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Nodaviridae familyasında yer alan betanodavirus’un neden olduğu Viral nervöz nekrozis (VNN) ya da bir diğer adıyla Viral ensefalopati-retinopati (VER) dünyanın pek çok yerinde hem deniz balıklarında hem de tatlı su balıklarında görülür. Larval ve yavru boylarda, nadiren de yetişkin balıklarda hastalığa neden olmaktadır. Özellikle yetiştiriciliği yapılan balık türlerinde önemli ekonomik kayıplara neden olduğu için son yıllarda enfeksiyonla ilgili araştırmalara odaklanılmıştır. Bu çalışmada, Antalya bölgesinde yetiştiricilik faaliyeti gösteren akvaryum işletmelerinde Koi ve Japon balığı türlerinde betanodavirus varlığı araştırılmıştır. Üç farklı akvaryum işletmesinden her bir türü temsilen en az 30’ar adet olmak üzere toplam 180 balık örneklendi ve Real Time RT-PCR (RT-qPRC) metodu ile test edildi. Çalışma sonunda hiçbir örnekte betanodavirus RNA’sına rastlanmadı. Bu çalışma ile Türkiye’de koi ve japon balığı türlerinde betanodavirus varlığı moleküler tekniklerle ilk defa araştırılmıştır.

Malignant catarrhal fever (MCF) is a fatal disease of ruminants and has a worldwide distribution. The MCF virus (MCFV) group has currently known to contain 10 members. Ovine gammaherpesvirus 2 (OvHV-2) is one of the members of MCFV group and has economically importance in cattle. Sheep is the reservoir host of OvHV-2 while domestic goat is naturally susceptible species, although infection is generally asymptomatic in goat. In this study, the presence of OvHV-2 was investigated in sheep and goats by hemi-nested PCR in Aegean Region of west Turkey. Total of 138 sheep and goat samples which consist of 73 whole blood, 39 internal organs and 26 aborted fetuses were investigated. Thirty-seven blood samples, four fetal samples, and seven internal organ samples were found to be OvHV-2 positive. While 45.1% of the total sheep samples were found to be positive, only one goat sample was found positive. Similarly, previous studies have showed that prevalence of OvHV-2 in goats lower than sheep.

In three consecutive articles published in recent years, quite different estimates were made for the Lyapunov time of comet 1/P Halley, whose orbit is known to have high precision. In this work, we examined the Lyapunov time of the comet 1/P Halley using the MEGNO method and compared our results with previous studies. To investigate the effects of numerical overflows on the results that may have occurred during the calculations, we conducted tests with and without the renormalization procedure. We used various renormalization intervals to see their possible effects on the results and to avoid improper ones. We reached the maximum Lyapunov exponents at renormalization times for 2250 yr, 2265 yr, and 3000 yr. In both cases where renormalization is used and not used, the Lyapunov time is calculated as 119 yr and 190 yr, respectively. Besides, we performed orbital integrations for ∓ 10 kyr for comet 1/P Halley with the clone orbits produced by the MCCM method and compared the standard errors of the means of the orbital parameters with the Lyapunov times. We conclude that calculated different Lyapunov times correspond to different levels of the standard errors of the means.

The aim of the present study was shedding light on the disease factors underlying mortality event among common carps inhabiting Hirfanlı Dam Lake in Türkiye in spring of the year 2021. For this purpose various parasitological, bacteriological and virological research techniques were employed. Five parasite genera, Dactylogyrus spp., Myxobolus spp., Eimeria spp., Trichodina spp., Diplostomum spp. were isolated from 13 common carps. The opportunistic bacterial pathogen of fresh water fishes Aeromonas hydrophila was also isolated from wounded fish. No viruses were detected. Fungal infections were encountered in the skin lesions of carps. The source of the encountered morbidity and mortality picture among the studied carps points to the combined action of parasitic, bacterial and fungal agents in these fish. Further investigations on seasonal variations of parasitofauna on the lake are needed for better understanding the dynamics in the ecology of the parasites which are hosted by carps in the Hirfanlı Dam Lake.

In this study, we carried out photometric, spectroscopic, and for the first time, polarimetric observations of the Amor-type near-Earth asteroid (2059) Baboquivari. Our findings represent the first reliable determination of Baboquivari's physical properties. We used data from a 1m-class telescope (T100) along with ALCDEF data for photometric analyses and a 1.5-m-class telescope (RTT150) for polarimetric, spectroscopic, and additional photometric observations. We obtained the synodic rotation period of Baboquivari as 129.93 +/- 2.31 hours and the standard phase function parameters H and G as 16.05 +/- 0.05, 0.22 +/- 0.02, respectively. Our colour index (V-R) measurement of 0.45 +/- 0.02 is consistent with spectroscopic observations, indicating an S (or sub-S) spectral type. Using the polarimetric and spectroscopic data, we found that the geometric albedo is 0.15 +/- 0.03, and the spectral type is Sq. Based on the estimated albedo and absolute magnitude, Baboquivari has an effective diameter of 2.12 +/- 0.21 km. Due to the scattered data in the light curve, its slow rotation and location among the NEAs suggest that Baboquivari may be a non-principal axis (NPA) rotator., Comment: 17 pages, 9 figures, accepted to publish in Planetary and Space Science (2023)

Viral nervous necrosis (VNN), caused by betanodavirus, is a significant viral infection that threatens marine aquaculture. Freshwater and marine fish farms in Turkey are subjected to annual pathogen screenings. In 2016, during the Nervous Necrosis Virus screening program conducted in the Black Sea, betanodavirus was unexpectedly detected using real-time reverse transcription-polymerase chain reaction in apparently healthy sea bass. Phylogenetic analysis of both the RNA1 and RNA2 segments of the virus determined that the betanodavirus detected was red-spotted grouper nervous necrosis virus genotype (RGNNV). Following the initial discovery of betanodavirus in the Black Sea, monitoring studies performed over a 3 yr period have not indicated any additional presence of the virus. The absence of clinical symptoms related to VNN disease in the area’s marine fish farms and the surrounding detection zone, and the fact that the virus has not been detected anew in monitoring programmes conducted following the initial detection, indicate that there is no virus circulation in the detection zone.

We describe results of a planetary defense exercise conducted during the close approach to Earth by the near-Earth asteroid (99942) Apophis during 2020 December–2021 March. The planetary defense community has been conducting observational campaigns since 2017 to test the operational readiness of the global planetary defense capabilities. These community-led global exercises were carried out with the support of NASA’s Planetary Defense Coordination Office and the International Asteroid Warning Network. The Apophis campaign is the third in our series of planetary defense exercises. The goal of this campaign was to recover, track, and characterize Apophis as a potential impactor to exercise the planetary defense system including observations, hypothetical risk assessment and risk prediction, and hazard communication. Based on the campaign results, we present lessons learned about our ability to observe and model a potential impactor. Data products derived from astrometric observations were available for inclusion in our risk assessment model almost immediately, allowing real-time updates to the impact probability calculation and possible impact locations. An early NEOWISE diameter measurement provided a significant improvement in the uncertainty on the range of hypothetical impact outcomes. The availability of different characterization methods such as photometry, spectroscopy, and radar provided robustness to our ability to assess the potential impact risk.

Amaç – Tüketicilerin satın alma öncesinde ürün ya da hizmeti deneme imkânı olmadığından, internet üzerinden yapılan paylaşımlar önem kazanmaktadır. Potansiyel tüketiciler birçok ihtiyaçta olduğu gibi yeme içme ihtiyacını karşılamak için de sosyal medyadan faydalanarak yiyecek içecek işletmesi tercihlerini yapabilmektedirler. Bu çalışmada, sosyal medya ve yeme-içme eylemleri arasındaki ilişki değerlendirilerek sosyal medya kullanımının tüketicilerin yiyecek içecek işletmesi tercihleri ve yeme-içme alışkanlıkları üzerinde nasıl bir rol oynadığı ve sosyal medya kullanan tüketicilerin yiyecek içecek işletmesi tercihlerinin demografik değişkenlere göre farklılık gösterip göstermediği ortaya çıkarılmaya çalışılmıştır. Yöntem – Çalışmada 2020 yılı Ocak ve Şubat aylarında kolayda örneklem yöntemiyle Muğla ilinde farklı demografik özelliklere sahip olan ve sosyal medya araçlarının bir veya daha fazlasını kullanan 403 tüketici ile anket uygulaması gerçekleştirilmiştir. Bulgular – Araştırma sonucunda; erkek tüketicilerin kadınlara kıyasla sosyal medyada yer alan fırsatlardan ve yiyecek içecek işletmelerinin yapmış oldukları paylaşımlardan daha çok etkilendiği, sosyal medya kullanımın daha çok genç yaşlardaki tüketicilerin yiyecek içecek işletmesi tercihlerini etkilediği ve bireylerin eğitim düzeyi yükseldikçe yiyecek içecek işletmesi tercihlerinde sosyal medyanın daha fazla etkin olduğu ortaya çıkarılmıştır. Tartışma – Tüketiciler her türlü sosyal medya aracını takip edip kullanarak kendileri için en doğru yiyecek içecek işletmesine karar vermekte ve işletmelerde yeni ürünlerini tanıtıp, ürünler hakkında etkileyici paylaşımlarını yapabilmektedir. Tüm bu paylaşımlar ve yorumlar, sosyal medya araçları vasıtası ile işletme ve tüketiciler arasında birbirlerini tamamlayıcı ve geliştirici bir bağ olduğunu göstermektedir. Yiyecek-içecek işletmeleri bu bağdan faydalanarak yiyecek-içecek paylaşımlarını artırmaktadır. Tüketicilerinin yapmış oldukları bu paylaşımlar, yiyecek-içecek işletmesi tanıtımı, yemek tanıtımları ve tüm bu bilgi aktarımının sürdürülebilmesi için önemli hale gelmiştir. Purpose – Since the consumers do not have the opportunity to try the product or service before purchasing, the sharing over the Internet gains importance. Potential consumers can make their food and beverage business preferences by using the social media in order to meet their eating and drinking needs, as in many needs. This study evaluates the relationship between social media and eating and drinking actions and attempts to reveal how social media use plays a role on consumers' food and beverage business preferences and eating and drinking habits, and whether consumers who use social media differ according to demographic variables. Design/methodology/approach – In the study, a survey was carried out with 403 consumers who had different demographic features and used one or more social media tools in Muğla province with convenience sampling method in January and February 2020. Findings – As a result of the research, it has been determined that male consumers are more affected by the opportunities in social media and the sharing of food and beverage businesses compared to women. It was determined that the use of social media in the food and beverage business preference mostly affects the consumers in the young age range. In addition, as the education level of the individuals increased, it was revealed that social media was more effective in food and beverage business preferences.

Aim: The aim of the study was to investigate the role of Bovine herpesvirus-1 (BHV-1), Schmallenberg virus (SBV), , Akabane virus (AKAV) and pestivirus in cattle abortion cases in the Aegean Region of Turkey between 2015 and 2019. Materials and Methods: In this study, 204 bovine abortions that occurred in the Aegean region of Turkey between the years 2015 and 2019 were investigated. While BHV-1, SBV, and pestivirus were examined with real-time PCR, AKAV was examined with nested-PCR. Results: In our study, 25 (12.3%) of the samples analyzed were positive for pestiviruses, 1 (0.5%) was positive for Akabane, and 1 (0.5%) was positive for BHV-1. SBV was not detected. According to these results, the viral agent causing most abortions in the Aegean region was found to be pestivirus. The most abortion-related material was sent to the lab in 2018, followed by 2019, 2017, 2016, and 2015. Conclusion: Based on the results of this study, future evaluations should consider the cattle abortion agents detected in the Aegean region, and control and monitoring studies should be established., Amaç: Çalışmanın amacı, Türkiye'nin Ege Bölgesi'nde 2015-2019 yılları arasında sığır abortus vakalarında Bovine herpesvirus-1 (BHV-1), Schmallenberg virus (SBV), Akabane virus (AKAV) ve pestivirus'ün rolünü araştırmaktır. Gereç ve Yöntem: Bu çalışmada, 2015-2019 yılları arasında Türkiye'nin Ege Bölgesi’nden toplanan 204 aborte fetüs örneği incelenmiştir. Bu amaçla Bovine herpesvirus-1 (BHV-1), Schmallenberg virus (SBV) ve pestivirus taraması için real-time PCR tekniği kullanılırken, Akabane virus (AKAV) için ise nested-PCR tekniği kullanılmıştır. Bulgular: İncelenen örneklerin 25'i (%12.3) pestivirus pozitif, 1'i (%0.5) Akabane pozitif ve 1'i de (%0.5) BHV-1 pozitif bulundu. SBV tespit edilmedi. Bu sonuçlara göre, Ege Bölgesi’nde en fazla aborta neden olan viral etkenin pestivirüs olduğu belirlendi. Laboratuvara en fazla abort materyalinin 2018 yılında gönderildiği, bunu 2019, 2017, 2016 ve 2015 yıllarının takip ettiği belirlendi. Öneri: Bu çalışmanın sonuçlarına dayanarak, Ege bölgesinde tespit ettiğimiz etkenler gelecek değerlendirmelerde dikkate alınmalı, kontrol ve izleme çalışmaları oluşturulmalıdır

Objective. This study was aimed to investigate the presence of pestivirus, schmallenberg virus (SBV), akabane virus (AKAV), and determined the seasonal distribution in small ruminant abortion cases Materials and Methods. A total of 164 small ruminant aborted fetuses (39 goats and 125 sheep) were investigated in West Turkey between the years of 2015 and 2019. While the SBV and pestivirus were examined with real-time RT-PCR, the AKAV was examined with nested-PCR. Results. In this study, while four sheep (2.3%) were found to be pestivirus positive, nine sheep and one goat (5.9%) were found to be AKAV positive. SBV was detected in none of the animals. According to the results of the studies carried out, AKAV, a vector-borne virus, was detected more than other viruses in sheep and goat abortions in West Turkey. A positive akabane virus sample detected in sheep fetuses was sequenced based on the partial S segment. This sample showed 99-100% similarity to the Adana-15, Aksu-1, and Aksu-2 isolates previously detected in Southern Turkey. Phylogenetic analysis showed that the sequenced isolate in this study was clustered within genogroup Ib. Another important piece of data revealed in this study was the determination of the seasonal distribution of sheep and goat abortions. Abortion cases which started to increase in November reached a peak in February and declined till August. Conclusions. This is the first study in the Aegean Region (including seven provinces) in which three important viral agents were simultaneously investigated in small ruminant aborted fetuses.

Sacbrood virus (SBV) is widely distributed in honeybees. It is an infectious and contagious disease, which affects both the larvae and adult stages of honeybees (Apis mellifera). This study reports the detection of sacbrood virus in Turkey in 2017. Phylogenetic analysis based on partial sequences encoding the polyprotein gene was carried out in SBV-infected bees from four different apiaries. Phylogenetic analysis revealed noteworthy results. Although European-South American, Asian, and Korean genotypes have a maximum of 5.3% variance with each other, the variation rates between them and the Turkish genotype were 10.4%, 11.4%, and 12.5%, respectively. Sequences of Turkish isolates did not fit into the previously reported genotype groups; furthermore, they created a completely separate branch according to phylogeny. This new branch was therefore named the Turkish genotype.

Amaç – Tüketicilerin satın alma öncesinde ürün ya da hizmeti deneme imkânı olmadığından, internet üzerinden yapılan paylaşımlar önem kazanmaktadır. Potansiyel tüketiciler birçok ihtiyaçta olduğu gibi yeme içme ihtiyacını karşılamak için de sosyal medyadan faydalanarak yiyecek içecek işletmesi tercihlerini yapabilmektedirler. Bu çalışmada, sosyal medya ve yeme-içme eylemleri arasındaki ilişki değerlendirilerek sosyal medya kullanımının tüketicilerin yiyecek içecek işletmesi tercihleri ve yeme-içme alışkanlıkları üzerinde nasıl bir rol oynadığı ve sosyal medya kullanan tüketicilerin yiyecek içecek işletmesi tercihlerinin demografik değişkenlere göre farklılık gösterip göstermediği ortaya çıkarılmaya çalışılmıştır. Yöntem – Çalışmada 2020 yılı Ocak ve Şubat aylarında kolayda örneklem yöntemiyle Muğla ilinde farklı demografik özelliklere sahip olan ve sosyal medya araçlarının bir veya daha fazlasını kullanan 403 tüketici ile anket uygulaması gerçekleştirilmiştir. Bulgular – Araştırma sonucunda; erkek tüketicilerin kadınlara kıyasla sosyal medyada yer alan fırsatlardan ve yiyecek içecek işletmelerinin yapmış oldukları paylaşımlardan daha çok etkilendiği, sosyal medya kullanımın daha çok genç yaşlardaki tüketicilerin yiyecek içecek işletmesi tercihlerini etkilediği ve bireylerin eğitim düzeyi yükseldikçe yiyecek içecek işletmesi tercihlerinde sosyal medyanın daha fazla etkin olduğu ortaya çıkarılmıştır. Tartışma – Tüketiciler her türlü sosyal medya aracını takip edip kullanarak kendileri için en doğru yiyecek içecek işletmesine karar vermekte ve işletmelerde yeni ürünlerini tanıtıp, ürünler hakkında etkileyici paylaşımlarını yapabilmektedir. Tüm bu paylaşımlar ve yorumlar, sosyal medya araçları vasıtası ile işletme ve tüketiciler arasında birbirlerini tamamlayıcı ve geliştirici bir bağ olduğunu göstermektedir. Yiyecek-içecek işletmeleri bu bağdan faydalanarak yiyecek-içecek paylaşımlarını artırmaktadır. Tüketicilerinin yapmış oldukları bu paylaşımlar, yiyecek-içecek işletmesi tanıtımı, yemek tanıtımları ve tüm bu bilgi aktarımının sürdürülebilmesi için önemli hale gelmiştir.

Viral Nervous Necrosis (VNN) is one of the most important problems in sea bass aquaculture. Although there are many studies in the world on detection and molecular characterization of betanodaviruses causative agent of VNN, there are not enough studies related to prevalance to provide epidemiological maps. The purpose of this study was to investigate the betanodavirus prevalence in all bass hatcheries actively operating and in some farms in Turkey by RT-qPCR. A total of 2460 samples including fertilized egg, prelarva, postlarva, and fingerling were collected from 16 hatcheries as covering all production stages. A total of 600 sea bass were also collected from 20 farms. Betanodavirus was detected in a hatchery and a farm in fingerling sized sea bass and prevalances were found to be 6.25% and 5%, respectively. Virus isolation initially could not be achieved in E-11 but later SSN-1. Partial genome analysis of both RNA1 and RNA2 segments of the viruses, revealed that they were Redspotted grouper nervous necrosis virus genotype endemic in the Mediterranean basin. The absence of mortality related to VNN in the hatchery and farm, the healthy appearance of the sea bass, the low viral load detected and also output of retrospective epidemiological studies indicate that the infection is subclinical. Not detecting betanodavirus in other age groups where biosafety is implemented indicates that there is no active infection. In the light of these findings, it can be concluded that there are no circulating betanodavirus in hatcheries and the detected virus could be of sea-water origin.

Viral nervous necrosis (VNN) is one of the most important problems in sea bass culture. Although there have been many studies on detection and molecular characterization of betanodavirus, the causative agent of VNN, there has been little focus on understanding its prevalence to create epidemiological maps. The purpose of this study was to investigate the prevalence of betanodavirus in active sea bass hatcheries and on selected farms in Turkey by RT-qPCR. A total of 2460 samples, including fertilized eggs, prelarvae, postlarvae, fry, and fingerlings, were collected from 16 hatcheries to cover all production stages. A total of 600 sea bass were also collected from 20 farms. Betanodavirus was detected in one hatchery (1/16) in fingerling-sized sea bass, and the prevalence of betanodavirus at the hatchery level was calculated to be 6.25%. Betanodavirus was also detected on one farm (1/20) in fingerling-sized sea bass, and the prevalence of betanodavirus at the farm level was calculated to be 5%. Virus isolation initially could not be achieved in E-11 cells, but later, SSN-1 cells were used successfully. Partial genome sequence analysis of the RNA1 and RNA2 segments of the viruses revealed that they were of the red-spotted grouper nervous necrosis virus genotype, which is endemic in the Mediterranean basin. The absence of mortality related to VNN in the hatcheries and on the farms, the healthy appearance of the sea bass, the low viral load detected, and the results of retrospective epidemiological studies indicated that the infection was subclinical. Not detecting betanodavirus in other age groups where biosecurity was implemented indicates that there was no active infection. In light of these findings, it can be concluded that there was no betanodavirus circulating in hatcheries, and the virus might have been of seawater origin.

Bu derlemenin amacı, Avrupa ve Dünya kültür balıkçılığında çok önemli bir yeri olan ülkemizde viral balık hastalıklarının mücadelesi ve bildirimi ile ilgili olarak güncel bilgiler ortaya koymaktır. Gelişmiş ve organize kültür balıkçılığı işletmelerine sahip olan ülkemiz, Avrupa’da üretim ve ihracatta önemli derecede söz sahibidir. Balık hastalıklarının büyük bölümünü oluşturan ve büyük ekonomik kayıplara neden olan viral balık hastalıklarının öneminin iyi bir şekilde anlaşılmasının yanısıra kontrol ve mücadele önlemlerinin bilinmesi ve doğru anlaşılması, sektörün gelişimine önemli katkılar sağlamaktadır. Ulusal ve uluslararası mevzuatları içeren bu derlemenin sektörün tüm paydaşlarına ulaşması ve varolan farkındalığı daha da artırması amaçlanmaktadır.

Most co-orbital objects in the Solar system are thought to follow tadpole-type orbits, behaving as Trojans. However, most of Earth's identified co-orbitals are moving along horseshoe-type orbits. The current tally of minor bodies considered to be Earth co-orbitals amounts to 18; of them, 12 are horseshoes, five are quasi-satellites, and one is a Trojan. The semimajor axis values of all these bodies librate between $0.983$ au and $1.017$ au. In this work, we have studied the dynamical behaviour of objects following orbits with semimajor axis within this range that may be in a 1:1 mean-motion resonance with Earth. Our results show that asteroids 2016 CO$_{246}$, 2017 SL$_{16}$, and 2017 XQ$_{60}$ are moving along asymmetrical horseshoe-type orbits; the asteroid 2018 PN$_{22}$ follows a nearly symmetric or regular horseshoe-type orbit. Asteroids 2016 CO$_{246}$, 2017 SL$_{16}$, and 2017 XQ$_{60}$ can remain in the horseshoe co-orbital state for about $900$ yr, $3300$ yr and $2700$ yr, respectively. Asteroid 2018 PN$_{22}$ has a more chaotic dynamical behaviour; it may not stay in a horseshoe co-orbital state for more than 200 yr. The horseshoe libration periods of 2016 CO$_{246}$, 2017 SL$_{16}$, 2017 XQ$_{60}$, and 2018 PN$_{22}$ are 280, 255, 411, and 125 yr, respectively., Comment: 14 pages, 8 figures, 2 tables. Accepted for publication in MNRAS

We study the contribution of JFC (Jupiter family comet) and Centaur regions to the NEA (near Earth asteroid) population having Tisserand parameters for Jupiter between 2 and 3. We define a region for JFCs (aphelion distance ( Q ) > 4.61 au, perihelion distance ( q ) 4.95 au, > 1.3 au) and we check the contributions of selected bodies (JFCs, Centaurs, Halley-type comets (HTCs), some elliptic comets, and some outer main belt asteroids) from various regions to the NEA region. Additionally, we integrated NEAs with Tisserand parameters for Jupiter ( T J ) between 2 and 3 and their clones backward in time to see whether there was a strong dynamical path between those NEAs and the defined JFC region. As a result, 35.1% of the orbits from the defined JFC region turned out to be Earth-crossing orbits for forward integrations, while 66.7% of NEAs ( 2 T J 3 ) reached the JFC region for backward integrations. Considering these probabilities, 304 orbits of today’s JFC regional bodies can contribute the Earth-crossing asteroids in 0.55 Myr. Almost 254 NEA regional bodies look like they came from the defined region in a comparable time interval (0.80 Myr).

Context. The study of non-principal axis (NPA) rotators can provide important clues to the evolution of the spin state of asteroids. However, very few studies to date have focused on NPA-rotating main belt asteroids (MBAs). One MBA known to be in an excited rotation state is asteroid (5247) Krylov. Aims. By using disk-integrated photometric data, we construct a physical model of (5247) Krylov including shape and spin state. Methods. We applied the light curve convex inversion method employing optical light curves obtained by using ground-based telescopes in three apparitions during 2006, 2016, and 2017, along with infrared light curves obtained by the Wide-field Infrared Survey Explorer satellite in 2010. Results. Asteroid (5247) Krylov is spinning in a short axis mode characterized by rotation and precession periods of 368.7 and 67.27 h, respectively. The angular momentum vector orientation of Krylov is found to be λL = 298° and βL =-58°. The ratio of the rotational kinetic energy to the basic spin-state energy EE0 1.02 shows that the (5247) Krylov is about 2% excited state compared to the principal axis rotation state. The shape of (5247) Krylov can be approximated by an elongated prolate ellipsoid with a ratio of moments of inertia of Ia: Ib: Ic = 0.36: 0.96: 1. This is the first physical model of an NPA rotator among MBAs. The physical processes that led to the current NPA rotation cannot be unambiguously reconstructed. © 2020 ESO., We are very thankful to the reviewer, Dr. M. Drahus for his positive criticisms, suggestions, and comments which greatly improved the original version of the manuscript. This research is supported by Korea Astronomy and Space Science Institute (KASI). Work at KASI was partly supported under the framework of international cooperation program managed by the National Research Foundation of Korea (2017K2A9A1A06037218, FY2018). The work of J.. Durech and M. Lehky was supported by the grant 18-04514J of the Czech Science Foundation. The work of C.-H. Kim was financially supported by the Research Year of Chungbuk National University in 2018. The work at Modra was supported by the Slovak Grant Agency for Science VEGA, Grant 1/0911/17. M.K. and O.E. thank to TUB.ITAK for a partial support in using T100 telescope with project number 14BT100-648. This research has made use of the KMTNet system operated by the Korea Astronomy and Space Science Institute (KASI) and the data were obtained at three host sites of CTIO in Chile, SAAO in South Africa, and SSO in Australia. The Joan Oro Telescope (TJO) of the Montsec Astronomical Observatory (OAdM) is owned by the Catalan Government and operated by the Institute for Space Studies of Catalonia (IEEC). This publication also makes use of data products from NEOWISE, which is a project of the Jet Propulsion Laboratory/California Institute of Technology, funded by the Planetary Science Division of the National Aeronautics and Space Administration.

Amaç: Bu çal›flmada lateral nazal duvar ve sinüs patolojilerinin distallakrimal kanal t›kan›kl›¤› etiyolojisindeki rolü araflt›r›lm›flt›r.Yöntem: Nisan 1999 ile Eylül 2003 tarihleri aras›nda endoskopikendonazal dakriosistorinostomi ve silikon entübasyonu planlanan 17kad›n ve 11 erkek hasta çal›flmaya dahil edildi. Hastalar›n lakrimal kanal t›kan›kl›¤› tan›s› için göz kliniklerinde Schirmer testi, flöreseinboya kaybolma testi, Jones I-II testleri, kanaliküler irrigasyon, kanaliküler problama, dakriosistografi, dakriosintigrafi gibi genel oftalmolojik muayeneleri yap›ld›. KBB kliniklerinde nazal kavite patolojileri için anterior rinoskopi ve diagnostik nazal endoskopik muayeneleri yap›ld›. Tüm hastalarda paranazal bilgisayarl› tomografi ile ostiomeatal kompleks hastal›¤›, etmoid hücre opasifikasyonu, konka bülloza, agger nazi hücresi varl›¤› de¤erlendirilerek 50 kontrol olgusundaki bulgular ile Fisher’in ki-kare testiyle karfl›laflt›r›ld›.Bulgular: Lakrimal kanal t›kan›kl›¤›n oldu¤u tarafta agger nazi hücresi 17 (%60.7), konka bülloza 10 (%35.7), etmoid hücre opasifikasyonu 6 (%21.4), osteomeatal kompleks hastal›¤› 4 (%14.2), bir veyadaha fazla bulgu 21 (%75) hastada saptand›. Bu lateral nazal duvar vesinüs patolojileri çal›flma grubunda kontrol grubuna oranla yüksekbulunmas›na karfl›l›k istatistiksel olarak anlaml› bulunmad›(p>0.05).Sonuç: Lateral nazal duvar ve sinüs patolojilerini distal nazolakrimalsistem t›kan›kl›¤› olan hastalarda yüksek oranda bulmam›za ra¤menetiyolojisini aç›klamakta yetersiz oldu¤u ve paranazal bilgisayarl› tomografinin bu hastalar›n de¤erlendirilmesinde artan öneme sahipolaca¤› kan›s›na vard›k., Objective: In this study, the role of lateral nasal wall and sinus pathologies in the etiology of distal lacrimal duct disease has been investigated.Methods: Seventeen female and 11 male patients who were scheduledfor endoscopic endonasal dacryocystorhinostomy and silicon tube intubation between April 1999 and September 2003 were included in the study.The patients underwent general ophthalmologic examinations such asSchirmer test, fluorescein dye disappearance test, Jones I-II tests, canalicular irrigation, canalicular probing, dacryocystography, dacryoscintigraphy for the diagnosis of lacrimal duct obstruction. In the clinics of ENT,for the detection of nasal cavity pathologies, anterior rhinoscopy anddiagnostic nasal endoscopic examinations were performed. All patientswere evaluated during paranasal computed tomographic examinationsregarding osteomeatal complex disease, ethmoid cell opacification, concha bullosa and presence of agger nasi cells and data obtained were compared with findings of 50 control subjects using Fisher’s chi-square tests.Results: On the side where lacrimal duct obstruction exists, agger nasicells were detected in 17 (60.7%) patients, concha bullosa in 10 (35.7%)patients, ethmoid cell opacification in 6 (21.4%) patients, osteomeatalcomplex disease in 4 (14.2%) patients, and one or more than one symptom were detected in 21 (75%) patients. Despite higher number of lateral nasal wall and sinus pathologies in the study group when comparedwith the control group, intergroup difference was not statistically significant (p>0.05).Conclusion: We have concluded that despite the higher rates of lateral nasal wall and sinus pathologies in patients with distal nasolacrimalsystem obstruction, its etiology has not been adequately expounded andparanasal computed tomographies will have increasing importance inthe evaluation of these patients.

Context. The so-called Barbarian asteroids share peculiar, but common polarimetric properties, probably related to both their shape and composition. They are named after (234) Barbara, the first on which such properties were identified. As has been suggested, large scale topographic features could play a role in the polarimetric response, if the shapes of Barbarians are particularly irregular and present a variety of scattering/incidence angles. This idea is supported by the shape of (234) Barbara, that appears to be deeply excavated by wide concave areas revealed by photometry and stellar occultations. Aims. With these motivations, we started an observation campaign to characterise the shape and rotation properties of Small Main-Belt Asteroid Spectroscopic Survey (SMASS) type L and Ld asteroids. As many of them show long rotation periods, we activated a worldwide network of observers to obtain a dense temporal coverage. Methods. We used light-curve inversion technique in order to determine the sidereal rotation periods of 15 asteroids and the convergence to a stable shape and pole coordinates for 8 of them. By using available data from occultations, we are able to scale some shapes to an absolute size. We also study the rotation periods of our sample looking for confirmation of the suspected abundance of asteroids with long rotation periods. Results. Our results show that the shape models of our sample do not seem to have peculiar properties with respect to asteroids with similar size, while an excess of slow rotators is most probably confirmed.© 2017 ESO., N.P. acknowledges funding from the Portuguese FCT - Foundation for Science and Technology. CI-TEUC is funded by National Funds through FCT - Foundation for Science and Technology (project: UID/ Multi/00611/2013) and FEDER - European Regional Development Fund through COMPETE 2020 - Operational Programme Competitiveness and Internationalisation (project: POCI-01-0145-FEDER-006922). SARA observations were obtained under the Chilean Telescope Allocation Committee program CNTAC 2015B-4. P.H. acknowledges financial support from the Natural Sciences and Engineering Research Council of Canada, and thanks the staff of Cerro Tololo Inter-American Observatory for technical support. The work of A.M. was supported by grant no. 2014/13/D/ST9/01818 from the National Science Centre, Poland. The research of V.K. is supported by the APVV-15-0458 grant and the VVGS-2016-72608 internal grant of the Faculty of Science, P.J. Safarik University in Kosice. M.K. and O.E. acknowledge TUBITAK National Observatory for a partial support in using T100 telescope with project number 14BT100-648.

Several mechanisms have been proposed for the formation of brown dwarfs, but there is as yet no consensus as to which -- if any -- are operative in nature. Any theory of brown dwarf formation must explain the observed statistics of brown dwarfs. These statistics are limited by selection effects, but they are becoming increasingly discriminating. In particular, it appears (a) that brown dwarfs that are secondaries to Sun-like stars tend to be on wide orbits, $a\ga 100\,{\rm AU}$ (the Brown Dwarf Desert), and (b) that these brown dwarfs have a significantly higher chance of being in a close ($a\la 10\,{\rm AU}$) binary system with another brown dwarf than do brown dwarfs in the field. This then raises the issue of whether these brown dwarfs have formed {\it in situ}, i.e. by fragmentation of a circumstellar disc; or have formed elsewhere and subsequently been captured. We present numerical simulations of the purely gravitational interaction between a close brown-dwarf binary and a Sun-like star. These simulations demonstrate that such interactions have a negligible chance ($, 10 pages, 8 figures, Accepted for publication in Astrophysics and Space Science

Using Python 3, astropy and astrometry.net, we have developed a pipeline to obtain photometric light curves of asteroids automatically queried by the SkyBoT database from sequential FITS images. The pipeline provides: pre-reduction of data, astrometry, standard differential photometry and light curves by auto-selecting multiple comparison stars (maximum user-defined) from NOMAD catalog via VizieR. The code is an open source, free and hosted on GitHub with the GNU GPL v3 license.

High Dimensional Model Representation (HDMR) is an efficient technique which decomposes a multivariate function into a constant, univariate, bivariate functions and so on. These functions are forced to be mutually orthogonal by means of an orthogonality condition. The technique which is generally used for high-dimensional input-output systems can be applied to various disciplines including sensitivity analysis, differential equations, inversion of data and so on. In this article we present a computer program that computes individual components of HDMR resolution of a given multivariate function. The program also calculates the global sensitivity indices. Lastly the results of the numerical experiments for different set of functions are introduced.

Maria family is regarded as an old-type (~3 +/- 1 Gyr) asteroid family which has experienced substantial collisional and dynamical evolution in the Main-belt. It is located nearby the 3:1 Jupter mean motion resonance area that supplies Near-Earth asteroids (NEAs) to the inner Solar System. We carried out observations of Maria family asteroids during 134 nights from 2008 July to 2013 May, and derived synodic rotational periods for 51 objects, including newly obtained periods of 34 asteroids. We found that there is a significant excess of fast and slow rotators in observed rotation rate distribution. The two-sample Kolmogorov-Smirnov test confirms that the spin rate distribution is not consistent with a Maxwellian at a 92% confidence level. From correlations among rotational periods, amplitudes of lightcurves, and sizes, we conclude that the rotational properties of Maria family asteroids have been changed considerably by non-gravitational forces such as the YORP effect. Using a lightcurve inversion method (Kaasalainen & Torppa 2001; Kaasalainen et al. 2001), we successfully determined the pole orientations for 13 Maria members, and found an excess of prograde versus retrograde spins with a ratio (N_p/N_r) of 3. This implies that the retrograde rotators could have been ejected by the 3:1 resonance into the inner Solar System since the formation of Maria family. We estimate that approximately 37 to 75 Maria family asteroids larger than 1 km have entered the near-Earth space every 100 Myr., 83 pages, 8 figures, 63 figures in Appendix A. Accepted for publication in The Astronomical Journal

Context. Near-Earth asteroid 162173 (1999 JU3) is a potential target of two asteroid sample return missions, not only because of its accessibility but also because of the first C-type asteroid for exploration missions. The lightcurve-related physical properties of this object were investigated during the 2011 - 2012 apparition. Aims. We aim to confirm the physical parameters useful for JAXA's Hayabusa 2 mission, such as rotational period, absolute magnitude, and phase function. Our data complement previous studies that did not cover low phase angles. Methods. With optical imagers and 1-2 m class telescopes, we acquired the photometric data at different phase angles. We independently derived the rotational lightcurve and the phase curve of the asteroid. Results. We have analyzed the lightcurve of 162173 (1999 JU3), and derived a synodic rotational period of 7.625 ± 0.003 h, the axis ratio a/b = 1.12. The absolute magnitude HR = 18.69 ± 0.07 mag and the phase slope of G = -0.09 ± 0.03 were also obtained based on the observations made during the 2011-2012 apparition. These physical properties are in good agreement with the previous results obtained during the 2007-2008 apparition. © ESO 2013., National Research Foundation of Korea: 2011-0030875 Korea Research Council of Fundamental Science and Technology 2012010270, ? Photometric data is only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr ( 130.79.128.5 ) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/550/L11 Kim Myung-Jin 1 2 Choi Young-Jun 2 Moon Hong-Kyu 2 Ishiguro Masateru 3 Mottola Stefano 4 Kaplan Murat 5 Kuroda Daisuke 6 Warjurkar Dhanraj S. 3 Takahashi Jun 7 Byun Yong-Ik 1 1 Department of AstronomyYonsei University , 50 Yonsei-ro, Seodaemun-gu , 120-749 Seoul , Korea 2 Korea Astronomy and Space Science Institute , 776 Daedeokdae-ro, Yuseong-gu , 305-348 Daejeon , Korea 3 Seoul National University , 1 Gwanak-ro, Gwanak-gu , 151-742 Seoul , Korea 4 German Aerospace Center (DLR) , Rutherfordstraße 2 , 12489 Berlin , Germany 5 Akdeniz Universitesi , Fen Fakultesi, Dumlupinar Bulvari, Kampus , 07058 Antalya , Turkey 6 Okayama Astrophysical Observatory, National Astronomical Observatory of Japan , Asaguchi, 719-0232 Okayama , Japan 7 Nishi-Harima Astronomical Observatory , 407-2 Nishigaichi, Sayo-cho, Sayo-gun , 679-5313 Hyogo , Japan e-mail: skarma@galaxy.yonsei.ac.kr e-mail: yjchoi@kasi.re.kr 04 02 2013 04 02 2013 2 2013 550 aa/2013/02 L11 31 10 2012 3 12 2012 © ESO, 2013 2013 ESO Context. Near-Earth asteroid 162173 (1999 JU3) is a potential target of two asteroid sample return missions, not only because of its accessibility but also because of the first C-type asteroid for exploration missions. The lightcurve-related physical properties of this object were investigated during the 2011–2012 apparition. Aims. We aim to confirm the physical parameters useful for JAXA’s Hayabusa 2 mission, such as rotational period, absolute magnitude, and phase function. Our data complement previous studies that did not cover low phase angles. Methods. With optical imagers and 1-2 m class telescopes, we acquired the photometric data at different phase angles. We independently derived the rotational lightcurve and the phase curve of the asteroid. Results. We have analyzed the lightcurve of 162173 (1999 JU3), and derived a synodic rotational period of 7.625 ± 0.003 h, the axis ratio a / b = 1.12. The absolute magnitude H R = 18.69 ± 0.07 mag and the phase slope of G = -0.09 ± 0.03 were also obtained based on the observations made during the 2011 - 2012 apparition. These physical properties are in good agreement with the previous results obtained during the 2007-2008 apparition. minor planets, asteroids: individual: (162173) 1999 JU3 idline A&A 550, L11 (2013) cover_date February 2013 first_month 2 last_month 2 first_year 2013 last_year 2013 M.J.K. was partly supported by Korea Research Council of Fundamental Science & Technology. Y.J.C. was partly supported by the collaborative research project between NRF-JSPS (2012010270). Y.I.B. acknowledges the support of NRF grant 2011-0030875. This study was based in part on data collected at Subaru Telescope/Okayama Astrophysical Observatory/Kiso observatory (University of Tokyo) and obtained from the SMOKA, which is operated by the Astronomy Data Center, National Astronomical Observatory of Japan.

The time-symmetric block time--step (TSBTS) algorithm is a newly developed efficient scheme for $N$--body integrations. It is constructed on an era-based iteration. In this work, we re-designed the TSBTS integration scheme with dynamically changing era size. A number of numerical tests were performed to show the importance of choosing the size of the era, especially for long time integrations. Our second aim was to show that the TSBTS scheme is as suitable as previously known schemes for developing parallel $N$--body codes. In this work, we relied on a parallel scheme using the copy algorithm for the time-symmetric scheme. We implemented a hybrid of data and task parallelization for force calculation to handle load balancing problems that can appear in practice. Using the Plummer model initial conditions for different numbers of particles, we obtained the expected efficiency and speedup for a small number of particles. Although parallelization of the direct $N$--body codes is negatively affected by the communication/calculation ratios, we obtained good load balance results. Moreover, we were able to conserve the advantages of the algorithm (e.g., energy conservation for long--term simulations)., Comment: 18 pages, 11 figures, accepted for publication in PASJ

We argue that brown dwarfs (BDs) and planemos form by the same mechanisms as low-mass hydrogen-burning stars, but that as one moves to lower and lower masses, an increasing fraction of these objects is formed by fragmentation of the outer parts (R ≳ 100 AU) of protostellar accretion discs around more massive primary protostars, which in turn formed in their own very-low-mass prestellar cores. Numerical simulations of disc fragmentation with realistic thermodynamics show that low-mass objects are readily formed by fragmentation of short-lived massive, extended protostellar accretion discs. Such objects tend subsequently to be liberated into the field at low speed, due to mutual interactions with the primary protostar. Many (~20%) are in low-mass (M1 + M2 < 0.2M⊙) binary systems with semi-major axes a ~ 1 to 2 AU or ~200 AU and mass ratios q ≡ M2/M1 ≳ 0.7. Most of the brown dwarfs have sufficiently large attendant discs to sustain accretion and outflows. Most of the BDs that remain bound to the primary protostar have wide orbits (i.e., there is a BD desert), and these BDs also have a significantly higher probability of being in a BD/BD binary system than do the brown dwarfs that are liberated into the field (just as observed). In this picture, the multiplicity statistics and velocity dispersion of brown dwarfs are largely determined by the eigen evolution of a small-N system, born from a single prestellar core, rather than the larger-scale dynamics of the parent cluster. Consequently, many of the statistical properties of brown dwarfs should not differ very much from one star-formation region to another.

The method of choice for integrating the equations of motion of the general N -body problem has been to use an individual time step scheme. For the sake of efficiency, block time steps have been the most popular, where all time step sizes are smaller than a maximum time step size by an integer power of two. We present the first successful attempt to construct a time-symmetric integration scheme, based on block time steps. We demonstrate how our scheme shows a vastly better long-time behavior of energy errors, in the form of a random walk rather than a linear drift. Increasing the number of particles makes the improvement even more pronounced.

WOS: 000356549000047, In this study, three different nickel based meshes are investigated as an anode side current collector and flow-field for solid oxide fuel cells (SOFCs) to reduce the fabrication cost. The same meshes are also tested on the conventional interconnectors with machined gas channels for comparison. Eight different short stacks are installed for this purpose. The characterizations of the short stacks are achieved via performance tests together with electrochemical impedance spectroscopy analyses. The experimental results reveal that the woven nickel mesh provides the required current collection and can act as an anode flow-field. It is also found that the spot welding of this mesh significantly improves the cell performance due to the enhanced contact between the mesh and the interconnector. Therefore, the spot welded nickel mesh can be directly employed on the anode interconnector as an effective anode current collector and flow-field without machining gas channels to reduce the SOFC cell/stack fabrication cost. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved., The Scientific and Technical Research Council of Turkey (TUBITAK) [213M030], The useful advices of Dr. Bora Timurkutluk from Nigde University and The Scientific and Technical Research Council of Turkey (TUBITAK) under contract number 213M030 are gratefully acknowledged.

Yer yakını bölgelerde bulunan yörüngeler arasında son yıllarda en çok dikkat çeken konulardan biri eş yörüngelerdir (co-orbital).Günümüzde teknolojik gelişmeler sayesinde bu yörüngelerdeki cisimleri gözlemleyebiliyoruz. Bunun yanı sıra geleceğe veya geçmişe dair simülasyonlar yapabiliyoruz. Eş yörüngelerin kapsadığı birkaç farklı özel yörünge bulunmaktadır. Bunlar At nalı (Horseshoe), İribaş (Tadpole), Yarı-uydu (Quasi-stellite) ve Truva (Trojan) yörüngelerdir. Bu yörüngeleri birbirinden ayırt edebileceğimiz iki temel faktör vardır; yarı büyük eksen ve ortalama boylam değerleri. Tez kapsamında bu faktörleri zamanda ileriye doğru hesaplayıp grafik olarak elde ettik.Bu faktörlere, rölatif konum ve üretilen klon yörüngeler de eklendi. Ayrıca eş yörüngelerin kararlılıkları son yıllarda oldukça önem kazanmıştır ve eş yörünge kararlılıkları hakkındaki çalışmalar uzun zamandan beri sürdürülmektedir. Bu tez çalışmasında, öncelikli olarak Yer ile eş yörünge hareketi yapan cisimleri tespit ettik.Seçilen cisimlerin yörünge elemanları için aralıkları belirledik.Eş yörüngelerde dolanan cisimlerin yörünge elemanlarını yakın zaman aralıkları için analiz ettik. Bu cisimler için kapsamlı kararlılık haritaları elde ettik ve bu haritalrı analiz ettik. Co-orbitals are one of the most interesting subjects in the recent years among the orbits located near the Earth. Today, thanks to technological developments, we can observe the objects in these orbits. We can also simulate the future or the past.There are several special orbits covered by co-orbitals. These are the Horseshoe, Tadpole, Quasi-satellite and Trojan orbits. There are two main factors that we can discriminate between these trajectories; semi-major axis and average longitude values. Within the scope of the thesis, we calculated these factors forward in time and obtained them graphically. To these factors, relative position and generated clone trajectories were also added. In addition, the stability of the co-orbits has gained considerable importance in recent years and studies on the co-orbital stability have been ongoing for a long time.In this thesis, we have determined the objects that make the same orbital motion with the Earth. We have determined the intervals for the orbital elements of the selected objects. We have analyzed the orbital elements of bodies orbiting co-orbits for near time intervals. We obtained comprehensive stability maps for these objects and analyzed them. 80

Bu tez çalışmasının amacı ardışık teleskop görüntülerindeki hareketli cisimleri Doğru Tanıma Yöntemi'ni (DTY) (Chen T. ve Chung K., 2001) kullanarak otomatik olarak tespit eden bir bilgisayar programı geliştirmektir. Doğru Tanıma Yöntemi, aslında, dijital görüntülerdeki doğruları tespit etmek için geliştirilmiş matematiksel bir yöntemdir. Bu yöntem, bu tez ile birlikte ilk kez teleskop görüntülerine uyarlanacak ve bu görüntülerdeki hareketli cisimlerin (asteroid, kuyruklu yıldız, vb.) tespiti için kullanılacaktır.Güneş sistemi cisimleri üzerine yapılan gözlemsel çalışmalar sırasında gece boyunca çok sayıda teleskop görüntüsü alınmaktadır. Bu görüntüler içerisine gözlenen cisimler dışında bilinen ya da bilinmeyen hareketli cisimler de girebilmektedir. Bu görüntülerin hızlı bir şekilde taranıp işlenerek görüntülerdeki hareketli cisimlerin tespit edilmesi hem daha önce gözlenmiş cisimlerin yörüngelerinin iyileştirilmesi hem de yeni cisimlerin keşfi açısından önem taşımaktadır.Hareketli güneş sistemi cisimlerinin çok sayıda teleskop görüntüsü kullanılarak klasik yöntemlerle tespit edilmesi yüksek zaman tüketimi ve iş gücü gerektirmektedir. Geliştirilen bilgisayar programı sayesinde ardışık teleskop görüntülerinin hızlı bir şekilde işlenmesi ve içerisindeki hareketli cisimlerin tespit edilmesi mümkün olmaktadır. Program, teleskop görüntülerinin analizinde daha önce hiç uygulanmamış olan Doğru Tanıma Yöntemi'nden esinlenerek Çoklu Görüntülerden Doğru Tanıma Yöntemi (Multiple Image Line Detection(MILD)) (Atay ve ark.,2016) kullanılarak, çalışması esnasında insan etkileşimini en aza indirecek şekilde hazırlanmıştır.Programda kullanılacak yöntemler işlem sırasına göre şu şekilde özetlenebilir: İsteğe bağlı olarak görüntüler ön indirgemeye tabi tutulmaktadır. Görüntülerdeki, teleskobun hareketinden kaynaklanan kaymalar ve gözlem koşullarından kaynaklanan ışık şiddeti farkları düzeltilir. Hareketsiz cisimlerin (yıldızların) büyük çoğunluğu görüntülerden çıkarılarak, Ay veya yıldız kaynaklı parlama etkileri büyük ölçüde azaltılmaktadır. Görüntülerde geriye kalan ışık kaynaklarının (potansiyel hareketli cisimler) koordinatları bu kaynakların parlaklık değerleri üzerinden tanımlanan `parlaklık merkezleri` hesaplanarak bulunmaktadır. Bu koordinatlar arasından gerçekten hareketli cisimlere ait olanlar MILD kullanılarak tespit edilir. Tüm bu işlemler otomatik bir şekilde gerçekleştirilmektedir.i MILD'nin kullanıldığı bu bilgisayar programı ile gecelik gözlemlerden elde edilen teleskop görüntülerindeki hareketli cisimlerin koordinatları hızlı ve otomatik bir şekilde elde edilebileceğinden, program yeni cisimlerin keşfi için önemli bir araç vazifesi görecektir. Arşiv görüntülerinden klasik yöntemlerle hareketli cisim tespit etmek hem zaman hem de iş gücü açısından yüksek maliyetlidir. Bu program ile istendiğinde bu tür arşiv taramalarının hızlı ve otomatik bir şekilde gerçekleştirilmesi mümkün olacaktır. The aim of this thesis is to develop a computer program that uses the Line Detection Method (Chen T. and Chung K., 2001) to detect any moving object in a given series of sequential telescope images. The Line Detection Method is actually a mathematical technique developed to detect lines in digital images. This technique is applied to telescope images for the first time and used to detect the moving objects (asteroids, comets, etc.) in these images.Many telescope images are acquired during the night long observations of various objects in our solar system. In addition to those already being observed, these images may contain other known or unknown moving objects. To discover new objects and to refine the orbital parameters of previously identified objects, it is important that these images are processed with high speed to detect all moving objects in them.The detection of moving solar system objects from multi-frame telescope images can be time-consuming and require too much work power if one resorts to classical methods. With this proposed computer program, it will be possible to process any number of telescope images with high speed and identify the moving objects in them. The improved computer program allows you to quickly and easily move telescope images quickly. Multiple Image Line Detection (MILD) (Atay et al., 2016) has been prepared, which has never been applied to the analysis of telescope images before, will be utilized for detection and human interaction will be minimized during operation.The methods that are used in various stages of the program can be summarized in working order as follows: The images are subject to an optional pre-reduction step. The translational shifts due to tracking errors and the intensity differences due to atmospheric changes are corrected for each image. Most of the stationary objects (stars) and Moon or star related glowing effects will be eliminated from the images. The center coordinates of the remaining light sources (moving object candidates) are calculated using a center-of-light function determined by the intensity values of the pixels in the images. The coordinates of the real moving objects among all candidates are identified using MILD algorithm. All these steps are performed automatically.Since with this computer program using the MILD, the coordinates of the moving objects in the telescope images will be calculated automatically with high speed, the proposed program is expected to serve as an important tool to discover new objects. Detection of moving objects from archive images using classical methods is notiii cost-effective in terms of time and work power. With this program, we're expecting that such archive scans will become fast and automated. 63

Yer'e Yakın Asteroidler (YYA), hem Yer'e çarpma risklerinin araştırılması hem de Yer'e yaklaşma mekanizmalarının öğrenilmesi açısından son yılların oldukça popüler ve önemli bir çalışma alanıdır. 21 Aralık 2015 tarihi itibariyle YYA sayısı 13677'dir ve bu sayı hızla artmaktadır.Bu tez çalışmasında, istatistiksel veriler oluşturularak YYA gruplarından en kalabalık olan Apollo grubuna kaynaklık eden bölgeler araştırılmış ve dinamik yollar belirlenmeye çalışılmıştır. Bunun için asteroidlerin, sayısal yöntemler kullanılarak zamanda geriye 10 milyon yıllık integrasyonu yapılmıştır. İstatistiğin artırılması için her bir Apollo asteroidinin 6 tane klon yörüngesi oluşturulmuş ve toplamda 38175 yörüngenin integrasyonu yapılmıştır. Sayısal integrasyonlar TÜBİTAK ULAKBİM'e bağlı Türk Ulusal Bilim e-Altyapısı'nın (TRUBA) yüksek hızlı işlemcilere sahip küme hesaplama araçları kullanılarak yapılmıştır.İntegrasyonlar, asteroidlerin Tisserand parametrelerine göre hazırlanan girdi paketlerine göre yapılmıştır. Sonuçlar, Tisserand parametresinin asteroidin yörünge evrimleri hakkında açıkça bilgi verdiğini göstermiştir. 10 milyon yıllık sonuçlara göre Tisserand parametresi küçük olan cisimlere kaynaklık edecek bölgeler Güneş sisteminin dış kısımlarına uzanırken, büyük olan cisimler daha iç bölgelerden gelmiş olabilir.Asteroidlerin integrasyon sonucunda, %63.69'unun integrasyon süresinin üst limiti olan 10 milyon yılı tamamladığı görülmüş, %18.44'ünün a değeri 50 AB limitinin dışına çıkmış ve %12.27'sinin yörüngeleri ise hiperbolik olmuştur (e > 1). Ayrıca, 10 milyon yıl sonunda %71.79'unun hala YYA olduğu görülmektedir.Bu tez çalışmasında ortaya çıkan bir diğer sonuç ise Jüpiter ve Venüs'ün, Güneş sistemi içerisinde oldukça belirgin sınır bölgeler oluşturduklarıdır. Bunlar özellikle enöte uzaklığı Q = 4.61 AB ve Q = 0.728 AB bölgelerini temsil eden doğrulardır. Bu bölgeler sırasıyla Jüpiter yörüngesini kesenler için mininum enöte uzaklık doğrusu ve Venüs'ün enöte uzaklığının doğrularıdır. Q=4.61 AB doğrusunun açıkça düşük yörünge basıklığına sahip bölgeler için alt, yüksek yörünge basıklığına sahip bölgeler için üst sınır oluşturduğu anlaşılmaktadır. Near Earth Asteroids (NEAs) is an important and popular subject in both research on the risk of a collision with Earth, and to explore their source mechanisms. Number of NEA population as of December 21st 2015 is 13677, and is increasing.In this thesis work, source regions of the Apollo asteroids which is the biggest population among NEAs has been studied, and dynamical routes has been tried to determined. For this, orbits were integrated for 10 Myr backward in time. To increase the statistics 6 clone orbits for the each asteroid orbit have been generated. In total, 38175 orbit integrations have been computed. Numerical integrations have been run on TÜBĠTAK ULAKBĠM-TRUBA clusters.Input orbits were prepared using each object's Tisserand parameters. Based on 10 Myr backward in time results show that source regions can be outer Solar System for objects have smaller Tisserand parameters and can be inner Solar System for objects have greater Tisserand parameters.At the end of the integrations 63.69% were terminated within normal integration time limit (10 Myr), 18.44% were terminated as their semi-major axis reached the 50 AU limit, 12.27% were terminated as hyperbolic orbits. Also, after 10 Myr of backward integration 71.79% of the orbits were still in NEA orbit region.In this thesis work, one other important result shows that there are two restricted regions caused by Jupiter and Venus. These regions are Q = 4.61 AU and Q = 0.728 AU lines which represents minimum aphelion for Jupiter crossers and Venus aphelion respectively. Q=4.61 AU region is also a lower limit for low eccentric orbits and upper limit for high eccentric orbits. 66