bluuebunny/crossref_metadata_2025_split huggingface dataset:
Conservative mass transfer on eclipsing binary AE Phe from O-C diagram analysis
Authors: Vidante C , Malasan H L 
Published: March 2022

Abstract
Eclipsing binary is an edge-on binary system where the components appear to be eclipsing one another. Eclipsing binaries therefore give a lot of information on the systems’ behavior, one of them from their period change. O-C diagram exhibits the deviation of the observed time of minimum from the calculated ones and its analysis will reveal the responsible mechanism, such as a hidden third component, apsidal motion, and mass transfer. AE Phe (V = 8.15 mag and spectral class G0V) is a W UMa W-type binary. Previous studies of its degree of contact have revealed AE Phe to be a shallow-contact binary. Photometric data were taken using PROMPT (Panchromatic Robotic Optical Monitoring and Polarimetry Telescopes), CTIO on October 4th, 2013 on four filters: B, V, R, and I. The Kwee and van Woerden (1956) method was also used to determine AE Phe’s time of minimum. Analysis of the O-C diagram (taken from 1975 toward our observation) suggest that the period of AE Phe shows a long-term continuous increase. These period increase and degree of contact suggest that AE Phe is undergoing thermal relaxation oscillation (TRO) and is evolving to a broken-contact phase, with a possibility of angular momentum loss (AML) through magnetic braking.
Morpho-kinematics study of planetary nebula Sh 2-71 based on astrophysical 3-d modeling
Authors: Fajrin M. , Malasan H. L. , Akbar E. I. 
Published: March 2022

Abstract
A planetary nebula is formed when a low to intermediate mass star approaches the end of its life. Before the ejected materials finally interact with and dissipate into the interstellar matters, the nebula will be visible surrounding its former stellar core. The variety of planetary nebulae visual appearances indicates that the material ejected and leave the central star behind in unique ways. Morpho-kinematics study aims to find out the 3-d shape using the help of imaging and spectroscopic observations. Imaging allows on to observe the projection of planetary nebulae onto the plane perpendicular to the line of sight to the observer, while spectroscopy gives the ability to infer the expansion characteristics from the spectrum produced by shells within planetary nebulae. We report the 3-d shape modeling of Sh 2-71 (PNG 035.9-01.1, α(J2000.0) = 19h01m59.96s, δ(J2000.0) = 02°09’16.1”) using images obtained from Gemini Multi-Object Spectrograph (GMOS), Hong Kong/Australian Astronomical Observatory/Strasbourg Observatory Ha Planetary Nebula (HASH PN Database), and DSS image combined with high-resolution long-slit spectra from San Pedro Martir Kinematic Catalogue of Planetary Nebulae. The 3-d modeling is carried out with software that specializes in modeling three dimensional astrophysical object SHAPE. The acquired data from observations show that Sh 2-71 possesses a torus with three bipolar lobes while modeling by SHAPE tells that the torus is inclined by 37° and the bipolar lobes are on the same plane.
Anisotropic quark star and the energy conditions
Authors: Claudia T.S. Gracella , Sulaksono Anto 
Published: March 2022

Abstract
One of the compact objects that are attractive for investigating their energy conditions is quark stars. The existence of radial and tangential pressure differences in quark stars can cause anisotropic effects on the stars. We focus on and examine the energy conditions of quark stars using the Einstein Field Equation Solution. The energy stability of an anisotropic quark star can be determined by evaluating the profile of the pressure and energy density of the star using the anisotropic EOS as an input. The used equation is the extended MIT Bag Model, which involves the constant B and interaction parameter a
4 and the corresponding parameters of anisotropic part. It is known that parameter a
4 affects the mass distribution of quark stars to be more anisotropic. This anisotropic pressure also affects the energy condition profile of the star. We find the energy state of an anisotropic quark star satisfies the energy state of an ideal fluid.
Membership and age determination of M67 open cluster using GAIA EDR3 data
Authors: Ghosh Esan Mouli , Sulistiyowati  , Tucio Princess , Fajrin Muhammad 
Published: March 2022

Abstract
We present our study on the membership and age determination of M67 (NGC 2682), one of the oldest open clusters known to date. Proper motions and parallax of stars collected in the Gaia Early Data Release 3 are used to derive the cluster members by employing the Hierarchical Density-Based Spatial Clustering of Applications with Noise algorithm, which is further improved upon using a Gaussian Mixture Model. We calculate the position of the cluster centre and the parallax to be α = 08h51m24s±1m33s, δ = 11°49’12"±0°22’48" and 1.1497±0.06 mas respectively. The proper motion of the cluster is obtained to be μa
= −10.96 ± 0.20 mas/yr and μs
= −2.90 ± 0.19 mas/yr. Subsequently, we perform an isochrone fitting to the Color-Magnitude Diagram (CMD) of M67 source members by using the Automated Stellar Cluster Analysis tool (ASteCA). Our findings estimate the log age, metallicity (z), reddening (EB–V
), and distance modulus (m – M)0 to be 9.630 ± 0.033 log-years, 0.01865 ± 0.001, 0.037 ± 0.008, and 9.409 ± 0.031 respectively.
Recurring Nova RS Oph spectroscopic observation at Bosscha Observatory and ITERA Astronomical Observatory (IAO)
Authors: Imaduddin I. , Fajrin M. , Muztaba R. , Hafizah I. , Akbar E. I. , Malasan H. L. 
Published: March 2022

Abstract
We report low and intermediate resolution spectra of the recurrent nova RS Oph taken at two observatories. A low resolution spectrum (R ≈ 1000) was taken at ITERA Astronomical Observatory (IAO) in Lampung by using 25 cm (f/8) RC Astrograph telescope equipped with a LISA Pack Spectrograph eight days after the outburst. Twenty intermediate spectra (R ≈ 5000) were taken on several consecutive nights using LHIRES III spectrograph attached to a 25 cm (f/10) Meade LX-200R telescope at Bosscha Observatory, Lembang. We identified significant change in the strength of atomic lines from low resolution spectrum compared to previous observations. A clear and distinct Balmer emission decrement can be seen from the spectrum. Our intermediate resolution spectroscopy revealed a variability of P-Cygni profile on a broad Hα line. The P-Cygni profile evolved and disappeared at recent observations. It is thought that there was a new shell formed after the outburst and later combined with the previous shell in the next days. From the broad Hα profile, we measured and found decreasement in expansion velocity during our observation. We estimated vexp
= 2907.97 ± 64.14 km/s and vexp
= 997.12 ± 8.18 km/s on 1.6440 and 22.729 days after the outburst, respectively.
Report on seeing, sky brightness, and meteorological properties measurements at Timau National Observatory site
Authors: Saputra M B , Danarianto M D , Murti M D , Alwan M A , Yanti R J , Chikmah  
Published: March 2022

Abstract
With the existence of the Timau National Observatory, the site testing of the observatory location must be carried out to provide supporting data regarding the quality of the National Observatory site. Some site testing that needs to be done are seeing, sky brightness, and meteorological properties measurements. In this paper, the seeing and sky brightness measurements in July-August 2021 are presented. These measurements were conducted using the Differential Image Motion Monitor (DIMM) method with a 20 cm telescope and a Sky Quality Meter (SQM) respectively. From the results of these measurements, it was found that the site of Timau National Observatory has good seeing conditions with median of 0.92 arcseconds and most sky brightness values are around 22.02 magnitude per square arcsecond. The monitoring results of meteorological properties, such as air temperature, barometric pressure, relative humidity, and wind speed and direction during August 2021 that recorded by an automatic weather station are also presented.
Artificial intelligence generated solar farside magnetogram using conditional generative adversarial network
Authors: Dani T , Muhamad J , Nurzaman M Z , Kesumaningrum R , Sulistiani S , Pangestu A D 
Published: March 2022

Abstract
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.
Potential hazards analysis of the space debris over 10 cm in size based on their orbital parameters
Authors: Neflia  , Ahmad N , Rohmah F 
Published: March 2022

Abstract
The increasing population of artificial space objects every year triggers a polemic about the safety of launching satellites into orbit as well as the safety of satellites operating in space. The artificial space object also provides a potential danger when it re-entry and then falls to Earth. Indonesia as a country that has the 2nd longest coastline in the world and has a span of 1/8 of the world’s circumference (± 5000 km) is very vulnerable to experience atmospheric re-entry of which these space objects might fall to the Earth. Space objects that have the potential to experience re-entry and then fall to the Earth originate from space objects with a size of more than 10 cm. Until 2020, there are 6560 space objects with size 0.1<RCS<1 m2 and 9526 space objects with size RCS>1 m2. There are 5678 pieces of space debris with 4435 pieces with size 0.1<RCS<1m2 and 1236 pieces over 1m2. Of all space debris, only those with an altitude below 200 km potentially fall to the Earth which is around 1517 pieces. In addition, the most dangerous debris over the Indonesia region commonly has a low inclination with the passage around 12 to 16 times a day. However, there are only 15 objects which satisfy this category with a small number. Hence, the need of space debris surveillance should be done for mitigation purposes.
Prototype of automatic satellite streak detection, identification and initial orbit determination pipeline from optical observation
Authors: Danarianto M. D. , Maharani A. M. , Falah B. M. , Rohmah F. 
Published: March 2022

Abstract
We present a working prototype of automatic satellite streak detection, identification and initial orbit determination pipeline from optical telescope images based on python. The pipeline process calibrated and plate-solved astronomical images in fits format. We utilized Hough transform-based feature detection to detect the light streaks and extract the equatorial position based on the image header information. The streaks were then identified by comparing their center position with the calculated SGP4 based satellite position from available TLE data. The corresponding initial orbit is calculated by utilizing the Laplacian method by interpolating the streak position and time. We test the pipeline by using 85 blind-survey 10 cm telescope images around the celestial equator. The pipeline correctly detects 123 lines with 0.85 sensitivity, automatically identify 92 detected satellites unambiguously and determine the initial orbit of 118 streaks.
The development of PIL extraction application in active region of SDO/HMI magnetogram
Authors: Utama A Z , Nurzaman M Z , Dani T 
Published: March 2022

Abstract
The Polarity Inversion Line (PIL) on the active region (AR) is a parameter that correlates with the occurrence of the solar flare. This research has developed application to extract the PIL length in the AR. Image processing techniques were used to detect and classify AR from the SDO/HMI Magnetogram image of 1024x1024 pixels. The detection of AR in magnetogram images has its challenges because the ARs are constructed by the white (black) regions represent the magnetic positive (negative) polarities. To improve detection accuracy, the application used The Solar Region Summary (SRS), compiled by SWPC, and the centroid position of sunspot on SDO/HMI Continuum as additional information. The results of AR detection had high accuracy because SRS stores the centroid position of the flaring active region at peak time with the Stonyhurst heliographic on the solar disk which is converted to Cartesian coordinates. The application test used 1450 images and obtained the PIL length on the peak time of the X-class and M-class flares from 2011-2017. The application detected the high distribution of PIL length in the range of 120 to 580 Mm for X class flare, and 120 to 390 Mm for M-class flare. This research provides new data that has the potential to improve the machine learning-based solar flare prediction models.
Africa mid and low latitude ionosphere response observed during the geomagnetic storms of July 15 and 9 March 2012 using GPS
Authors: Anoruo Chukwuma Moses , Okeke Francisca Nneka , Okpala Kingsley Chukwudi 
Published: March 2022

AbstractIn this paper, the initial and recovery phases of July 15 and March 9, 2012 geomagnetic storms in African mid and low latitudes ionosphere has been studied using GPS. We employ relative total electron content (rTEC) variations using 2 stations from the Africa Geodetic Reference Frame (AFREF) to characterize African sector ionosphere responses during both storms. To characterize rTEC, we employ 15-day median-average sliding-window during the storm. Both storms lasted 18 h with Dst minima -139 nT for July 15 and -145 nT for March 9, when solar plasma wind speed recorded 545 km/s and 712 km/s respectively. The recovery phase lasted 48 h for -139 nT storm and 46 h for -145 nT when solar plasma wind speed recorded 485 km/s and 428 km/s respectively. It may be attributed that storm recovery phases do not depend on storm severity but the response of ionosphere during storms. Results show Positive storm dominates during the recovery phase and interplanetary electric field and solar plasma wind speed contribute to storm enhanced density. Ionospheric disturbances observed due to prompt penetration electric field shaped the magnetic field and prompted pre-storm rTEC enhancement. Plasma convection at mid-latitudes of African sector observed rTEC enhancements which did not appear in other studied sector results. Further observations should be carried out using other storms.
A model of the deviation between IRI-2016 and ionospheric TEC observation based on GISTM at low latitude Indonesia region
Authors: Husin A. , Suraina  , Putra AY. , Rasidi H. 
Published: March 2022

Abstract
The diurnal variation pattern of total electron content(TEC) from the International Recurrence Ionosphere (IRI-2016) model is generally is good agreement with observational data at all latitudes. However, at low latitudes the IRI TEC is not as accurate as in midlatitudes. Some reports showed that the IRI-2016 TEC model at the maximum and minimum solar activities at low latitudes tends to be underestimate. In this paper, TEC from GISTM (GPS Ionospheric Scintillation and TEC Monitoring) that is installed at Pontianak station (0.03° S;109.33°E geomagnetic latitude 9.7°S ) used for validation and evaluation of IRI-2016 TEC model over the low latitude Indonesian sector. Data from the 2012 - 2014 period representing solar maximum and data from 2018 representing solar minimum, were used in this study. We also developed VTEC deviation (ΔTEC) model by using multiple linear regression and tested the model by using data 2019. Results show that IRI-2016 generally reproduces the diurnal variations pattern but underestimates the observation data for many hours each day especially during maximum solar activity 2012-20114. The highest deviation in the equinoctial months and lowest during the June and December solstice. The deviation (ΔTEC) model showed good agreement with observation data on January and December but not for other months especially on equinox months. Testing of the VTEC deviation model using 2019 data did not show significant improvement compared to the IRI-2016 itself, which generally produces good TEC prediction in most of the months except for equinox months.
The feasibility study of Barus city as the new astrotourism destination from astronomical and meteorological aspect
Authors: Butar-Butar Arwin Juli Rakhmadi , Putra Singgih Prana , Hidayat Muhammad , Putraga Hariyadi 
Published: March 2022

Abstract
Astrotourism is a tourist activity that shows attractions in the form of astronomical phenomena and outer space. Astrotourism activities that can be carried out by tourists are such as studying and exploring astronomical phenomena such as eclipses, meteor showers, and so on in the conditions of the night sky. An important condition for the advancement of astrotourism in an area is that the area has dark skies that are characterized by no severe light pollution and had adequate atmospheric conditions such as at least clouds covering the sky so that celestial objects can be observed properly, temperature, humidity, wind speed. and good rainfall so that visitors or tourists can comfortably be at astronomical tourist sites for a long time. We’ve done collecting atmospheric data using portable weather station and sky brightness data using Unihedron Sky Quality Meter LU-DL type device from July 10th - 11th 2021 and we collected data from windy.com for atmospheric particle content and cloud coverage during those dates. The results showed that Barus can become a new potential astrotourism destination specifically in Northern Sumatera or broadly in Indonesia where the Light pollution in Barus city is quite low, with a maximum value of brightness sky of 21.6, 20.8, and 21.8 MPSAS for the east, zenith, and west directions, respectively; Atmospheric conditions are quite good with an average temperature of 25.9 °C, the humidity of 89.2%, wind speed of 2.07 km/h, rainfall of 33.1 mm, amount of particles in the atmosphere 0.13 AOD and heat index of 27.2 °C Future study is needed from other aspects to make Barus become a new astrotourism destination in Indonesia.
Study of Cassegrain-type antenna for radio telescope
Authors: Sobirin Farhan Fatwa , Nugraha Satia , Haz Fauzia , Sitompul Peberlin 
Published: March 2022

Abstract
There are many critical parameters in the design of a radio telescope, such as antenna gain and antenna resolution. In telecommunications, radar, and radio telescopes, an antenna is a very important component. There are many designs of the antenna, such as dipole array and parabolic antenna. Parabolic antennas also have many sub-reflector and antenna methods that control the radio wave, such as the Cassegrain type. A Cassegrain-type antenna is a parabolic antenna in which the feed antenna is mounted at or behind the surface of the main parabolic reflector dish. For the transmitter system, the beam of radio waves from the feed antenna illuminates the secondary reflector (sub-reflector), which reflects it back to the main reflector dish and then forward to space. The Cassegrain design is widely used in parabolic antennas, for large antennas in satellite ground stations, communication satellites, and radio telescopes. In this paper discusses the design of a Cassegrain-type antenna for radio telescope, basic calculation, diameter size of the main reflector of 20 meters, the diameter size of sub-reflector of 2.5 meters, and frequency of 22 GHz and 43 GHz.
Floating microplastic loads in the nearshore revealed through citizen science
Authors: de Haan William P , Uviedo Oriol , Ballesteros Maria , Canales Íngrid , Curto Xavier , Guart Montse , Higueras Sara , Molina Alex , Sanchez-Vidal Anna 
Published: March 2022

Abstract
Research on plastic pollution has rapidly expanded in recent years and has led to the discovery of vast amounts of microplastics floating on the surface of subtropical oceanic gyres. However, the distribution of floating plastic in the ocean is still poorly constrained, and there is a lack of information from a few meters from the coastline where the largest plastic emissions take place. Here, we provide a comprehensive study on the loads of plastic debris in the coastal surface waters of the NW Mediterranean Sea using data from 124 manta trawl deployments collected along 7 months by citizen scientists. Our results reveal that pollution by microplastics in the nearshore is likely subject to seasonal variations associated to a combination of hydrodynamic and anthropogenic pressures. The high proportions of microplastics found indicate that potential breakdown of plastics in the nearshore may take place in line with previous works. We prove that citizen science is a powerful tool in plastic research to monitor microplastics in the nearshore as it provides scientifically meaningful results while stimulating citizen engagement. Future studies may benefit from targeting specific scientific open questions by using the citizen science methodological approach presented here.
Lifetime based axial contrast enable simple 3D-STED imaging
Authors: Ma Yuanqing , Macmillan Alex , Yang Ying , Gaus Katharina 
Published: March 2022

Abstract
Stimulated Emission Depletion (STED) microscopy increase spatial image resolution by laterally sharpening the illumination profile of the confocal microscope. However, it remains compromised in axial resolution. To improve axial STED resolution, constructive interference of the STED depletion beam must be formed surrounding the focal plane to turn off the fluorophores beyond the focal plane. For isotropic 3D-STED resolution, this axial STED interference pattern must be overlayed with the doughnut STED beam at nanometer accuracy. Such optical configurations can be challenging in alignment. In this current work, we introduced a straightforward lifetime based axial contrast in STED microscope by imaging the samples on an ITO coated glass coverslip. The STED laser generates surface plasmon resonance on the ITO surface that enhanced the metal induced energy transfer MIET effect on the ITO surface. The enhanced MIET effect established a lifetime gradient with ∼20% dynamic range that extend for mor than 400 nm from the ITO surface. The axial contrast based on the lifetime gradient was directly used for 3D-STED imaging of tubulin fibers inside COS-7 cells, where the vertical displacement of single tubulin fiber was revealed. Lifetime gating could be applied to further improve lateral spatial resolution. Considering that most common implementation of STED microscopes uses pulsed lasers and timing electronics, there is no optical modification of the microscope is required in the current 3D-STED approach.