdiwijaya; Baju Indradjaja
Indonesian Journal of Physics Vol 13 No 2 (2002): Vol. 13 No.2, April 2002
Publisher : Institut Teknologi Bandung

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Abstract

Monthly sunspot numbers during period 1749 to 2000 were used to determine their fractal properties. Lomb’s algoritm and Morlet wavelet were applied to detect the distinct period of 11 year. By using Detrended Fluctuations Analysis (DFA), fractal dimension was measured. It is shown that during the last two centiries, 11-year wavelet amplitude showed doubled increment, in contrast with Gleissberg period. The evolution of fractal dimension varied in between 0.5 to 1.5, which imply that sunspot number time series are nonstationary and correlated to each other within 132-year period. The detected cross-over feature at D=1.3 corresponds to 11-year period and granulation size.
DIY photometer in determining the beginning of dawn time in Cimahi City Cahyo Puji Asmoro; Hana Susanti; Judhistira Aria Utama; Dhani Herdiwijaya
Gravity : Jurnal Ilmiah Penelitian dan Pembelajaran Fisika Vol 10 No 1 (2024)
Publisher : Universitas Sultan Ageng Tirtayasa

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30870/gravity.v10i1.22873

Abstract

The use of SQM as a calibrated portable photometer is currently a hot topic in astronomical research in terms of measuring the brightness of the night sky; DIY Sky Quality Meter (SQM) with the name Photometer D.I.Y – CJ'01 has been successfully made and tested on a limited basis, the output data obtained by the photometer This is the magnitude value per square arc second (mag/sq arc second ~ mpsas). This research aims to determine the performance of the D.I.Y - CJ'01 Photometer in measuring the night sky's brightness to determine the start of dawn. The research method used was an experiment with data collection from the D.I.Y Photometer – CJ'01 and SQM Unihedron in Cimahi City during the New Moon and Full Moon. The results of data processing using the solver method show that the D.I.Y - CJ'01 Photometer has almost the same performance as the SQM Unihedron based on the inflection point value that determines the start of dawn and also indicates the existence of pseudo-night in the city of Cimahi which is by typical urban areas dominated by light pollution and air pollution
Evaluasi Kejadian dan Indikator Fisis Skala Cuaca Antariksa berdasarkan Variasi Angin Matahari tahun 1963 – 2023 (Evaluation Occurance and Physical Indicators of Space Weather Scale based on Solar Wind Variations in 1963 to 2023) Herdiwijaya, Dhani
Prosiding Seminar Nasional Sains Teknologi dan Inovasi Indonesia (SENASTINDO) Vol. 6 (2024): Prosiding Seminar Nasional Sains Teknologi dan Inovasi Indonesia (Senastindo)
Publisher : Akademi Angkatan Udara

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Abstract

Space weather refers to changes in environmental conditions in near-Earth space as a consequence of the behaviour of the Sun, the nature of the magnetic field of interplanetary space, and the Earth's atmosphere, in particular the magnetosphere and ionosphere layers. The components of space weather are plasma particles, electromagnetic energy and magnetic fields. Solar activity always emits plasma particles into space and creates a plasma stream known as the solar wind. The energetic phenomenon of solar activity comes from solar explosions and corona mass ejections that can cause extreme space weather, namely geomagnetic storms. The intense energy of these storms can damage satellites, disable satellite communications and navigation, disrupt power grids on Earth's surface, and be dangerous to spacecraft. The NOAA (National Oceanographic and Atmospheric Agency) Space Weather Scale, USA was introduced as a way to communicate to the general public about current and future space weather conditions and their possible impacts on humans and space technology systems. The scale is useful for space technology users and those interested in the effects of space weather on spacecraft. The scale describes space environment disturbances for three types of events: geomagnetic storms, solar radiation storms, and radio blackouts. The scale has levels from low to high that are numbered 1 to 5, indicating severity. Each level also lists the likelihood of the impact occurring, the frequency with which the event occurs, and provides a measure of the intensity of the physical cause. The NOAA space weather scale evaluation was conducted for 60 years of solar wind data. Geomagnetic storms with Kp index indicator (N=525960) extreme scale (scale 5) with Kp index of 9 is only 0.11% (N=597). Solar radiation storms with an indicator of proton flux energy> 10 MeV (N = 365015) there are no extreme scale achievements, namely 100 000 particles. The highest flux was 67749 particles (scale 4). Most of the flux (99.85%) was below 1000 proton particles. The extreme radio storm (scale 5), with a solar flare strength of more than X20, has only occurred five times (from 1976 to 2023).
Koneksi Matahari-Bumi 25 - 26 Agustus 2018: CME, MC, dan Badai Geomagnetik Kuat Khamdani, Muhamad; Herdiwijaya, Dhani
Sunan Kalijaga Journal of Physics Vol. 2 No. 1 (2020): Sunan Kalijaga Journal of Physics
Publisher : Prodi Fisika Fakultas Sains dan Teknologi UIN Sunan Kalijaga Yogyakarta

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Abstract

Basis Revolusi Industri 4.0 adalah perkembangan teknologi, termasuk teknologi informasi dan komunikasi yang sangat rentan terdampak cuaca antariksa. Baik berupa gangguan sementara atau kerusakan permanen pada sistem teknologi landas Bumi dan, terlebih teknologi ruang angkasa. Dampak masif badai geomagnetik menjadikannya dianggap sebagai inti dari cuaca antariksa. Data per jam parameter geomagnet (indeks Dst) menunjukkan terjadinya badai geomagnetik kuat selama 9 jam pada 26 Agustus 2018. Puncak badai geomagnetik kuat ini terjadi pada pukul 06:00 UT dengan indeks Dst -174 nT. Tujuan dari penelitian adalah mengetahui penyebab badai geomagnetik kuat yang terjadi pada fase menurun siklus Matahari ke-24, baik yang berada di ruang antar planet maupun di permukaan Matahari. Data plasma angin surya, medan magnet antar planet, dan parameter geomagnet yang digunakan dalam penelitian diperoleh dari laman OMNIWeb Plus yang disediakan oleh The Space Physics Data Facility (SPDF) dengan resolusi satu jam, sementara data lontaran massa korona (CME) diperoleh dari laman katalog CME yang dihasilkan dan dikelola oleh Coordinate Data Analysis Workshop (CDAW) Data Center. Berdasarkan analisis data (kecepatan dan temperatur) plasma dan rapat proton angin surya, medan magnet antar planet (komponen By dan Bz), dan turunan keduanya, kami menemukan awan magnetik (MC) di ruang antar planet. Dengan demikian, dapat disimpulkan bahwa penyebab badai geomagnetik ini adalah lontaran massa korona yang terdapat di ruang antar planet (ICME). Lebih lanjut, keberadaan CME dan kondisi permukaan Matahari didiskusikan dalam tulisan ini. Penelitian ini penting untuk mematangkan pengetahuan dan teknologi yang dikembangkan untuk memprediksi cuaca antariksa beserta mitigasi dampaknya.
Correlation of Solar Activity and Interplanetary Parameters on Cosmic rays Intensity Investigated through Multivariate Analysis from 1964 to 2020 Putri, Annisa Novia Indra; Herdiwijaya, Dhani
Journal of Multidisciplinary Applied Natural Science Articles in Press
Publisher : Pandawa Institute

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.47352/jmans.2774-3047.369

Abstract

This study investigated the relationship between the most influential solar and interplanetary plasma parameters and cosmic ray modulation. A principal component analysis (PCA) method was used. The variations of the cosmic ray intensity were obtained at 6 different locations with different latitudes and cutoff rigidities. These stations were located at mid- to high latitudes (SOPO, OULU, and NEWK), while the remaining three were located at low latitudes (MXCO, TSMB, and PSNM). A parameter ranking based on PCA confirmed that sunspot number, interplanetary magnetic field (IMF) magnitude, heliospheric current sheet (HCS) tilt, halo coronal mass ejection (CME) velocity, Bz, and proton density have the highest link with the modulation of cosmic ray intensity. Meanwhile, the PCA analysis at low latitudes revealed that the cone angle and the magnetic field components By and Bx along the y- and x-axes, the mean magnetic field of the Sun, the HCS tilt, and the IMF magnitude exert the greatest correlation on the cosmic ray intensity modulation at this station. The correlation between the analyzed parameters and cosmic ray modulation appears to vary with latitude.
Co-Authors A.A. Ketut Agung Cahyawan W Abdul Salam Achmad Fariz Arief Syaichu Rohman, Arief Syaichu Asep Akmal Fadia Nurhalim Asmoro, Cahyo Puji Baju Indradjaja Dadang Darmawan Emanuel Sungging Mumpuni Hana Susanti Judhistira Aria Utama Khamdani, Muhamad Mitra Djamal Najmi Hiyan Fathinah Pranoto Hidaya Rusmin Putri, Annisa Novia Indra Rani Nur Widiawati REZA PAHLEVI Rusydati Khaerani , IzzahFaizah Siti Sherly Imelda Thomas Djamaluddin