N.N.M. Shariff

Indication of Radio Frequency Interference (RFI) sources for solar burst monitoring in Malaysia

Apart of monitoring the Sun project, the Radio Frequency Interference (RFI) surveying in the region of (1-1200) MHz has been conducted. The main objective of this surveying is to test and qualify the potential of monitoring a continuous radio emission of Solar in Malaysia. This work is also an initiative of International Space Weather Initiative (ISWI) project where Malaysia is one of the country that participate a e-Callisto Spectrometer network in order to study the behavior of Solar radio burst in frequency of (45-800) MHz region which will be install in this October. Detail results will indicate the potential of monitoring a solar in Malaysia.

Designing and Constructing Log Periodic Dipole Antenna to Monitor Solar Radio Burst: e-Callisto Space Weather

A Log Periodic Dipole Antenna (LPDA) for solar burst monitor in the range of (45 -870) MHz applications is presented. In this paper, we make an effort in designing a portable LPDA that suitable with the criteria, specification and practical enough although is the boom length size of the antenna is 5.45 meter. We choose value of 0.14 spacing factor τ= 0.8 as a directivity of antenna. This LPDA is constructed by using two (2) rod aluminums type with nineteenth (19) elements of different sizes. Some of suggestions on improving this design are also presented.

Observations of coronal mass ejections (CMEs) at low frequency radio region on 15th April 2012

We have carried out a case study on Coronal Mass Ejections (CMEs) as a massive burst of solar wind and magnetic fields rising above the solar corona. During 15th April 2012, solar filament eruption was accompanied by intense CMEs. This explosion of CMEs observed by the Solar Dynamics Observatory with sunspot AR1458 is crackling with C–class solar flares. Solar flare type B3 and C2 were observed beginning 2241 UT and 0142 UT in the active region AR1458. In the present work, we focus in the range of the low frequency region from 150 MHz to 400 MHz. At preliminary stage, starting from 12.00 UT till 1.00 UT there is a strong signal which indicates a formation of burst. Type II burst originated from solar corona can be observed in the range of 150 MHz to 230 MHz. Instead of type II, a moving type IV and continuum type III burst can be detected at 150 MHz and lasting for 1 hours. This event is considered as second largest CMEs been detected since five (5) years. We can then conclude that currently, the Sun is i...

Dynamical structure of solar radio burst type III as evidence of energy of solar flares

Observations of low frequency solar type III radio bursts associated with the ejection of plasma oscillations localized disturbance is due to excitation atoms in the plasma frequency incoherent radiations play a dominant role at the meter and decimeter wavelengths. Here, we report the results of the dynamical structure of solar flare type III that occurred on 9th March 2012 at National Space Centre, Sg Lang, Selangor, Malaysia by using the CALLISTO system. These bursts are associated with solar flare type M6 which suddenly ejected in the active region AR 1429 starting at 03:32 UT and ending at 05:00 UT with the peak at 04:12 UT. The observation showed an initial strong burst occurred due to strong signal at the beginning of the phase. We also found that both solar burst and flares tend to be a numerous on the same day and probability of chance coincidence is high. It is clearly seen that an impulsive lace burst was detected at 4:24 UT and it is more plausible that the energies are confined to the top of t...

Evaluation of signal to noise ratio (SNR) of log periodic dipole antenna (LPDA)

Logarithmic periodic dipole antenna (LPDA) was constructed for monitoring Sun in the range of (45 -870) MHz to precisely match the solar monitoring requirements. In our work, we choose rod aluminiums type as a conductor with nineteenth (19) elements of different sizes. Beside established construction techniques, several test setups have done to make sure that we possibly obtain a good data. The performance testing has been done at National Space Agency (PAN), Sg. Lang, Banting Selangor by connecting to the CALLISTO spectrometer. In this case, we choose input impedance, R0 = 50 ohm for this LPDA antenna. We also select element factor (τ) and spacing factor (σ) give in the subtended angle of 3.43 degrees. As a result, a bandwidth ratio (B = 870 MHz /45MHz) of 19.33 gives a bandwidth as 2.14. The power flux density of the burst is 4.53841 × 10-21 W/m2Hz. From the evaluation, we found that the signal to noise ratio is 3.9 dB. Although there are still needs to be improved, this construction of LPDA is considered successful and suitable for to observe the Sun activities at low frequencies.

Magnetic Reconnection of Solar Flare Detected by Solar Radio Burst Type III

The Sun is an ideal object of a blackbody with a large and complex magnetic field. In solar activity specifically solar flare phenomenon, the magnetic reconnection is one of the most significant factors of the Sun that can simplify a better understanding of our nearest star. This factor is due to the motion of the plasma and other particles through the convection mechanism inside the Sun. In our work, we will highlight one of the solar burst events that associated with solar flares. This event occurred on 13th November 2012 from 2:00:03 UT till 2:00:06 UT. It peaked with M2.0 solar flare at 2.04 UT. Within short time intervals of about l02 ~ 103s, large quantities of energy of 1022 ~ 1026J are emancipated. The changing magnetic field converts magnetic potential energy into kinetic energy by accelerating plasmas in the solar corona. It is believed that the plasma is channelled by the magnetic field up and away from the Sun. It is also accelerated back down along the magnetic field into the chromosphere. In conclusion, we showed that the structure of the solar radio burst type III is an indicator of a starting point of magnetic reconnection.

Effect of light pollution on night sky limiting magnitude and sky quality in selected areas in Malaysia

We investigate the effect of light pollution as the important considerations that limits the quality of the sky brightness for the astronomical purpose. Selected sites that covered: Klang, Selangor, Merlimau Melaka, Ipoh, Perak ad Kuala Lipis, Pahang, Malaysia have been chosen in order to investigate the visual estimation magnitude for observing visible stars. The results also based on Bortle scale theory provides glimpses of potential quality of night sky quality that is currently lost in most urban area in Malaysia. From the results, Kuala Lipis, Pahang is the best candidate site for astronomical purpose with the range of magnitude from 20.3 till 21.5 magnitudes per arc second. Some recommendation for a better solution will also be discussed.

The significance of e-CALLISTO system and construction of log periodic dipole antenna (LPDA) and CALLISTO system for solar radio burst study

The solar radio burst data by using the e-CALLISTO (Compound Astronomical Low-cost Low-frequency Instrument for Spectroscopy in Transportable Observatory) network is presented. This project is an alternative to support new country that interested in solar astrophysics. Until now, there are 45 sites used the same system over the world. In this system, we are monitor the solar activity in the range of (45- 870 MHz) using a Log Periodic Dipole Antenna (LPDA). The International Space Weather Initiative (ISWI) program was conducting this project in order to observe the solar activities within 24 hours per day and a portable LPDA were designed which suitable with the criteria with boom length size of the antenna. The rod has gain about 7.01 dB and has 19 elements which made up by two (2) aluminums rods. The rod aluminum are built in order to signify different frequencies. The gain of the antenna is very important for preamplifier to amplify the signal of the sun. There are some suggestions on improving design also presented.

Solar Radio Bursts Detected by CALLISTO System and Their Related Events

The solar radio bursts are the results of solar flares take place on the surface of the Sun. Some of them could reach the surface of the Earth and can be detected by the ground base antenna. The CALLISTO system is used to interpret the radio bursts that have been detected by the antenna before the results appeared on the computers screen. The CALLISTO system consists of software and hardware with the aim to observe the solar radio emission for astronomical science. There are five types of solar radio bursts that have been classified based on their characteristics since 1960s. However, all these types of solar radio bursts have their own related events due to different process before their formations. Based on the result, it shows that all related events of the bursts such as Coronal Mass Ejections, prominences and flares occurred several minutes or hours before the bursts appeared on the computers screen.

The Application of Sky Quality Meter at Twilight for Islamic Prayer Time

Abstract —The aim of this study is to detect elusive light that indicate the prayer time (Isha’). Therefore, we focused on optical sky brightness at dusk from May 2007 through April 2008 intermittently. The measurements of twilight sky brightness were covered at one (1) site covering; West coast of Peninsular Malaysia. The measurements were done by applying Sky Quality Meter (SQM) which covered between 400-700 nm in accordance of human eyes and SQM range. Results showed that there are clear indications of light changes when Sun at certain degree below horizon that visible by plateau form in twilight sky brightness dependences versus solar zenith angle. It is clarified that the yearly averages of solar depression by observation are best correlated within the range of 17.3o – 19.5o for Isha’. Index Terms —Twilight; prayer time; sky quality meter. I. I NTRODUCTION Early studies done by astronomers such as Ibn Muadh, al-Biruni, al-Qayini, Ibn Yunus etc.[1], [2]. Ibn al-Shatir adopted various value for each prayer times such as 17