Solar activities eject high energetic particles, instead of electromagnetic radiation. The well-know solar activity main indicator is the existence of sunspot which has mean variation in 11 years, named by solar cycle. Solar activities are related to the space weather affecting all planets atmospheric variability, moreover to the Earth's climate variability. The big question arises to the relation between solar forcing energy to the Earth's global volcanic activities. We search its connectivity from yearly volcanic activities refer to Volcano Explosive Index (VEI) and sunspot number within year of 1900 to 2013 (113 years) which represent the global warming period and the range of Maunder minimum within year of 1615 to 1751 (136 years) which known as the global cooling period. We found that the declining solar cycle significantly show more volcanic activities (VEI=1 to 5) with more than 40% occurrences for both warming and cooling periods. They have mean occurrences of (50.1±4.5) % and (42.0±10.4) %, respectively. In the rising phase of solar cycle, the average occurrences are (27.1±3.3) % and (28.8±5.3) %, respectively. When we selected the interval time in 3 years around the peak of maximum and minimum of the solar cycle, the global warming period had average of (27.1±5.5) % and (32.1±4.4) %, respectively and the global cooling period showed an average of (32.7±11.1) % and (21.3±5.0) %, respectively. The minimum phase showed higher frequency events of volcanic activity than the maximum phase during the warming period, opposite to the cooling period. Although the physical reason is far for explanation, we argue that solar activities have a clear relation with global volcanic activities.

In 2015, a joint collaboration project to build a new observatory in Mount Timau, East Nusa Tenggara was initiated between LAPAN, ITB, UNDANA, Kupang Regency and East Nusa Tenggara governments. The site selection is based on preliminary studies conducted on nearby location. This paper presents in situ measurements report on seeing, weather and sky brightness obtained on July 2018 using Differential Image Motion Monitor (DIMM) with 20 cm-telescope, Davis Vantage Vue automatic weather station, and Sky Quality Meter, respectively. Despite the high humidity and foggy condition on the afternoon, the site has good seeing condition with median of 0.93 arcsecond and sky brightness around 22.18 magnitude per arcsecond square after midnight.

A solar flare occurs due to a magnetic field reconnection above the active region. The active region magnetic complexity observed in the magnetogram could be used as proxies for solar flare forecasting. It is also known that solar flares that occur from emerging active regions located near the solar disk eastern limb can still have an impact on the Earth. Therefore, magnetic observation of active regions in the solar farside is important to forecast east limb flares occurrences. This study utilizes the conditional Generative Adversarial Network (cGAN) model to generate Artificial Intelligence (AI) solar farside magnetogram. Our model was trained using the solar frontside observations dataset from Solar Dynamic Observatory (SDO)/Atmospheric Imaging Assembly (AIA) 304 Angstrom as input images and SDO/Helioseismic and Magnetic Imager (HMI) magnetogram as output images. Our model generates solar farside magnetogram using solar farside observation from Solar Terrestrial Relations Observatory (STEREO)/Extreme Ultraviolet Imager (EUVI) 304 Angstrom. We also conducted validation on the similarity of our AI-generated magnetogram with the magnetogram observation from SDO/HMI using the Structural Similarity Index (SSIM) method. SSIM obtained an average similarity value of 0.61±0.06 for training data and 0.47±0.02 for validation data which contain active regions producing flares.

Photospheric vector magnetic field data which have several Space-weather HMI Active Region Patches (SHARP) parameters are used to study active regions that produced major solar flares. SHARP parameter data obtained from the Helioseismic Magnetic Imager (HMI) instruments onboard Solar Dynamics Observatory (SDO) have a good spatial and temporal sampling. We consider three SHARP parameters with high F-scores, namely total unsigned vertical current, total photospheric magnetic free energy, and total unsigned current helicity as a useful predictor for major solar flares. In this paper, we present the data analysis procedure and sample results focusing only on major solar flares (M and X class flares). The preliminary results showed in some cases, one of SHARP parameters for the M-class flare almost has the same value as X-class flare in which ideally should be higher.

Timau National Observatory will be the new Indonesia’s astronomical observatory in East Nusa Tenggara, planned for 2020. Besides the main 3.8-m optical telescope, it will host two 0.5-m “off-the-shelf” f/3.8 and f/8.0 telescopes, equipped with two CCD cameras and two filter wheels. The system will be controlled with a robotic system for autonomous operation. In this paper, we present the system description and current development progress, as well as the future plan for the facility, including its two potential scientific studies: near-Earth objects and exoplanetary transits.